Document 0qy19OaLRGqM46mRdLrozDbmO

Intensified research is needed to minimize their dangers Carl G. Gustafson, Federal Water Quality Administration, Athens, Ga. tv ' B /aring the past three years, a special class of compounds, called polychlorinated biphenyls (pcb's), has claimed 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.S., despite the fact that they have been available com mercially for 40 years. Interest in pen's has arisen because they arc frequently found in fish, bird, water, sediment, and other environmental samples.when such samples are examined for chlori nated pesticide residues. That a wide variety of samples containing pcb'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 arc made by substituting chlorine atoms for one or more of the hydrogen atoms at the The Monsanto Co. stated recently in a letter to Congressman William F. Ryan of New York that as of August 30, it would ha longer sell pen's to - customers for use in general plasticizer operations wuere disposal of the end- products cannot he controlled. After some lag period--the time it takes to eventually dispose of the products made from pea's and currently in processor's inventories--the quantity of pcb's getting into the environment may be :israntially reduced. If Monsanto . tanner customers look for pcb substitutes rather than purchasing PCB's from manufacturers in Japan and Europe, the projected decrease could become a reality. . C~>) C. Cnstafson numbered positions of the biphenyl structure. Aroclor. pcb's are also manufactured in Europe and Japan, under trade names such as Phenochlor and Clophen. The various Aroclors are dif ferentiated by a four-digit number, with the last two digits indicating the percentage of chlorine in the mixture. Properties The three most important physical In the process of replacing hydrogen properties of the pcb's arc low vapor atoms with chlorine atoms, a large pressures (they have high boiling number of substitution combinations points), low water solubility, and high arise. For example, three monochloro- diclcctrie constants. They are mis biphenyl isomers are possible, 12 di- cible with mdst organic solvents and chlorobiphenyl isomers, 21 trichloro- compatible with many types of poly biphenyl isomers, and so on. Theoreti mers. Although some individual polv- cally, 210 compounds can be prepared chlorobiphenyl compounds are crys by this substitution process; a typical talline, the Aroclor mixtures are either example would be 2,4,6,2'4'-penta- liquids or resins. chlorobiphenyl. - The chemical properties that make Whenever aromatic hydrocarbons . pcb's desirable industrial materials are such as biphenyls are chlorinated, the their excellent thermal stability, their product is a mixture of compounds, in strong resistance to both acidic and cluding isomers. It is quite difficult basic hydrolysis, and their general in to synthesize single, specific chloro- * ertness. They are quite resistant to biphenyl compounds in the laboratory oxidation. Monsanto reports, in a tech unless involved procedures arc em nical bulletin on PCs s. tha: hey cap. ployed. Consequently few of the indi be healed to 140 C. -under 1 ff p.s.i. of vidual compounds have been prepared oxygen pressure "without si .-wing any in the pure form for study. . evidence of oxidation as jue_ ec by de In the commercial process tor ;>cb velopment of acidity or fo.r.uior. of manufacture, biphenyl is chlorinated sludge.'' with anhydrous chlorine in tall cy ' The physiological proper; c-. of the lindrical towers with cither iron filings pcb's make them potentially significant or ferric chloride as the catalyst. The contaminants of v- environment. For by-product is hydrogen chloride; the any pollutant, two tuetors ar. involved: product is a mixture of several pcb's. acute toxicity, wire . is immediately The degree of chlorination is deter evident because of a h.gh den:.. -,.:e or mined by measuring the spccuic gravity other maiming effect; and ch tox of the mixture or, when the product icity, which is th. r. . t of .. ow ac is more viscous the ball-and-ring soft cumulation of the poimn in , hod> ening-point test is used. The whole pro and is a subletha! effect.. ' -r.e\e- cess takes from 12 to 36 hours. acutc toxicity is high., a po ! : wii! In the U.S., the sole manufacturer be readily recognized and , ropriate of pcb's is the Monsanto Co., which remedial actions will oe intr. a need, if, markets them under the trade name on the other hand, acute toxicity is love. (14 Environmental Science Technology 0 H (WU.JJSWU-! UUMJUW DSW 282666 STLCOPCB4063995 ^ I^wtosical' effects.jv3!