Document ZRYYkkGKJyQ7ZLrd0065nqqO

feature mm. lusu wur^u^lkiiitf send ps*SQ3&ja& Intensified research is needed to minimize their dangers Cart Q. QliltaftOn, Federal Wider Quality Administration, Athens, Go. j^uring the put three years, a special class of compounds, called polychlorinated biphenyls (pc*'a), baa claimod the attention of ecologists and pesticide analysts in this country. These compounds were not discovered in the environment until 1966 in Swe den and 1967 in the U., despite the fact that they have been available com mercially for 40 years. Interest in Fes's hat arisen beoause they are frequently found in fish, bird, water, aedimenv and other environmental sample* when such samples are examined for chlori nated pesticide residue?. That a widt variaty of sampios containing rot's has been collected from England, Scandi navia, The Netherlands, Antarctica, Central America, and many different parts of the U.S. makes them truly ubiquitous pollutants. Polychlorobiphenyls are made by substituting chlorine atoms for one or more of the hydrogen atom* at the The Monsanto Co. slated recently In a letter to Congressman William F. Ryan of New York that cut of August SO, it would no longer sell Pea's to customers for use In gt neral pieslidter operations where tilspost I of the endproducts conn." he coni-oiled. After ` some lag period--the tone it takes to eventually dispose of the 'products made from pea's and cu re/iuy in processor's inventories-- // c quantity of FCB's getting into the en\-`ron.nent may he substantially reduced. It Monsanto's former customers l>,ok for Fca substitutes, rather -hon pun nosing pen's from trunufociin^is in Ja on und Europe, the projet ted Jecetiue could bet om, a reality 'art Cl. CustufiM numbered positions of the biphenyl In the process of replacing hydrogen atoms with chlorine elonw, a large number of substitution^ combinations arise. Por example, three monochlorobiphenyl isomers are pomlbla, 12 dichlorobiphenyl isomentr Zl tricblorobiphenyl isomers, and ao on. Theoreti cally, 210 compounds can be prepared by this substitution process; a typical example would be 2,4,6,2'4'-pontachktrobiphenyl. Whenever aromatic hydrocarbons such as biphenyls an chlorinated, the product ie a mixture of compounds, in clining isomers. It la quite difficult to synthesize single, specific cblorobiphenyl compounds in tbe laboratory unless involved proeedBres are em ployed. Consequently the of the indi vidual compounds hada been prepared in the pure form for study. In the commercial process for ren manufacture, biphenyl si chlorinated with anhydrous chlorlat in tall cy lindrical towc:s with either iron filings or ferric chiom.c as the ca..iiyst J Iw by-product is hydrogen chloride, the product ie e mixture of several p.-b's. The degree of chlorination deter mined by measuring the specific gravity of the mixture or, when the product ie more viscous, the baU-and-ring soft ening-point test is used. The wt ole pro cess takes from 12 to 36 hour-,. In tho U.S., the sole manufacturer of nrp'g is the Monsanto Co., which muteSs them under the trade name SIS t'mSr--mi.ImI SclrM' St Tsrtwiilnsjr Arocior. rca'a are also manufactured in Europe and Japan, under trade names such as Phsnocblor and Clophen. The various Aroclors are dif ferentiated by a four-digit number, with tha last two digits indicating the percentage of chlorine in the mixture. The three most important physical properties of the pci's ere low vapor pressures (they have high boiling ,-oints), low water solubility, and high dielectric constant* They are mis cible with most organic solvents and compatible with many type* of.gply- mers. Although tome individual chlorobiphenyl compound* asp'dry*'' talline, the Arocior mixtures aye either liquids or resins. The chemical properties thst make pep's desirable .industrial materials are their excellent thermal stability, their strong resistance to both acidic end basic hydrolysis, and tneir general in ertness. They arc quite resistant to oxidation. Monsanto reports, in a tech nical bulletin on pen's, that they can bs heated to 140 C under 260 p.s.1. of oxygen pressure "without showing any evidence of oxidation as judged by de velopment of ac.oi'y or to- :'-i!on of sludge." The physiologicil property ol the PCI's make then-, potentially Munificent contaminant!, if environ For any pollutant, iw- factors are involved: acute toxicity, which is iir.uw ..a:c!y evident because of :i high dcu.li or other maiming ctieci. ,,nd ch \ . .