Document LKbVdKavVRMEkGy5Z6Bqr016w

QW1079594 RESIDUES IN THE ENVIRONMENT Soils In monitoring surveys conducted by the Agriculture Research Services, USDA, six study areas revealed that soil residues of 2,4-D were minor. Only four soil samples (average concentration of 0.032 ppm) were positive for 2,4-D residue. In another survey, 99 soil samples were collected from wheat fields in 16 states with known histories of 2,4-D use. Analysis revealed only four samples contained measurable residues (0.751, 0.06, 0.05, and 0.04 ppm)(Kearney, 1970). Water Manifold and Schulze (1969) reported on an extensive survey of pesticides in water, conducted by the U. S. Geological Survey from October 1966 through September 1968. The survey was con ducted at twenty sites on the major streams in the western United States and included the herbicide 2,4-D. Out of several hundred observations, 2,4-D was identified 26 times, ranging from 0.01 to 0.35 ppb. Norris (1971) stated that, in his investigations of stream contamination from spray projects on range and forest lands in Oregon, measurable concentrations occurred shortly after application but seldom exceeded 0.1 ppm'. Animal A study of sheep and cattle fed a daily die^ containing 2,000 ppm of ^2,J4-D had only 1 ppm or less in the muscle after 28 days of feeding (Clark, et al., 1975). The milk from cows grazing on pastures that were sprayed with 2,4-D esters, GGGGG31contained 0.01-0.09 ppm of 2,4-D during the first two days IV-1 7632 OQVflV 07959' .-.after spraying and lower amounts thereafter. When cows were .'"put into the pastures four days after spraying, residues in milk were below 0.01 ppm (Klingman, et al., 1966). In 1969, the Consumer and Marketing Service, USDA, analyzed 2U-0 samples of red-meat fatty tissue for 2,4-D. These samples were taken at different- geographic locations in the continen tal United States. Results of this survey are shown in Table 2. According to this survey, 2,4-D residues in red meat do not appear to be significant in meat products currently marketed in the United States (Harvey, 1971). Table 2. Residues of 2,M-D in Red Meat Parts per Million 2,U-D Negative 0.01-0.10 0.11-0.50 0.51-1.0 >1.0 Number Samples 231 6 2 1 0' Percent 96.2 2.5 0.8 O.U 0 Food In a- continuing program to monitor pesticide residues inlfood, the Food and Drug Administration, U. S. Department of Health, Education and Welfare, found a decreasing level of 2,H-D in food samples during the period 196^-1970, (Duggan and Corneliussen, 1972). The program, commonly known as the "total diet prograr-'m"b, involves examination of food ready to be eaten. This investigation measures the amount of pesticide chemicals found in a "high-consumption" varied diet. The CG06G32samples are collected in retail markets and prepared for 7633 DOWJ 079596 consumption before analysis. Table 3 summarizes the data on 2,U-D for six years. Table 3. Average Incident and Daily Intake of 2,4-D Year [T= < 0.001 mg] Percent Positive Composite Daily Intake (mg) 1965 1966 1967 1968 1969 1970 U .2* 3.0** 1.7*** 0.6*** 0.3*** 0.3*** O'.005 0.002 0.001 0.001 T T * 216 composites examined ** 312 composites examined *** 360 composites examined Investigations of the persistence of 2,U-D in the environ ment indicate that this herbicide is relatively short-lived. m* Likewise, examination of soil, water, animal tissue, milk and foodstuffs revealed low levels of 2,^-D residues, despite the extensive use of this herbicide in this country. Based on the review of the above persistence and residue studies, it seems unlikely that 2,u-D would accumulate to significant levels as a result of its use in forestry management. GG0G033 ABSORPTION, DISTRIBUTION AND EXCRETION DOW1079597 Experimental Animals Several investigators have studied the absorption, dis tribution and excretion of the herbicide 2,4-D with experi mental animals. Reported studies indicate that the herbicides are readily absorbed from the gut and become widely distributed in the tissues. The major route of elimination of 2,4-D is via the urine, primarily as the parent compound and, to a much lesser extent, as a conjugate of the parent compound. In rats, pigs, calves, and chickens, 2,4-D administered in doses of 50-100 mg/kg bw orally as salts was readily ab sorbed and eliminated mainly in the urine, with plasma half- lives varying from 3-12 hours (Erne, 1966 a,b). Pigs excreted 2,4-D in the urine primarily as the parent compound, but also as an unidentified acid hydrolyzable conjugate(s). In pigs and rats given oral doses of the butyl ester of 2,4-D the free acid and traces of esterified 2,4-D were present in the plasma, red blood cells, urine, and liver. Khanna and Fang (1966) fed rats 1-100 mg of 2,4-D (l^C-label in either one or two positions of the side chain) and then monitored the expiratory gases, urine, feces, nd various tis sues for No 1^C02 was detected in the expiratory air. r The rats excreted from 75.5 to 93.3 percent of the in the feces and urine*7within 144 hours (most within the first twenty- four hours after dosing). The rate of the excretion (expressed as percent of the dose) decreased as the size of the dose in creased. The level of radioactivity in the tissues was maximum COOoOaS635 DOW 07959r from 6-17 hours after dosing and then declined. A study of the intracellular distribution indicated that the soluble fraction .contained more radioactivity than the nuclear, mitochondrial .and microsome fractions. There was no significant difference -'in the distribution of in the various fractions when dif ferent dose levels were given. Chromatography studies indi c a t e d that most of the l^C in the urine and tissues was as the parent compound. However, at least one unidentified metabolite was also present in the urine. Clark, et al. (1964) administered a single oral dose of 2,4-D-C^ (acid form) to a sheep (dose 106.3 mg of 2,4-D, sheep weight 26.6 kg) and reported that approximately 96 percent of the 1AC was excreted in the urine with at least 1.4 percent in the feces (the expiratory gases were not analyzed for 1^C02) within seventy-two hours. The level of ^ C in the blood reached a maximum *.25 hours after dosing and rapidly declined (see Figure 4 ). Comparative chromatography and electrophoresis, studies indicated that all of the ^ C in the urine was the free parent compound. The nature of the l^C labeled compound(s) in ( thev feces and tissues were not determined. Lisk, et al. (1963) fed a steer 5 ppm of 2,4-D for one day; approximately 88 percent of the dose was eliminated in the urine as the parent compound within three days. However, the feces ** r and tissues were not analyzed for the parent compound or meta bolites. oud V-2 6S6J.01 MM lu Figure if. Appearance of C in the blood of^a sheep after oral administration of 2,4-D-u (Clark, et al., 1964) Humans Feldman and Maiboch (1974) studied the percutaneous pene tration of 2,4-D in man. Data were presented on the proportion of 2,4-D-C^ which was absorbed after application of 4 jig/cm^ to the ventral forearm. Because ^C-metabolites were measured in the urine, it was necessary to determine the extent to which these metabolites appear in the urine after parenteral administra tion. All results were calculated as percent of the injected or applied dose. In the topical studies, the results were cor</ rected for incomplete excretion. For example, if 50 percent of the test compound was excreted after I. V. administration, all values after topical administration were doubled. Urinary ex cretion of 2,4-D after I. V. administration was 100 percent cgggggs oJ7 V, after five days. Urinary excretion after topical administra te tion of 2,4-D was 5.8 percent after five days. It appears that C^D very little of the 2,4-D is absorbed through the skin. Skin ^ absorption is incomplete because much of the applied chemical is: lost from the skin surface by washing (subjects did not 3^^3 ws*a''Vs'*h skin for twenty-four hours), evaporation or the gradual exfoliation of outer layers of the stratum comeum. Also, human skin appears to be a more effective barrier to penetration than that of certain small animals, at least for the quantities used in this investigation (Malkison and Rothman, 1962). The pharmacokinetic profile of 2,4-D has been determined in five male volunteers (Saueroff, et al., 1976). After inges tion of a single 5 mg/kg oral dose, 2,4-D was eliminated from plasma in an apparent first-order process with an average half- - life of 11.7 hours. All subjects excreted 2,4-D in the urine with an aver*age half-life of 17.7 hours, mainly as free 2,4-D (82.3 7.) , with a smaller amount excreted as a 2,4-D conjugate (12.8 Z). Kohli, et al. (1974) studied the absorption and urinary excretion of 2,4-D acid in six subjects following oral inges- \V tion (5 mg/kg administered in a gelatin with water). The 2,4-D was 99 percent pure. 2,4-D was determined as its ethyl ester by gas-liquid chromatography (g.l.c.). The absence of significant quantities of metabolites is based on a comparison rf of the g.l.c. profiles of blood and urine samples from indivi dual volunteers before and after ingesting 2,4-D. In every case the only additional peak in chromatograms corresponded to the 2,4-D ethyl ester. Recovery experiments w i t h `2,4-D 7B38 T096oriW) added to blood indicated a recovery of almost 95 percent. Concentrations of 2,4-D in plasma, expressed in ng/ml, following administration of a single dose of 5 mg/kg, are given in Figure 5 , which shows the curve from one indivi dual and the mean curve of plasma concentration of six sub jects as a function of time along with the standard error of determinations at each interval. Although there is a marked degree of individual variation, it would appear that the com pound is absorbed fairly quickly; a significant amount of the compound was detected one hour after administration. The highest concentration of 2.4-D in plasma is reached in 7-24 hours, and then declines steadily. In general, the concen tration reached in the plasma paralleled the amount excreted in the urine. --- Curve from one subject .*> O Curve from six subjects, + S.E. CG0G33 7639 w / 07960'- Studies of absorption, distribution, and excretion of 2,4-D in both animals and humans indicate that when this herbicide is-ingested, it is rapidly absorbed through the gut and ex creted, for the most part, in the urine. A large percentage is excreted as the parent compound and a lesser amount as'a conjugate of the parent compound. However, it is evident in these studies that the investigators did not determine a total "mass balance". This may reflect, in the individual studies, one or more of the following shortcomings: (1) incomplete recovery by the methods used, (2) detected, but unidentified 2,4-D metabolites, and (3) incomplete examination of tissues, urine, and feces for the presence of 2,4-D or its metabolites. Particularly lacking in the studies is information con cerning the nature of 2,4-D metabolites. In some cases, no attempt -was made to determine the presence of metabolites; in other studies, metabolites were noted but could not be identified. However, in one study, 2 ,4-dichlorophenol, a presumed 2,4-D metabolite, was identified in the liver and kidneys of sheep. ..The importance of identifying 2,4-D metabolites and studying their toxicity is illustrated by 2,4-dichlorophenol. Boutwell and Bosch (1959) found that when topically applying 0.3 percent dimethylbenzanthracene in benzene as an initiator (may induce tumors by itself or may be enhanced by or require the presence of another compound), and applying 20 percent (312 mg/kg) 2,4-dichlorophenol as the promotor (enhances, but does not induce tumors by itself), papillomas and carcinomas were CC0oCj33 D0WI1079603 noted after thirty-nine weeks. Although this is not analogous to an environmental exposure to 2,4-D (eg. different route of exposure and presence of an initiator compound), it does illu strate the importance of recognizing that the toxicity of a metabolite may be as/or more important than the parent com pound. t) 7641 CG06G10 V-7 OOWil 079604 ACUTE TOXICITY There are two kinds of toxicity. Acute toxicity is the rapid response of organisms to a few large doses of a chemical received over a short period of time. Chronic toxicity is the accumulation cf effects resulting from exposure over a long in terval. Thus the nature of the response is determined by the magnitude and duration of the dose the organism receives. Experimental Animals The acute toxicity of 2,4-D in animals is considered because (1) animals are frequently used as models to indicate toxicity, to humans and (2) it is important in evaluating potential herbicide effects in the context of an environmental statement. In review ing the acute toxicity of 2,U-D, it should be kept in mind that the nature of the dose-response relationship varies with both the chemical and the organism. Also, there is some individual vari ation Within a given species. Figure 6 shews a generalised dose-response relationship for 2,4-D to several organism groups (Newton and Norris, 1976). ' This example shows that higher plants are the most sensitive organisms v to 2,4-p. Clearly this is the basis for the use of 2,*f-D as a chem ical agent for selective control of vegetation. A significant amount of the literature on the acute toxicity cf 2,4-D to various animals is summarized in Table *,(U.S.EPA, 197*+) om C006041 " VI-l r Figure (i Typical dosage-response spectra for 2 ,4-dichlorophenoxyacetic acid for five classes of organisms(Newton and Norris, 1976) * DOW] 079605 100 < M I to I O aO C) o w OE) CO Absorbed Dosage, mg/kg Body Weight Table *4. Toxicity of 2,M-D Birds, Fish and Invertebrate Rat Acute oral Mouse Acute oral * Rabbit Acute oral Dog Acute oral Guinea pig Acute oral Mule deer Acute oral Rat Dietary, 2-yr Dog Dietary, 2-yr Rat Three-generation re product ion Cattle Sheep Mallard Acute Oral 25 CDOD3 86 CDOD3, 112 CDQlr 7 CDOD3, 10 CDOD'* 8 CDOD3 Acute oral Dietary, 5-day Ring-necked pheas ant Acute oral Dietary, 5-day Pigeon Acute oral Chicken Chorus frog tadpole 10 c d o d J 10 CDOD, 10 CDOD Acute, 2*i-hr Bluegill Rainbow trout Paphnia magna Acute, 2*-hr Acute, 24-hr Acute, M8-hr 0 Ganunarus fasciatus Acute, M8-hr Table * continued - notes (Acid*) to Karoroals, (from EPA, 197*0 I 6G6 mg/kg 375 mg/kg 800 mg/kg 100 mg/kg 1000 irp/kg 100-800 mg/kg 1250 ppm 500 ppm 500 ppm "so LDS0 LU50 LD50 LD50 LI>5p No effect No effect No effect 250 mg/kg' 200 mp./kgj* 100 mg/kg 1 50 m g /kg% 500 mg/J^g? 250 mg/kg!. 100 mg/kg >1000 mg/kg >5000 ppm*" 172 mg/kg, >5000 ppmA 668 mg/kg 500 mg/kgj 250 mg/kg? 100 mg/kg^ 100 ppm 5 ppm 5 ppm >100 ppm 3.2 ppm Significant effects Significant effect^ Significant effect* No effect 9 Significant effect Significant effect No effect LD50 LCS0 bC50 LDS0 , Significant effect* Significant effect^ No effect LC50 No mortality No mortality LC',50 : ' 909GiO I MMLC50 IVt fiyrjv:' i'f'i 1. There is very little variation in toxicity among the various salts and esters of 2,*+-D in mammals and birds; however, certain esters are more toxic than acid to fish ( ^ 1 ppm.'. 2. Weight less, reduced weight gain or illness. 3. CDOD = consecutive daily oral doses each at the given dosage. U. Alkanolamine salts Table S shows a range of L D ^ ' s and TLM's (summarized from the literature) for various groups of organisms for 2,U-D (from Norris, 1971). Table 5. Acute Toxicity of 2,-D (from Norris, IS71) Organisms 2,U-D Birds LE50 mg/kg 360-2000 Rodents LDS0 mg/kg if* " Ruminant s LD50 mg/kg 375-800 uoo-soo Other Mammals LDS0 mg/kg 100 Fish , TLM ppnr 1-60 Other Aquatics TLM ppm1 1-5 1. Forty-eight-hour median tolerance limit, i'.e., the concentration of herbicide in water which will kill 50 per ceiyt of an exposed population of aquatic organisms*in *+8 hours. CC06044 It can be seen that 2,M-D is generally less toxic to birds than to mammals. The toxicity to fish is greater than to mammals, but is highly variable. 2,^-D is absorbed after ingestion trans- r>r.T'-r> \ri niaswa. concentrated in the kidnevs and raoidlv eliminated in the urine (see section on Absorption, Excretion and Distribution);. However, the dog has lower capacity to ex crete 2,U-D, and as a result 2,U-P is about three times more toxic to dogs than to other test animals. 2,4-D is essentially . "zq -05 ncntexic to insects and related organisms and is not significantly O 00 fungicidal or bactericidal (CAST, 1975). A summary of symptoms of acute toxicity of 2,4-D to various organisms is given in an International Agency for Research on Cancer monograph, (IARC, 1977). . Symptoms of acute toxicity in nice, rabbits, guinea pigs, and rats are essentially similar. Some animals die suddenly, apparently from ventricular fibrillation; those that do not die immediately develop stiffness of the extremeties, incoordination, lethargy, stupor, and coma prior to death. In mice acutely in toxicated with 2.U-D, dilation of the blood vessels of the lungs, liver and'kidneys can be observed. Rats and guinea pigs adminis tered lethal doses of 2,H-D exhibit congestion of the viscera and enlarged kidneys; microscopically, there is massive cloudy swelling of the proximal convoluted tubules with cast formation. In dogs, toxic symptoms are often not present until six hours after oral administration of a lethal dose of 2,U-D; the animals become ataxic with progressive increase in spasm. Death appears to be due in most cases to hepatic congestion or to pneumonia. Pathological changes are limited to the gastrointestinal tract, lung c/ and liver and follow the development of anorexia, weight loss and myotonia. Dogs exhibit evidence of liver damage more frequently than ether animals. CGG6G4J 7046 VI-5 60962,01" Acute toxic doses of 2,4-D produce fatty degeneration of the liver, spleen, kidney, and heart, and hemorrhagic gastroenteritis in .chickens, and acute toxic doses have similar effects in sheep and cattle. Human The literature contains several descriptions of acute poi soning in man by 2,**-D. These include accidents and attempts at suicide. The exposures were quite high but varied within wide limits. Estimation of the fatal dose is difficult because in some cases the purity or the constituents of the commercial herbicide were not known, the magnitude of dermal exposure could only be guessed at, and in the case of exposure by ingestion, vomiting occurred. Goldstein, et al. (1959) reported three cases of polyneuritis as a result of accidental exposure. -Patient histories indicated that exposure to the herbicide 2,4-D preceded the development of the neuritis. The time relationship was such that it seemed rea sonable that the herbicide caused the neurological disease. In each case severe sensory and motor symptoms necessitated hospital ization. In each case the disorder began some hours after the use of preparations of 2,**-D to kill weeds. Initial symptoms were nausea, vomiting, diarrhea, and headache. Symptoms of muscular weakness, swelling or aching of the feet and legs,`with malaise and headache, persisted for 10-20 days. In one case, it is known that the individual spilled about 2 fluid ounces (60 cc> of a 10% solution of an ester of 2,U-D on his forearms without washing it 7off. All that is known about the exposure of the other two indi- viduals is that their extremities were wetted with 2,U-D solution C00o04o D O W '!0 7 9 6 1 0 during spraying operations. The symptoms progressed through a period of days until pain, paresthesias and paralysis were severe.' Disability was protracted and recovery was incomplete even after a period of years. Electromyographic examination supported the diagnosis of peripheral neuropathy. Although it seems likely that the authors were correct in assuming that the 2,4-D caused the neuritis, they did not describe the details of manufacture or purity of the 2,4-D ester preparations. Therefore, it might be suggested that some other agent used in pre paring or making a sclution of the 2,4-D produced the neuritis and not the 2,4-D itself. Berkley and I-iagee (19S2) reported on a case of 2,4-D exposure to a farmer who repeatedly used his bare hands to correct plugging up of a weed sprayer. The fanner was using an aqueous solution of the dinethylamine salt of 2,4-D (40% solution). The individual's symptoms .were a constant pricking of fingers, toes, mid-abdomen, upper chest, and anterior thighs. Hypersensitivity to touch and stiffness of the hands and knees were also noted. A diagnosis of primarily sensory, peripheral polyneuropathy was made and it was concluded the condition was probably produced by exposure to 2,4-D. Seabury (1963) tentatively treated two patients suffering from coccidiosis by intramuscular or intravenous injection of the sodium salt of 2,4-D acid. Cne patient died of his disease, however, after having received no more than 40 mg. The other man received in the course of 34 days a total of 12.7 grams, beginning with very small doses, which were gradually increased. The last two doses were 2.0 and 3.6 grams. Towards the end cf the course of treatment, various neurological signs and symptoms were noted including muscle weakness, CGG5G47 7648 VI-7 fibrillary twitchings, and psychomotor retardation. Nielson, et al. C1965) described a case of fatal poisoning v' .. UUWLI07961.1 in man by 2,4-D, in which a 23-year-cld farming student committed .- suicide with the dimethylamine salt of 2,4-D. The total amount of 2.4- D in the body was estimated to be no less than 6 grams. This ,*..v. . " corresponds to 80 mg/kg bw. However, this estimate of dosage was probably low due to loss of the chemical by vomiting. Death seems to have been preceded by convulsions and vomiting. Acute congestion -w.v of most organs was observed. Also, severe degenerative changes of the ganglion cells were found in the central nervous system. _.V;. Berwick (1970) describes a case of 2,4-D poisoning in a ME- year-old farmer who accidentally ingested approximately 30 ml of * ' j 2.4- D concentrate. The patient exhibited fibrillary twitching, paralysis of intercostal muscles, myotonia, and muscle weakness. There was evidence of generalized skeletal muscle damage as indicated by marked elevation of serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactic dehydrogenase, aldolase, and creatine phosphokinase levels. The constituents of the her bicide involved in this poisoning were known. Laboratory tests, the patient's elevated symptoms, and toxicological knowledge of this commercial herbicide ruled out toxicological response by the patient to the constituents other than 2,4-D. By calculation it would appear that the patient ingested 7,200 mg of 2,4-D acid. The patient's weight was 65 kg (143.3 lbs.) and he, therefore, in- gested 110 mg-2,4-D/kg bw. A case of fatal human ingestion of 2,4-- D is reported by Dudley and Thapar (1972). An elderly man with senile dementia died 6 days 7649after ingestion of a large amount of 2,4-D (approximately 1 pint in . Cu0oG4!