~0>: una-^ f.cuecd until the chronic effects mak"e themselves evident. When this happens, the problem may have advanced be yond immediate or easy correction. Acuta toxicity ...... . ; All studies of pcb's in animals indi cate that acute toxicity is not a signifi cant fSetor. Their acute toxtemes are on the order of those of other chiori- l nated aromatic compounds. Monsanto has sponsored two investigations of the acute toxicities of Aroclor mix tures. In the first, at the Kettering Laboratory at the University of Cin cinnati. Dr. J. F. Treou and his co workers investigated the toxicity of Aroclor vapors for guinea pigs, mice, rabbits, and rats. All animals survived a 24-day exposure to 0.S3 p.p.m. of Aroclor 1242 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, 'three groups of beagles are fed Aroclor 1242, 1254, 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 Schoettger of the Sport Fish eries and Wildlife Fish-Pesticide Re search Laboratory in Columbia, Mo., reports that 96 hour-TLM toxicities of the Aroclors to trout range from 1.17 to 60 p.p.m. Compared to dot, whose 96 hour-TLju toxicity is U.UUZ to 0.009 p.p.m. for trout, the Win's liavc-a rela- tivelyTow acute toxicity. With the more sensitive blucgill, the 96 hour-TLM for Aroclor 1248 is 0.278 p.p.m., while that of ddt is 0.008 p.p.m. Aroclor tox icities appear to be inversely propor tional to the chlorine content of the mixture. . Shellfish, oysters, and shrimp are more sensitive to pcb's. Ur. Tom ''Duke, at me uuTcail of 'Commercial Fisheries Pesticide Field Station, re ports 100%^mortality of juvenile pink shrimp cxposcd~to"0710 p.p.mTof'Aro- dor 1254^ih water for 48 hours. This concentration of Aroclor 1254 will cause a 100% decrease in shell growth of oysters after 96 hours. To achieve thc-Same effects with Dpf in these ex periments, only 0.0006 p.p.m. and 0.01 p.p.m., respectively, were required. There is very little evidence that pcb's arc toxic to insects. Studies to date show that they arc less toxic than tficldrin dr dot. As with fish, their, tox- .. croscoplcally the kidneys showed city appears to be inversely propor- marked tubular dilation and numerous tlonal to the chlorine content of the casts."......... mixture. -- : . Another chronic effect of pen's is Based on the above data, it is un related in wildfowl. The accumulation derstandable why the polychlorobi- of high concentrations of chlorinated phenyls, commercially available for hydrocarbons in birds resulted in dis 40 years, have only recently attracted ruption of normal breeding behavior attention as toxic environmental con and in the formation of thin-shelled taminants. eggs. A dramatic example of this effect Chronic toxicity has been observed in the case of the brown pelican. On the Anacapa Islands The chronic toxicities of pcb's pre- off the California coast, no young were senfa more disturbing situation; several hatched last year from 300 pairs of chronic effects have been observed. It nesting birds. The shells of most eggs was discovered, quite by accident, that laid were so thin that a dent occurred pcb's have a toxic effect on chickens. when the egg was picked up. Professor E. L. McCune and his co There are two possible causes for workers at the University of Missouri the laying of thin-shelled eggs by wild found their chickens dying after they fowl. One is a low calcium reserve in were placed in a feeding house, parts the bird; the other is the inability of of which had been freshly painted with the bird to deliver the needed calcium an epoxy paint Careful investigation to its oviduct,' where the eggshell is revealed that the toxic factor was Aro forming. The calcium level in the avian clor 1242, a binder in the paint When biosystem and the calcium reserve in Aroclor 1242 was fed to the chicks it the secondary bone structure or medul produced the same characteristic effects lary bone, found' only in female birds as chick edema factor. McCune re when they are breeding, are controlled ported: "Gross pathology included hy by the hormone estrogen. A high es dropericardium, hydroperitonium, en trogen level is associated with the for larged heart, liver, and kidneys, and mation of this calcium reserve. Chlo hemorrhage of internal organs. Mi- . rinated hydrocarbons, such as ddt. ""S' STLCOPCB4063996 enzyme* m *e itver^trwcn transform jrtroiffl jbp.'a'jSore. watcMofubfc compound that tc readily eliminated from the bird** body. This mean* that when estrogen levels arc low, calcium reserves will also be low, and there fore very little calcium will be avail able for strong eggshell production. Dieldrin and Pen's arc more effective Uhan dpt in this type of enzvme-induc- tTon~activity. Aroclor 1262 has an es- 'tradiol degrading potential four to fiye times that of p.p'-DDE or technical grade dot. . . The ability of the female bird to deliver calcium to her oviduct during the last 20 hours, when the eggshell is being formed, is related to the func tioning of the enzyme carbonic an- hydrase. When birds that have ex hibited the ability to lay normal eggs arc injected with a metabolite of ddt (doe) just-prior to the formation of the eggshell, they will lay thin-shelled eggs. Ibis indicates that dot also in hibits the~activity ot carbonic anhy- drase, the enzyme that controls the flow of calcium from the blood stream of the bird into its oviduct Since dieldrin seems to have no effect on carlxmic auliydra.se, we may assume that neither do the pen's.