* n > icity, which is the \njlt of a V ac cumulation of the >oion in the ooJ> and is a sithleth.. ctfoct WHo'cvr- acute toxicity is ,i. a pollutant wi'l be readily roeogni.cd and , pro remedial actions wi.i hr imro.luord. If. on tha other hand, acutv msi >a low, DSW 032914 STLCOPCB4016876 Ihe physiological cITcclh will go un noticed until the chronic clTccts make themselves evident. When this happens, the problem may have advanced be yond immediate or easy correction. Acute toxicity All studies of Pen's in animals indi cate that acute toxicity is not a signifi cant (actor. Their acute toxicilics arc on the order of thoce of other chlori nated aromatic compounds. Monsanto has sponsored two investigations of the acute toxicilics of Aroclor mix tures. In the first, at the Kettering Laboratory at the University of Cin cinnati, Dr. J. F. Troon and his co workers investigated the toxicity of Aroclor vapors for guinea pigs, mice, rabbi u, and rats. All animals survived 24-day exposure to 0.83 p.p.m. of Aroclor >242 for 7 hours per day on 17 of those days. Even after more pro longed tests, there were no severe ef fects from Aroclor 1242. In the second investigation, still in process, throe groups of beagle* arc fed Aroclor 1242, 1234, and 1260, respectively, at a rate of 100 p.p.m. in their diets. After three months no significant abnormalities have been noted. Similar studies on fish have been per formed in several laboratories. Dr. Richard Schocttgcr of the Sport Fish eries and Wildlife Fish-Pesticide Re search Laboratory in Columbia, Mo., reports that 96 hour-n.n0 toxicities of the Aroclors to trout range from 1.17 to 60 p.p.m. Compared to ddt, whose 96 hour-TLM toxicity is 0.002 to 0.009 p.p.m. for trout, the pcb'i have a rela tively low acute toxicity. With the more sensitive blucgill, the 96 hour-TLao for Aroclor 1248 is 0.278 p.p.m., while that of odt is 0.008 p.p.m. Aroclor tox icides appear to be inversely propor tional to the chlorine content of the mixture. Shellfish, oysters, and shrimp are more sensitive to pea's. Dr. Tom Duke, at the Bureau of Commercial Fisheries Pesticide Field Station, re ports lOO'f mortality of juvenile pink shrimp exposed to 0.10 p.p.m. of Aroelor 1254 in wmer for 48 hours. This concentration of Aroclor 1254 will cause .i I <10r,o decrease in shell growth -i oysters alter 96 hours. To achieve the same effects with dot in these ex periments, only 0.0006 p.p.m. und 0.01 p.p.m., respectively, were required. There is very liltlo evidence that pen's are toxic to insects. Studies to date show that they arc lest toxic than dicldrin or dot. As with fish, their tox icity appears to be inversely propor tional to the chlorine content qf the mixture. Based on the above data, it it un derstandable why the polychlorobiphenyls, commercially available for 40 years, have only recently attracted attention as toxic environmental con taminant*. Chrenle texlelty The chronic toxicities of pea's pre sent a itiore disturbing situation; several chronic effects have been observed. It was discovered, quite by accident, that pea's have a toxic effect on chickens. Professor E L. McCune and hie co workers at the University of Missouri found their chickens dying after they were placed in a feeding house, parts of which had been freshly painted with an epoxy paint. Careful investigation revealed that the toxic factor was Aro clor 1242, a binder in the paint. When Aroclor 1242 was fed to the chicks it produced the same characteristic effects as chick edema factor. McCune re ported: "Cross pathology included hy dropericardium, hydroperitonium, en larged heart, liver, and kidneys, and hemorrhage of internal organs. Mi croscopically the kidneys showed marked tubular dilation and numerous casts." Another chronic effect of pcb's is related in wildfowl. The accumulation of high concentrations of chlorinated hydrocarbons in birds resulted in dis ruption of normal breeding behavior and in the formation of thin-shelled eggs. A dramatic example of this effect has been observed in the ease of the brown pelican. On the Anacapa Islands off the California coast, no young were hatched last year from 300 pairs of nesting birds. The shells of most eggs laid were so thin that a dent occurred when the egg was picked up. There are two possible causes for the laying of thin-shelled eggs by wild fowl. One is a low calcium reserve in the bird; the other is the inability of the bird to deliver the needed calcium to its oviduct, where the eggshell is forming. The calcium level in the avian biosystem and the calcium reserve in the secondary bone structure or medul lary bone, found only in female birds when they are breeding, are controlled by the hormone estrogen. A high es trogen level is associated with the for mation of this calcium reserve. Chlo