^ ?!T9fii0l MOO a kerosene-like solvent). Death was presumed to be due to ven tricular fibrillation induced by the cardiac muscle irritability associated with 2 ,4-B ingestion. Tissue concentrations in various / organs were as follows: blood 57.60 ppm; brain 93.40 ppm; kidney 193.35 ppm; liver 407.87 ppm; and muscles 117.50 ppm. An autopsy of the patient revealed wide-spread plaques and acute demyelination in all parts of the brain. These perivascular plaques resemble those formed by multiple sclerosis and certain toxins, such as arsenic and carbon monoxide. The authors suggest that it is pos sible 2,4-D or one of its metabolites can induce demyelinaticn. In summary, the data from the above reports are variable and incomplete. However, ingestion of relatively large doses of 2,4-D does present the clinical triad of gastroenteritis, skeletal and cardiac myotonia, and central nervous system, depression, which are the same symptoms observed in 2 ,4-D exposures to animals. Incidents of peripheral neuropathy following the use of a 2,4-D spray and exposure have also been observed. An LB.n for humans cannct be accurately determined but can be estimated for the purposes of illustrating the nature of the acute toxicity of 2,4-D to humans. Kill and Carlisle (19475 have esti mated an LD50 fcr humans extrapolated from, their animal data. "Assuming that man is no more resistant cr susceptible than the rabbit or monkey-the largest estimated tolerated dose for a 75 kilogram man would be 15 grams (200 mg/Kg). With the exception of the monkey, all laboratory animals used lacked the vomiting reflex, so that they were unable to relieve'- themselves of irritating materials by vomiting. The experiments conducted on monkeys indicate that the material is a gastric irritant in large doses, so that the possibility of acute poisoning in humans would seem rela tively remote, because of the large dcse which man could presumably tolerate. Assuming that man is no more susceptible than the most susceptible animal tested, the mouse, then the calculated LD5- for man would amount to approximately 28 grams or 1 ounce." VT-9 7C6G500GG43 DOWJ 079613 CHRONIC TOXICITY Animal Rats fed 1,000 ppm of 2,4-D in their diet for one month showed no signs of toxic effects (Hill and Carlisle, 1947). No adverse effects were noted in young female rats fed 100 and 300 ppm of 2,4-D in their diet for periods up to 113 days, while those given 1,000 ppm over the same period had increased mortality, depressed growth rate, and slightly cloudy swelling of the liver. Animals fed 3,000 or 10,000 ppm of 2,4-D in their diet were sacrificed after twelve days because of food refusal and rapid weight loss. Increased liver and kidney weights were noted (Rowe and Hymas, 1954). Rabbits were dermally exposed (intact and abraded skin) to three commercially available formulations of 2,4-D (the dimethyiamine salt and the isoocytal and butyl esters). Doses of 15 ml were applied five times weekly for three weeks at two concentrations, 0.6267. and 3.137. (the dimethyiamine salt was diluted in .water and the esters in either oil or water). There were no significant adverse effects upon the following parameters attributable to 2,4-D: (1) body weight, (2) sur vival, (3) hematologic values, (4) clinical chemistry, and (5) orgn/body weight ratios (Kay, et al., 1965).* Subacute Intoxication was produced in dogs by the daily administration of 25 mg/kg bw (intravenously) over a six day period with the development of liver damage (Hill and Carlisle, 1947). However, no adverse effects related to 2,4-D admini- ^05^ stration were observed when groups of three male and three GGGuGjQ DOIflLl 079614 female beagle dogs were fed 10, 50, 100, or 500 ppm of 2,4-D in their diet (96.6% pure, with no detectable dioxin content) for two years starting at 6-8 months of age. Twenty-eight dogs that survived the two-year period were clinically normal (Hansen, et al., 1971). ? ' No adverse effects were seen in cattle and sheep with an intake of 50 mg/kg bw and 100 mg/kg bw respectively of two formulations of 2,4-D (the alkanolamine salt and the propy lene glycol butyl ether ester). The doses were administered for 112 days to cattle and 481 days to sheep (Palmer and Radeleff, 1964). Young pigs treated with 50, 100, or 200 mg/kg bw of com mercial triethanolamine or butyl ester of 2,4-D, for varying intervals up to 103 days, exhibited symptoms of intoxication and pathology analogous to those seen in laboratory animals. Clinical signs of anorexia and retarded growth were found in one animal given fifty-one doses of 50 mg/kg bw triethanol amine salt over 103 days. Pigs fed 500 ppm of the triethanol amine salt of 2,4-D in their diet for up to twelve months developed locomotor disturbances of increasing severity after about one month. Animals sacrificed after 2-12 months had normal organ weights and no gross pathological changes. Clinico-chemical observations included lowered hematocrit t and hemoglobin values, reduced albumin and albumin:globulin K *./ ratios, and elevated glutamic-oxaloacetate transaminase in the treated animals (Bjorklund and Erne, 1966). i 7652 COOGGoi Human In a study of 292 persons (248 men and 44 women) engaged ilOVU 079615 in manufacture of the amine salt and butyl ester of 2,4-D, with exposure ranging from under five years to 6-10 years (for 194 and 98 persons, respectively), 637. of these workers complained frequently of weakness, rapid fatigue, headache or vertigo. About 20% had disturbances of the cardiovascu lar system (mainly hypotension and bradycardia). Various liver dysfunctions were found and were more pronounced in workers with longer exposures to the herbicides (Bashirov, 1969). In a brief paper, lacking numerical data and many impor tant details, Festisov (1966) describes some results of health examinations on 105 workers engaged in the production of 2,4-D including salts and esters, and on forty-five persons engaged in aerial spraying of 2,4-D herbicides in agriculture. Symptoms, which were reported and which appeared to increase with the degree of exposure, were headaches and fatigue at the end of the workday, loss of appetite, pains in the stomach and liver, and occasionally symptoms in the upper respiratory tract. - Impairment of taste sensitivity was noted in some cases. The symptoms usually disappeared by the next morning. No examinations on comparable control populationsr are mentioned. The concentration of the chemical in the air of the factory was extremely-hgh, containig up to 28-44 mg/m3. In a similar study, Radionov, et al. (1967) reported on symptoms manifested by several groups of workers whose duty 7653VII-3 C0 bQ5 X it was to thin-out and weed maize fields, the day following ' CD or, in some cases, several days after the treatment of the 0791 . fields with 2,4-D. The formulations used were the sodium, amine and dimethylamine salts of 2,4-D. Dosages ranged -from 1.5-3 kg/hectare. Workers complained (usually within 'one hour of beginning work) of headache, vertigo, nausea, "weakness, irritation of the eyes and the nasopharyngeal mucosa, burning sensation of the skin, and substemal pain. Occasionally, some workers vomited. The workers usually recovered within a few days. No permanent damage was noted. One point of interest is that dry weather seemed to aggravate the situation. .Under these conditions, more dust is generated and the plants and upper strata lack the moisture which would partially prevent atomization of the herbicide in the air. In a report on 220 workers exposed in a manufacturing plant to a concentration of 30-40 mg/day of 2,4-D for periods ranging from 0.5-22 years, Johnson (1971) stated that no "meaningful" differences were noted when clinical results on these workers were compared to those obtained on a control population of 4,600 men not exposed to 2,4-D. However, the clinical tests were not specified and no supporting data were provided. No chromosomal effects were noted in ten workers whose chromosomes were karyotyped. These health studies of people occupationally exposed to J 2,4-D generally have serious shortcomings that limit their usefulness. All of the available studies are cross-sectional; the exposed populations were examined only once or, in some cases, twice. CGGGu5o 7S54 Mo longitudinal studies, in which the same persons are observed at regular intervals over longer periods of time, have been made. Thus, temporary and also delayed effects may have been overlooked. There is, however, no evidence for delayed effects in the animal experiments. In spite of these shortcomings, the fact that three of the studies reported similar symptoms in exposed human populations is sufficient to suggest that chronic exposure to high concentrations of 2,4-D can produce adverse health effects in humans. O <? C> CCG6G547655 QOW10.79618 TERATOGENICITY An agent or chemical is considered as teratogenic when it causes developmental disturbances in the embryo resulting in congenital malformations. If an agent kills the embryo, it is said to be embryocidal, and if it produces tissue damage (not necessarily resulting in malformation), it is embrvopathic. The term embryotoxic will refer to any harmful effect on the embryo, or fetus. Schwertz, et al. (1971) fed 2,4-D acid at levels up to 87.5 mg/kg/day (maximum tolerated dose), equimolor doses of propylene glycol butyl ether ester of 2,4-D up to 142 mg/kg/day, and isooctyl ester of 2,4-D up to 131 mg/kg/day to rats (SpragueDawley), on days 6-15 of gestation,, the time when the rat embryo is most sensitive to teratogenic agents. Embryotoxic responses were seen including edema, delayed ossification, decreased fetal m body weight, and wavey ribs. However, no genuine teratological effects were seen even at the higest dosages. The highest level of esters decreased viability and lactation in the mothers, but had no effect on the growth and development of the offspring. Kheraand McKinley (1972) in prenatal studies on Wister rats showed that 2,4-D induced embryotoxic effects and increased the incidence of skeletal anomalies after single oral doses of 100-150 mg/kg/day on days 6-15 of gestation. At the higest dosage of 150 Ag/kg/day, the isooctyl ester, and butyl ester, and butoxyethynol and dimethylamine salts of 2,4-D were all associated with significantly increased teratologic incidence. The butyl and isooctyl esters also tended to decrease fetal weight. VIII-1 At a lower dosage, 2,4-D, and its salts and esters induced no apparent harmful effects. Collins and Williams (1971) found in the progeny of hamsters treated with three commercial samples of 2,4-- D at levels up to 100 mg/kg/day on day 6-10 of pregnancy, occasional anomalies of the fused rib type. However, the percentages were not signifi cantly different from that of the control population. Fetal viability decreased significantly at the higher dose levels, but again was not clearly dose-related. ' Sprague-Dawley rats were given 1,000 mg/1 2,4-D in their drinking water during pregnancy and for a further 10 months, 2,4-D was also administered to the second generation for up to 2 years. Pregnancy and parturition were normal; litter size was not significantly reduced, and no malformations were noted in the young. Except for retarded growth and increased mortality in the second generation, no unequivocal clinical or morphological changes were seen (Bjorklund and Erne, 1966). Female rats (10 per group) were fed 2,4-- D at levels up to 2,000 mg/kg of diet for 95 days and then mated with untreated males and continued on their respective diets through gestation and lactation. Pups born to females fed the highest level were small at. birth; 94% died before weaning; some deaths also occurred in pups of rats fed the lower level (1,000 mg/kg)(Gaines and Kimbrough, cited in Hansen et al., 1971). In a three-geheration study, Osborne-Mendel rats were fed 100 or 500 ppm of diet 2,4-D that was 96.7% pure, with no detectable (< 1 ppm) TCDD. No adverse effects were noted (fertility, mean litter size or viability of pups). However, diets, containing 7 0 5 7 V III-2 CC0CG3S 1,500 ppm 2,4-D, while apparently affecting neither the fertility of either sex nor litter size, sharply reduced the percentage of ^ pups that survived to 21 days of age and depressed the weights of these weanlings (Hansen, et al., 1971). When 2,4-D was administered at a concentration of 500 ppm of TO diet during the entire pregnancy of a sow, anorexia was observed. ? The piglets were clearly underdeveloped and apathetic and did not willingly suck. Ten of the 15 newborn piglets died within 24 hours. No malformations were noted in the dead piglets. .Continued feeding of 500 ppm of diet to the survivors until they were 8 _ months of age caused marked growth depression, persistent anemia and moderate degenerative changes of liver and kidneys (Bjorklund and Erne, 1966). A study that attempted to simulate field conditions for spraying with 2,4-D and to evaluate the effect on pheasant eggs and development of chicks was done by Lutz-Ostertag and Lutz (1970). A high mortality rate and morphological alterations were observed in most of the surviving embryos, and 50% of surviving chicks were sterile. Gyrd-Hansen and Dalgaard-Mikkelson (1974) studied the effect of 2,4-D on the hatchability of hens (leghorn) eggs and the viabil ity of the chicks, both by injecting the herbicide into the yolk and by immersing the eggs into solutions of the herbicide. A pure compound containing 99.5% 2,4-D as the dimethylamine salt and a commercial product containing about 93% 2,4-D as the dimethylamine salt were used in the investigation. Dose levels in the injection experiments ranged from 0.1 to 10.0 mg/60g egg. 58 VIII-3 C00G57 In the immersion experiments, eggs were soaked in either 10 or 50 g/1 aqueous solutions of 2,4-D. In the injection experiments, hatchability and viability were reduced at the 2-mg-and-above * CCMD level. 2,^-D injected into the yolk exhibited both embryotoxic and teratogenic properties at high dose levels. However, immersion -oCD in a 1% 2,4-- D solution had no effect and a 5% solution showed only a moderate effect on the hatchability of the eggs and the viability of the chicks. The 1% immersion level corresponds to the levels used in spraying operations, however, in the immersion experiment, the entire surface of the egg is exposed. The authors state that their investigations show that 2,4-- D has little effect on hen eggs after immersion. This is in contrast to the con-, elusions from the Lutz-Ostertag and Lutz study. Verrett (1970) reported that 2,*+-D produced fetal anomaly and chick edema syndrome following injection into the yolk sac. Eggs were injected with 2.5 mg 2,4-D/egg either prior to incu bation or <at-the fourth incubation day (96 hours), the latter being a time at which the embryo is more sensitive to some teratogenic agents. 2,U-- D did not show any particular acute toxicity to the embryo when treatment was pre-incubationai; however, occurrence of abnormal embryos was high. Treatment at 96 hours resulted in higher toxicity and also a high percentage of abnormal embryos. The results from egg injection studies are difficult to interpret due to the extreme sensitivity of this test procedure. The results of the teratogenesis studies in animals with . 2,4-- D were variable. The studies with birds presented conflicting data. One study that simulated environmental spraying c o n d i t i o n i n g v111- " C00G033 DfllYj 079622 resulted in a significant teratogenic effect on pheasant eggs. However, a similar immersion study with chicken eggs had no effect. Egg injection studies also produced teratogenesis. These studies are not particularly applicable to a human exposure because a human embryo would not be exposed in this manner and also because of the greater degree of protection afforded the human embryo by its mother. However, these studies do indicate a possible ecological impact on bird wildlife as a result of spraying 2,4-D in forests. In studies of mammals, which are more applicable to humans because of similar routes of exposure to the embryo, teratogenic effects are observed but only at doses that approach maternal toxicity. The phenomenon of teratogenesis, unlike carcinogenesis and mutagenesis is thought to have a "no-effect" level, that is a threshold below which no teratogenic response is observed. It is apparent from the studies of mammals that this threshold is very 'high and is in all probability considerably above the level of any potential environmental exposure Csee section : Comparison of Estimated Maximum Intake of 2,4-D and Acceptable Daily Intake). Therefore, it is very unlikely that levels of 2,u-D used in forestry management would produce teratogenesis in humans. VIII-5 np|Q 0006053 MUTAGENICITY D0W .1079623 2,U-D was negative in the rec-assay test (Shirasu, 1975). The rec-assay is believed to give an indication of reparable DNA damage; it is a simple method capable of detecting DNA- damaging capacity by analyzing differences in growth sensitiv ities of H17 Rec+ and MU5 Rec" mutant cells of Bacillus subtilis. 2,U-D was also not mutagenic in reverse mutation systems (Anderson, et al., 1972; Shirasu, 1975; Shirasu, et al., 1976; and Zetterberg, et al., 1977). The reverse mutation systems employed were the histidine-requiring mutants of Salmonella typhimurium [Ames test (TA1535, 1536, 1537, and 1538)] and two tryptophane-requiring mutants of Esherichia coli WP2 hcr+ and WP2 her" . Zetterberg, et al.(1977), using host-mediated assays with S . typhimurium strains TA1530 or TA1531 or with S. cerevisiae DU, observed no mutagenic effects when adult male mice were given 6 mg 2 ,U-D (200 mg/kg) by gavage. 2,U-D did not increase dominant lethal mutations in mice when given as a single i.p. injection of 125 mg/kg bw, or when given orally on five successive days for a total dose of 75 mg/kg bw (Epstein, et al., 1972). No increase in the number of recessive lethals was observed when 2-day-old adult male Drosophila melanogaster flies were fed U .5 or 9.D mM 2,U-D in sucrose (Vogel and Chandler, 197U). The above investigations have concluded, within the limits of the sensitivity of the tests employed, that 2,U-D is not mutagenic. However, there are several studies that indicate 7661CGOuGoO IX-1 that 2,4-D may possibly have mutagenic properties. Commercial 2,4-D tested for induction of mitotic gene con -> ersion in a diploid strain of the ascomycete Saccharomvces b~ --- * 'cerevisiae showed weak mutagenic activity when compared to -- (known mutagens. However, the treatment concentration was very S^high Cl,000 ppm) and survival rate of the yeast cells was only .22% (Siebert and Lemperle, 1974). Mitotic recombination in . cerevisiae D5 was also increased by 2,4-D (300 ug/ml)(Zetterberg, et al., 1977). Treatment of cultured human lymphocytes with 2.5x10 -7M . CO.02 yg/ml) 2,4-D increased the number of chromatid aberrations and, to a lesser extent, of chromosomal aberrations. In mice, toxic concentrations (100-300 mg/kg bw) of 2,4-D administered as a single oral dose significantly increased the frequency of 'errant metaphases (2-4 fold) in lymphocytes; single fragments were the primary aberration (Pilinskaya,1974, cited in IARC, 1977). In terms "bf'human relevance, the above mutagenic studies can be categorized as submammalian and mammalian systems, (See Table 6 for classification and results). The relevance of data obtained from submammalian test.systems is uncertain in view of factors such as cell uptake, metabolism, detoxification dosage and method of administration. Mammalian systems entail fewer of these limitations and may be considered more useful for pro viding evidence of a potential mutagenic hazard to humans. ,/ IX-2 0* "I*O ,* CoOuuGi Table 6 Classification and Results of the Mutagenicity Studies Reviewed Submammalian Mammalian Rec-assay B. subtillis (-) Reverse mutation S . tVDhimurium E. coli (-) (-) Recessive lethal D. melanogaster (-) Gene conversion S. cerevisiae Cl) Mitotic recombination S. cerevisiae () Host mediated assay S. tyohimurium/mice S. cerevisiae Dominant lethal mice Cytogenetic test . Human lymphocytes (in-vitro) Mouse lymphocytes (in-vitro) >_ .o CD 05 O cn ( ( (- ('!) (+) (-) Negative (+) Positive () Weak Activity Except for the gene conversion and recombination studies, which showed some weak activity, the submammalian systems were negative. Mammalian systems were negative, except for the human and mouse lymphocyte studies. A positive result in this test system is of concern, because mammalian tests are more relevant in assessing the potential hazard to humans than submammalian tests. However, these positive results are not sufficient evidence to conclude that 2,u-D will produce mutagenic disorders in humans at levels normally encountered. 7663 C&QSGS2 IX-3 CARCINOGENECITY Oral Administration - Animals The Bionetics Research Laboratories under contract with the i ( National Institute of Health carried-out a large-scale study / designed to screen selected pesticides (including 2,4-D) and industrial compounds for tumorigenicity in mice. A summary of the'results of the oral administration portion of this investi gation is reported by Inns, et al., (1969). O si CD 05 O 05. Groups of mice were orally administered maximum tolerated doses (duration of exposure was 7 days to 18 months) of commercial 2,4-D acid and several of its esters (see Table 7 for the compounds and the dose regime used). Tumor incidences of the treated groups were compared with those observed among groups of 79, 87, 90 and 82 control mice, which had either been untreated or had received gelatin only. Results of the experiment indicated that mice treated yith 2,4-D compounds listed in Table 7 did not have a statistically significant elevation of tumor incidence of any type of tumor in any sex-strain subgroup or combination of groups. The Food and Drug Administration studied the effects of long term feeding of 2,4-D on rats (Hansen, et al., 1971). Groups of 25 male and 25 female 3-week-old Osbome-Mendal rats were fed for 2 years on diets containing 0, 5, 25, 12$, 625, or 1,250 ppm of 2,4-D (free acid, 96.7% pure) in the basal diet. IJhe 2,4-D con tained no detectable levels of dioxin compounds; the limit of sensitivity of the method of analysis was 1 ppm. Results of this study indicated that the total number of rats with malignant tumors were 6 , 8 , 7, 7, 8 , and 14 in the control and in the .5, 25, 125, 625, 7684and 1,2 50 ppm groups, respectively. X-l CCG6GS3 ' DOW ll 079G27 Table 7 2,M-D Dose Regime (from Innes, et al. , 1969) % Compound ' Purity of Compound Strain of Mice No. of Mice 1. 2 ,M-D acid 2 . 2, M-D acid 3. 2,M-D Isopropyl ester 4. 2,M-D Butyl ester 5. 2,M-D Isooctyl ester 90% (C57BL/6xC3H/Anf)F, 18m, 18 f (C57BL/6xAKR)F, 18m, 18f 90% II h 99% If 1 99% II II 97% II II Daily Dosage mg/kg Vehicle M6 .M 100 M6 .M 0.5% gelatin II II M6 .M II M6 .M II ppm 1M 9 323 111 1M 9 130 Notes 1. Used during stomach intubation only (days 7-28 age). 