-How ever, these compounds delay breeding time significantly. Many ornithologists feel that late breeding h'as a stronger influence on the reduction of bird populations than does the laying of thin-shelled eggs. If this is true, pen's arc a more potent threat than ddt to our declining bird populations, es pecially for predatory birds that ac cumulate fairly high levels of pen's be cause they cat smaller animals that al ready have concentrated pen's in their own tissues. . Other investigators have produced 'evidence to show that pcb's are simi lar to dot in their activity. Dr. Joseph Street at Utah State University has shown that when pen'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 SO p.p.m. of Aroclor 1254 or Aroclor 1260. After 10 days on this diet, the test animals were administered hcxobarbitol at a dose of 100 p.p.m. to induce sleep. In comparison with a control group, the sleeping time for these rats was reduced by 65 to 80%. Street also found that Aroclor, when fed at the same level, will reduce dieldrin stor age in adipose tissue by 90 to 95%; in crease aniline oxidation by 200 to 300%; and increase epn detoxication by 430 to 470%. In addition, the pea's cause activation of organothiophosphate compounds, which adversely af fect the system. This latter effect coun terbalances the detoxification of dicldrin.' Normally, when a substrate activates an enzyme, it is converted to a watersoluble form that will be eliminated from the system; however, this is not the ease with pen's. Because they re main in the system for prolonged pe riods of time, their enzyme induction activity is always present. In this way the normal concentration of important body chemicals may be lowered to the 816 Environmental Science A Technology point of bringing about malfunctions in the system. For example. Street be lieves that the pcb's bring about steroid degradation, which can lead to altered endocrine relationships. The chronic toxicity to man is as follows: Like the chlorinated naphthalenes, the chlorinated diphenyls have two distinct actions on the body, namely, a skin effect and a toxic action on the liver. The lesion produced in the liver is an acute yellow atrophy. This hepaTO-toxic action of the chlorinated di phenyls appears to be incensed if there is exposure to --...'hon tetrachloride at the same ::nte. The higher the chlorine cor.;ent of the diphenyl compound, the more toxic it is liable to be. Ovde> of chlorinated diphenyls are more DSW 282668 STLCOPCB4063997  toxic than Ote uncxidmed ma---- ~ Teriaft-f'" ~ ......... ~~ The skin lesion is knowiw as ;___ chloracne. and consists of small .. _ pimples and dark pigmentation of the exposed areas, initially. Later, ---- comedones and pustules develop. In persons who have suffered r--'~ svstemic intoxication, the usual signs and symptoms arc nausea, vomiting, loss of weight, jaundice, edema, and abJomina! pain. Where the liver damage has been severe, the patient may pass into . - coma and die. ... Sax. N. Irving, "Dangerous Prop erties of Industrial Materials," 3rd ed.. Van Nostrand-Rcinhold, New York. 1968. . The ubiquity of pcb's is related to the wide spectrum of applications that have been found for them. The largest single use of pcb's is related to their electrical properties--as coolant-insu lation fluids in transformers. For this purpose the Aroctors are also sold under such trade names as Chlorextol (Allis-Chalmers Mfg. Co.), Dykanol (Federal Pacific Electric Co.), Inerteen (Westinghouse Electric Co.), Noflamol (Wagner Electric Co.), Pyranol (General Electric Co.), and Therminol (Monsanto Co.). . Other uses of pcb'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 askarcltype transformers; and plasticizers of vinyl chloride polymer films. Because of their thermal stability and fire re sistance, the pcb's also find application in high-pressure hydraulic fluids, spe cialized lubricants and gasket sealers, heat 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 Aroclors in an encapsulated form. Generally the kinds of applications described above mean that the pcb's will be in many types of products that eventually find their 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 are used that do not use carbon paper, one may find pen's formulated into the micro capsules of dye that comprise the re- Aroclor 1254 is approximately 10 times those of the pesticides in A, hence it is un derstandable why PCB's were not readily recognized in pesticide chromatograms. Gas chromatograph (Packard 7620) conditions: gas flow 80 ml./min. nitrogen; tem peratures--oven, 210* C., inlet, 230* C., detector, 218* C-; Nic electron capture detector; 5* X V&" glass column packed with 8% SE-30 on Chromosorb Q 80-90 mesh. _ ' [producing layer of the business form. [pcb's have also been found on the transparent receipts used in credit card charge forms. As plasticizers they can be expected to appear in many con sumer plastics. Since the chronic toxicitics arc so significant, it becomes important to know just how extensively the pcb's are distributed in the ecosystem, and just how they find their way into the environment. Rainwater in En gland, brown seals off the coast of Scotland, white-tailed eagles in Swe den, cod in the Baltic Sea, mussels in The Netherlands, adelie penguin eggs in the Antarctica, brown pelican eggs in Panama, Arctic terns, shrimp in Florida, river water in Japan, waters in the Great Lakes, human hair, and human adipose tissue--samples of all these have been found to contain pcb's. 1v _____________ Volume 4, Number 10, October 1970 S17 STLCOPCB4063998 ~:r-thm wakiafi than * of widely '' 'dispersed pollutants.'"