rinated hydrocarbons, such as dot. OSW 0 3 2 9 1 5 STLCOPCB4016877 ilii'Mi'iiU ami ivu'k. activate enzymes in the liwr which Inmsfurm estrogen into .1 more water-soluble compound iliai i* readily eliminated from the bird'* body. Thi mean* that when estrogen level* are low, calcium reserve* will alto be low, and there* lore very little culeuim wilt be avail* able for tlrong cg.ydtcll production. Dlcldrin and Pcs'* arc more effective than dot in this type of enzymo*lnduc* lion activity. Arocior 1262 hot an es tradiol degrading potential four to five timet that of p.p'-odb. or technical grade dot. The ability of the fomale bird to deliver calcium to her oviduct during the last 20 hour*, when the eggthell it bcihg formed, it related to the func tioning of the enzyme carbonic an* hydrate. When birds that have ex hibited the ability to lay normal eggs are injected with a metabolite of dot (doe) jutt prior to the formation of the eggshell, they will lay thin-ahclled eggs. Thit indicatet that dot alto in hibits the activity of carbonic anhydrotc. the enzyme that controls the flow of calcium from ;hc blood stream of the bird into its oviuuct. Since dicldrin tceins to have no effect on carbonic anhydrate, we may assume that neither do the pen's. How ever, these compounds delay breeding time significantly. Many ornithologist* feel that late breeding ha* a stronger influence on the reduction of bird populations than does the laying of thin-shelled eggs. If this is true, pci's are a more potent threat than dot to our declining bird populations, es pecially for predatory birds that ac cumulate fairly high levels of pea's be cause they eat smaller animal* that al ready have concentrated pea's in their own tissues. Other investigators have produoed evidence to show that pea's are simi lar to dot in (heir activity. Dr. Joseph Street at Utah State University has shown that when pea's accumulate in the liver, they induce microsomal en zyme activity by bringing about more rapid metabolism of drugs, insecticides, and other foreign compounds. He fed rats a diet containing 5o p.p.m. of Arocior 1254 or Arocior 1260. After 10 days on (hit diet, the test animals were administered hexobarbitol at a dose of 100 p.p.m. to induce sloop. In comparison with a control group, the sleeping time for theao rata was reduced by 65 to 0%. Stroot also found that Arocior, when fed at the r tamo level, will reduce dieldrin stor age in adipose tissue by 90 to 95%; in crease aniline oxidation by 200 to 300%; and increase ipn detoxication by 430 to 470%. In addition, the pea's cause activation of organothiophosphato compounds, which adversely af fect the system. This latter effect coun terbalances the detoxification of dicl drin. Normally, when a substrate activate* an enzyme, it is converted to a watersoluble form that will be eliminated from the system; however, this is not the case with rca's. Because they re main in the system for prolonged pe riod* of time, their enzyme induction activity is always present. In this way tho normal concentration of important body chemicals may be lowered to the point of bringing about malfunctions in the system. For example, Street be lieves that the rca't bring about steroid degradation, which can lead to altered endocrine relationships. The chronic toxicity to man it as follows; Like the chlorinated naphthalenes, the chlorinated diphenyls have two distinct actions on the body, namely, a skin efTcct and a toxic action on the liver. The lesion produced in the liver is an acute yellow atrophy. This hcpJto-toxic action of the chlorinatcJ di phenyls appears to be increased if there is exposure to carbon tetrachloride at the tame time. The higher the chlorine content of the diphenyl compound, the more toxic it is liable to be. Oxide* of chlorinated diphenyl* are more DSW 0 3 2 9 1 6 STLCOPCB4016878 toxic (halt the unoxidized ma terial.'. The skin lesion is known an chlei.icnc. and consists of small pimples ami dark pigmentation of the exposed areas, initially. Later, cotttedones and pustules develop. In persons who have suffered systemic intoxication, the usual signs and symptoms arc nausea, vomiting, loss of weight, jaundice, edema, and abdominal pain. Where the liver damage has been severe, the patient may pass into coma and die. Sax, N. Irvins, "Dangerous Prop erties of Industrial Materials," 3rd at.. Van Nostrand-Reinhold, New York, 196S The ubiquitx of pcb's is related to the wide spectrum of applications that have been found for them. The largest single use of res'* is related to their electrical properties--as coolant-insu lation fluids in transformers. For this purpose