2. Dosage in diet ad libitum (after 28 days of age). ( C00Gi)64 Ol i/l/tYJ079628 The authors state that from the pathological interpretation of the tumor incidence, it is apparent that the tumors were not "target organ" types and they were randomly distributed types normally found in aging Osborne-Mendel rats. In addition, the number- of animals surviving the two year study did not differ from group to group, whereas with a carcinogenic substance, one would expect fewer survivors' in the high dose group. When the tumor incidence was analyzed, a statistical increase (P< 0.05) of malig nant tumors occurred in male rats fed 2, **-- D at 1250 ppm (the highest dose), and a trend toward increased tumor formation with log dose in female rats was noted. Despite the statistical calculations on tumor incidence, it is the author's opinion that the patho logical interpretation indicates that a carcinogenic effect by 2,^-D has not been shown. / Another interpretation of this study has been offered by Rueber (1975), an independent pathologist, who reviewed the data for the'u/ S. Senate Subcommittee on Administrative Practice and Procedure. He concluded that the data suggested that the tumors were of a "target organ" type and that the statistical interpre tation of the data verifies that "2,4-- dichlorophenoxyacetic acid vis carcinogenic in rats". Subcutaneous Administration - Animals The Bionetics Research Laboratories also tested the tumorigenicity of 2,U-D and several of its esters in mice with subcutaneous administrations of the herbicide. Groups of mice, 18 male and 18 female (C57BL/6xC3HAnf)F mice, and 18 male and 18 female (C57BL/6xAKR)F mice,were given 3 CCQ6G&J /u0b Utttuim single subcutaneous injections of 215 mg/kg bw 2,4-D (90% pure) in dimethyl sulphoxide on the 28th day of life and observed up /s ^ to 78 weeks of age, at which time 16, 17, 18 and 18 mice in the w rfour groups, respectively, were alive. Tumor incidences were compared with those in groups of 141, 154, 161, and 157 controls that were either untreated or were injected with dimethyl sulphoxide 0.5% aqueous gelatin or corn oil. The tumor incidence in any group or combination of groups was not significantly different from that in controls (P>0.05). No increase in the incidence of tumors was observed in similar groups of mice treated with single s.c. injections of 215 mg/kg bw butyl or 100 mg/kg bw isopropyl esters of 2,4-D (both 99% pure). Of mice treated with 21.5 mg/kg bw isooctyl ester of 2,4-D (97% pure), 5/17 females of the second strain developed reticulum-cell sarcomas (P=0.01)(NTIS, 1968). Humans Axelson and Sundell (1974) reported that in an epidemiological investigation of tumor incidence and mortality among Swedish rail road workers, exposed to different herbicides, showed a twofold excess of all cancers, as compared with the national average. The situation is difficult to evaluate because of the combined exposure of many workers to more than one herbicide. The excess cancer V appears to be due to exposure to 3-amino-l,2,4-triazole(amitrole). Those subgroups that had been exposed to phenoxy acids (2,4-D and/ or 2,45-T) had about normal tumor incidence (5 cancers at all sites observed versus 2.8 expected). X-4 CG06GGG 096l0[~MQff Comments on Carcinogenicity Data The International Agency for Research on Cancer has reviewed and evaluated studies on the carcinogenicity of 2,4-D, includin'; those reported above (IARC, 1977). IARC initiated a program in 1971 to evaluate the carcinogenic risk of chemicals to man. IARC is supported in part by the National Cancer Institute of the United States and is regarded by government authorities as a source of expert, independent scientific opinion on environmental carcinogenesis. The IARC comments on the carcinogenicity of 2,H-D are as follows: Animal data. 2,4-D and several of its esters were tested in rats and mice by oral administration and in mice by subcutaneous administration. All of these studies had limitations, due either to inadequate reporting or to the small number of animals used. Therefore, although increased incidences of tumors were observed in one study in which rats received 2,4-D orally and in another in which*mice received its isooctyl ester by subcutaneous '`njection, no evaluation of the carcinogenicity of this compound could be made. Human data. The results of the single cohort study of a small number of workers exposed to various herbicides, including 2,4-D, .2,4,5-T and 3-amino-l,2,4-triazole (amitrole), are not sufficient to evaluate the carcinogenicity of 2 ,^-D to man. 0000057 766* /&TE9fi0: ( ' M M ! COMPARISON.OF ESTIMATED MAXIMUM INTAKE OF 2,4-D AND ACCEPTABLE DAILY INTAKE Estimate of Exposure The 1977 herbicide monitoring program in the Chippewa and Superior National Forests of Minnesota was done in part to determine if there were any adverse impacts on the water quality and the wildlife in these forests. It did not directly address the question of human health impact from exposure to 2,**-D, as a., result of the conifer release spraying project, to people living in or near the forests or the people using the forests (St. MN. , 1977). Exposure to 2,4-- D would logically occur through the food chain to the hunter, fisherman, gardener, and foraging naturalist. Although, at this point in time* it is difficult to accurately determine the level of exposure and any associated health effects, an estimation of 2,4-D intake for a "maximally exposed individual" can be c1alculated using wildlife monitoring and water quality data. A "maximally exposed individual", for the purpose of this calculation, is assumed to be an adult male whose total diet is derived from the forest habitat and the forest surface waters. Dietary intake is based on data for the "standard man" (70 kg bw), (U.S. HEW, 1970). The total non-fluid daily intake for a "standard man" is approximately 1600 grams and daiiy fluid intake is approx imately 2000 grams. The data available are 2,4-D levels in the kidneys and livers of small rodents >te. g., ground squirrels, chipmunks, shrews, voles, and mice) and birds (e.g., sparrows, flycatchers, warblers, etc.) from the U. S. Forest Service 1977 monitoring program in Chippewa VVitlQ. XI-l GG06GG3 079,632 National Forest. Specimens were collected before and after a typical conifer release spraying episode. The wildlife monitoring data from the Superior National Forest, collected by the Minnesota . Department of Natural Resources, were not used in the exposure estimation because of a lack of positive data. Water quality data rs available for both forests before and after conifer release spraying from the monitoring programs of both the Minnesota Pollution Control Agency and the U. S. Forest Service. It is assumed that the non-fluid portion of the dietary intake of the "maximally exposed individual" consists entirely of animal tissue. 'rVegetables, fruits, etc., are not considered in the non-fluid portion of the diet, although 2,U-D levels on their surfaces might initially be higher than that found in animal muscle tissue. However, it is likely that these foods would be washed before being eaten, reducing the exposure from this source to something which is in all probability less than the exposure from animal tissue. The individual's non-fluid dietary exposure to 2,4-D is calculated by multiplying the mass of the non-fluid diet by the projected animal tissue 2,*+-D concentration. The projected tissue concentrations were calculated using data from an animal study in which kidney, liver, and muscle tissue levels of 2,^-D were determined after exposure to a diet containing 2,4-D. The animal study chosen (Erne, 1966a) involving feeding rats and chickens 1000 ppm of 2,4-D amine in their drinking water for two months. At the end of this time, the animals were sacrificed and various tissues were analyzed for 2,^-D content. From this data, a ratio of 2,U-D concentration in the liver tissue to muscle tissue can be developed for both rats and chickens. These CG0o0S3 XI-2 7S70 ratios are than applied to the average 2,^-D concentration found in the liver tissue of the mammals and birds, which were analyzed in the U. S. Forest Service's Chippewa wildlife monitoring project. This gives the estimated maximum concentration of 2,U-D in the muscle tissue of these mammals and birds. This concentration represents a maximum value because it is calculated from measured concentrations in animals collected at a time (three days after CCS. CO ^ spraying) that theoretically has allowed 2,4-D levels in the animal tissue to reflect the maximum concentration resulting from spraying. To use these concentrations to estimate the 2,U-D intake for the "maximally exposed individual" requires the assumptions that (1 ) the liver to muscle 2,4-D ratio for rats and chickens, as measured in laboratory experiments, does not differ by orders of magnitude from the liver to muscle 2,^-D ratio for the small rodents and songbirds which were collected as part of the Chippewa wildlife monitoring program, and (2) the liver to muscle 2,^-D ratio for the "Small rodents and songbirds does not differ drasticxly from the liver to muscle 2,U-D ratio for the large mammals and birds, such as the rabbit, deer, grouse, etc., which would actually comprise the diet of the "maximally exposed individual". . The calculation for the mammal muscle tissue is as follows: (1) Liver: muscle ratio in rats from the laboratory animal study = 3.6:1. (2) Average 2,4-D concentration in the liver tissue of twenty`six mammals from Chippewa National Forests 1.19 ppm. XI-3 GCOuu7D DOW1.07963 (3) Estimated 2,4-D concentration of muscle tissue of Chippewa 'mammals = 1.19 ppm/3.6 = 0.33 ppm. The calculation for the bird muscle tissue is as follows: Cl) Liver: muscle ratio in chickens from the laboratory animal study = 5:1. (2) Average 2,4-D concentration in the liver tissue of eight birds from Chippewa National Forest = 0.48 ppm. .(3) Estimated 2,4-D concentration of muscle tissue of Chippewa birds = 0.48 ppm/5 = 0.10 ppm. Assuming that the non-fluid portion of the diet consists of one-half mammal muscle tissue and one-half bird muscle tissue, then the average 2,4-D concentration in animal muscle tissue consumed is 0.22 ppm; therefore, exposure of 2,4-D to the "standard man" from non-fluid food intake is: (1600 grams/day) (0.22 ug 2 ,4-D/gram muscle) = 352 ng 2,4-D/day) The intake of 2,4-D through the fluid portion of the diet was determined by using the average 2,4-D concentration found in water samples taken twenty-four hours after spraying. The twenty-four hour values were used becasue the concentrations of 2,4-D in the water appeared to peak at that time. Only the Minnesota Pollution Control Agency water quality data were used because the detection was lower and the program provided data twenty-four hours after spraying. The Minnesota Pollution Control Agency program included data from both Chippewa and Superior forests with- data from both forests being averaged for this calculation. The average twenty-four hour. 2,4-D level in water at all sites in both forests was 0.42 ppb; therefore, assuming that the total intake of fluid consumed by the "maximally exposed individual" is forest surface water, the exposure is calculated as follows: XI-4 GGGovyvi, DOW ] 079635 Cl) Fluid intake = 2 liters/day (2) Concentration of 2,4-D in water = 0.42 yg/1 (3) 2,4-D intake from the fluid portion of the diet = C2 1/d)C0.42 yg/1) = 0.84 yg 2,4-D/day. Then the total dietary intake of 2,4-D is: 352.0 yg 2,4-D/day (non-fluid intake) + 0.84 yg 2,4-D/day (fluid intake) 352.84 yg 2,4-D/day (total intake) This is approximately 0.35 mg of 2,4-D/day. The contribution from the water portion of the diet is seen to be negligible. For the 70 kg "standard man" the intake per unit of body weight is: '70.0,k'|I?/~ y s *005 2,4-D/kg bw/day Earlier, it was indicated that exposure to 2,4-D would probably occur to an individual eating fish taken from bodies of water within the area impacted by spraying. The contribution of fish to the non fluid portion of diet is judged to be negligible and was not considered in the estimation of 2,4-D exposure. Fish are not likely to accumulate 2,4-D over the concentration in the water (Smith and Isom, 1967 and Schultz, 1973), and since the water quality indicate that the 2,4-D levels in the forest waters are very low, V the level in fish tissue would be negligible in comparison to the level estimated in the muscle tissue of mammals and birds. There fore, excluding any contribution of 2,4-D from fish to the non fluid portion of the diet actually maximizes the estimated 2,4-D intake. <^ XI-5 7673 FAO/WHO Allowable Daily Intake The Food and Agriculture Organization of the United Nations and the World Health Organization have jointly studied and ..evaluated possible hazards to people arising from the occurrence "-1079636 of residues of pesticides in foods. From these efforts, they have, in some cases (including 2,4-- D), been able to establish an acceptable daily intake (ADI) for humans. The ADI is expressed as milligrams per kilogram body weight (mg/kg bw). Vettorazzi (1975),' in discussing the ADI, states that: "the concept is based on the widely accepted fact that all chemicals are toxic, but their toxicities vary markedly, not only in nature, but also in the amount that is required to produce signs of toxicity. The figure (mg/kg bw) is indicative of the amount of a chemical that might be in gested daily even over a lifetime, without appreciable risk to the consumer. 'Without appreciable risk' is taken to ' mean the practical certainty that injury will not result after a lifetime exposure". To establish an ADI for a pesticide, the FAO/WHO evaluates data from long-term studies in animals, observations on humans, and other pertinent toxicological data. From this, they deter- mine a "no-effect level", which is that daily dose that produces no indication of toxic effects in the test animals or human subjects. Then, in order to extrapolate to a safe level for human^intake, a safety factor is generally applied. No hard- and-fast rule is established with regard to the magnitude of the safety factor. Although the widely accepted figure of 100 is often employed, in practice, this factor has varied from ten to several hundred. The FAO/WHO has established the maximum ADI for 2,4-D at 0.3 mg/kg bw. A summary of the "no-effect level" and other GG06G XI-6 rf ,0 f0 elements that have been chosen by the FAO/WHO as a basis for the ADI of 2,4-D is given in table 8 . * n r j 079G37 Table 8 : Summary of Toxicological Data (from Vettorazzi, 1975) Compound Animal species Kind of toxicological test Levels tested Levels causing no toxicological effects Safety factor employed Maximum acceptable daily intake (ADI) mg/kg bw Brief indication of effects 2,4-D . Rat Two year 0, 5, 25, 125 625, 1250 ppm 625 ppm in the diet (31 mg/kg bw) 0.3 Macrocystosis; slight polychromasia, and hypochromasia References Remarks Hansen, et al., 1971 "An ADI for man was established on the 2-year feeding study in the rat." Comparing the Estimated Exposure to the ADI When comparing the estimated 2,U-D exposure of a "maximally exposed individual" in the northern Minnesota forests to the maximum acceptable daily intake, several things are apparent. First, the estimated exposure is approximately sixty times less than the ADI (0.005 mg/kg bw vs. 0.3 mg/kg bw). Since the ADI / has a hundred fold safety factor, the estimated exposure is approximately 6,000 times below the "no-effect level" measured in the rat study. XI-7 Based on this comparison alone, there appears to be little potential for an adverse health effect to the "maximally exposed individual". This conclusion is further supported by the fact hat the projected exposure for the hypothetical individual living in the forest was the "worst case" exposure. In reality, the actual exposure, even if it ever reached the calculated maximum level, would decline quickly to a much lower level, because 2,4-D is rapidly degraded in the environment. What we have done, in essence, is to compare a short term 2 ,M-- D intake to an ADI, which is meant to be used for a lifetime exposure. UOWJ079638 XI- 8 i C&OG 6e96iorM00 CONCLUSIONS AND RECOMMENDATIONS Conclusions Various possible adverse health effects resulting froir. exposure to 2,4-? have been examined, including acute toxicity, chronic toxicity, teratogenicity, mutagenicity, and carcinoge nicity. A review of the literature of the toxicology of 2,*+-D, the data from the 1977 monitoring programs of the Chippewa and Superior National Forests, and the calculation of the estimated 2 ,*+-P exposure to a "maximally exposed individual", supports the conclusion that, although certain adverse health effects are not likely to occur, there is significant doubt about some areas of the toxicology of 2,4-B which precludes an absolute assumption of safety relating.to its use in forestry management. The adverse human health effects that do not seem likely to occur as a result of exposure"to 2,^-D, as it is used in forestry management, include: 1. Acute Toxic Response. Although accidental poisonings involving 2, U-D have occurred, the dose levels were very high. Numerous studies in animals indicate that acute toxicity occurs only at high doses and it has been estimated that the LDgg for man is approxi mately one ounce of 2,4-D. 2. Chronic Health Effects. Chronic health effects, excluding mutagenicity and carcinogenicity resulting from 2,^-D exposure have been observed in both animals and humans. Effects in humans have been associated with long-term occupational exposure to high ccncentrations of 2 ,+-D. Symptoms of chronic toxicity include gastri- bt. , tis, less of appetite, headache', vertigo, weakness, and disturbances XII-1 G&Oouio OW I 079640 of the cardiovascular and respiratory systems. Although chronic health effects can occur, it is unlikely that exposure to an individual living in a spraying area would result in such effects since the exposure would be of short duration. However, acute and chronic health effects could be of concern to the applicator. a * ` 3.' Teratogenesis. Considerable concern has been expressed over the possibility of a teratogenic response as a result of exposure to 2,^-D. Based on a comparsion of animal teratogenicity studies and the estimated maximum exposure resulting from the use of 2,4-D in forestry, it is expected that 2,4--D would not produce teratogenesis in humans. Teratogenesis observed in experimental animals (mammals) was only produced at dose levels that approached the i level of maternal toxicity. The levels at which this effect began to appear in mammals are at least one-hundred fold above the A D I , .id are approximately five-hundred fold above our estimated expo sure to a "maximally exposed individual". Although reasonably definite conclusions can be drawn withregard to the above three areas,'there remain questions relating to the toxicology of 2,>+-D which prevent the assumption that the V use of 2,**-D in forestry is completely safe. Such an assumption will require further definitive research in the following areas: 1. Mutagenicity. The results of the mutagenicity studies present conflicting results making it difficult to conclude that 2,^-D is not mutagenic in humans. The fact that at least one study has found that 2,^-D produces aberrations in the chromosomes of human .Lymphocytes at low dose levels is cause for concern. XII-2 2. Carcinogenicity. The results of the carcinogenicity studies are also inconclusive. Only a limited number of studies have been done, the results of which have been subject .to conflicting DOIV 079641 interpretation. An adequate assessment of the carcinogenic poten tial of 2,4-D will require further studies involving large numbers of animals of several species. 3. Contaminants and Metabolites of 2,4-D. It is now known that the production of 2,4-D, at least theoretically, will not result in its contamination by the very toxic compound tetra-dioxin. However, hexa-dioxin has been identified in commercial 2,4-D and although not nearly as toxic as tetra-dioxin it has been shown to produce a toxic reaction in animals. Other contaminants have also been identified in commercial 2,4-D, but little or nothing is known of their toxic properties. Several studies have examined the absorption and excretion of 2,4-D. These studies indicate that 2,4-- D is rapidly absorbed through the gut and excreted in the urine mainly .as the original compound. Although these studies are able to account for a large percentage of ingested 2,4-D in the urine and feces of test animals and human volunteers, there is still a small fraction which is not excreted as the original 2,4-D compound. The same studies have re vealed the presence of several metabolites of 2,4-D in the urine including 2 ,U-dichlorophenol, a suspected carcinogenic promoter. u. Environmental and Wildlife Monitoring. The 1977 monitoring c program in the Chippewa and Superior National Forests did not provide the type and amount data necessary to adequately assess the extent of 2,4-D exposure to humans. A more complete risk assessment 7679 XI1'3 GG0S073 DOW 1 079642 will require more data from the human food chain (e.g., rabbit, deer, fish, grouse,-vegetation, and water). o. Acceptable Daily Intake. The A D I , as was explained earlier, is based on a "no-effect level" observed in an animal study and an ^arbitrary safety factor of 100. It is possible that some health effects, such as carcinogenicity or mutagenicity, may not manifest themselves in the particular species or at the particular dose level used in the study. If future studies on several species of animal indicate that 2 ,*+-D is mutagenic or carcinogenic, a more conservative approach to the establishment of an ADI will be required. These concerns leave some doubt as to the safety of 2,H-D. The available scientific data suggests that 2,4-D is possibly a -ak carcinogen or mutagen.- However, even if 2,*+-D is carcinogenic or mutagenic the risk of the development of cancer or mutagenic disorders in an individual is small at levels of exposure which are approximately that of the "maximally exposed individual". As a ' matter of fact the risk to such an individual is most likely not high in comparsion to that which we face daily from the thousands of untested, possibly carcinogenic or mutagenic, chemicals used by society. If the population exposed to 2,4-D residues at the estimated maximum level numbered in the tens of thousands, there would be cause for more serious Concern since low level exposures to carcin ogens or mutagens in large populations may produce disease. However, . .e population exposed to such levels as a result of the use of 2,^-D in forestry management in Minnesota is very small. GGuuu XII-4 9^96^01 M n n The small size of the population coupled with the low level of 'risk to an individual make it difficult to conclude that there is a reasonable chance of disease occurring as a result of spraying. However, it is equally difficult to conclude that 2,U-D is absolutely safe. Recommendations In the absence of clear evidence that 2,+-D poses no threat to the public's health, a prudent policy governing the use of 2,*+-D should provide, Cl) assurances that exposure is minimized for residents, workers, and persons participating in all activities in spray areas and (2) for the acquisition of sufficient information which, coupled with future toxicological research, will allow a more complete assessment of health risk. Such a policy should include as a minimum the following: 1. Environmental and Wildlife Monitoring Program. The program should be implemented in areas where herbicides are used for for estry management and should provide data on 2,**-D concentrations in the human food chain. Of course the program can be designed to address concerns relating to the ecological impact of the use of 2,4-D also. 2 . Human Health Studies. Limited studies of human populations exposed to herbicide spraying should be done. This might include, for example, analysis of blood and urine samples for the presence of 2,*+-D or 2,4-D metabolites. The Minnesota Department of Health is currently planning to establish an Environmental Pathology Laboratory which could perform ,j specialized studies on biological specimens from people exposed to 2,**-D. This laboratory would be capable of providing highly sophis ticated and very valuable studies involving, for example, the XII-5 C005G30 u u flj U73644 analysis of urine for the presence of mutagenic substances. f The more conventional forms of epidemiology, i.e., measuring disease incidence in the exposed population, should also be conducted if sufficiently large exposed populations can be identified. 