......... ~ Readily absorbed -- _ Tle properties of pcb'i that make ' them - industrially useful are the same properties that cause them to persist in the environment These in . dude thermal stability, resistance to oxidation and hydrolysis, solubility in a wide range of organic solvents, water insolubility, high dielectric constant, ' and compatibility with many types of macromolcculcs. Their resistance to oxidation and hydrolysis also makes pen's more stable and persistent than dot. Consequently, they could even tually accumulate to a higher conccn- tration than ddt, especially if the use of dot is sharply curtailed in the U.S. ' The solubility of pen'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 acute toxicity. But as they slowly build up in a living system their con centration approaches toxicity levels,' at which point chronic effects make themselves evident. i It has been established that fish-eatJr ing birds will accumulate large concenS nations of pcb's, as in the case of the . f white-tailed eagle, which has been found to have as much as 14,000 p.p.m. of pcb'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 way as they accumulate dot and other chlorinated pesticides. Because of the low solubility of pcb'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 occurrence hours, they accumulated 1300 p.p.b. of pcb's, which represents a 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 pcB-frcc water for four days, 1 still had a concentration of 33,000 I The reason that pcb's have not been found in the ecosystem as extensively as ddt, and arc not present in environ mental samples at as high a concen tration as ddt, is that pcb's find their way into the environment accidentally. ddt is deliberately spread because this p.p.b. of pcb's, which constitutes a *- is the only way its insecticidal proper 3300-fold concentration. This means ties can be utilized, pcb's arc not in that even though the concentrations of tended to get into the environment, but pcb's are in the parts-pcr-billion range they do because their unique chemical in the environment, their high lipid properties prevent them from being de solubility causes them to collect in fatty stroyed by our usual waste disposal tissues of lower animals and marine methods. Thus, they inadvertently es life. Therefore, species at the top of a cape and become widely dispersed. food chain will also accumulate pen's In Sweden, where the use of dot in their bodies, particularly in their has been banned, and where the main lipid tissue and liver, in much the same power source is hydroelectric, investi gators find that die concentration of pcb's in the environment is as high as that of ddt. There are several ways by which pcb's get into the ecosystem. One of these is by incineration. Products con taining pcb's, such as carbonless re producing paper in business forms, 'plastics (especially polymer film and sheeting that contain pcb's as plasti cizers), spent ballasts from fluorescent light fixtures, and objects coated with PCB-formulated coatings, all find their way to the city dump or incinerator for burning. The pcb's do not bum but are 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 become widely dis tributed throughout the global environ ment. Another source is probably land run-off from industrial wastes and dumps. A third source is the point of manufacture and the plants where pen's are processed into other products. They can escape through the plan: ven tilation and exhaust systems into the atmosphere and through its waste treat ment system into sewers or directly into waterways. ^ 118 Environmental Science & Tccttnology TJ * Ji"a _.4*5.LI1 DSVV 282670 STLCOPCB4063999 fi4t*fcier:s ct~. d*romalonpfcy; to, separate? - What is the fate of pen's in hat- 'Jcticc of rcn's In environmental snnt-^~~rm's frodf chlorinated pesticides. At a'" _urnl walers? More needs to be known pi.-< is highest in industrialized andnr-. . recent -meeting. sponsored by-tho-- -of. their partition coefficients between banizcd areas. Biol* whose primary___ pwqa's National Water. Quality Lab-__; . bottom sediments and water. This is habitat is the San Francisco Bay area _' -oratory, Duluth, Minn., a general pro- vital if we arc to estimate how long it have a larger concentration of pen's - ccdure was recommended for separa- will take for a river bed to dean itself per unit of body weight than those lo tion of pcb's from pesticides. In this of contamination. It will also be useful cated in Baja, Calif., which is com-: ~ procedure for biosamples, the sample when assessing the effects of pcb's on plctely rural. Aquatic life in the Archi ' is extracted with hexane as in regular marine life that feed on the bottoms of pelago of Stockholm, the most indus pesticide analysis. It is then partitioned lakes, rivers, and estuaries. We should trialized area of Sweden, were found with acetonitrile to