the Aroclors are also sold under such trade names as Chlorcxtol {Allis-Chalmers Mfg. Co.). Dykanol (Federal Pacific Electric Co.), Incrteen (Weslinghouse Electric Co.), Noflantol (Wagner Electric Co.), Pyranol (General Electric Co.), ami Thcrminol (Monsanto Co ). Other uses of rot's include formula tion into ballasts for fluorescent fix tures; impregnation of cotton and as bestos for braided insulation of elec trical wiring: a plasticizer in wire and cable coatings; capacitors and askareltype transformers; and plasticizen of vinyl ch'oride polymer films. Because of their thermal stability and fire re sistance, the rca's alio find application in high-pressure hydraulic fluids, spe cialized lubricants and gasket sealers, beat transfer agents, and machine tool cutting oils. Miscellaneous uses in clude: formulation into some epoxy paints; protective coatings for wood, metal, and concrete; adhesives; and in carbonless reproducing paper. One of the primary manufacturers of carbon less reproducing paper also sells Aroclon in an encapsulated form. Generally the kinds of applications described above mean that the rca's will be in many types of products that eventually find ihcir way to the domes tic market. When used in manufacture of ballasts for fluorescent fixtures they will be found in kitchens, bathrooms, stores, and offices throughout the coun try. Wherever office forms arc used that do not use carbon paper, one may find rca's formulated into tho micro capsules of dye that comprise the re Gas chromatogram A is of a standard pesticide mixture, B Is typical of Aroclor 1254, and A -f B la the chromatogram of a 50 : 50 mixture of both. The concentration of Aroclor 1254 la approximately 10 times those of the pesticides In A, hence it Is un derstandable why PCB'b were not readily recognized In pesticide chromatograms. Gas chromatograph (Packard 7620) conditions: gas flow 80 ml./mln. nitrogen; tem peratures--oven, 210* C,, inlet. 230* C., detector, 218* C.; Ni" electron capture detector; 5' X Vi" glass column packed with 8% SE-30 on Chromoeorb Q 80-90 math. producing layer of the business form, rca's have also been found on the transparent receipts used in credit card charge forms. As plasticizers they can bo oxpoctod to appear in many con sumer plastics. Sine* the chronic toxicitios are so significant, it becomes important to know just how extensively the rca's are distributed in the ecosystem, and lust how thev find their wn Utn the environment. Rainwa:er in En gland, brown teals otl the coast of Scotland, while-tailed eagles in Swe den, cod in the Baltic Sea, mussels in The Netherlands, adclic penguin eggs in the Antarctica, brown pelican eggs in Panama, Arctic terns, shrimp in Florida, river water in Japan, waters in tho Great Lakes, human hair, and human adipose tissue--samples of all thlUA kxu.s V.s.sw __________ ____ : ---------------- - DSW 0 3 2 9 1 7 STLCOPCB4016879 Uni* making Uwm a dun ot widely di*|'crxed polluinnix. Readily abMrlwd The properties of rep's that make diem industrially useful are the tame properties that cause them to persist in the environment. These in clude thermal stability, resistance to oxidation and hydrolysis, solubility in a wide range of organ m solvents, water insolubility, high didoctric constant, and compatibility witli many types of macromolcculcs. Their resistance to oxidation and hydrolysis also makes pea's more stable anil persistent than dot. Consequently, they could even tually accumulate to a higher concen tration than dot, especially if the use of dot it sharply curtailed in the U.S. The solubility of rca's in nonpolar solvents explains why they are readily absorbed into fatty tissue and into the liver. Their resistance to oxidation or other types of chemical degradation explains their persistence in the en vironment and accumulation in animal tissue. The latter effect is enhanced both by their insolubility in water and solubility in organic solvents. Their chemical inertness and resistance to metabolism account for their low acuto toxicity. But us they slowly build up in a living system their con centration approaches toxicity levels, at which point chronic effects make themselves evident. It has been established that Ash-eat ing birds will accumulate large concen trations of pcb's, as in the case of the white-tailed eagle, which has been found to have as much u 14,000 p.p.m. of pci's. Peregrine falcons, taken off the coast of California, were found to have as much as 2000 p.p.m. in their lipid tissue. When shrimp were exposed to 10 p.p.b. of Aroclor 1254 for 48 hours, they accumulated 1300 p.p.b. of pea's, which represents s 130-fold