3. Herbicide Analysis Program. The herbicides used in forestry management should be routinely analyzed for contaminants prior j to application. The toxicology of 2,U-D is, to some degree, known; however, studies have indicated that contamination of commercial 2,H-D does occur and it is conceivable that contaminants such as the dioxins could have a serious adverse impact on human health. A policy relating to the use of contaminated herbicides should also be established. t. Physical Control of Exposure. Regulations providing strict control on overspraying, drift, limited access to spray areas, posting of warnings and protection of applicators should be established ""to minimize human exposure. XII-6 76 CGGoGSi Sf-96i 0LMOff 4 REFERENCES Alexander, M. and M. I. H. Aleem, 1961, "Effect of Chemical Structure on Microbial Decomposition of Aromatic Herbicides," J. Agr. Food Chem. 2:44-47, 1961. Allebone, J.E., R. J. Hamilton and B. Ravenscroft, 1975, "Environ mental Organic Chemistry of 2 ,4-Dichlorophenoxyacetic Acid," Environmental Chemistry 1:160-190, 1975. Anderson, K. J., E. 6 . Leighty and M. T. Takahashi, 1972 , "Evaluation of Herbicides for Possible Mutagenic Properties," J. Agr. Food Chem. 0:649-656, 1972. " Axelson, 0. and L. Sundell, 1974, "Herbicide Exposure, Mortality and Tumor Incidence. An Epidemiological Investigation on Swedish. . Railroad Workers," Work-Environm.-Hlth. 11:21-28, 1974. Bashirov, A. A., 1969, "Health Condition of Workers Producing Herbicides of Amine Salt and Butyl Ether of 2,4-D Acid," Vrach. Delo. 10: 92-95, 1969. Berkley, M. C. and K. R. Magee, 1963, "Neuropathy Following Exposure to a Dimethylamine Salt of 2,4-D," Archives of Internal Medicine 111:351-352, 1963. Berwick, P., 1970, "2,4-Dichlorophenoxyacetic Acid Poisoning in Man," JAMA 214:1114-1117, 1970. Bjorklund, N. E. and K. Erne, 1966, "Toxicological Studies of Phenoxyacetic Herbicides in Animals," Acta. Vet. Scand. 364-390, 1966. B o u t w e l lR. K. and D. K. Bosch, 1959, "The Tumor-Promoting Action of Phenol and Related Compounds for Mouse Skin," Cancer Research 19:413-424, 1959. Clark, D. E., J. S. Palmer and R. D. Radeleff, et al., 1975, "Residues of Chlorophenoxy Acid Herbicides and Their Phenolic Metabolites in Tissues of Sheep and Cattle," J. Agr. Food Chem. 23:573-578, 1975. ~" V Collins, T. F. X. and C. H. Williams, 1971,. "Teratogenic Studies with 2,4,5-T and 2,4-D in the Hamster," Bull. Environ. Contam. Toxicol. 6:559-565, 1971. ... Council for Agricultural Science and Technology, 1975, "The Phenoxy Herbicides," Weed Science 23:253-263, 1975. * DeMarco, J., J. H. Symons and 6 . G. Robeck, 1967, "Behavior of Synthetic Organics inStratified Impoundments," J AWWA 59:965-976, 1967. XIII-1 GGQoOSS 7683 DOVITI 079646 Dudley, A. w. and N. T. Thapar, 1972 , "Fatai Human Ingestion of- 2,4-D, a Common Herbicide Archives of Pathology 04:270-275, 1972. ''uggan, R. E. and P. E. Corneliussen, 1972, "Dietary Intake of Pesticide Chemicals in the United States," Pesticide Monitoring J. 5:331-334, 1972. "" pistein, S. S., E. Arnold and J. Andra, et al., 1972, "Detection of Chemical Mutagens by the Dominant Lethal Assay in the Mouse," -- Toxicol. Appl Pharmacol. 23:288-325, 1972. Erne, K . , 1966a, "Distribution and Elimination of Chlorinated Phenoxyr acetic Acids in Animals," Acta Vet. Scand. 7_:240-256, 1966 . Erne, K . , 1966b, "Studies on the Animal Metabolism of Phenoxyacetic Herbicides," Acta Vet. Scand. 7^:264-271, 1966. Feldman, R. J. and H. I. Maibach, 1974, "Percutaneous Penetration of Some Pesticides and Herbicides in Man," Toxicol. Appl. Pharmacol. 28:126-132, 1974. : '"t Festisov, M. I., 1966, "Occupational Hygiene in the Application of Herbicides of the 2,4-D Group," Hygiene and Sanitation 31:383-386, 1966. ` 1 Frank, P. A. and R. D. Comes, 1967, "Herbicidal Residues in Pond Water and Hydrosoil," Weeds 15:210-213, 1967. ines, T. B. and R. D. Kimbrough, 1970, Personal Communication. Goldstein, N. P. and P. H. Jones, 1959, "Peripheral Neuropathy After Exposure to An Ester of Dichlorophenoxyacetic Acid," JAMA 171: 1306-1309; 1959. Gyrd-Hansen, N. and Sv. Dalgaard-Mikkelsen, 1974, "The Effect of Phenoxy-herbicides on the Hatchability of Eggs and the Viability of the Chicks," Acta Pharmacol, et Toxicol. 5^300-308, 1974. Hansen, W. H . , M. L. Quaife and R. T. Habermann, et al., 1971, "Chronic Toxicity of 2 ,4-Dichlorophenoxyacetic Acid in Rats and Dogs," Toxicol. Appl. Pharmacol. 20^:122-129 , 1971. Harvey, W. E., 1971, 23rd Ann. Proc. California Weed Conference, page 6 8 , 1971. Hill, E. V. and H. Carlisle, 1947, "Toxicity of 2 ,4-Dichlorophenoxy acetic Acid for Experimental Animals," J. of Industrial Hygiene and Toxicology 29:85-95, 1947. " </ House, W. B., H. Goodson and H. M. Gadberry, et al., 1971,'"Assessment of Ecological Effects of Extensive or Repeated Use of Herbicides," U.S. Dept, of Defense ARPA 1086 p. 369, 1971. XIII-2 70 CCOuGov DOW. 1 079647 i *f * Huston, B. L., 1972, "Identification of Three Neutral Contaminants in Production Grade 2,4-D," J. Agr. Food Chem. 2J3:724-727 , 1972 IARC, 1977, IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man, 15, Some Fumigants, the Herbicides 2.4- D and 2,4-5-T, Chlorinated Dibenzodioxins and Miscellaneous Industrial Chemicals, pp. 111-138. ' ' - Innes, J. R. M., B. M. Ulland and M. G. Valerio, et al., 1969, "Bioassay of Pesticides and Industrial Chemicals for Tumorgenicity in Mice: A Preliminary Note," J. Natl. Cancer Inst. 42:1101-1114, 1969. " Johnson, J. E . , 1971, "The Public Health Implications of Widespread Use of the Phenoxy Herbicides and Picloram," BioScience 21:899905, 1971. Kay, J. H., R. J. Palazzolo and J. C. Calandra, 1965, "Subacute . . Dermal Toxicity of 2,4-D," Arch. Environ. Health 11:648-651, 1965. Kearnev, P. C., 1970, "Herbicides in the Environment," FAO International Conference on Weed Control, Davis California PP* 496-512, July, 1970. Khanna, S. and S. C. Fang, 1966, "Metabolism of C^1* ~ Labeled 2,4Dichlorophenoxyacetic Acid in Rats," J. Agr. Food Chem. 14:500503, 1966. Khera , K. S. and W. P. McKinley, 1972, "Pre-and Postnatal Studies on 2,4,5-Trichlorophenoxyacetic Acid, 2 ,4-Dichlorophenoxyacetic Acid and Their Derivatives in Rats," Toxicol. Ad d I. Pharmacol. 2: 14-2 8 , 1972. Klingmafi, D. L., C. H. Gordon and G. Yip, et al., 1956, "Residues in the Forage and in Milk from Cows Grazing Forage Treated with Esters of 2,4-D," Weeds 14:164, 1966. Kohli, J. D., R. N. Khanna and B. N. Gupta, 1974, "Absorption and Excretion of 2 ,4-Dichlorophenoxyacetic Acid in Man," Xenobiotica 4:97-100, 1974. vLisk, D. J., W. H. Gutenmann, and C. A. Bache, et al., 1963, "Elimina tion of 2,4-D in the Urine of Steers F.ed 4-(2,4-DB) or 2,4-D," J. Dairy Sei. 46:1435, 1963. Lutz-Ostertag, Y. and H. Lutz, 1970, "Action Ne faste de l 'herbicide 2.4- D Sur le Development Embryonnaire et la Fecondite du Gibier a Plumes," C. R. Acad. Sci. (Paris), Ser. D. 271:2418-2421, 1970. Malkinson, F. D. and S. Rothman, 1962, "Percutaneous Absorption In: Hand buch^der Haut-und Geschlechtos KrankheitenCJ. Jadassohn, Ed.), 1962 . Manigold, D. B. and J. A. Schulze, 1969, "Pesticides in Selected Western Streams - A Progress Report," Pesticide Monitoring J. 3:124-135, 1969. XIII-3 GCG6GS* 7685 DOW J079648 :iewtpn, M. and L. A. Norris, 1976, "Evaluating Short-and Long-Term ..v; Effects of Herbicides on Nontarget Forest and Range .Biota," Down ~to Earth 32:18-26 , 1976. Jielsen, K. B. Kaempe and J. Jenson-Holm, 1965, "Fatal Poisoning in Man by 2 ,4-Dichlorophenoxyacetic Acid (2,4-D): Determination of the Agent in Forensic Materials," Acta Pharmacol, et Toxicol. 22:224-234, 1965. lorris, L. A., 1966, "Degradation of 2,4-D and 2,4,5-T in Forest Litter,"' J. Forestry 64:475-476, 1966. Morris, L. A . ,1971, "Chemical Brush Control: Assessing the Hazard," J. Forestry 69:715-720, 1971. iTIS CNational Technical Information Service), 1968, Evaluation of Carcinogenic,Teratogenic, and Mutagenic Activities of Selected Pesticides and Industrial Chemicals,Carcinogenic Study, Vol. 1, Washington, D.C., U. S. Department of Commerce, 1968. tinier, J. S., and R. D. Radeleff, 1964, "The Toxicologic Effects of Certain Fungicides and Herbicides on Sheep and Cattle," A n n . N. Y. Acad. Sci. 111:729-736, 1964. 3ilinskaya, M. A., 1974, "Cytogenetic Effect of the Herbicide 2,4-D on Human and Animal Chromosomes," Tsitol. Genet. 8:202-206, 1974. :ar' mov, A.D., A. N. Chumachenko and I. I. Kirilenko, 1967, "The Toxic Properties of the Herbicide 2,4-D," Hygiene 6 Sanitation 32.:116-118, 1967. .euber, M. D., 1976 , "Preliminary Review of Some Oncogenicity Studies for 2 ,4-diciilorophenoxyacetic Acid," Appendix to Staff Report. Subcommittee on Administrative Practice and Procedure, December, 1976, pp. 471-476. lowe, V. K. and T. A. Hymas, 1954, "Summary of Toxicological Information on 2,4-D and 2,4,5-T Herbicides and an Evaluation of the Hazards to Livestock Associated with Their Use," Amer. J. Vet. Res. 15:622-629, 1954. .~ k " 'auerhoff, M. W., W. H. Braun and G. E. Blau, et al.,1976, "The Fate of 2 ,4-Dichlorophenoxyacetic Acid (2,4-D) Following Oral Administration to Man," Toxicol. Appl. Pharmacol. 3_7:136, 1975. chwetz, B. A., J. M. Norris and G. L. Sparschu, et al., J.973, "Toxicology of Chlorinated Dibenzo-p-dioxins" Environmental Health Perspectives, 87-99, 1973. C/ chwetz, B. A., G. L. Sparscha and P. J. Gehring, 1971, "The Effect of 2 ,4-Dichlorophenoxyacetic Acid (2,4-D) and Esters of 2,4-D on Rat Embryonal, Foetal, and Neonatal Growth and Development," Fd. Cosmet. Toxicol. 9:801-817, 1971. xni-* CGOoG^j 7686 Schultz, D. P., 1973, "Dynamics-of a Salt (2,4-Dichlorophenoxy) acetic * Acid in Fish, Water, and Hydrosol," J. Agr. Food Chem. 21:186-192. 1973. Seabury, J. H., 1963, "Toxicity of 2 ,4-Dichlorophenoxyacetic Acid for Man and Dog," Arch. Environ. Health 2:202-209, 1963. Shirasu, Y . , 1975, "Significance of Mutagenicity Testing on Pesticides," \ ' Environmental Quality and Safety j4:226-231, 1975. . Shirasu, Y., M. Moriya and K. Kato, et al., 1976, "Mutagenicity Screenin', of Pesticides in the Microbial System," Mutation Research 40:19- 30, 1976. ' Siebert, D. and E. Lemperle, 1974, "Genetic Effects of Herbicides: Induction of Mitotic Gene Conversion in Saccharomyas cerevisiae," Mutation Research 22:111-120, 1974. Smith, A. E., 1972, "The Hydrolysis of 2,4-Dichlorophenoxyacetate Esters to 2,4-Dichlorophenoxyacetic Acid in Saskatchewan Soils," Weed Res. 12:364-372, 1972. Smith, G. E. and B. G. Isom, 1967, "Investigation of Effects of LargeScale Applications of 2,4-D on Aquatic Fauna and Water Quality," Pesticide Monit. J. 1:16-21, 1967. State of Minnesota, 1977, Report on the Findings of the 1977 Herbicide Monitoring Program in the Chippewa and Superior National Forests of Minnesota, November,.197?. ~ U. S. Environmental Protection Agency, 1974, Herbicide Report: Chemistry and Analysis, Environmental Effects, Agricultural and Other Applied Uses EPA-SAB-QQ1, 19^4. 'J. S. Department of Health, Education, and Welfare, 1970, Radiological Health Handbook, 1970. errett, J., 1970, "The Effects of 2,4-D, 2,4,5-T and Their Contaminants on the Developing Chicken Embryo,", 1970. ttorazzi, G., 1975, "Toxicological Decisions and Recommendations Resulting from the Safety Assessment of Pesticide Residues in Food," CRC Critical Reviews in Toxicology 4^125-183, 1 9 7 5 , el, E. and J. L. R. Chandler, 1974, "Mutagenicity Testing of Cyclamate and Some Pesticides in Drosophila Melanogaster," Experientia 30:621-623, 1974. son, E. A., R. F. Thomas and P. D. J. Ensor, 1972, "Survey of Polychlorodibenzo-p-dioxin Content in Selected Pesticides," J. Agr. Food Chem. 2_0:351-3ifc4, 1972. " rberg, G., L. Bush and R. Elovson, et al., 1977, "The Influence of pH on the Effects of 2,4-D C2,4-dichlorophenoxyacetic acid, ia Salt) on Saccharomyas cerevisiae and Salmonella typhimurium," :ut*tion Research 42:3-18, 1977. XIII-5 CGOG c C ( i'O 2 ,A -D . IN THE URBAN AND SUBURBAN ENVIRONMENT AND ( HUMAN HEALTH E . C . Pa c k e e , Ph . D, Presented to the Nanaimo Parks and Recreation Commission Bowen Park Complex March 29, 1979 ss ( 0000214 0008 470 FORWARD "2,4-D in the Urban and Suburban Environment and Human Health" was prepared as a private contribution for a meeting called to review the use of 2,4-D by the governmental agencies of the city O and school district of Nanaimo. The information presented in Q the report is equally valid for forestry uses. Of major concern in forestry is the exposure of the applicator to 2,4-D. Since no substance, natural or artificial, known to man is absolutely safe under all conditions, it is essential to think in terms of risk or hazard; in the purest sense of the word, no substance is safe! Therefore, it is commonsense to minimize unnecessary exposure to a substance. For 2,4-D this means good personal hygiene and use of protective equipment as necessary must be enforced. In reading this report, which was orally presented, be certain to refer to the appropriate visuals which are attached. A numbe indicated as follows, (4 ) t refers to visual number 4 . t 7690 0000215 SOOO CONTENTS Introduction Misconceptions Concerning 2,4-D 1. 2,4-D was developed for chemical warfare. 2. 2,4-D has been shown to cause birth defects and cancer in Vietnam. 3. Because 2,4-D belongs to the phenoxy herbicide group it has the same contaminants and physio logical effects - the family likenes's -syndrome. 4. 2,4-D accumulates in the environment%md mammalian tissue. 5. The South Okanagan Environment Coalition's "'The Other F.ace of 2,4-D...' stands up to rigorous scientific scrutiny," is the best scientific docu ment on 2,4-D and is fair. Lethal Toxicity to Humans Sublethal Toxicity to Humans 2.4- D and Carcinogenicity 2.4- D and Mutagenicity 2.4- D and Embryotoxicity Summary Cited Literature Tables and Illustrations C O 7691 0000216 N *? 2,4-D IN THE UP3AN AND SPBU33AN ENVIRONMENT AND HUMAN HEALTH 8 0 0 0 M 0(J Obviously, this meeting is the result of the division of the public and, to a lesser degree, scientists over the safety and benefits of 2,4-D, one of the phenoxy herbicides. As in any controversy, the opposing parties include both reasonable and unreasonable people and individuals with vested interests or personal ambitions. Because of the use and abuse of scientific and pseudo-scientific jargon, hogwash and whitewash, and publi city generated by both sides, sincere citizens have become con fused, are concerned, and are clamoring for action. Furthermore, there are fundamental philosophical differences over herbicide usage. At one extreme are those who consider inserting any synthetic chemical into the environment as funda mentally wrong, regardless of benefits and proven safety. At the other extreme are those who are unable to accept any sug gestion that some chemicals, although used successfuly and with no apparent problems in the past, might actually constitute a hazard which is only becoming evident now. i As a scientist, I deal with theories, hypotheses, and facts. Decisions must be based on supported hypotheses or facts. The .aO /* 0000217 AKC' 2 facts are found in juried journals and reports. (1) The news media is rarely a source of reliable scientific facts. This illustration (2 ) provides examples of sources for scientific facts. Regardless of the source, however, the questions raised by the media and the public deserve an answer - I am part of the public and I, too, want answers. (3 ) Before discussing the safety aspects of 2,4-D, I would like to dispel some misconceptions. (0 This will greatly reduce the time needed for discussion. 1. 2,4-D was not developed as a weapon of war (5) / Shortlyafter the turn of the century researchers were attempting to synthesize plant growth stimulating sub stances; such work is continuing today. In August 1941, Dr. Kraus, a University of Chicago botanist, suggested to two former graduate students that they investigate the planting killing aspects of growth stimulators. They ob tained various substances, one of which was 2,4-D. In 1942, recognizing the crop-killing potential of growth regulating substances, Dr. Kraus advised the National Aca demy of Sciences about the potential dangers of biological warfare. .It was not until-1944 that herbicide research was included in the research program at Camp Dietrick (Peterson 19 67;`Davis 1979). -. / .. ./3 7693 0000218 I'Ll7 8 0 0 0 3 2. 2,4-D has not been shown to have caused birth defects or cancer in Vietnam. 2,4-D was always used in mixture (5) with either 2,4,5-T as agents orange or white or with' picloram as agent purple (Council for Agricultural Science and Technology.1975; O Whiteside 1970). Thus it is impossible to attribute the Q birth defects to 2,4-D or 2,4,5-T or picloram specifically. Follow-up research on agent orange indicated that the 2,4,5-T component was highly contaminated with TCDD (Council for Agricultural Science and Technology 1975? Whiteside 1970) a known teratogen. Agent orange was applied at 5 to 10 times normal levels used for agriculture in North America (Council for Agricultural Science and Technology 1975); Whiteside (1970) states 13 times. Many areas were retreated. The estimated amount of TCDD distributed in South Vietnam is 120 to 165 kg. Dr. William Wells, Acting Director, Special Pesticide Review Division, Office of Pesticide Programs, U.S. E.P.A., Washington, D.C., assures me that the major concern about the phenoxy herbicides -to which 2>4-D and 2,4,5-T belong is. the TCDD contaminant. Costle's (1979a and 1979b) recent 'decision and emergency suspension orders regarding 2,4,5-T and 2,4,5-TP which state, "It is reason- r able'to assume that the adverse human reproductive effects observed in'yAlsea which have been attributed to -low-level exposure to 2,4,5-T are due primarily to the TCDD in the ( ( ( 4 c 2,4,5-T/" support the concern over TCDD. Even Ton That (l and associates (1973) attribute increased liver cancer to 1 herbicides "containing TCDD"! TCDD is not present as a ^ contaminant or by-product of 2,4-D (I.A.R.C. 1977a and C 19 77b). 3. Because a chemical belongs to a particular family of chemicals or only varies by one molecule, it does not follow that it behaves in all cases like the similar compounds. For example, HjO and vary by only one atom, but we all know that water and hydrogen sulfide are vastly dif ferent. Similarly, ethanol and methanol axe alcohols, but the -former is grain alcohol and the latter wood alco hol. Because 2,4-D and 2,4,5-T belong to the same family, the chlorophenoxys, it does not mean that they are produced the same way. 2,4-D is produced from dichlorophenol and 2,4,5-T is from trichlorophenol. The former precludes pro duction of (7) TCDD but not DCDD; the latter includes pro duction of TCDD as a by-product. The use of the word dioxin is misleading, it denotes a family of compounds called chlori nated dibenzodioxins. The point is - oversimplification or generalizations' can lead to erroneous conclusions; this is demonstrated in the following table (8) - quite a dif ference in the survival of OCDD and DCDD treated animals. Reports (Warhock and Lewis 1978) that hexa, hepta, and octa- { chlorodibenzo-parc-dioxins are contaminants are unsubstanti ated; however, I must note that Woolson. and associates (1972) 7 6 9 50 000-220 DOW 0008 476 5- reported finding less than 10 ppm of a hexacnlorodibenzopcrc-dioxin in one of the 28 samples of 2,4-D; this obser vation has never been duplicated, and all chemists whom I have queried believe the contaminant entered the 2,4-D after production. Also, the "International Conference on Chlor inated Phenoxy Acids and Their Dioxins" (Anonymous 1977) concluded that the only dioxin found in phenoxy herbicides which is of environmental concern is TCDD. 4. 2,4-D does not accumulate in the environment or mammalian tissues. 2,4-D is readily absorbed by planttissues and translocated generally in the direction of food sinks principally at the active growing points of shoots and roots (Crafts 1964). On reaching the soil, 2,4-D is adsorbed and bound to soil particles and is retained in the upper part of the soil * profile (Council for Agricultural Science and Technology 1975). Once bound, 2,4-D does not leach into groundwater nor does it move in significant quantities in surface run off (Sheets et al. 1972; Manigold and Schultze 1969). In or on the soil 2,4-D is immediately attacked and broken down by soil organisms (Audus 1969; Kaufman and Kearny 1976). Generally, 90% or more is degraded within 35 days of appli- 1 cation (Norris 1970; Altom and Stritzke 1973); fdrmulation does not affect rate of decomposition (Norris and Greiner 1967). L L V 8000 M o a 6 All available data suggests that 2,4-D entering streams will be lost by volatilization, adsorption to sediment particles, absorption by biota, microbial degradation and decomposition by sunlight (Tutass 1966; Tutass and Crosby 1965; Aly and Faust 1964; Schultz and Harman 1974). A portion of herbicide material will be lost to the atmos phere through drift or volatilization. In areas of heavy agricultural spraying, maximum average 24-hour concentra tions of combined droplets and vapor were o\ 123 pg/m^ with \3 an absolute maximum concentration of 2.65 pg/m . By compari son the U.S.S.R. acceptable ceiling concentrations are 1 mg/ro^ (I.A.R.C. 1977); thus the levels in eastern Washington are 8130 and- 377 times below the acceptable U.S.S.R. value which is only 1/10 of that of the U.S. or West Germany. Vapor/ droplet levels due to parks and playfield treatment in Nanimo would never reach the levels found in those agricultural areas. 2,4-D in the atmosphere will break down in sunlight or will be washed out by precipitation. If 2,4-D were to be absorbed and become well distributed throughout an animal's body, does it persist or bioaccurau- late? First, how does a substance get into an organism? (9) Skin absorption, inhalation, and ingestion. 