remove fats, the also learn more about pcb solubility in to have a higher concentration of pen's clcancd-up extract is passed through a water of various ionic strengths. than fish samples taken from the west Fluorisil Column and then through a * Are present waste treatment sys- ern coast of Sweden, a less developed - silicic acid column. Finally, the sample terns adequate to handle pcb's? Do spe area. Sediment samples taken from ' is analyzed by gas chromatography, cial measures need to be taken when southern portions of Lake Michigan with a chloride-specific detector, in this pcb's are part of the waste effluent be have a higher concentration of pea's way the pesticides are retained on the ing treated? than those from other parts of the lake. silicic acid column for later elution and By trying to get some of these an Monsanto states that until a recent identification. . swers now, we may find that we are in change in marketing policy (see inset, a position to control the escape of page 814), sales of Aroclors were in creasing at the rate of 8% per year. Research needs pcb's into the environment before ad ditional damage is done. So frequently, While this increase does not seem sig To assess fully the significance of action is taken only after it is evident nificant, it may be important if the in pcb's as environmental pollutants, ad that massive damage has resulted from creased consumption was in consumer ditional research is needed. No one a particular pollutant In the case of products and thus would find their way really knows the extent of the chronic the pcb's we may have an opportunity into our normal solid waste disposal effects of these chlorinated hydrocar to resolve the situation before that systems. Such an occurrence would bons. Some problems that need to be happens. - mean a definite increase of pcb residues considered are: m the environment, and therefore a Although pcb's are known to ac marked increase in their chronic tox cumulate in human organs we do not icity effects. . know at what concentration they will Detection.. -~ - begin to exhibit toxic effects. Will these chronic effects be. similar to those. pcb's were not discovered irfenviron-;' .shown' in"-'animals--microsoqpd en- mental samples until very recently for -'zyme'activity, calcium metabolism in- several reasons. First, as indicated'; * hibition, and so on? What are other above, they have not been deliberately possible chronic effects? . . Additional Reading Hubbard, H. L, "Chlorinated Biphenyl and Related Compounds," Encyclo pedia of Chemical Technology, 2nd ed., 5, Interscience' Pub!., New York, N.Y., 1964, pp. 289-298. Reynolds, L M., Bull. Environ. Contain. Toxicol. 4,128 (1969). Risebrough, R. N., et. a/.. Nature 220 (1968). distributed about the ecosystem/ Sec Which of the -many pcb com ondly, because of their relatively low . pounds in the commercially available acute toxicities, their presence was not mixtures are responsible for their tox immediately evident. Finally, they are difficult to detect analytically. icity? Can commercial pcb mixtures be modified to eliminate the toxic com The pcb's were first detected as in terfering peaks in the gas chromato ponents? Pure samples are required to answer these questions. At the present graphic analysis (gc) of environmental /time work is continuing at the fwqa's samples being analyzed for chlorinated Southeast Water Laboratory to sep pesticide residues. When pcb's are pres ent in a sample they give a pattern of several cc peaks, whose retention times are similar to those of dicldrin, dot, ooe. aldrin, and heptachlor oxide. Be cause the peaks were not large or sharp, investigators tended to ignore them until S. Jensen, in Sweden, and X. Riscbrough. at the University of California at Berkeley, identified them * corresponding to common constitu ents of environmental samples being arate each of the Aroclor mixtures into its many components, and to identify each component. . * We need to know all the uses for the pen's. What is the annual produc tion of pcb's? Our knowledge of these facts is limited and needs to be 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. Carl G." Gustafson, chairman of the Department of Chemistry of King's College. BriarclifJ Manor. N.Y., re ceived a Ph.D. in organic chemistry from the University of Delaware in 1957. During the 1969-70 academic year, he was on leave at. the fwqa Southeast Water Laboratory in Athens. "alyzed for persistent pesticides. The problem of the. interferences of * In view of the complexity of the isolation and accurate quantitative Ga.. where he studied trace organic analysis in waste effluents. As a mem w:th the analysis of other chlori `--c`l l^siicidcs has been largely over , come by prior treatment of the sam- analysis of pen's in chlorinated resi dues, a straightforward, unambiguous measurement of them needs to be de ber of the National Water Contami nants Charactcrizjntion Research Pro gram, he worked with pcb's and pulp y'*' Several investigators have used veloped and paper mill effluents. *3!*"J* 'JUJWfnM'fvHaup DSW 282671 Volume 4. Number 10, October 1910 S19 CTPsar <". je~ STLCOPCB4064000