con centration in a very short time. Oysters, exposed to an identical concentration of Aroclor 1254 for 96 hours and then placed in pca-frcc walor for four days, stiU had a concentration of 33.000 p.p.b. of pea's, which constitutes a 3300-fold concentration. This moans that oven though the concentrations of pea's are in tho parts-per-billion range in tho environment, thoir high lipid solubility causes them to collect in fatty tissues of lower animals and marine life. Therefore, species at tho lop of a food chain will also .tcciimuiaio pea's in their bodies, puriieulurly in their lipid tissue and liver, much Ihe sumo way u they accumulate dot and other chlorinated pesticides. Because of the low solubility of pen's in water, when a solution or dispersion of them is discharged into a river or lake, they will accumulate on the sedi ment in relatively high concentrations. Subsequently, they will redissolve very slowly in the water as conditions change. Therefore, it will usually take a long time to flush out a contaminated area. Accidental soosinrenei The reason that peat have not been found in the ecosystem as extensively u dot. and are not present in environ mental samples at si high a concen tration at dot, it that pea's And their way into the environment accidentally. dot it deliberately spread because this is the only way its insecticidal proper ties can be utilised, rca't ere not in tended to get into the environment, but they do bocause their unique chemical proportioe prevent thorn from being doatroyod by our usual waste disposal molhod*. Thus, they inadvertently es cape and bocomc widely dispersed. In Sweden, where the use of nor hit* been banned, and where the main power source is hydroelectric, inve*li- gatori find that the concentration of pea's in the environment is ss high as that of dot. There are several ways by which pea's get into the ecosystem. One of these is by incineration. Products con taining pea's, such as carbonless re producing paper in business forms, plastics (especially polymer film and sheeting that contain pci's u plasti cisers), spent ballasts from fluorescent light fixtures, and objects coated with pea-formulated coatings, all find their way to the city dump or incinerator for burning. The pea's do not bum but arc vaporized. They are then carried into the atmosphere, where they collect on particulate matter and are subse quently returned to the surface of the earth, into the rivers, lakes, and oceans. In this way they bccomo widely dis tributed throughout the global environ ment. Another source is probable land run-off from industrial wastes and dumps. A third source is the point of manufacture and the plants where rca's arc processed into other products. They can escape through the plant ven tilation and exhaust system* into the utnuwphere and through it* wa*tc treat ment system into newer* or directly into Waterway*. DSW 032918 STLCOPCB4016880 ' it is ijiiorcxiing to note that the inci* donee of 1`i n's in environmental am ple* i* hiphosl in industrialized anil ur banized areas, birds whose prima;y habitat is the San Francisco Buy area have a larger concentration of pen's per unit of boily weight than those lo cated in Baja, Calif., which is com pletely rural. Aquatic life in the Archi pelago of Stockholm, the most indus trialised area of Sweden, were found to have a higher concentration of pen's than Ash samples tsken from the west ern coast of Sweden, a less developed srea. Sediment samples taken from southern portions of Lake Michigan have a higher concentration of pen's than those from other parts of the lake. Monsanto states that until a recent change in marketing policy (see inset, psge SI4), sales of Aroctors were in crossing at the rate of 8% per year. While this increase docs not seem sig nificant, it may be important if the in creased consumption was in consumer products and thus would find their way into our normal solid waste disposal systems. Such an occurrence would mean a definite increase of pea residues in the environment, and therefore a marked increase in their chronic tox icity effects. Detection pen's were not discovered it environ mental samples until very recently for several reasons. First, us indicated above, they have not been deliberately distributed uIxhu the ecosystem. Sec ondly, because of their relatively low acute loxicitic*. their presence was not immediately evident. Finally, they ate difficult to detect analytically. The ren's were first delected os in terfering peaks in the gas chromato graphic analysis (oc) of environmental samples being analyzed for chlorinated pesticide residues. When Pea's are pres ent