'Once in the body it can be transported to a number of body components. / 000022-2 DOW 0008 478 7 Note that in many cases there are one-way routes or possibly two-way routes. The two-way routes don't always guarantee the return to body fluids. Now let's look specifically at 2,4-D. The amine and alkali salts of 2,4-D are readily absorbed and completely distributed in the body of calves, pigs, rats and chickens; 2,4-D ester is incompletely absorbed and reaches only a low level in the body fluids and tissues. Highest tissue levels are commonly found in the liver, kidneys, spleen and lungs; these tissue levels can exceed the levels found in the body fluids. Penetration of 2,4-D into placental tissue of pigs is a matter of record; however, there is little or no evidence of penetration into adipose tissue or the central nervous system (Bjorklund and Erne 1966; Leng 1977). Traces of orally administered 2,4-D (50 ppb or 0.05 mg/kg of body weight) were detected in the milk of lactating rats for six days; also within 24 hours of treatment about 17 percent of the dosage was found in the uterus, placenta, fetus and amniotic fluid (Fedorova and Belova 1974). However, detectable residues did not appear in the milk of cows consuming up to 300 ppm . of 2,4-D in the diet for two to three weeks (Clark et al. 1975; Leng 1972 and 1977). Since the fetus is an integral r part of the mother's body, physiological processes of the mother are- a'lso active in the fetus. . ../B ri 0000223 800C/^Oq Noting the two-way street symbol for tissue/bone/brain, liver and blood cells compartments, there is a potential pathway for the removal of the 2,4-D from these compart ments. (10) In reality, the mammalian system does elimi nate 2,4-D. In fact elimination of 2,4-D from the body of mammals is quite rapid. The body fluid half-life is about 3 hours in rats, 8 hours in calves (also chickens) and 12 hours in pigs; tissue half-life values range from 5 to 30 hours (Way 1969). The rate of elimination^appears to be dosage dependent (Way 1969; I.A.R.C. 1977). The major route of excretion is in the urine with minor amounts in the feces (Way 1969). A 4 mg/kg dose of 2,4-D, the maximum daily dose likely to be ingested from grazing pasture, fed to sheep was excreted within 72 hours, in excess of 98 percent was via kidneys and only 1.5 percent was present in the feces (Clarke et al. 1964). In support of this is the work of Sauerhoff and associates (1977); five male human volunteers (29 to 40 years of age) ingested 5 mg/kg of analytical grade 2,4-D acid. Within 24 hours 16.8 to 39.1 percent of the -2,4-D as both the free compound and conjugate had been excreted; after 144 hours an average in excess of 90 percent had been excreted with the range of recovery being 87..6 to 106.3 percent. No explanation of the 106.4 percent figure is given, but it can be assumed to be analytical error with regards to precision. The half-life value for clearance from body fluids . ' . ... . ' ___ ... _ 0000-22751699 0008 480 DOY/ - 9- was 11.6 hours. Kohli and associates (1974) Calculated a half-life for excretion: of 33 hours. Thus, there is absolutely no evidence to support the fear that 2,4-D will accumulate in children and create problems in later life. 5. The South Okanagan Environment report is not the best scientific document on: 2,4-D. (H) Let's not kid ourselves about this red herring. It wouldn't rate a passing grade in any reputable science class; it might make it in a creative writing course. It is full of unsubstantiated claims, gross misinterpretations of scientific reports, misrepresentations of expertise, half-truths, and deliberate attempts to mislead. It is biased. -In fact, this report is so unscientific, it really warrants no further discussion. Lethal Toxicity to Humans Acute toxicity of 2,4-D is low to moderate. (12) The Merck Therapeutics Index states, "Clinical.reports of 2,4-D poisoning are rare and show no consistent pattern." Less than a dozen deaths have been related to 2,4-D; most were confirmed suicides. Kraus reported on individual ingestion of 500 mg/day for 21 days; he reported no ill effects (Mitchell et al. 1946; I.A.R.C. 4 1977) . Sauerhoff and associates (1977) reported on five males who ingested 5 rig/kg of body weight (70 kg person ingested 350 mg and a 90 kg person ingested 450 mg) ; again no ill effects. Seabury (1963) treated two patients at Louisiana State University 0000225 r-' ./10 School of Medicine with terminal cases of disseminated coccidiodomycosis, a fungal infection, with 2,4-D. One patient ( ;-* c <; received about 16.3 g of 2,4-D over a 34-day period; an indi vidual dose of 2 g (37 mg/kg of body weight) produced no symp toms of toxicity; however, a dose of 3.6 g (66 mg/kg of body weight) caused intoxication symptoms. The likelihood of a per- i son, even a child, receiving a dose similar to the above examples from the Park's or School Board's programs is essentially nil'. **,, v Sub lethal Toxicity to Humans > Sublethal effects of 2,4-D in humans is dependent upon the dose; the greater the dose the more serious the symptoms. Data sug gest that the sublethal effects of 2,4-D are temporary. One apparent exception to this is the case of a 37-year-old Russian woman who suffered acute poisoning because of non-observance of hygenic and sanitary labor conditions (Kaskevich and Soboleva- 1978) . This woman continues to be disabled three years later? the authors state that observation has revealed the progressive course of the pathological process. Careful review of a trans lation suggests there is an element of doubt that the herbicide caused the entire problem. Symptoms of 2,4-D poisoning such as fibrillary twitching and muscle paralysis have been reported following ingestion of large quantities (Berwick 1970? Seabury 1963; Gesselin et al. 1976) or excessive dermal exposure (Goldstein et al. 1959). Numbness / and aching of feet and hands and partial paralysis for several 0000226-11 11 CS* GO ' * months have resulted from excessive dermal exposure (Goldstein t GO O et a l* 1959; I.A.R.C. 1977). In all-cases, large doses were CO ^ involved. a More typical symptoms of 2,4-D include fatigue, weakness, dizzi D ness, loss of appetite, nausea, vomiting and diarrhea. "Protracted inhalation of spray is likely to irritate the nose, eyes, throat and bronchi causing disagreeable local burning sensations and coughs." (U.S. E.P.A. 1977). Sare (1972) reported that spray operators experience headaches and double vision. Dennis (1976) conducted a questionnaire survey of farmers and grain elevator operators in Saskatchewan. "Twenty percent of 3330 surveyed reported that they had experienced ill effects from working with agricultural chemicals, 2,4-D apparently being the most troublesome. Symptoms were generally confined to the season or time of spraying, and were similar among those affected. They included nausea, loss of appetite, weight loss, and occasional vomiting. A small number reported a skin rash. The symptoms observed one year were often more extreme than those' observed in previous year(s) , requiring a number of farmers to contract out their spraying to other operators. This report suggests a possible development of sensitivity to the spray with repeated exposure." (National Research Council of Canada 1978). Assouly (1951) reported that workers employed in the production of an ester of 2,4-D developed symptoms of drowsiness, loss of appetite, neuralgic pain in the stomach or the forward walls of i the abdomen, increased salivation, a swqet taste in the mouth, * a sensation of*.drunkenness, heaviness of the legs, and excessive acuteness of the* sense of hearing. Symptoms noted above are similar to exposure to some petroleum solvents (Browning 1965) a 1 - 000227../12 P O T . AA 12 and products. Seabury (1963) questions whether the symptoms identified by Assouly were related to the 2,4-D acid or to the chemicals used in the process of esterification. He states, "Certainly a sweet taste in the mouth with sialarrhea [heavy salivationjsuggests the symptoms were related to the chemicals used in esterification." Unfortunately, there are no adequate epidemiological studies to clarify the point. The Saskatchewan study has not been submitted for peer review. Except for the rash, the symptoms are firmly believed to_be of minor consequence and transitory in terms of applications within the urban/suburban setting. If the rash is chloracne, then there is a problem and a need for real concern. However, all evidence indicates that the rash is not chloracne. The chloracne issue must be reviewed in depth since.the South Okanagan Environmental Coalition Report suggests or states in numerous places that the phenoxy herbicides produce chloracne. Warnock and Lewis (1978) state "there is evidence that all the phenoxy herbicides produce chloracne, even 2,4-D and 'purified* 2,4,5-T." They state, "Poland and his colleagues found chloracne among workers in plants manufacturing 2,4-D and 2,4,5-T,..." They also state, "Two doctors have reported treating more than 40 cases of chloracne contracted by workers in . plants engaged in the synthesis of 2,4-dichlorophenol and 2,4,5-trichlorophenol. There was some question as to whether TCDD exposure (from the making of 2,4,5-T) was responsible for the chloracne in all cases." 7703 ..,/13 0000228 Cr*S CO o o o 0c 13 No reference is provided for the above "two doctors." Finally they refer to a report by Dr. M.Kay of the U.S. Public Health Service who tested commercial preparations of 2,4-D and 2,4/5-T through open patch skin tests on his own arms. They state, "... both induced chloracne on his arm (Bleiberg and Brodkin, 1964)." Careful review of the report by Poland and colleagues (1971) suggests that the chloracne was associated with the manufacture of 2,4,5-T; however, it was statistically impossible to correlate the chloracne with any job location within the plant since the workers commonly worked in more than one location. Their comments on chloracne are completely concerned with 2,4,5-T, trichlorophenol, and. TCDD (the last, a known and severe acnegenic agent). They also state, " Although the structures of 2,4-D and 2,4,5-T (...) differ only by one chlorine, the commercial syntheses of the two compounds are dissimilar," and, "In 2,4-D production there is no formation of the TCDD." There was only one manufac turing plant involved in this study. Waraock and Lewis (1978) leave the impression that several plants were involved and it can be construed from their wording that at least one only manufactured 2,4-D.. Since no specific reference is available for the second reference f of Warnoc.k and Lewis (1978) to chloracne in manufacturing plants, a review of the, Dertinent literature was made. I.A.R.C.(1977b) made no reference to chloracne in their discussion of 2,4-D. However, they gave extensive coverage to chloracne in their 0000229 r- J j w Jf. ... '14 14 o 008 485 discussions of 2,4,5-T (I.A.R.C. 1977c) and the chlorinated ( dibenzodioxins (I.A.R.C. 1977a). The National Research Council of Canada (1978) makes no reference to a relationship between chloracne and 2,4-D. In an attempt to determine specifically if 2,4-D was related to chloracne of workers employed in its manufacture, Dow Chemical Canada Limited, a major Canadian producer of phenoxy herbicides was queried. Dr. H.B. Wallis, M.D., Dow's Corporate Medical Director replied, "To the best of my knowledge and belief no Dow Chemical of Canada employee associated with the production and/or formula tion of Dow 2,4-D SIC Acid has ever developed signs suggestive of Chloracne" (Wallis 1978). Dow chemical, D.S.A. also reports a no-incidence status (Carney 1978). If chloracne were caused ( by 2,4-D, undoubtedly the Therapeutics Index (Gesselin et al 1976) would have mentioned such a relationship. Also the D.S. E.P.A. (1977) makes no specific comment about chloracne; theU.S..E.P.A. simply states, "Irritation of the skin follows excessive contact with many chlorophenoxy compounds." The chloracne incident reported by Bleiberg and Brodkin (1964) is interesting in that it is contrary to experience and more recent research results. Although I have not exhausted the literature search, I am convinced that 2,4-D is not a cause of chloracne. In conclusion, sublethal effects of 2,4-D as used in an urban/ y suburban area'will be of a minor and transitory nature and co ( not- pose a serious hazard to the public. 7705 0000230 .../is 15 D O W TM 03 486 2,4-D and Carcinogenicity Before discussing 2,4-D specifically, it is necessary to review a few definitions and concepts concerning cancer(13). It is obvious that cancer and carcinogenicity have different meanings for different people. The next table Q4) lists some substances that are known to be carcinogenic. Note tobacco on the list. The long term trend of cancer, exclusive of lung cancer, in North America, is downward. If lung cancer is included in the average, the trend is upward and we know that there is a cause and effect relationship between tobacco and lung cancer. Looking specifically at 2,4-D, all scientifically acceptable attempts to demonstrate that 2,4-D causes cancer have failed or are considered "inconclusive". Innes et al (1964) screened 120 compounds for tumourgenic properties in mice; 2,4-D as the acid, the isopropyl ester, the butyl ester, and the isooctyl ester were classed as "Experimental compounds which did not cause a significant increase in tumours after oral administration". Despite statements by many environmentalists, toxicologists and statisticians, these conclusions still stand as valid. Hansen and associates (1971) fed groups of 25 female and 25 male rats 0, 5, 125, 625, and 1250 ppm of 2,4-D acid in the basic diet. They also investigated the effects of 0, 00, 500, 1500 ppm of 2,4-D through three generations of rats. The tumour / (15)incidence found in the rats is given in this table . Their conclusions, "from the pathological interpretation of the rumour 000023 i2 1) .../16 DOVVC8 487 . incidence it is apparent that the tumours were not 'target organ' types and they were randomly distributed types nor mally found in aging Osborne-Mendel rats. In addition, the number of animals surviving the 2 year study did not differ from group to group, whereas with a carcinogenic substance one would expect fewer survivors in the high dose group." They concluded "the raw data, however, support the pathological interpretation that a carcinogenic effect has not been shown." Several persons.have disputed this conclusion. A review of peer opinions is desirable. I.A.R.C. (1977) commenting on this report states, "Therefore, although increased incidences of tumours were observed in one study in which rats received 2,4-D orally, no evaluation of the carcinogencity of this compound could be made" when considered in the light of other data. The U.S. National Cancer Institute determined that the above study "presented no convincing evidence of carcinogenicity" (Johnson 1978). The U.S. National Center for Taxicological Research evaluated the statistical analysis and found the data suggestive of positive evidence of carcinogencity (Johnson 1978). The Center also felt that "the data demonstrated the potential for other chronic health effects, which were not evaluated by the research ers." A consultant for the Cancer Assessment Group of the U.S. E.P.A. "informally reported that he felt the data presented \ in the study indicated positive evidence that 2,4-D is a / ./17 ^00^000232 0008 488 - 17 - carcinogen," however, the Cancer Assessment Group (CAG), itself, "has neither formally or informally reviewed the .study in question" (Johnson 1978). Johnson (1978) states, "Therefore neither CAG nor EPA has taken a position on O whether 2,4-D is or is not a carcinogen." C In contrast to the above, Warnock and Lewis (1978) state "The F.D.A.`s study revealed that 2,4-D caused malignant tumours in male and female rats tested: he concluded that "2,4dichlorophenoxyacetic acid is carcinogenic in rats." "He"is Dr. Kelvin Reuber, "the consultant to CAG". Officially, the "informal review" attributed to CAG was never conducted." "Reuber*s review was conducted totally independent from CAG. CAG never authorized the review, and they have no records on it. Just recently when shown the review,"_______ ________* indicated they could not comment, or support, its content" . (Lambert 1978) . Also, W a m o c k and Lewis (197 8) state, "Research by the Biometics Research Laboratory (1967) and the U.S. Food and Drug Administration (1963) demonstrates that 2,4-D causes malignant tumours in laboratory rats and mices:" The Biometics Research Laboratory is the report of Innes and associates (1969) and the U.S. Food and Drug Administration study is the report of Hansen and associates (1971) which have s just been reviewed above. .../IS 7 7 0 8 0000233 30W0008 489 18 ( The conclusion, 2,4-D does not pose a demonstrated cancer threat to the citizens of Nanaimo. It is worth looking at the Kansen et al. (1971) data once again. Experimental design dictates enough animals, doses, and controls. Note that even the control animals have tumours. To evaluate such data requires an appropriate statistical design which includes a control; the control accounts for back ground noise. j 2,4-D and Mutagenicity ^ A mutation is an inheritable change in a chromosome (Watson 1976). Emphasis is on the word "inheritable." For an agent to be considered a mutagen, the change must be passed on to the next generation! 2.4- D-was demonstrated to be non-mutagenic in Escherichia coli and Salmonella typhimurium (Anderson et al. 1972; Nagy et al. 1975; Zetterberg et al. 1977). A test involving Bacillus subtilis believed to give an indication of reparable DNA damage proved negative, thus suggesting that 2,4-D does not damage DNA (Shirasu 1975). Serum from 2,4-D orally dosed rats had no mutagenic effect on Salmonella typhimurium (Styles 1973). Vogl and Chandler (1974) demonstrated no mutagenic activity of 2.4- D in male Drosphila melanogaster flies. Epstein and > associates (1972) found that a total of 75 mg/kg of body weight of 2,4-D given' over a 5 day period did not increase dominant ( 7709 .../19 0000234 (JOOS 400 19 lethal mutations in mice; single injection of 125 mg/kg of body weight also had no effect. Injection of 100 mg/kg of body weight of 2,4-D did not increase the micronuclei of O mouse bone marrow erythrocyte (hemoglobin-rich blood) cells; G the compound did/ however depress slightly mitotic activity (Jensen and Renberg 1976). ( Using cell culture techniques and experimental methods not widely recognized nor readily interpretable Ahmed and associates (1977a) demonstrated that 2,4-D can produce DNA damage in human fibroblast cells; however, the cells were able to repair the damage. They have also shown that 2,4-D fluid acts as a weak mutagen of a specific'cell line derived from the lung of a male hamster; they suggest that this approach, if coupled with other assays, might be used as a prescreen for mutagens (Ahmed et al. 1977b). In essence, it is not known whether Ahmed and associates work has practical application. For example, how does one relate the artificial cell culture technique to the way the cell behaves in the body and how the physiological processes of the body effect the cell? Several studies have referred to chromosomal abberations (break age, pairing of fragments, inverted linkage of fragments) in animals (Shaw 1970; Bongso and Basrar 1973) and even in humans (I.A.R.O.' 1977; Golberg 1971). Some clastogens (chromosome, abberation causing agents) are presented in this table (16)* ( TGt s o o o m c * 20 In all of the clastogen positive studies involving 2,4-D, none have concluded that 2,4-D causes mutations in animals or bacteria! The reason for mammals being: mammalian systems have defense mechanisms to prevent the damage from being passed onto succeeding generations, for example, cells can repair the damage, damage may prevent the cell from reproduc ing, the cell may die, the cell may be killed by natural antibodies. Because 2,4-D acts as a plant growth regulator it can be assumed that it is a plant clastogen and/or mutagen. It' does not follow that if an agent causes mutations in plants, that it will cause mutations in animals. If such were the case, there would be no need to test'with laboratory animals. Before concluding, it is worth looking at the three generation rat study of Hansen and associates (1971) (17). Three genera tions of rats fed a diet containing 2,4-D and no genetic abnorma lities were mentioned. All evidence demonstrates that 2,4-D is not a mutagenic agent in mammals. 2,4-D and Embryotoxicity Karnofski's Law (18) "Any drug administered at the proper dosage, at the proper stage of development, to embryos of the proper species,- 'will be effective in causing disturbances in embryonic t development" (Wilson 1972). The law holds true for many other, if not all, types of chemicals. This (19) is a very incomplete 0000236 DOW 0008 492 21 list of products or substances known to have embryotoxic effects/ in this birth defects, on at least one species of laboratory mammal. Embryotoxic effects of a chemical are manifested in many ways: spontaneous abortion or miscarriage, stillbirth, decreas ed fetal weight, deformities, wavy ribs, and immature (soft) bones. Agents causing birth defects are called teratogens. There is no evidence that 2,4-D causes spontaneous abortions, miscarriages, or stillbirths. There is no suggestion in the current scientific literature that even suggests such a hazard exists. We must remember that at least one conception in seven results in a spontaneous abortion.. I believe that it is valid to say that 2,4-D is no hazard in terms of spontaneous abortion. Hansen and associates (1971) data suggest that reproductive function of rats in the three generation study was not altered by the 500 and 1000 ppm 2,4-D diet. However, percentage of pups surviving to weaning and weanling weight was decreased by 1,500 ppm of dietary 2,4-D. There is no likelihood that a person would consume such a level in a normal or even fad diet. We now can look at teratogenicity. Most work has been done with rats' and mice, hamsters, guinea pigs, monkeys, and live stock. Dost (1978) concludes that sheep apparently are not J subject to 2,4-D induced birth defects. 7712 0000237 CGI' 8000 MC 22 (20)Mice, contrary to environmentalists, and some biologists, are highly sensitive to many chemicals and drugs. Laboratory mice have a great propensity for a (21)specific defect called cleft palate. This lists only some of the agents known to cause birth defects in mice. This certainly questions the use of mice for teratogenicity studies. Schwetz et al. (1971) determined that 2,4-D at the higher -daily doses (75 mg/kg as 2,4-D, 75 mg/kg's 2>4-D propylene glycol butyl ester; 87.5 mg/kg as 2,4-D isooctyl ester), levels just below the maternal toxic dose, caused decreased fetal weight, subcutaneons edema, delayed bone ossification,and wavy ribs. Khera and McKinley (1972) observed wavy ribs or fused sternum in rats associated with 2,4-D doses as low as 25 mg/kg/ day. 2,4-D at doses of 100 mg/kg/day through days 6-10 of pregnancy caused a low incidence of anomalies, usually fused ribs.- A woman weighing 50 kg would have to consume 5000 mg or 5g of 2,4-D for at least 5 days of her pregnancy; cutting this to half begins to approach a dose that is non-lethal (based on Seabury's observations). Levels involved are well above levels one could ever anticipate a person receivingwithout knowing. Summary There is no evidence to suggest that 2,4-D as used by Parks or School Board employees is a hazard to the public of Nanaimo. 7713 //2& 3w .. . 0000238 0008 491 rn - 23 - In conclusion there are many of us, like the local Council of Women, who are genuinely concerned for the well-being of our children. Too often we become emotionally involved and have not or cannot make an objective evaluation of the data or even accept new data. It is unfortunate that there O >* o are individuals and groups who, for whatever reason, attempt to subvert this genuine concern. 2,4-D and its supporters have been vilified; the benefits of 2,4-D to us and future genera tions have been ignored. The prime achievement of these vilifiers has been to confuse and frighten the public. Like cancer, confusion and fright will spread and destroy. [ [ ri* L r L' cl p 0 7714 0000239 L r L.. DOW 0008 40 LITERATURE CITED Ahmed, F.E. , R.W. Hart and N.J. Lewis.. 1977a. Pesticide induced DNA damage and its repair in cultured human cells. Mutt. Res. 42:161- Ahmed, F.E. , N.J._ Lewis and R.W. Hart. 1977b. Pesticide induced ovabain resistant mutants in Chinese hamps ter V79 cells. Chem. Biol. Interact. 19:369-374 01 Alton, J.D. and J.F. Stritzke. 1973. Degradation of dicamba, picloram, and four phenoxy herbicides in soils. Weed Sci. 21:556-560 Aly, O.S. and S.D. Faust. 1964. Studies -on th fate.of 2,4-D and ester derivations in natural surface waters'. J. Agric. Food Chem. 12:541-545 ^ Anderson, K.J., E.G. Leighty and M.T. Takahashi. 1972. Evalua tion of herbicides for possible mutagenic properties. J. Agric. Food Chem. 20:649-656 Anonymous. 1977. ' International conference on chlorinated phenoxy acids and their dioxins. Ambio 6:242-243 Assouly, M. 1951. Dsherbants slectifs et substances de crois sance. Aperu technique. Effet pathologique sur l'homme au cours de la fabrication de l'ester du 2,4-D. Arch. Mal. Prof. 12:26-30 (Original not seen; quoted from Gesselin at al. * (1976), I.A.R.C. (1977b), Seabury (1963)). Audus, L.J. 1964. Herbicide behaviour in the soil, In: Audus, L.J. The physiology and biochemistry of herbicides. Academic Press, N.Y. p. 163-206 Audus, L.J. 1969. Should read Audus, L.J. 1964 (see that citation) Behar, J.V., E.A. Schuck, R.E. Stanley and G.B. Morgan. 1974. Integrated exposure assessment monitoring. Environ. Sci. and Tech. 13(1):34-39 Berwick, P. 1970. 2 ,4-dichlorophenoxyacetic acid poisoning in man. Some interesting clinical and laboratory findings. J. Amer. Medical Assoc. 214:1114-1117 Bjorklund,N.E. and K. Erne. 1966. Toxicological studies of phenoxyacetic herbicides in animals. Acta. Vet. Scand. 7:364-390. / Blair, E.H. 1973. Chlorodioxins - origin and fate. Amer. Chem. Assoc. Advances in chemistry series 120. 141 p. 0000240 DOW 0008 496 -2- Bongso, T.A. and P.K. Basrur. 1973. In vitro response of bovine ceils to 2,4-dichlorophenoxy acetic acid. In Vitro 8:416-417 Brown, K.S., M. C. Johnston and J.D. Niswander. 1970. Effects of transportation by air on the production of isolated cleft palate in mice. Abstr. 10th Ann. Meet. Teratology Society. P. 198 Browning, E. 1965. Toxicity and metabolism of. .industrial sol vents. Elsevier Publ. Co., Amsterdam. 739 p. Carney, N. 1978. Letter to E. Packee for DOW Chemical of Canada Ltd., Sarnia, July 13/ 1978. 2 p. Clark, D.E,, J.S. Palmer, R.D. Rade left, R.R. Crookshank and F,M. Farr. 1975. Residues of phenoxyacetic acid herbicides and their phenotic metabolites in tissues of sheep and cat tle. J. Agr. Food. Chem. 23:573-578 Costle, D.M. 1979a. Decision and emergency order suspending registrations for the forest, rights-of-way and pasture uses of 2 ,4,5-trichlorophenoxyacetic acid. U.S. E.P.A. 95 p. Costle, D.M. 1979b. Decision and emergency order suspending registrations'for certain uses of 2-(2,4/5-trichlorophenoxy) propionic acid. U.S. E.P.A. 86 p. Council for Agricultural Science and Technology. 1975. The phenoxy-herbicides. C.A.S.T. Report No. 39. 21 p.. Council for Agricultural Science and Technology. 1975. Effects of herbicides in Vietnam and their relation to herbicide use in the United States. C.A.S.T. Report No. 46. 13 p. (Note: this report refers to data in Illustration 6). Courtney, K.D. 1977. Prenatal effects of herbicides: evalua tion by the prenatal development index. Arch. Environ. Contarn. Toxicol. 6:33-46 Crafts, A. 1964. Herbicide behaviour in the plant. In: Audus, L.J. , The physiology and biochemistry of herbicides. Academic Press, N.Y. p. 75-110 Davis, D.E. 1979. Herbicides in peace and war. Bioscience 84: 91-94 Dennis, ,C.A. 1976. Health effects of 2,4-D (Nat. Research Council of Canada) ,-November 15, 1976. Prairie Institute of Environmental Health, Regina, Saskatchewan. 1 p. letter Dost, F.N. 1978. Toxicology of phenoxy herbicides and hazard assessment of their use in reforestation. U.S.D.A. Foirest Service, California Rgion (San Francisco) 134 p. i 7716 0000241 OOW0008 4S7 3 Epstein, S.S. , E. Arnold, J. Andrea, W. Bass and Y. Bishop. 1972. Detection of chemical mutagens by the dominant lethal assay in the mouse. Toxicol. Appl. Pharmacol. 23:288-325 Fedorova, L.M. and R.S. Belova. 1974. Incorporation of 2,4dichlorophenoxyacetic acid into the organs of animals: paths and dynamics of its excretion. Gig. i. Sanit. 2:105-107 Gesselin, R.E.,.H.C. Hodge, R.P. Smith, M.N. Gleason. 1976. Clinical toxicology of commercial products. Acute poison ing. Section III. Therapeutics Index. The Williams and Wilkins Co., Baltimore, p. 112-116. (Note: This is the "Merck Therapeutics Index"). Golberg, L. 1971. Trace chemical contaminants in food: potential for harm. Food Cosmet. Toxicol. 9:65-80. Goldstein, N.P., P-.H. Jones and J.R. Brown. 1959. Peripheral neuropathy after exposure to an ester ^ f dichlorophenoxyacetic acid. J. Amer. Med. Ass. 171:1306-1309 Hansen, W.H., M.L. Quaife, R.T. Habermann and O.G. Fitzhugh. 1971. Chronic toxicity of 2,4-dichlorophenoxyacetic acid in rats and dogs. Toxicol. Appl. Pharmacol. 20:122-129 I.A.R.C. (International Agency for Research on Cancer). 1977. Should read I.A.R.C. 1977b, see. that citation. I.A.R.C. 1977a. Chlorinated dibenzodioxins. I.A.R.C. monog. on.the evaluation of the carcinogenic risk of chemicals to man: 15:41-102 I.A.R.C. 1977b. 2,4-D and esters. I.A.R.C. monog. on the evaluation of the carcinogenic risk of chemicals to man 15:111-138 I.A.R.C. 1977c. 2,4,5-T and esters. I.A.R.C. monog. on the evaluation of the carcinogenic risk of chemicals to man 15:273-299. Innes et al. 1964. Should read Innes et al. 1969 (see that citation) Innes, J.R.M. , B.M. Dlland, M.G. Valerio, L. Petrucelli, L. Fishbein, E.R. Hart, A.J. Pallotta, R.R. Bates, H.L. Falk, J.J. Gart, M. Klein, I. Mitchell and J. Peters. 1969 Bioassay of pesticides and industrial chemicals for tumorigenicity in mice: a preliminary note. j. Nat. Cancer Inst. 42:1101-1114 S Jensen, D. and L, Renberg. 1976. Distribution and cytogenetic test of 2,4-D and 2,4,5-T phenoxyace.tic acids in mouse blood tissues. Chem.-Biol. Interact. 14:291-299 0000242 V ( il/ 4- DOW 0008 498 Johnson, E.L. 1978. Letter to the Honoroable James. A. Nielsen, Minister of the Environment, Province of British Columbia. Dated May 2, 1978. 2 p. ( Kalter, H. and J. Warkany. 1959. Experimental production of cogenital malformations in mammals by metabolic procedure. Physiol. Rev. 39:69- Kasevich, L.M. and L.P. Soboleva. 1978. Case of acute 2,4-D herbicide poisoning. Gig. Tr. Prof. Zabol. 10:49-50 Kaufman, D.D. and P.C. Kearny. 1976. Microbial transformation in soil. In: Audus, L.J. Herbicides - physiology, bio chemistry, ecology. Academic Press, N.Y. p. 29-60. Khera, K.S. and W.P. McKinlay. 1972. Pre- and postnatal studies on 2,4 ,5-trichlorophenoxyacetic acid 2 ,4-dichlorophenoxyacetic . acid and their derivations in rats. Toxicol. Appl. Pharmacol. 22:14-28 King, M.E. , A.M. Skefner and R.R. Bates. 1973. Carcinogenesis bioassay of chlorinated dibenzodioxins and related chemicals. Environ. Health Perspectives 5:163-170 Lambert, J. 1978. O.S. E.P.A. interoffice memo E.L. Johnson from J. Lambert concerning information memorandum for recent Canadian interaction regarding 2,4-D. April 27, 1978. 5 p. ( Leng, M.L. 1972. Residues in milk and meat and safety to live stock from the use of phenoxy herbicides in pasture and rangeland. Down to Earth 2*8 (1) :12-20 Leng, M.L. 1977. Comparative metabolism of phenoxy herbicides in animals. In: Ivie, G.W. and H.W. Dorough. Fate of pesti cides in large animals. Academic Press, N.Y. p. 53-76 Kohli, J.D., R.N. Khanna, B.N. Gupta, M.M. Dhar, J.S. Tandon and K.P. Sircar. 1974. Absorption and excretion of 2,4dichlorophenoxyacetic acidin man. Xenobiotica 4:97-100. Manigold, D.B. and J.A. Schultze. 1969. Pesticides in selected western streams - a progress report.' Pesticide Monito. J. 3:124-135 Mitchell, J.W., R.E. Hodgson and C.F. Gaetjens. 1946. Tolerance of farm animals to feeds containing 2 ,4-dichlorophenoxyacetic acid.'. J. Animal Sci. 5:226-232 Nagy, Z., I. Mile and F. Antonio. 1975. The mutagenic effect of pesticides on Escherichia coli WP2 try. Acta. Microbiol. Acad. Sci. Hung. 22:309-314 ' ( ,0000243 DOW 0008 499 5 National Research Council of Canada. Subcommittee on Pesticides and Related Compounds. 1978. Phenoxy herbicides - their effects on environmental quality with accompanying scientific criteria for 2,3,7,8-tetrachlorodibenzo-f-dioxin (TCDD). NCRC No. 16075. 440 p. Nishiroura, H. and S. Miyamoto. 1969. Teratogenic effects of sodium chloride on mice. Acta. Anat. 74:121- Norris, L.A. 1970. Degradation of herbicides in the forest floor. In: Youngberg, C.T. and C.B. Davey. Tree Growth and forest soils. Oregon State University, Corvallis, p. 387-411 Norris, L.A. and D. Greiner. 1967. The degradation of 2,4-D in forest litter. Bull. Environ. Contamination and Toxicology 2:65-74 Peters, S. and M. Strassburg. 1969. Stfess als teratogener faktor. Arzneimittal-Forsch. 19-1106- Peterson, G.E. 1967. The discovery and development of 2,4-D. Agric. Hist. 41:243-253 Poland, A.P. , D. Smith, G. Metter and P. Possick. 1971. A health survey of workers in a 2,4-D and 2,4,5-T plant. Arch. Environ. Helath 22:316-327 Rosenzweig, S and F.M. Blaustein. 1970. Two techniques for studying stress as a cause of cleft palate in mice. Abstr. 10th Ann. Meet. Teratology Soc. p. 209 Sare, -W.M. 19 72. The weedicide 2,4-D as a cause of headaches and kiplopia. Amer. Med. J. 75:173-174 Sauerhoff, M.W., M.B. Chenowith, R.J. Karbowski, W.H. Braun, J.C. Ramsey and P.J. Gehring. 1977. The fate of 2,4dichlorophenoxyacetic acid (2,4-D) following oral admini stration to man. Toxicology 8:3-11 Schultz, D.P. and P.D. Harman. 1974. Residue of 2,4-D in pond waters, mud and fish, 1971. Pesticide Monitor. J. 8:173-179 Schwetz, B.A. , K.D. Nitschke and R.E. Staples. 1977. Cleft palates in CF-1 mice after deprivation of water during preg nancy. Toxicology Appl. Pharmacology 40:307-315 Seabury,`J.H. 1963. Toxicity of 2,4-dichlorophenoxyacetic acid for man and dog. Arch. Environ. Health 7:202-209 ./ Schwetz, B.A., G.L. Sparschu and P.J. Gehrin. 1971. The effect of 2 ,4-diehlorophenoxyacetic acid (2,4-D) and esters cf 2,4-D on rat embryonal, foetal and neonatal growth and develop ment. Fd. Cosmet. Toxicol. 9:801-817 ^ *q0000244 DOW 0008 500 6 Shaw, M.W. 1970. Human chromosome damage by chemical agents. A. Rev. Med. 21:409- Sheets, T.J., W.L. Rieck and J.F. Lutz. 1972. Movement of 2,4-D, 2,4,5-T and picloram in surface water. Proc. Southern Meed Sci. Soc. 25:427 yV* Shirasu, Y. 1975. 1975. Significance of mutagenicity testing on-pesticide^. Environm. Qual. Safety 4:226-231 Styles, J.A. 1973. Cytotoxic effects of various pesticides in vivo and in vitro. Mutation Res. 21:50-51 Ton That, T., A. Tron Thi, T. Nguyen Dang, P. Pham Hoang, B. Hguyen Nhu, B. Ton That, S. Hoang Van, S. Do Kim. 1973. Le cancer primaire du foie au Vit-nam. Chirurgie 99:427-436 Tutass, H. 1966. Photodecomposition of 2,4-D. Proc. 18th Annual California Weed Conference p. 13-14 Tutass, H.O. and D.G. Crosby. 1965. The photodecomposition of 2,4-D. Abstr. 189th Amer. Chem. Soc. Meeting. Detroit, Mich. p. lia U.S. E.P.A. 1977. Recognition and management of pesticide poisonings. E.P.A. 540/9-77-013 Vogel, E., and J.L.R. Chandler. 1974. Mutagenicity testing of cyclamate and some pesticides in Drosophila melanogaster. Experienta 30:621-623 Wamock, J.W. and J. Lewis. 1978. The other face of 2,4-D, a citizens' report. South Okanagan Environmental Coalition, Penticton, B.C. Mallis, H.B. 1978. Letter: TO WHOM IT MAY CONCERN. For DOW Chemical of Canada, Ltd. Sarnia. July 11, 1978. 1 p. Watson, J.D. 1976. Molecular biology of the gene. W.A. Benjamin, Inc., Menlo Park, Calif. 7'39 p. Way, J.M. 1969. Toxicity and hazards .to mem, domestic animals, and wildlife from some commonly used auxin herbicides. Residue Reviews 26:37-62 Whiteside, T. 1970. Defoliation. Bal-lantine Books, Inc. N.Y. 135 p. ,/ 7720 0000245 TOC ROnn DOV Wilson, J.G. 1972. Teratogenic potential of 2,4,5-T. Address to the 25th Ann. Meet, of the Southern Weed Science Society at Dallas, Texas. January 18, 1972. Reprint, 4 p. Woolson, E.A., R.F. Thomas, P.D. Ensol. 1972. Survey of polychlorodibenzo-p-dioxin content in selected pesticides. J. Agr. Food Chem. 20:351-354 Zetterberg, G. ,.L. 3usk, R. Elorson, I. Starec-Noraenhammer and H. Ryttman. 1977. The influence of pH on the effects of 2,4-D (2,4-dichlorophenoxyacetic acid, Na salt) on Saccharomyces cerevisiae and Salmonella typhimurium. Mutation Res. 42:3-18 'V /ECP / April 5, 19 79' 0000246 DOW 0008 50 C\* ( An example of misleading editorializing by the press; lack of objectivity and truthfulness. 0000247 ( O Ar u< ini EVRIUATIGTC OP TH CAJCI.'OTOIUC RISE cr CHEMICALS TO h~_\': ( A'c* o )V .o' Oc^ } <.,,<. O* G cT cD V S' ^ * Fumigants, the Herbicides 2,4-D and 2,4.5-T, Chlorinated Dibenodioxins and Miscellaneous Industrial Chemicals Volume 15 V This publication represents the views of an C anadian IA7C Working Croup on the Evaluation of the Carcinogenic Risk of Chemicals to Man T ournaio f j. whichret in Ivon, F o restResean jQjy 8-15 February 1977 F. Ay The N a tional Res. Voi ANADIAN C a i 2 a d j e n r r a ^ a h t\ \ c ^ echJJ? & & V Q r $ A - r .e c V v ^ a JOURNAL OF SOIL S C IE N C E -/ A O V " ' 1' >40^i'bct1 November J978 N o. 4 *c 1974 ,ve^ SV^ American Institute of Biological Sciences EBRUARY 1979 VOL. 29 " * W iI h m e 68 > < 0. ."51& vars' ,b 0000247823 now oTf< 10 GO QUESTIONS FOR WHICH I SEEK ANSWERS AS A O O FOREST ECOLOGIST AND POSITIVE ENVIRONMENTALIST O {' . What effect will 2,4-D have on the function and specific components of the ecosystem? . What are the risks of 2,4-D in terms of: lethality, carcinogenicity, teratogenicity, mutagenicity, abortagenieity, embryotoxicity? . What are the hazards to man, animals and plants when 2,4-D is used normally? . What are the benefits and costs to society of the use of 2,4-D? . What are the alternatives? ( 4 (s/ 0000249 0008 505 O (O Z -MAJOR MISCONCEPTIONS CONCERNING 2,4-D 1. 2,4-D was developed for chemical warfare. 2. 2,4-D has been shown to have caused birth defects and cancer in Vietnam. 3. Because 2,4-D belongs to the phenoxy herbicide group it has the same contaminants and physiological effects the family likeness syndrome. 4. 2,4-D accumulates in the environment and mammalian tis sues. 5. The South Okanagan Environment Coalition's claim that "'The Other-Face of'2,4-D* stands up to rigorous scien r tific scrutiny," is the best scientific document on 2,4-D and is fair. / r 0000250 (3 ; O O W 0008 506 DISCOVERY AND DEVELOPMENT OF 2,4-D 1880- Darwin discovered plaint growth toward light governed by 1890 tip. 1925 Frits Went discovered "auxin," a growth promoter. 1934 F. Kogl discovered Indoleacetic acid (IAA), a growth promoter, in plant tissues. 1941 R. P o k o m y reported 2,4-D and other chlorophenoxyacetic acids. 1941 Dr. E.S. Kraus suggested that growth stimulators be looked at for plant-killing ability. 19 42 Dr. Kraus aware of crop-killing potential of growth regu lators; advised U.S. National Academy of Sciences. 1943 Dr. Kraus reported formally `to-National Academy of Sciences on herbicides. 1944 U.S. Army, Camp Dietrick, herbicide research begun under direction of Dr. Kraus. 1944 Mrs. Fanny-Fern Davis began testing 2,4-D on turf (golf courses and parkways). 1944 2,4-D used on German grain field (unsuccesfully) to destroy alcohol source for V-2 rockets. 1945 Japan already producing 2,4-D commercially. 0000251 AAOn /n o 1946 2,4-D introduced to North American farmer. 1968 D.S. 2,4-D production 36,000,000 kg. 1970 .S. 2,4-D production 20,000,000 kg. D.S. 2,4-D production 27,000,000 kg-used as follows: ' _%_ Million kg - wheat and small grains 31 8.4. - corn and grain sorghum 26 7.0 - pasture and range 25 6.8 - industrial and commercial 9 2.4 - lawns and turf 5 1.4 - aquatic weed control 3 - 0.8 - rice and fruit 1 0.3 1975 Japanese 2,4-D production 511,000 kg. European production (western) 3,000,000 to 30,000,000 est. European production (eastern) <10,000,000 kg est. C 0000252 DW 0008 508 HERBICIDE FORMULATIONS USED IN VIETNAM BY U.S. MILITARY-^ Formulation Millions of * Gallons (1965-1971) Herbicides Ratio Cone., lb/gal Agent Orange Agent White 11.22 5.24 2,4-D:2,4,5-T 1:1 4 + 4.6 ,2 4-DiPicloraro 4:1 2 + 0.54 Agent Purple - 2/4- D :2,4,5-T 1:1 - Agent Blue 1.12 Cacodylic Acid 3.1 (1.7 is arsenic) (Note: Agent Purple replaced by Agent Orange in 1964) t -- From Council.for Agricultural Science and Technology. 1975. Effects of herbicides in Vietnam and their relation to herbicide use in the United States.' C.A.S.T. Report No. 46. 13 p. 772 ( V 0000253 An PARTIAL LIST OF COMPOUNDS OF THE DIOXIN FAMILY (Theoretically 75 isomers are possible - Blair 1973) DCDD (May be in 2,4-D) TCPD (Not in 2,4-D) 1- Chlorodibenzo-pqnq-dloxin 2- Chlorodibenzo-pqrq-dloxin 1 .3- Dichlorodibenzo-parq-dioxin 1 ,6-Dlclilorodlbenzo-para-dloxin 2 .3- Dlchlorodlbenzo-pqra-dloxln ." "------ - ; . ( 2,7-Dlchlorddlbenzo-para-dloxin DCDD/ 2 ,8-Dichlorodlbenro-pqrq-dloxln 1.2.4-Trlcltlorodibenzo-pqrq-dioxin 2 ,3.7-Trlclilorodlbenzo-pqra-dloxln 1 .2 .3 .4 - Tetrachlorodibenzo-pqrq-dloxin J_,_2j3,8-Tct rachlorodibenzo-parYi-dioxln 1,1,<*,fl-T<*I rnchlorodlbenzo-ggra-dloxln si 1 .3 ,7 ,8-Tetrachlorodibenzo-parg-dloxin -a 07' 2.3.6.7- Tetrachlorodlbenzo-para-dioxin 2 .3 .7 .8 - Tetrachlorodibenzo-parq-dloxlnTCDlP^) 1.2.3.7.8- Pentachlorodlbenzo-pqrq-dloxin 1.2.4.7.8- Pentachlotlodlbenzo-pqrq-dioxln 1.2.3.4.7.8-Hexachlorodibenzo-pqrq-dloxln 1.2,3|6,7,8-Hexachlorodibenzo-para-dloxln 1.2.3.6.7.9-llexachlorodlbenzo-para-dloxln 1.2',3,7,8,9-Hexachlorodibenzo-pam-dloxln 1.2.4.6.7.9- Hexachlorodlbenzo-pqrq-dioxln 1,2,3,4,6,7,8-Heptachlorodibenzo-parg-dloxln 1 .2 .3 .4 .6 .7 .8 .9 - Octachlorodlbenzo-parq-dioxln OCDD m oo 0000254 OTS 8000-MOO NUMBERS OF ANIMALS SURVIVING AFTER VARIOUS TREATMENTS WITH OCDD AND DCDD (DIOXINS) 1/ Compound Mice (50/group) Rats (35/group) Week Week of No. of of No. of Sex Test Survivors Test Survivors Controls M 31 F 31 50 34 50 34 35 35 1% DCDD M 17 49 .17 35 F 17 48 17 35 0.5% DCDD M 17 F 17 50 17 49 17 35 35 1% OCDD M 10 0 32 0 F 37 5 22 0 0.5% OCDD M 8 0 37 0 F 37 45 25 0 0.25% OCDD M 17 1 17 28 F 15 0 17 15 --` King/ M.E., A.M. Skefner, R.R. Bates. 1973. Carcino genesis bioassay of chlorinated dibenzodioxins and related chemicals. Environmental Health Perspectives 5:163-170. 0000255 n i& ^ c AE MN BV II ER N0 TN M E N T r\. HUMAN EXPOSURE PATHWAYS--^ I BLOOD CELLS TISSUES/BONE/BRAIN SWEAT GLANDS ------L IV E R ------------------KIDNEYS | --- ------------- SWEAT FECES URINE E L I M I N HAIR/NAILS -=-- ------------ --------^ ----------------- - FECES < t-- lj a 0000256 Adapted from U.S. E.P.A. (Behar, J.V., E.A. Schuck, R.E. Stanley, G.B. Morgan. 1979. -a Integrated exposure assessment monitoring. Environ. Sci. and Tech. 13 (1):34--39). -,T CO O YTO MO- I A E 'V, SKIN MN Absorption B V ----- > Droplets Residue 1I Vapors ER N0 INHALATION TN M .. > Vapors Droplets E N ----T INGESTION Water Food HUMAN EXPOSURE PATHWAYS 1/ -- y BLOOD CELLS TISSUES/BONE/BRAIN SWEAT GLANDS LIVER KIDNEYS HAI R/NAILS ;008 512 D'OVV SWEAT FECES r.s% - -- > U R IN E ----- > FECES E L I M I N A T E D DTJt)025 -I / Adapted from U.S. E.P.A. (Behar, J.V, , E.A. Schuck, R.E. Stanley, G.B. Morgan. 1979. Integrated exposure assessment mohitoring. Environ. Sci. and Tech. 13 (l):34-39). -I "* ;s-K ` ` . - -o 4 .. . $ - *^>F ;>W..- Vv > "-VC -- Ir ':'*.*. ..*i rs7VV >- f'~ % -' ^ ' ` ' " r f;t- : .C2-''.oja VIA'.'t .'. >';* jsTgijr O* o A Citizens' Report SOUTH OKANAGAN e n v i r o n m e n t a l COALn^O^ -~:--; fe*rnr:v>*:**;,*V ' Ar'is'r5v3fl Jv \v y. #i `''-7Vr--\'2; H-"vrV*:>.: >-. -.*.;?.>" .. : ':: - Y r - t -cv'-.-v j :;;=-^ .-.- A?:;--Ti'-V - ,,-.i V ..-?-;. . ' r '* -M .:-V>^r''-*:'/-'VT?-- v; .r v '**T*r\v* v:;y *.: .* .*.-v:; . . -r-:'Lr'v-T-ir ."*'i\":;rr 'i'-v . *'- ```w.Vv ` .'*~:y - l : -: - . ...... 1111 0000258 0008 51 ACUTE TOXICITY RATING OF SOME COMMON SUBSTANCES Amphetamine Aspirin Borax Caffeine Ethyl A.lcohol Gasoline Gravol Salt 2,4-D Warfarin (rat poison) Rating 2 4 5 3 4-5 3 4 4 3 1 Oral LD50 (Mg/Kg for Rats) 5 750-1750 5560 200 450-13700 150 500 3300 300-1000 1 i 0000259 i i30 CANCER TERMINOLOGY CANCER An abnormal and unrestrained growth in cells and tissues that producesdeterious and often fatal effects. CARCINOGEN (broad sense) An agent capable of producing either benign or malignant tumors in a variety of tissues. -CARCINOGEN An agent capable of producing a malignant (strict sense) tumor. MALIGNANT An inherent tendency of cells .'to invade the body widely and relentlessly, to become dis seminated by subtle means'; and eventually to kill the host unless all malignant cells are eliminated. BENIGN An inherent tendency of the cells to remain in contact with each other in one' solid mass centered on the site of origin; a benign tumor can cause death purely by virtue of location. TUMORIGEN An agent capable of producing a tumor. ONCOGEN . An agent capable of producing a tumor. ,/ 0000260 DQVW3008 516 KNOWN CARCINOGENS Carcinogen is'used here in the broad sense. Alkaloids (Tansey tea) Arsenic Asbestos Benzene Chromium trioxide Ergot Estrogen Sodium nitrite Tobacco Liver tumors Respiratory tract Lung Leukemia Nasal and sinus cavities; larynx and lung Nerve tumors Uterus; fibrous tumors Gas trointes tinal Lung; mouth and throat i 7735 0000261 ^ ..tiT'.t jr. d e k y i n ".", t s j o: )R0 NO). ;et a c : - ?0P y e ; 1/ Total number of rats Rats with tumors Rats with amlignant tumors Pituitary adenoma Pitpitary adenocarcinoma Mammary' fibroadenoma --^ Mammary adenoma Mammary adenocarcinoma --^ Fibroma Fibrosarcoma --^ Lymphos arcoma Endometrial sarcoma Interstitial cell tumor ilemangiosarcoma (ovary) Granulosal cell carcinoma (ovary) Aednocarcinoma (pancreas) Adenocarcinoma (lung) Adenoma of liver Adenocarcinoma of thyroid Adenoma of adrenal Adenoma of lung Hemangioma of ovar-ies 1250-/ 625 125 25 5 Control M FMFM FM FMFMF 25 25 25 25 25 25 25 25 25 25 25 25 7 15 6 17 6 14 5 13 5 9 3 12 685325 43 2615 060 6220 4110 2 0 0. 0 0 0 2 0 0 0 0 0 0 0 7 0 12 .0 8 0 8 0 3 0 7 010000000000 0 7 0 20 2 1 30 40 3 100000000000 2 0 20 1 0 0 0 1 2 10 20 30 10 30 11 00 0 1000 0 01 00 0 1 00 2010 10 10 20 0 1 9' 0 0 0 0 0 0 0 0 1 0101000000 00 0 0 0 0 1 0: 0 0 0 0 0 0 1 0 0 0 o' /'I 0 0 0 0 0 0 001000000000 1 0 0 0 ,0 'o 0 0 0 0 0 0 00010002 1300 000100000000 0 00 0000 1 0 0 00 0000262 Only one rat mammary tumor counted when multiple *<1 v' only one fibrosarcoma counted when multiple. CO Hansen et al. 1971. IT P C A P O M o a GO H o00 o o KNOWN HUMAN CELL CLASTOGENS AGENT Aflatoxin Benzopyrene Caffein Cyclamate Methanol ? Monosodium glutamate ? 2,4-D Tobacco Smoke ? SOURCE Peanut butter Burnt toast Coffee, tea, cola drinks Artificial sweetener Food seasoning Herbicide Cigarettes, Cigars t s ooootf* Gl - 1AT `' R1 ` 5DU .......... ON " JDTf 1 R, .i ~ 1 2. t)IC" ")R0 NO) 2,4-D In Diet (ppm) Number of Females Mated Cl/ Fertility^ Number of X Pups Born .. Litter Size-' Pups Weaned Number % :e t a c : Number of Pups Lost or Dead (2, l WeanlnR WeRht(R) Female Male 0000264 N Ni Co 05 0 100 500 1500 0^ 100 500 1500 0 100 500 1500 0 100 500 1500 0 100 500 1500 0 100 500 1500 Fla Generation 19 100 t 19 95 9.6 11.4 20 95 10.5 18 100 8.1 20 100 19 100 19 95 17 100 Fib Generation 9.3 11.2 9.9 8.4 19 100 20 100 20 100 2 100 F2. Generation 8.4 9.5 10.4 8.0 18 100 20 100 20 100 3 67 F2b Generation 8.5 9.8 10.6 11.0 20 90 20 85 20 100 4 100 F3. Generation 9.9 11.2 10.6 11.5 F3b Generation 20 95 11.6 20 70 12.4 20 100 10.9 4 100 * 11.3 Number of litters/numbers of females mated x 100. --^ Mean values. 177 97 159 78 119 60 73 50 5 46 80 72 130 70 55 160 75 53 127 71 51 28 20 114 147 92 142 75 193 93 10 38 12 47 14 6 120 78 168 86 163 77 14 36 .33 28 49 8 169 95 170 89 173 82 33 62 9 21 39 13 188 85 133 76 182 84 28 62 32 41 35 17 33.8 30.1 32.8 24.5 36.6 41.6 35.6 26.0 38.5 40.8 37.3 31.1 41.3 38.5 33.7 31.1 37.6 38.4 38.5 30.7 52.0 49.3 45.3 32.4 32.5 28.9 30.5 21.7 35.7 38.2 33.4 24.7 38.1 37.8 34.3 31.1 39.7 37.2 32.1 35.0 36.1 35.4 38.4 28.3 49.1 46.9 42.0 35.1 GTS ROOD MOn O N 10 O O K AR N O FSK I'S LAW O a Any drug administered At the proper dosage. At the proper stage of development To THE EMBRYOS OF THE PROPER SPECIES/ Will be effective in causing disturbances in EMBRYONIC development. SOURCE: Wilson 1 9 7 2 . ` ( 0000265 ^^1c3 3 t T Z 9 8000 Mon DRUGS AND CHEMICALS THAT CAUSE BIRTH DEFECTS IN AT LEAST ONE SPECIES OF LABORATORY MAMMAL^ SALICYLATES (Aspirin, oil of wintergreen) CERTAIN ALKALOIDS (Caffeine, Nicotine) TRANQUILIZERS (Meprobamate, Chlorpromazine) ANTIHISTAMINES (Buclizine, Meclizine, Cyclizine) ANTIBIOTICS (Chloramphenacol, Streptonigrin, Penicillin) ANESTHETICS (Nitrous Oxide, Pentobarbital) SOLVENTS (Benzene, Dimethylsulfoxide/DMSO, Propylene Glycol) -- Wilson, James G. 1972. Address presented to 25th Annual Meeting Southern Weed Science Society. 4 p. (Dr. Wilson is with Children's Hospital Research Foundation and Departments of Pediatrics and Anatomy, University of Cincinnati, College of Medicine) i. i L. ./ ( 0000269 DOW 0008 522 r a t s YSOIC >*'H/`.rV*** |,.. * <-> p p 'l ` ,wili l& U `:IY PRENATAL EFFECTS Dr HERBICIDES: EVALUATION BY THE PRENATAL DEVELOPMENT INDEX m . : ,, ir i| K. Diane Courtney" . t u jji; is.? I jj \\1 <*"; ; ____ hJ'"] ' C J F - r r 'A ^ r t i 1Presented in part at the 15th Annual Meeting of the Teratology Society, Hav 11-K , 1975 Pennsylvania. - . Pesticides end Toxic Substances Fffect's Laboratory I <UIMIIwlWU IW ** */!