in a sample they give a pattern of several oc peaks, whose retention times aro similar to those of dieldrin, dot, doc, aldrin, and hcptachlor oxide. Be* esute the peaks wore not large or sharp, investigators tonded to ignore them until S. Jensen, in Sweden, and R. Risebrough, at the University of California at Berkeley, identified them as corresponding to common constitu ents of environmental samples being analyzed for persistent pesticides. The problem of the interferonoes of pea's with tho analysis of other chlori nated pesticides has been largely over come by prior treatment of the pampie. Several investigators have used column chromatography to separate pen's from chlorinated pesticides. At a recent minting, sponsored by the pvvyx's National Water Quality lab oratory, Duluth, Minn., a general pro cedure was recommended for separa tion of Pen's from pesticides. In this procedure for biosamplcs, the sample is extracted with hexane as in regular pesticide analysis. It is then partitioned with acotonitrilo to remove fata, the cleaned-up extract is passed through a Fluorisil column and then through a silicic acid column. Finally, the sample la analyzed by gas chromatography, with a chloride-specific detector. In this way the pesticides are retained on the silicic add column for later elution and identification. Research needs To assess fully the significance of pen's as environmental pollutant*, ad ditional research ia needed. No one really knows the extent of the chronic effects of these chlorinated hydrocar bons. Some problems that need to be considered are: * Although pen's axe known to ac cumulate in human organs we do not know at what concentration they will begin to exhibit toxic effects. Will these chronic effects be similar to those shown in animals--microsomal en zyme activity, calcium metabolism in hibition, and so on? What are other possible chronic effects? * Which of the ntuny pen com pounds in the commercially avuiluble mixtures arc responsible for their tox icity? Can commercial res mixtures be modifiod to eliminate the toxic com ponents? Pure samples arc required to answer those questions. At the present time work is continuing at the fwqa'i Southeast Water Laboratory to sep arate each of the Aroclor mixtures into its many components, aad to identify each component. * We noed to know all the uses for tho pea's. What is the annual produc tion of Pea's? Our knowledge of these facts is limited and noeda to bo ex panded. These facts should be known if we are to accurately determine how they get into the environment, and take steps to prevent further environmental contamination by them. * In view of the complexity of the isolation and accurate quantitative analysis of pea's in chlorinatod resi dues, a ftraightforward, unambiguous measurement of them needs to be de veloped. * * What is the fate of pea's in nat ural waters? More needs to be known of their partition coefficients between bottom sediments and water. This is vital if we are to estimate bow long it will take for a river bod to clean itself of contamination. It will also be useful when investing the effects of pea's on marine life that feed on the bottoms of lakes, riven, and estuaries. We should also learn more about pea solubility in water of various ionic strengths. * Are present waste treatment sys tems adequate to handle pcb's7 Do spe cial measures need to be taken when pea's are pan of the waste effluent be ing treated? By trying to get some of these an swers now, we may find that we are in a position to control the escape of pea's into the environment before ad ditional damage is done. So frequently, action is taken only after it is evident that massive damage has resulted from a particular pollutant. In the case of the pea's we may have an opportunity to resolve the situation before that happens. Additional Reading Hubbard, H. L, "Chlorinatod Biphenyl and Related Compounds," Encyclo pedia of Chemical Technology, 2nd od.. 5, Interscionce Publ., Now York. N.Y.. 1964, pp, 289-298. Reynolds. 1. M.. Bull. Environ. Content. Toxicol. 4, 128 (1969). Rioebrough, R. N., ot. at., Nature 220 (1968). Carl G. Gustafson, chairman of the Department of Chemistry of King'f College, BriarcUQ Manor. V. Y.. re ceived a Ph.D. in organic chemistry from the University of Delaware in 1957, During the 1969-70 academic year, he woe on leave at the fwqa Southeast Water Laboratory In Athene, Ca., where he studied trace organic analysis in waste effluents. As a mem ber of the National Water Contami nants Characterization Research Pro gram, he worked with PCa'r and pulp and paper mill effluents. DSW Q 3 2 9 1 9 STLCOPCB4016881