( Research Triangle Park, North Carol ins'27711 RUNNING TITLE: Herbicides: Prenatal Development Index # #. TABLES: 9 . ' '' SEND PROOFS 10:idr. X. Diane Courtney fZr.Z* t'^7^ ] \ Pesticides end Toxic Substances Effect Laboratory Environmental Protection Agency J Research Triangle Park, North Carolina 27711 '' KEY WORDS: Teratology, Herbicides, 2,4,5-T,. 2,4-U, Silvex, Agent Orange, i" . Phenoxyacetic Acid. Esters, Fetal Toxicity, Prenatal Bevel cjwr.ent, Prenatal Development Index. 0000267 57 ^ r*U/Ji! ./'y?*,;*.>**,. 1 lUr*> i*r **irj Jl*r " " * a%n AJfif.: T ^ g a v K'J T" /wc< fijo-T 77^A ZP/y_/Q a F G F s t /^t / 'Ps.f'-t ~7&a jLS\-r. -TS~ n/r/../rts(JS ^ H iF H . ^-:rr-- : -r f AGENTS DEMONSTRATED TO CAUSE BIRTH DEFECTS IN LABORATORY MICE Agent Defect Airplane^ ride Cleft palate 24-hour fast Movement limitation Cleft palate Subcutaneous sodium chloride 5C temperature change 2,4-D Cleft palate Water deprivation Cleft palate Raisin diet 1 day Cleft palate Loud noises Source Brown, et al. 1970 Kalter and Warkany 1959 Rosenzweig & Blaustein 1970 Nishimura & Miyamoto 1969 Davis 1979 Courtney 1977 Schwetz, et al. 1977 Peters & Strassburg 1969 Davis 1979 / 0000268 P W onnnAAOG 7743 151 Un A `k , . caBhfatineldrsMapfrafaedyciistneogdni 2 _<3 ^iog-i Countywide ban bn 2,4-Dto ctwAfWiwilarrygeheteeMhweeadndetwAnbstrhkeaDhpOsiniiIrslldhnSealraaeaeOpyydarndaeN2gradP-,eef4bbanttWehyeirtnekesrinswsah.VccaeaiDc(itesrlAehylbxeteitPnippledcda)omaoi,mdsraf--wptefem,idos.cheThrieoaiaahnsztlrdoees-t dhwsdnRbipooosyhT.rmTncteaihphkShfneyeai,ate.eearrdkdpg2cm's1ahetthoyhidsilnuraemdaapttofeaZofwtnrrreahoitairnhcpuemstshrmaoe,barnftikrfrcdbywieUcieeadniaWnncateseetailvasdamDicerswhareswasntuheeiniateinrieydlssdel-l Hospitals. sstawsbpgtbttcasheieonehieseouhhfiNeiWrn"ztnaJ`ntnztietaTedcumaehItsoumInearhomvrcvcrsscecacecnehdieihuemhthace.rdea-kroeeifatna.ptsnebsfmeafnhplsr,eee'nyi"toeehawWetscnircdhclvinmseahtfahiedoesatiadenefeausena.n,emelccrdvsssnlkhtsaa,lel.eMmsitdeatnohsheesilitn-ynedieoenaIadIrwtt'nritwdi.hmstgy'dlwhtshosaWiehegeZafneihrdaheidetikaaeeezrcet,rirncdden"hsuhhetshhhesnareedhaisouWceeapeamtioifmtrsldpdsheentyhdiajteueedrcauhaachnelol.apiiyedhsstissnfal,st sesw"paxfaW"riWridassaItyansasbdcepct,eohi"dhrcntamte"he'wytnneaeidkdyatdsohnofansnotnieAekdwkelr,.lag3irehsft0nhhia,astiiessdhaOshoiahrdomfhaeemhnreebge.peielcwwaainodcaandeses ffmclcaseoiheetacarAraettnvellmigecenyienaadigjncsugueVattstnnahliiOsgnteseehlgmtwirearnraehaynisoemiglsgcclforofehooslh,ucpdwWaetcruiratieaieshannlrsertgsibhdVo,.tlhvnaritaensmeaonttntneedwrdardaceamhoiafbnnino.flysse agwrteeneimsWndfpeitotaahbncpleehsrilitoribpeebdnlrvelodaeebfuomolngtesrhkhmehtseisaascrni,hnddoReefmherveteZihoacaeaunanclsndhceswao.yhran3siys.s to be sought in Madison .Milwaukee Journal 10/10/80 * i cC Ot o* C Ol UI - Special to The journal j jj'jrth defects, especially in a-place w here people boe J3wiooVauridd4aCisnioonduntrn,tohtWydeuiMsBc.eoa--adrridseL,osynosnlauCnitdiiHtoynaTaCshnoueuirnnns,dcaiatlhymceaetlhmlCianbotgeursnfhootyefr ssaaengndHedathtaohenfeeCtinhrietksyiamdCidseotausoshnuepcrilelai.syi,no"pbbtioemtshiasittdihc.e aCb oouunt ttyheB opaarsd- bn lt diW"gdIhaedtcoshwentl'ealt nshkdinossopnhwrkoamyst faeeiad.d,shna feeeawrp laahsci sef reahxnoitmsi tces ,a"fathneedr tshaeidh said, ai2akAHs1imseglcHTulmeieboehtanreyrdoeatalinnintpeTOotebvhaWrhnroeirsau'uykssanrom'rssgilantrddeetoeia.,ftqsnreayhuantrPahtenedhadasesoaferptrttkan,oheu,tfnressoJneerswarZeiimbozhaaautlfersheecrrttsehehbfhs,toeipeWtcmryrwhicadheeohyaeiWdrrisis,banlndintaegicoe'ncessixrdhrdtihvpVhatueeoooyeminm2suede,wtsw4endow-.hsaenDyimeaktls.deos,-. - z^lciuhf"erT"WaTe.srih"gmvajeceWuceeadhWslnnalttfeecaiarhnvnhocfadethtmteenrohtnerdnseUdnlebkieodrenisnonihswvckaowZekihmsdraiaasfecctieih.hthdyihia.MslardHypasoowrpiysnneapndsitsstheauttarltfeeotfWceastrtmeheeedadddepnaeaebthncseIdhedncaeadmysmuei.sysiie--- Tun Page s 'lAsnblueeelggaariWAMnevgmisnihlgarnlebtesacdgh.nothOetrWatobahersytlanoOhtaanhdocemrgsohdraaceanntnthoenikgdmnauoy,eddntaeVof3islcnfan0aieoiwe,tkVcnnttnnsitlisteaenaashatiamiginensdsdpasttpmWhrhhaatec.heeysaihrrtrereewdwomsev'ofafhefinosocsetrepacnhrslcrwsaaipapndnesregaiwseoo.hydphnfaeolsicddecrohwinpcnwrta>lr :Zeamchparroybalnemd as daanudghfoterr.cRonegeaennnitea.l 3p. roblem s of Herbicide The Environmental Protection Agency has io:udlscZsbeufaresoaedenHMnutsushetc2etnaareed,agaet4duyandau-inassDrapstoeaueni"trpnlnooe'mosotniptiinfMrholtrohtseterrthuatashtsohymoetMaenoesolfauacraeriiynthtdnEtuhiJyeiiofPmenbosm.onA"ogeerhinilmocncetnaighSaraHslbslatkstl.iieiuhstooncaeenmitlfsdMhtocheioecrh"alnrskecdDedmaoitissenshiaocspchcefniaoalaeaurdnealtts'yftmn"siifa^vnsdeuelieSucrgsnDetauentseana,sivdfnicaoasiiyeeaft 2 , 4 - D bah asked FnmPtttl I 'm a n adult, b u t I can't stand it w h en It happens to ttaem. It's chemical genocide." he said. , Seizure-prone tinhfeWecrateicsohuntletnWodfeodbnnikretshsdaiaddyefhewicshtssi,ochannwmd aitsghhastteihhzeauvrheea-pdlrooawnneereeaaidrs SnhipcerkiHnagemmaliatghnh,tDakneepeaapridtmteheetnobt atrhneepIonmrteafywfoearcs,t seiasvsieduneSda.kfotHefe-r IllsNreevsiesrttahneclees. s, he said, triggered the seizure. he feels the chem icals would then aw ait EPA findings. us.' sWaiead Sn ekoisordadmlailnyiMcg. kataod ihsHaoadna npb eaenerkn, st,uhnae latcwhhoaeurmegihcoafSl pthhraainst gubnneuetinnl A gDaeinnsnt istheKWroallr,, corfititchizeedVtiheetncahmemViceatle'sraunsse nh"epmIaritkchsai.ln kth aitt cisauisnessanneertvoe sdparmayagpe,arckasncwerithanda CGQS713 7?45 Stevens Point Journal 10/6/80 J?OVV945096 Public intervenor urges dialogue between farmers, environmentalists iw"WdWbaawcCroDattpapeafciSDahheroabbhbuandeoreedeiorhaETaaEeeieiprutoc"oiorssvninvssnhwiwllmiyigftaethaFunuucneccdcitnreitiaznuarloschstroercottvravgrelyroesobtosemirinysnsimrfierdecdneIlnuttnrnaaiusrAasmstS,hhartaeoeehoiiri,ererhrnlnseumestidsfmnefcnedrietsaaCmp'a.idtfsgoslmirs"amrhaseaetbceeeingsonaaiDnadteecCroaeorfdgrnoep"emictntedytosaobpaudi.oreistnuwenoyd,tomniuohwlmt,ti,rbuatanoetrrzganuneIaaa"lbiimsfrrteimbtidtlnrleaoeolrtioFopcfSenioieaeitsa.ecdkenatsmfuersesuaifdghbcswsrttntesttiIrnfdihpsoiumoshnstngrmncsdaddpaiiweesrnouPetoocnntdianprepeeaiimeetaecitaiinrgiyCtisorrdkrsdtnrsnirilosntvcshteskeohsheekwtsgsgeessnsoielgoftnyotucrsatunhhrtistuuahtunouaatughsiohntoeirehntdheeeeclurrlrhamdtataott,,riddd"eeoyoe.eohoed"e"rlr,ttt,f cotmooff"oBuniW,cstu"aettechbfDteoemarstmwhauheiesasdlotdp.pner.uesbbaaelciitcdhw intervenor's out to them ae edni sftai nr mc t ieorns astacsACzlftaahuadoontolwOa"rggvanndinmAnsgocsernts"tueiesecaesueac,lrsi,anrmgotfntutsyDaetreeel(irdfaddoaot-rfmiuiwol.DftnehrerfsddPeecIearoTbnrupb,rom,npyhosgesyanattietssricelrfoatmrtryiaeiTcueiutaecdprtetmlfinprimi.timdoana,vsa"ernegedtibrmsrrnheete.omha"eertBngabrisomsmsotauafuaaiifaeonstdnrfhonreders.Ideee)srft, sesMdDIanntoall"radovvwiOonemuiasarnttsoehogitgdoneenrsnlrimamsawyioaletdeifioinsdsnfett.a,tmeaIt"nhalWsiitntelphseyocetegostfoyrhnhua,ameeurstmreegepwddeiscdl,sie.olnxlnaoPecgttseebhrb,tpsly"oee-tt DmdfpdttmhoaoiraaurDraeowomljstaroeohutscsgeergohpbruhnosieesttp.eottItsehhaasWaansfdaetdiaue,tdedvrpe'asr,mashrereonaeseapspcsvrnpoeeoessensedtdss,ticetitlbboichlddtaeuiheulkdirtlenfreeeyreigtevenonIpmirgmsscuowsietalaopuht.eiidhe"nentashneess,,t SSap ugct e(hbrHvoileicoecnulahsNrl eitPnouaovgrr.iiesnn1tg2wAsa intrlhedldiase1bpS3f ae)ea.lnrl.tihmoerledHnitga'hst ' skassefpIttdtppcwnaudwhsAmpthhnahthaanhnagoneeerepaeiouahhreHregATd"oiuA"feoiraodrlcesratvlitmdeodbiteTareEupitloslwtdtheovrnechibnicc,iteip,ttilcostr.hsceyciiiwvnwetynyuoiusidciutnoewstcioalue,crgeapmrgtpldltgibeiognoynriahltstidsnosi,uUsrsedtrolimuev,d"nmna,heeutvicou.bswiocrekrscwdcnaopree.rthlcltuweterrtthlieeohpuoshIrmeDeoaoanchaasnoseseodhnelhsransnanelyugteesaaBfhnmtnontlasefesh,eoattraubas,ilwsuv,taud.tgpapocdatetrmaruleu"hlspyiigisr,idciaeaiwtrlirntrnfr"edcsnoooserDihhrartroaidtisritesedcavgtniteDletltnsebtybamurpbyslian.titssIthienmwaneoeeswehteomstgaubpaseisBswwsuhagu,oreooshnehse.ntoarntapthtrerouisifenonoiohttiWbaeeentmaooetonedtDwfopttaertxhtacpdatnenmho.dnsenorrIooaptaprtirucnorbetheslsnmnnbtwddeupaotytsovnao"matyoa,obatutspitWtiietttttarttepsnhdlhinnohohhhgahthhmexorItidaiIo'log.ngene'oecseeydnpcneheneeefttt.f cewapesssudtOaIheWaaebuunrb"tsrphnhaetaefbofbfngtbnensoeuusefrraAfafTfeciH"ei"ccaoienosodrcptvutemgeededpnttWliritoodtpWnatuuhneauineeclccrs.ice.egerr,acuordettrrttgtd,ettues"meodedssi,thinhsshaeieettsTldmenateheiedoektmoaudsdpDplaceionuldthmyoeoonaowenielcteilhstnoaarIreatnennrdsiekhonsnpks.rctoeewdnautordeupgeateemut'qhWnri.anrtnlsdtgksdWnfoisateobuoieusntfkaaiuuvonhn.Wsgplipiwwlasliacpsagstnyteictsntoeecesbauilhlicchrnoehesneisa.iaswtvctieperoetare,awhtdd,tWgtreceyerrsaoenn'mkhinireeosoweatDxttomsscateeinw`eehasamtvimfiinunpakcsofsheaedeanwsesnftaishpfgtsphc,hewodesteeig,sa,def"retpoianueripokrrrdeclabenfrcsoaouteugnfteernrlaftticawoedtgDifnia,hobtlvcsic"ssorstntteegndssesc,ileiui,isuwiaewtcduldrinmsmssyotsk.abidwcrotlstau",brnhitgt.rrentse"laajuveoairwsupeoieittterointtiinfn.nnhbeohhonnhhhnmbeerdIcoiweiggdyddnaleeeenesgsnreeeest.tf,l. (See pesticides page 2) QD is. is. pesticides (Continued from page 1) Kcthoesantnpciaceegplsdtetiemcsiuhedsoneeutr,lIudshleeIbsns.etaeigIdnr,caaltuendddePdtheIasntt ' j' anladsItdaetpplieotnsAaeapepctdmellrliuasitdnofcohsriiawatnsocshtmttugiainabavogteesnuenihrndofn,spftatneeroirogrttdwhplseszeohoaeo,ocsafretnfDaedsmeldaassgwsr.atepaorasdfineoudpcjsdtnsavruoteoicalswcdvtaneuiiiidndncbdrtdeoeeee.t 1I i srbeIounaevnLlnecfeirocslatsuhtrbspicedhiroleaoiintnymusys,lagdefmonhirneeatcvlnliiusodfcaodleairesdtntim,aoasddnnaerasiendnfdqstdahauraotadaoutnnhtrsldeydde, ! - rreevgoisctartaitoino.n suspension an d |1 cGJAFthooanrIeonzannsteyrtnfoo,,Ko,tltvlhrrlieusoecceaewreocsgaicmurencehrrgtmt,eaiaoriircr.ontymhtf,efaaeitaichnrneem;rdrsepMa:-enAeas;lrtuMeivrccKeeatiledeerldynane . ptbSItrtrhhhneeearTeeecctionenoohadgpggrrdesrqddroomauccsuetoaaoiaenxnlnrsmdildpeduitsyarPmupwte,crpesiaatfsotsoeatttotirfieednntvMrreigdneotoagahncrfnluoeIstaitalnhonelgDcedsrcweew.ieaClmcresuwenuneeednsrntanobotitrvtnrncooaiei'ghnnnnslr GG03713 >* t 4 1 $ lc2 C-PC2 0*i?9 CCTvP'-' 021 lCr5 01-31-8? D0WO971711 f M. Ci FOONG E M & * V CC: s. ANDREWS MARCM 2030 r.1 TANC- HNGKM i V* J. KUPCTA DPENCKPOHI HMGKM BICPM 5008 B C C : R. F. KINC A I D CORPM 223?. 2.4.5-T / FSTEPON TRADEMARK t I PAVE KAI SEPARATE DISCUSSIONS T r STIPPEN ANDREWS, JCEN D R E N C K P O E 1 ANE BOB KINCAID OM THE ABC VI SUBJECT. I CFS'S VIEW IS THAT THE ESTERCN TRADEMAP. IS TO BE U S E D ON 2,4,5-T P R C I U C T S C M ! . WT. CANNOT S D P P C R T TEIS TRADEMARK B E I N G U S E D FOR MCPA. I TCtR CSE CF ESTERCN TRADEMARK FCR 2,4,5-T PRODUCTS SUCH AS FSTERON HI ESTER T, ESTERCN 2,4,5-T EUTTL ESTER AND ESTERON BRUSHYILLER 404 ( ARE VERY CICSE AGREEMENT. STEPHEN WILL ANSWER SEPARATELY. TO SHOW ECU CLCSI YOU ARE, EE IS GOING TO SUGGEST ESTERON 404 BRUSHEILLER, II P P A C T ICABL F . I KNOWING THAT YOU HAD PREVIOUSLY SOLD ISTERON BRUSHKILLE? AND THAT EICAUSE YOU NOW HAVE TO PE-SCURCE CN IWE FOR A DIFFERENT FORMULATION, I YCU HAVE ALSC GOOE REASONS TO USE ISTERON BRUSEKILLZR 404. THIS W I L L TELL USERS THIS IS E S T E P O N B R U S H K I L L E R BUT W I T H A SMALL DIFFERENCE. < I HAL TEE OPPORTUNITY OP GIVING STEPHEN MORE BUSINESS BACKGROUND. HE WILL RESPOND TC YCU MORE FULLY AND NC DOUBT SOME PRACTICAL SOLUTIONS f WILL EE O F F E R E D . | IF I CAN IE CF FURTHER HELP, PLEASE EC NOT H E SITATE TO CONTACT ME. BEST REGARDS. *A 1 - 3 1 - e e IK i 2030 CCRPM I < i i { ( c 0005720 15 S ISS ?K74G Or--' MN 05 5 6 8 0 to DOW0 7 3 0 2 9 0 -L '-xOl .li 4.J J* .ii Jo ^ 1 1 -- 1 1 1 LO 1 1 -i1 1 11 11 ci r r--r 0N0 rc*XnTcT- cXr* pnrrv- A- pv oe *aXc*r. (XN CN (X1 \--ni < 7 . t 'N J. ----, ~ " --- n -_4 O - i .* ' 0 N -- -- I_ -- ..A- . -- -- .___ *-- (N V r - 'jr> >Aj X J. 4-- <x. -- X 1 .r- ft % P* * X -- - - /, ... > -- x r c -- v - -- T -- -ii c .1 _ - . * . -- \ 1 *-- --. T c r n rC*- . X ; CT\ cVr - \ '* -i <X rjn r^, N O C .' -- t. ' y* --. .iI. .i i. LAX f2 7* -- 'O Ni -- 1 a ._i. _ 1 _1 : t _ -- .i -- L*J, o_ j_ U A. 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W U A M I T TES OM HAND T t11- S 1 <L L, U"i i l l 0 b F F t - 1 Dh F L r T IC :'.'. (4 ) t r - L i L A ] 1O 10 -"* i D 0 fc. PRO JC T I G * S FF r A F F h L'V t RS ; a . L . C L D CA C 29 AIJG F 0 l'< F . \ t ir b T E l HU GS ? 7 AP F FO S . J . j L S !J l- i- -' G u . ? a F ) As0 J.r . J l_ t* 'J1 C . L' TLI >C *" 1 A PR FO CGOS u ;(.: / w a a 9 a ! i G 0 0 r 1- C Fo 1 5 J m m - U (. 2 1 ' u 1jL- S t 5C l a j U r 0 J . - , r^a>ru Cr.Pl. -St F 9 0 AP1FlV tS :u j V-CrF 1 : 1;A1F- :AFFFTVAL.S :DIV-UtFi : GATE FN11\j(.'. M )(" * f ! ' i 111 Vs I r l o r C t - I C -`i 1 t l i- l S I I I -I ( a I /, r ij J o " I c S " i * i 1--! jL l ' C ! Ir G f i * t- I ' ,,I i - I. + ;in '-`c SH I.PfF[ - 1 c, K E h 1 rst f mc;e C04144 m y 15V 7751 HAT? f < COMPARATIVE TOXICOLOGY OF VARIOUS CHLORINATED DIOXINS AS RELATED TO CHEMICAL STRUCTURE * Marguerite L. Leng Health and Environmental Sciences The Dow Chemical Company Midland, Michigan U.S.A. 1*861*0 SUMMARY The generic term "dioxin" pertains to a family of compounds which are structurally similar hut vastly different in toxicity. It is often used incorrectly to designate one member of the family, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). There are 75 possible polychlorinated dibenzo-pdioxins (PCDDs) with a million-fold spread in the dosage level required to kill laboratory animals. Those with four or five chlorines located at all four lateral positions (2,3,7 and 8) are extremely toxic. The toxi city is progressively decreased by moving one or more chlorines to peri positions (l,fc,6-or 9), and/or by having fewer or more positions substi tuted. Data are reviewed from a number of studies demonstrating this relationship. The relative hazard from potential exposure to the highly toxic 2,3,7,8-TCDD is also discussed. FORMATION OF DIOXINS Low levels of polychlorinated dibenzo-p-dioxins (PCDDs) can be formed as byproducts during the manufacture of chlorqphenols under alkaline condi tions at elevated temperatures and high pressures. The reaction is a two-step process involving bimolecular condensation of chlorcphenates followed by internal ring closure. The number and position of the chlorine substituents on the dioxins depend on the chlorcphenates present in the reaction mixture. For example, trace amounts of the highly toxic 2,3,7,8-tetrachlorodibenzop-dioxin (TCDD) are formed during the manufacture of 2,U,5-trichlorophenol by alkaline hydrolysis of 1,2,^,5-tetrachlorobenzene (Figure l). This TCDD can be carried through into products made from 2,U,5-trichlorophenol, such as 2,U,5-trichlorqphenoxyacetic acid (2,b,5-T) and hexachlorqphene (2,2'-methylene bis ( 3 ,6-trlchlorophenol)J. Similarly, condensation of 2 ,6-trichlorophenate during its manufacture under alkaline conditions produces the expected 1,3,6,8-TCDD, as well as the isomeric 1,3,7,8-TCDD by Smiles rearrangement (Figure 2). On the other hand, the expected 2,7dichloro isomer is not likely formed by condensation of 2,k-dichlorophenate under the acid conditions used in its manufacture by chlorination of phenol (Figure 3). o U1 Vl-J yji * Presented at symposium of Collaborative International Pesticide Advisory Council (CIPAC), Baltimore, Maryland, June 7, 1979 0002236 In all, 75 possible PCDDs could originate from condensation of chlorophenols with two to five chlorine substituents (Table 1). Of these, 22 are tetraehloro isomers'. However, as shown in Figures 1, 2 and 3, only symmetrically substituted isomers with an even number of chlorines are likely to be formed from reaction mixtures containing predominantly one chlorophenol such as in manufacturing processes. Other isomers could also result from progressive chlorination or dechlor ination of lower or higher analogs (Figure k). However, photolysis in solution appears to preferentially remove chlorines from the lateral posi tions (Buser and Rappe, 1978). Thus isomers substituted at the 2,3,7,8positions are not likely to be formed from higher PCDOs by the action'of light. TOXICOLOGY OF CHLORODIOmS Acute Oral Toxicity The acute oral toxicity of several PCDDs has been investigated in guinea pigs, rats and mice (Schvetz et al., 1973; McConnell et al., 1978b). Table 2 lists the amount of chemical which would be expected to cause death of 50% of the animals vithin 30 days after administration of various isomers as a single dose by stomach tube in each species which has been tested. (Large numbers mean low toxicity and small numbers indicate high toxicity.) In all cases, guinea pigs were more sensitive than rats, and rats vere more sensitive than mice. The degree of toxicity is highly dependent on the number and position of the chlorine atoms. The lateral positions at 2,3,7 and 8 must be chlori nated to achieve the greatest toxicity. Additional chlorine atoms at the peri positions 1,U,6 and 9 reduce toxicity but not nearly to the degree caused by deletion of one or more chlorines at the lateral positions. The toxic symptoms produced by single doses of the various isomers are similar if not identical -- the only difference is the amount of the isomer required to produce a given effect. The effects of single lethal doses of TCDD in guinea pigs, mice and female monkeys are compared in Table 3 (McConnell et al., 1978a,b; Moore 1978). typically there was an almost immediate dose-related effect on body weight, with loss of up to 50% in weight prior to death. Only monkeys exhibited cutaneous lesions comparable to the chloracne observed in humans, such as in some of the children accidentally exposed to TCDD following a runaway reaction in a trlehlorcphenol plant at Seveso in Italy in 1976 (Regglanl, 1978). Enzyme Induction The ability of various PCDDs to induce enzyme production'is also corre lated to structure in much the same way as acute toxicity. The 2,3,7,8TCDD has been shown to be a potent inducer of ^-aminolevulinic acid 0002237 DOW372192 -3- synthetase (ALA) and aryl hydrocarbon hydroxylase (AHH). ALA is the rate limiting enzyme in the synthesis of heme and porphyrins vhile AHH is an enzyme which catalyzes hydroxylation of compounds such as benzo[a]pyrene, a known carcinogen in humans. The effect of PCDDs on these enzyme systems has been investigated by injection of p-dioxane solutions of 15 congeners into chick embryos (Poland and Glover, 1973b). Data outlined in Table U show a well-defined structure-activity relationship, requiring halogen atoms in at least three of the four lateral positions and at least one nonhalogenated ring position to cause induction of both enzymes in chick livers. The 2,3,7,8TCDD has been reported to be at least three orders of magnitude more potent than aqy other compound known to produce experimental porphyria (Poland and Glover, 1973a). However, there'was no significant increase in ALA synthetase activity nor porphyrin accumulation in mice given four weekly doses of 1 or 5 ug/kg TCDD (Goldstein et al., 1973). Induction of AHH by 23 halogenated isomers has also been studied jLn vitro using rat hepatoma cell cultures (Bradlaw et al., 1976). Table 5 compares the concentration in piccmoles required to cause 50% of maximum induction of AHH activity in this system. The dose-response relationship for 2,3,7,8-TCDD induction of AHH in liver of female rats has also been studied (Kitchin et al., 1978). The single oral dose ED^q was 0.62 ug/kg and the lowest dose which significantly increased AHH activity was 0.002 ug/kg. Radiotracer experiments using ^H-TCDD indicated that 1.1$ of this minimal dose was incorporated per gram of liver at 3 days after administration. The authors estimated that this amounted to about 65 molecules per hepatocjrte. Induction of AHH activity per se may not be a toxic response, but its correlation with toxicity suggests that this response is in some way a clue to the mechanism of the toxic action of 2,3,7,8-TCDD and its congeners (Poland and Gover, 1978). Chick Edema Disease An extensive outbreak of a disease in broiler chickens in 1957 led to the discovery that PCDDs in toxic fat added to feed could cause excessive fluid to collect in the heart sac (pericardium) and the abdominal cavity of chicks (Firestone, 1973), Table 6 summarizes the results of bioassays for chick edema in which the test chemicals were fed to chicks for 21 days beginning at 3 days of age (Schwetz et al., 1973). Positive effects were produced by 2,3,7,8-TCDD at 1 and 10 ug/kg per day, and by mixed hexachloro isomers at ten times these levels, with all chicks dying at the higher dose in each case. On the other hand, little effect was produced by the octachloro Isomer, even at 0.5$ in the diet equivalent to about 500 mg/kg/day. 0002238 DOV 372193 -u- Chloracne Classical chloracne is a hallmark of exposure to certain PCDDs in humans (IARC 1978). It is a form of acneform dermatitis which is occupationallyrelated to the manufacture of chlorqphenols, chloronaphthalenes, poly chlorinated biphenyls (PCBs), and related compounds. A bioassay to evaluate the potential for a substance to cause chloracne is conducted by painting solutions of the test substance on the inner ear of rabbits and observing the degree of hyperkeratosis produced. Table 7 summarizes the results obtained with PCDDs containing from two to eight chlorines. A solution containing 0.0U ppm 2,3,7,8-TCDD caused a positive response when 0.1 ml was applied five days per week for four weeks. However, a concentration of 5000 ppm was needed to elicit a positive response with a mixture of 1,3,6,8 and 1,3,7,9-TCDDs (Dow unpublished data). The reaction produced by a 10 ppm solution of mixed hexachloro isomers was likely due to the presence of isomers substituted at three or four key positions. The 2,7-dichloro and octachloro isomers were negative when tested as chloroform extracts from 10% suspensions indicating they have little or no acnegenic activity (Schwetz et al., 1973). Fetotoxicity and Teratogenicity The relative potential of several PCDDs to cause teratogenic or fetotoxic effects has also been studied. In these investigations, the chemicals were administered to pregnant animals by stomach tube daily during the critical period of development of the fetuses. In rats, this was generally on days 6 thraigh 15 or 16 of the 21 day gestation period. Table 8 compares the findings in studies conducted in rats in Canada (Khera and Ruddick 1973) and by Dow (Schwetz et al., 1973; Sparschu et al^ , 1971). The absolute values for 2,3,7,8-TCDD in the two studies depend on the strains of animals used and on minor differences in experi mental conditions. It is apparent that the 2,7-dichloro and the octa chloro isomers are relatively innocuous. The potential for 2,3,7,8TCDD to cause felotoxic effects is relatively great, provided there is significant exposure to this specific isomer. Effects in Monkeys Studies have also been conducted in a limited number of female monkeys. The results of three studies by Allen's group in Wisconsin are summarized in Table 9 for 15 adults fed 2,3,7,8-TCDD at 500 parts per trillion (ppt) in the total diet for 9 months (Allen et al., 1977; Barsotti et al., 1979), or at 50 ppt for up to 2 years (Schantz et al., 1979); and for two Juveniles fed the 1,2,3,6,7,8-hexa isonmr at 5000 ppt for up to 10 months (Allen et al., 1979). 7755 00022'$) -5- Preliminary data have also been reported for a study in Oregon where eight pregnant monkeys were given 2,3,7,8-TCDD by intubation three times per week for three weeks with little or no food during the critical stages of gestation (McNulty, 1978). Total doses administered ranged from 0.2 to 5 ug/kg of body weight as nine relatively large doses at two to three day intervals. These were equated by the author to levels of 200 to 5000 parts per trillion in the diet (Table 10). However, the effects from individual large doses without food are likely exaggerated compared to what might occur from slow assimilation of the same total dose from the diet. Carcinogenicity Studies T2hkeoInngtoeirnngatlioonnga-lteArgmenccayrcifnoorgeRneisceiatrychstoundiCeasnceonr (IARC, 1978) PCDDs (Table listed 11). To date, only two of these studies have been reported (Kociba et al., 1978; NCI, 1979). The results of biassays conducted with 2,7-DCDD in rats and mice were reported recently by the U.S. National Cancer Institute (Table 12). Under the conditions of the study, it was not carcinogenic at 5000 or 10,000 parts per million in the diet of rats of either sex or for female mice. The marginal increased incidence of combinations of tumors in only male mice was considered "suggestive" of a carcinogenic effect in these animals. Thus, 2,7-DCDD has an extremely weak potential for causing cancer (NCI, 1979). Table 12 also summarizes the results of an extensive study by Dow on 2,3,7,8-TCDD in a total of kJ2 rats of both sexes (Kociba et al., 1978). It is interesting that continuous administration of TCDD at 0.1 ug/kg/day for 2 years caused an increased incidence of tumors in the liver, lungs, palate, nasal turbinates and tongue, and a dramatic decrease in the incidence of tumors in mammary glands, uterus, adrenals, pituitary and pancreas compared to the normal incidence for these sites in Sprague Dawley rats. Positive findings were also reported for TCDD in rats in a study conducted by Allen's group at the University of Wisconsin (Van Miller et al., 1977). However, they used only 10 male animals per dosage level and their experimental design was deficient in many respects. Thus, their conclusions about effects produced at dosage levels below 1000 ppt TCDD in the diet are not valid (U.S. EPA, 1919). Mutagenicity Studies Available data on the genetic toxicology of chlorinated -dibenzo-p-dioxins have been reviewed (Wassom et al., 1977/1978). No definite conclusions coild be made abort potential mitagenicity since only four compounds were evaluated; unsubstituted dibenzo-p-dioxin, the 2,7-dichloro isomer, 0002240 DOW37219S -6- 2,3,7,8-TCDD, and the octachloro isomer. However, the positive mutageni city and cytological effects reported seemed to depend on the position of chlorine substitution, and the most active form was 2,3,7,8-TCDD, as in other studies. Metabolism Primary metabolism of dibenzo-p-dioxins in rats is by hydroxylation, and appears to take place exclusively at the 2,3,7, or 8 position in the molecule (Tulp and Hutzinger, 1978). Thus, detoxification by hydroxyla tion would likely be delayed by substitution of chlorines at all four key positions. In the case of 2,3,7,8-TCDD, little or no metabolism has been noted in studies reported to date (Piper et al., 1973; Vinopal and Casida, 1973; Fries and Marrcv, 1975; Rose et al., 1976; Allen et al., 1975; Van Miller et al., 1976). Unchanged compound was excreted in the feces with a wholebody half-life of abort one month. Most of the total body burden was found in the liver and fat, and was unchanged TCDD. Data from a study in rats indicate that a steady state concentration of about 20 times the dosage level would be reached with 13 wereks of continuous administration `(Rose et al., 1976). Analyses for TCDD in tissues of rats from the Dow 2-year feeding study suggests that TCDD levels are higher in liver than in fat when dosage levels are high enough to cause toxic syz^toms (Table 13). It should be noted that the amount accumulated in liver was only about 2.5* of the total amount fed to the animals over the 2-year treatment period. PERSPECTIVE ON HAZARD FROM EXPOSURE TO DIOXINS Th relative toxicity of various dioxins has been reviewed. The hazard due to the presence of these compounds in the environment is also rela tive, and is a function of exposure to them as well as of their inherent toxicity. Available data indicate that 2,3,7,8-TCDD may be the most toxic simple molecule known to man -- perhaps ten times more toxic than aflatoxin (Harris, 1978). Thus, great care should be taken to avoid human expo sure, particularly during synthesis or experimental investigations involving the chemical itself. However, as reported by others in this symposium, the potential for exposure to residues of 2,3,7,8-TCDD in the environment is extremely low. Dr. Bosshardt has discussed the work of Rappe et al., and of the need to differentiate among the various polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs) which can form during burning of chlorophenols or polychlorobiphenyls (PCBs). Dr. Harless has also discussed the need for great specificity and sensitivity of analytical methods used in analyzing for TCDD in samples collected for monitoring purposes. 000224 ; DOW372196 -7- Dr. Crummett has reported negative findings in monitoring studies for TCDD in a variety of likely substrates using a GC/MS method developed ty Stehl et al., with low part per trillion sensitivity. The results of these analyses have been reported for samples of beef fat (Kocher et al., 1978); cow's milk, (Mahle et al., 1977); fish, human milk, rice, water, and soil (Shadoff et al., 1977), all collected from areas where the herbi cide 2,U,5-trichlorophenoxyacetic acid (2,U,5-T) had been used for up to 30 years for control of weeds and brush. Dr. Wipf has reported the levels of TCDD in soil and crops from the Seveso area in Italy, both shortly after accidental release of a relatively large quantity of this toxic chemical during a runaway manufacturing reaction in 1976, and one and two years later. His data demonstrate that there is little potential for uptake of residues by plants from soil contaminated with TCDD. The relative hazard from exposure to TCDD near Seveso is infinitely greater than from potential low level exposure in areas treated with 2,^,5-T. For example, the maximum residue found in Seveso was 15*8 parts per million TCDD in a sample of grass collected near the factory. In contrast, application of 2,1*,5-T containing the maximum permissible level of 0.1 ppm TCDD at a rate of 1 lb/A (l.l kg/ha) would result in a residue of only about 10 parts per trillion TCDD in/on the grass at the time of treatment, and such residues would decrease with a half life of less than one week (Getzendaner and Hummel, 1975). Numerous studies have demon strated that TCDD undergoes photodegradation within a few hours in the presence of lydrogen donors such as the herbicide carrier (Crosby et al., 1971; Crosby, 1977; Crosby and Wong 1977; Botre, 1978; Plimmer, 1978). Contamination of soil would also be orders of magnitude less than at Seveso. For example, the maximum amount of TCDD deposited during treat ment with 2,U,5-T at 1.1 kg/ha would not exceed 0.01 microgram per square meter of horizontal surface, amounting to less than 0.1 part per trillion TCDD in the top 3 inches (7.6 cm) of soil. On the other hand, the highest level of contamination at Seveso was 5000 ug/n, equivalent to about 50 parts per billion TCDD in soil. Similarly, analyses of soil from a horse arena in Missouri revealed a level of 33 parts per million TCDD, as a result of spraying waste oil containing more than 300 ppm TCDD and very large quantities of 2,h,5-trichlorophenol. Symptoms of toxicity were observed in humans exposed to these high levels of TCDD. The chief syuptom at Seveso was chloracne in 22 children who were heavily exposed (Reggiani, 1978). Similarly, one child was affected in Missouri (Carter et al., 1975). In both cases a large number of animals died from exposure to the toxicant. However, it is highly unlikely that the extremely low levels which might result from use of 2,1*,5-T herbicide would cause any significant effect. 0002241 CONCLUSION A number of studies with various PCDDs confirm that the inherent toxicity of the compounds is greatly enhanced by substitution at the four lateral positions. Since hydroxylation is generally a detoxification process, and takes place exclusively at the 2,3,7 and 8 positions in dioxins, substitution of chlorine at all four key positions in TCDD may prolong its half life sufficiently in animals so that much smaller doses are toxic. It should also be noted that, although TCDD tends to bioaccumu late in liver and fat, the amount retained by animals is only a small fraction of the total dose ingested over a long period of time. Thus the hazard from eating immeasurably small residues in food vould be infinitely slight. REFERENCES Allen, J. R., D. A. Barsotti, J. P. Van Miller, L. J. Abrahamson and J. J. Lalich (1977). Morphological Changes in Monkeys Consuming a Diet Containing Low levels of 2,3,7,8-Tetrachlorodibenzo-p-dioxin. Fd. Cosmet. Toxicol. 15.: UOl-UlO. Allen, J. R., J. P. Van Miller, D. A. Barsotti and L. A. Carstens (1979) Toxicological Responses of Nonhuman Primates to 2,3,1+,6,7,8-Hexachlorodibenzo-p-dioxin (HCDD). Presented at l8th annual meeting of Society of Toxicology, New Orleans, LA, March 11-15 Allen, J. R., J. P. Van Miller,, and D. H. Norback (1975). Tissue Distri bution, Excretion and Biological Effects of [^ C 1-Tetrachlorodibenzo-pdioxin in Rats. Fd. Cosmet. Toxicol. JL3: 501-505. Barsotti, D. A., L. J. Abrahamson and J. R. Allen (1979). Hormonal Alterations in Female Rhesus Monkeys Fed a Diet Containing 2,3,7,8Tetrachlorodibenzo-p-dioxin. Submitted for publication in Bull. Environ. Contam. Toxicol. Bradlav, J. A., L. H. Garthoff, N. E. Hurley, and D. Firestone (1976). Aryl Hydrocarbon Hydroxylase Activity of Twenty-three Halogenated Dibenzop-dioxlns. Toxicol. Appl. Pharmacol. 38.: Abstract No. 66. Botre, C., A. Memoli, and F. Alhaique (1978). TCDD Solubilization and Photodecomposition in Aqueous Solutions. Environ. Science and Technology 12: 335-336. Buser, H. R., and C. Rappe (1978). Identification of Substitution Patterns in Polychlorinated Dibenzo-p-dioxins (PCDDs) by Mass Spectro metry. Chemosphere 7., 199-211. 0002243 DOW372198 -9- Carter, C. D., R. D. Kimbrough, J. A. Liddle, R. E. Cline, M. W. Zack, and W. F. Barthel (1975)- Tetrachlorodibenzo-dioxin: An Accidental Poisoning Episode in Horse Arenas. Science 188: 738-7^0. Crosby, D. G. (1977). Conquering the Monster -- The Photochemical Destruction of Chlorodioxins. Presented at 17^th National Meeting of the American Chemical Society, Chicago, IL, August 30. Crosby, D. G., K. W. Moilanen, and A. S. Wong (1973). Environmental Generation and Degradation of Dibenzodioxins and Dibenzofurans. Presented at Conference on Chlorinated Dibenzodioxins and Dibenzofurans, Raleigh, NC, April 3. Crosby, D. G. and A. S. Wong (1977). Environmental Degradation of 2.3.7.8- Tetrachlorodibenzo-p-dioxin (TCDD). Science 198: 1337-1338, March 25. Crosby, D. G., A. S. Wong, J. R. Plimmer, and E. A. Woolson (1971). Photodecomposition of Chlorinated Dibenzo-p-dioxins. Science 173: 7l8-7U9. Fries, G. F. and G. S. Marrow (1975). Retention and Excretion of 2,3,7,8Tetrachlorodibenzo-p-dioxin by Rats. J. Agr. Fd. Chem. 23,: 265-269* Firestone, D. (1973). Etiology of Chick Edema Disease. Environ. Health Persp. 5_: 59-86. Getzendaner, M. E. and R. A. Hummel (1975). Disappearance of TCDD from Grass following Field Treatment with ESTERON 2^5 Herbicide. Unpublished report of The Dow Chemical Compary submitted to the U.S. Environmental Protection Agency in Response to the Rebuttable Presumption Against Regis tration of 2,1*,5-T (File 30000/26, # 16). Goldstein, J. A., P. Hickman, H. Bergman and J. G. Vos (1973). Hepatic Porphyria Induced by 2,3,7,8-Tetrachlorodibenzo-p-dioxin in the Mouse. Res. 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Polychlorodibenzo-p-dioxins: Perinatal Effects and the Dominant Lethal Test in Wistar Rats. ^ E. H. Blair (ed.) Chlorodioxins -- Origin and Fate. Advances in Chemistry Series Ho. 120, American Chemical Society, Washington, DC, pp. 70-81*. Kocher, C. W., N. H. Mahle, R. A. Hummel, L. A. Shadoff, and M. E. Getzendaner (1978). A Search for the Presence of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Beef Fat. Bull. Environ. Contam. Toxicol, lg.: 229-236. Kociba, R. J., D. G. Keyes, J. E. Beyer, R. M. Carreon, C* E. Wade, D. A. Dittenber, R. P. Kalnins, L. E. Frauson, C. N. Park, S. D. Barnard, R. A. Hummel, and C. G. Humiston (1978). Results of a Two-Year Chronic Toxi city and Oncogenicity Study of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Rats. Toxicol. Appl. Pharmacol. 1*6: 279-303* Mahle, N. H., H. S. Higgins, and M. E. Getzendaner (1977). Search for the Presence of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Bovine Milk. Bull. Environ. Contam. Toxicol. 18: 123-130. McConnell, E. E., J. A. Moore, and D. V.' Dalgard (1978a). Toxicity of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) in Rhesus Monkeys (Macaca mulatta) following a Single Oral Dose. Toxicol. Appl. Pharmacol. 1*3: 175-187. McConnell, E. E., J. A. Moore, J. K. Haseman, and M. W. Harris (1978b). The Comparative Toxicity of Chlorinated Dibenzo-p-dioxins in Mice and Guinea Pigs. Toxicol. Appl. Pharmacol. J*l*_: 335-356. McNulty, W. L. (1978). Letter of July 27 to U.S. Environmental Protec tion Agency in response to Rebuttable Presumption Against Registration of Herbicides Containing 2,1*,5-T. (File 30000/26, # 915). Moore, J* A. (1978). Comparative Toxicity of DIbenzodioxins and Dibenzo furans. International Agency of Research on Cancer (IARC). Report of meeting on dibenzodioxins and dibenzofurans, Lyon, France. Poland, A. and E. Glover (1973a). 2,3,7,8-Tetrachlorodibenzo-p-dioxin: 1 A Potent Inducer of ^-Aminolevulinic Acid Synthetase. Science 179: 1*76-1*77. J. 00022-1 n Poland, A. and E. Glover (1973b). Chlorinated Dibenzo-p-dioxins: Potent Inducers of -Aminolevulinic Acid Synthetase and Aryl Hydrocarbon Hydroxylase. II. A Study of the Structure-Activity Relationship. Molecular Pharmacology : 736-7^7. Poland, A. and E. Glover (1978). 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Enzyme Induction. In_ C. Ramel (ed.) Chlorinated Phenoxy Acids and Their Dioxins. Ecol. Bull. (Stockholm) 27: 1U5-1 U8. Piper, W. N., J. Q. Rose, and P. J. Gehring (1973). Excretion and Tissue Distribution of 2,3,7,8-Tetrachloro-dibenzo-p-dioxin in the Rat. Environ. Health Persp. 5_: 2^1-2U*. Plimmer, J. R. (1978). Photolysis of TCDD and Trifluralin on Silica and Soil. Bull. Environ. Contam. Toxicol. 20; 87-92. Rappe, C., H. R. Buser, and H.-P. Bosshardt (1979). Polychlorinated Dibenzo-p-dioxins (PCDDs) and Dibenzofurans (PCDFs): Occurrence, Forma tion and Analysis of Environmentally Hazardous Compounds. CIPAC Symposium, Baltimore, MD, June 6-7. Reggiani, G. (1978). The Estimation of the TCDD Toxic Potential in the Light of the Seveso Accident. Presented at the 20th Congress of the European Society of Toxicology, West Berlin, June 25-28. Rose, J. Q., J. C. Ramsey, T. H. Wentzler, R. A. Hummel, and P. J. Gehring (1976). The Fate of 2,3,7,8-Tetrachlorodibenzo-p-dioxin following Single and Repeated Oral Doses to the Rat. Toxicol. Appl. Pharmacol. 36: 209-226. Schantz, S. L., D. A. Barsotti and J. R. Allen (1979). Toxicological Effects Produced in Nonhuman Primates Chronically Exposed to Fifty Parts per Million 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). Presented at 18th annual meeting of the Society of Toxicology, New Orleans, LA, March 11-15. Schvetz, B. A., J. M. Norris, G. L. Sparschu, V. K. Rowe, P. J. Gehring, J. L. Emerson and C. G. Gerbig (1973). Toxicology of Chlorinated Dibenzop-dioxins. Environ. Health Perspect. 87-99 Shadoff, L. A., R. A. Hummel, L. Lamparski and J. H. Davidson (1977). A Search for 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) in an Environment Exposed Annually to 2,U,5-Trichlorophenoxyacetic Acid Ester (2,U,5-T) Herbicides. Bull. Environ. Contam. Toxicol. 18: 1*78--U85 Smith, F. A., B. A Schweiz and K. D. Nitschke (1976). Teratogenicity of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in CF-1 Mice. Toxicol. Appi. Pharmacol. 38 : 517-523. O W 37 to O O 0002246 OOV/372201 - 12- Sparschu, G. L., F. L. Dunn and V. K. Rove (l9Tl). Study of the Terato genicity of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in the Rat. Fd. Cosmet. Toxicol. 9: 405-412. Stehl, R. H. and W. B. Crummett (1979). The Search for Polychlorinated Dibenzo-p-dioxins in the Environment. CIPAC Symposium, Baltimore, MD, June 6-7. Submitted for publication in Science. Tulp, M. Th. M. and 0. Hutzinger (1978). Rat Metabolism of Polychlori nated Dibenzo-p-dioxins. Chemosphere 1_(9), 761-768. U.S. Environmental Protection Agency (1979)* Memorandum on EPA Labora tory Audit of Van Miller et al., February 8. U.S. National Cancer Institute (1979) Bioassay of 2,7-Dichlorodibenzo-pdioxin (DCDD) for Possible Carcinogenicity. Carcinogenesis Technical Report Series No. 123, Public Health Service, National Institutes of Health, U.S. Department of Health, Education and Welfare. Van Miller, J. P., R. J. Marlar, and J. R. Allen (1976). Tissue Distribu tion and Excretion of Tritiated Tetrachlorodibenzo-p-dioxin in Nonhuman Primates and Rats. Fd. Cosmet. Toxicol. l4; 31-34. Van Miller, J. P., J. J. Lalich and J. R. Allen (1977). Increased Inci dence of Neoplasms in Rats Exposed to Low Levels of 2,3,7,8-Tetrachlorodibenzo-p-dioxin. Chemosphere 6: 537-544 (also 625-632). Vincpal, J. H. and J. E. Casida (1973). Metabolic Stability of 2,3,7,8Tetrachlorodibenzo-p-dioxin in Mammalian Liver Chromosomal Systems and in Living Mice. Archiv. Environ. Contain. Toxicol. _1: 122-132. Wassom, J. S., J. E. Huff, and N. Loprieno (1977/1978). A Review of the Genetic Toxicology of Chlorinated Dibenzo-p-dioxins. Mutation Research 47: 141-160. Wipf, H. K., E. Homberger, N. Neuner, U. B. Ranalder, W. Vetter and J. P. Vuilleumier (1979) TCDD-Analysis in Vegetation Samples from the Seveso Area. CIPAC Symposium, Baltimore, MD, June 6-7. 'S3 0002247 DOW372202 Table 1. Number of Polychlorinated Dibenzo-p-dioxins (PCDDs) Possible from Condensation of Polychlorinated Phenols. Chlorophenols Di + Di Tri + Di Tri + Tri Tetra + Tri Tetra + Tetra Penta + Tetra Penta + Pentja Dioxins a Di Tri Tetra Penta Hexa Hepta Octa TOTAL Number Possibl< 10 14 22 14 10 2 1 75 a Total number of chlorines minus the two which are removed during bimolecular condensation of chlorophenates to predioxins and internal ring closure to form dioxins. S$ 0002248 Table 2. Acute Oral Toxicity of Polychlorinated Dibenzo-pdioxins as Dose Expected to Cause Death of 50% of the Animals within 30 Days. DOW372203 PCDD Di 2,7 2,8_ Tri 2,3,7 Acute Oral LD50, ug/kg Body Weight G. piq a Rat b Mouse a >300,000 >1,000,000 >2,000,000 30,000 >3,000 Tetra ' . i t l } 2,3,7,8 Penta 1,2,3,7,8 1,2,4,7,8 Hexa 1,2,3,4,7,8 1,2,3,6,7,8 1,2,3,7,8,9 Mixed isomers Hcptfl X,2,3/4/6#7,8 Octa 1,2,3,4,6,7,8,9 0.6 b 2.1 b 2 >100,000 c 22 (M) 45 (F) 280 3 1,100 340 >5,000 73 70-100 60-100 100,000 825 1,250 >1,440 >600 >1,000,000 >4,000,000 a McConnell et al, 1978. b Schwetz t al., 1973. c Dow unpublished data. &$ 0002249 Table 3. Comparison of the Effects Produced by a Single Lethal Dose of 2,3,7,-TCDD in Guinea Pigs, Mice and Female Monkeys. a DOW372204 Effect Noted Body weight loss G - pigs Mice +++ ++ Monkeys +++ Thymus involution +++ +++ +++ Spleen reduction ++ + Bone marrow hypoplasia ++ + Liver degeneration - +++ - Bile duct hyperplasia Testicle degeneration +++ ++ +++ b ,Renal pelvis hyperplasia ++ - + Urinary bladder hyperplasia ++ - - Adrenal cortical atrophy ++ - - Intestinal hemorrhage ++- Adrenal hemorrhage ++ - - Peritoneal edema Cutaneous lesions - ++ + .-- +++ a McConnell et al., 1978 a,b; Moore, 1978. b Not applicable for female monkeys. 6s 0002250 DOW372205 Table 4: Induction of '-Aminolevulinic Acid Synthetase (ALA) and Aryl Hydrocarbon Hydroxylase (AHH) in Liver of Chick Embryos by Injection of Chlorodioxins into Eggs. a Chlorodioxin nsubstituted Mono 1 Di I'l 2,7 2,l Tri 1,2/4 2,3,7 Tetra 1,2,3,4 1,3,6,8 2'2'l f Penta 1,2,3,4,7 Hexa 1,2,3,4,7,8_ 1,2,4,6,7,9 (90%) Octa 1,2,3,4,6,7,8,9 ALA ++ ++++ ++ ++ AHH ++++ + a Poland and Glover, 1973b. 00022^? Table 5. _In Vitro Induction of AHH in Rat Hepatoma Cell Cultures by PCDDs, as Picomoles Required to Cause 50% of Maximum Response. a Chlorodioxin Unsubstituted Di 1,3 or 1,6 2 , 3 or 2,8 I'Z Tri ,3,7 Tetra 1,2,2,4 1.3.6.8 1.1.3.8 1,1,7,f 2.3.7.8 chloro bromo Penta 1,2,4,7,8 1,2,3,1,1 1 ,2 ,3,7,8 p re d io x in Hexa 1,2,4,6,7,9 1 1*3,6,7,9 1,2,3,6,7,8 1257,,9 12,5,4,7,8 Hepta 1,2,3,4,6,7,9 1,,3,4,6,7,8 Octa 1,2,3,4,6,7,8,9 a Bradlaw et al., 1976. ED50 (p mol) Negligible at 5,000 Negligible at 5,000 Negligible at 5,000 Detectable at 500 4,600 Negligible at Negligible at 5,000 5,000 3,300 114 1 3 Detectable at 500 121 20 Negligible at 50,000 Negligible at Detectable at 5,000 500 701 84.5 49.9 3,790 129 3,400 DOW372206 ",> 0002252 Table 6. Production of Chick Edema Disease by Feeding PCDDs to Chicks for 21 Days. a Chlorodioxin Tetra 2,3,7, ugAg/day 21 Days positive at 1 or 10 Hexa (2 isomers) positive at 10 or 100 Octa 1,2,3,4,6,7 8,9 negative at 0.1 or 0.5 x 106 (0.1 or 0.5% in diet) aSchwetz et al., 1973. DOW 37 2207 0002253 Table 7. Chloracnegenic Potential of PCDDs as Measured by Concentration Required to Cause Rabbit Ear Hyperkeratosis. a Chlorodioxin Di 2,7 Tetra 1,2,3,4 ]1,3,6,8 mixed b 1,3,7,9 2,3,7,8 Hexa (2 or 3.isomers) Octa 1,2,3,4,6,7,8,9 Response + + + ___ EEL. > 100,000 50 50 5000 0.004 0.04 10 >100,000 Oo * 03 -1 TO TO O CD a Schwetz et al., 1973. b Unpublished data for mixture of 1,3,6,8 and 1,3,7,9-TCDD isomers. 000225^ 607.Z1CMOQ Table 8. Comparison of Effects Produced by PCDDs in Two Teratologic Studies in Rats (in Canada a and by Dow b). Chlorodioxin Mono Di 2,7 2,3_ Tetra 1,2,3,4 2,3,7,8 ug/kg/day 2,000 2,000 2,000 800 0.125 >0.25 >1 4 Effect Slight Slight None None None Edema, hemorrhage Fetotoxic Toxic to dams Embryolethal Di 2,7 Tetra 2 ,m3m,^7m,8mm Hexa (2 isomers) Octa 1,2,3,4,6,7,8,9 100,000 0.03 >0.125 >10 100,000 None None Loss in weight Edema, hemorrhage Fetotoxic None a Khera and Ruddick, 1973 b Sparschu et al., 1971; Schwetz et al., 1973 . 0002255 Table 9. Observations in Female Monkeys Fed 2,3,7,8-TCDD or 1,2,3,6,7,8-HCDD in Diet for up to 2 Years. ppt in Diet Months Fed Tetra 2,3,7,8 50 a 24 Total -V3A9 1 Effects Noted 2/8 showed slight effect around eyes; 6/8 conceived; only 2 bore normal young 500 9 3 5/7 died; 2 aborted 3 failed to conceive; 1 unaffected, bore normal infant; 1 recovered and later bore normal infant O CT oTzsA.eMoa Hexa 1,2,3,6,7,8 5000 c 7-10 80-85 2/2 died. Symptoms similar to 500 ppt 2,3,7,8-TCDD but less severe. Animals were juveniles so not bred. Schantz et al., 1979. Allen et al., 1977; Barsotti et al., 1979 Allen et al., 1979. DOW372211 Table 10. Effects of ,3,7,^-TCDD in Pregnant Monkeys Given Three Doses per Week for Three Weeks by Intubation. a Dosage Total Dose Dietary No. of Rate in 3 weeks Equivalent Abortions (ug/kg/dose) ug/kg) (ppt) vs. total 0 0 0 0/4 Maternal Effects None 0.022 0.2 200 1/4 None 0.11 1.0 1000 3/4 None in 3. One had slight chloracne months later. 0.55 5.0 5000 2/2 Both well at end of 3-week treatment period. One died 7 weeks later and one died 14 weeks later. Both had chloracne and other signs of toxicity due to TCDD exposure. a McNulty/ 1978. 0007.2-' Table 11. Long-Term Carcinogenicity Studies on PCDDs Currently Underway or Recently Reported. a Chlorodioxin Unsubstituted Di I'l Tri 2,3,7 Tetra 2,3,7,8 Hexa 1,2,3,6,7,8 i,2,3 ,7,8,9 Octa 1,2,3,4,6,7,8,9 Diet Mouse Rat Mouse b Rat b Rat c Mouse Rat Gavage Mouse Rat Mouse Mouse Rat Mouse Rat Mouse Skin Mouse +DMBA 1 Mouse +DMBA Mouse Mouse Mouse Mouse Mouse ZrZSAEMOa a IARC, 1978. b U.S. National Cancer Institute, 1979. c Kociba et al., 1978; Van Miller et al., 1977. Dimethylbenzanthracene. fy 0002258