Document x5eJB1ee0Byz9xaY8RjVV79Gg

BY KEVIN P. SHEA \ The worldwide pollutant that nobody noticed. Nftvwnb* ItJJ* THE FOLYSTY RENE COFFEE cup you used thss morning, plastic liners for baby bottles, frozen-food bags, bread wrappers, and many other products which come into contact with food contain PCBs, or polychlor inated biphenyls. While recently issued federal standards restrict these toxic materials to much less than 1 part per million in most foods, PCS concentrations in the food containers just named have been measured at s high as 6.6 parts per million. No one knows whether these PCBs leach out into the milk held by baby-bottle liners or the coffee held in polystyrene cups; this is just the latest in a long senes of riddles surrounding the use of PCBs. Polychlorinated biphenyl compounds had been in use for 36 years before their discovery in 19661 in the flesh of fish from the Baltic Sea set in motion an intensive worldwide research effort to determine the extent of their distribution tn ecological systems and the possible danger their distribution may pose to human health- Since their belated discov ery as important global pollutants, PCBs have chalked up an impressive record of finding their way into human food chains, sometimes by totally unexpected routes, and have been responsible for huge economic losses in the food industry and, at least in one case, for a serious epidemic of human poisoning. Although important steps have been taken to ' prevent such episodes from recurring, there remain a number of ques tions to be answered regarding the uses of PCBs, their effects on biological systems, and their routes of entry into the environment. Oddly, it was the experience gained in the pursuit of information about another group of environmental contaminants, the chlorinated synthetic pesticides (DDT and'its relatives), that both helped and hin dered in tracking down the various pathways through winch PCB might enter and spread throughout ecological systems. By the middle 1950s analytical techniques had been developed (gas chromatography) iliat were able to detect very small amounts of environmental contaminants Analytical chemists, however, could not, with any certainty, identify a particular compound unless they knew precisely what they were looking for. In the case of DDT. for example, they could compare known samples of DDT with results obtained from chromatographic analysis of environmental samples. In 1964 the Swedish Royal Coi*'*">ion on Natural Resources em- MONS 208549 25 ployed Dr. Sorcn Jensen of Ihe Univer sity of Stockholm to begin a study of chlorinated pesticides in the Swedish en vironment. it was dunnf this study that Dr, Jensen and his colleagues began to ee evidence on their chromatograms of several substances totally unknown to them but apparently related to the chlo rinated pesticides.1 At first it was thought that the compounds might be unidentified breakdown products of chlorinated pesticides. To check this idea. Dr. Jensen collected from the Swedish Museum of Natural History feathers from specimens of the whitctoiled eagle for each year dating back to llll By this technique it was learned that Ihe unknown compounds first oc curred in feathers in 194 2 and could therefore not be chlorinated pesticides or their breakdown products. It was not until two years later, after a great deal of detective work, that the contamin ants were fully verified is polychlorin ated biphenyls. Part of the problem in identifying PCBs was the difficulty during analysis of separating DDT residues from those of PCbs. With analytical equipment widely used until 1965, the identity of certain PCB compounds and one of the breakdown products of DDT could easily be mistaken for caeh other In Dr. Jensen's opinion it is quite likely that many ddt analyses made prior to 1965 could have been wrong. However, since 1966, with a steady improvement in analytical methods and a rapidly grow ing interest in the biological activity of rest, it has now been established that pegs are among the most abundant, persistent, and widely dispersed environ mental contaminants A comparison of production figures for the U S alone shedi some light on the selsttve importance of DDT and pegs During the period |9dJ to lp6>, U.S. production of DDT was about 933 million pounds ' It tt certain that nearly all of that production was sprayed into the environment somewhere in the world. During the years 1930 to 1970, total U.S. production of PC as was ap proximately .one biltiOM pounds, of which, it hat been estimated, 7B0 mil lion pounds has entered the environ ment via the atmosphere, water system, and dumps,* Add to these figures the production of PCbs in Europe, Russia, and Japan, and the total amount of pegs entering the environment on a global basis may approach that of DDT, Japan, for instance, produced 114,660.000 pounds of PCBa between t9$4 and 1971. Physiological Effects While the amounts of Peas and DDT released to the environment may be wnt- 26 - liar, other information indicates that PCSs may be the most important in terms of ecological damage. First, I'Ctts seem to be far more stable - that is. because of their chemical structure they are less susceptible lo being broken down by sunlight, water, and micro biological action thin are Ihe chlorin ated pesticides When DDT and I'CDs are added to an activated sewage sludge and are digested anaerobically, DDT is broken down, mainly to ODD and other compounds, within a few days Peg compounds, however, will remain intact activities such ss reproduction In the past, DDT has been implicated >n Ihe disruption of ihe reproductive cycle of some birds, and it is thought that the mechanism has something to do with hormonal Imbalance brought about by Ihe increased production of liver enzymes at the wrong time. PCDs have other effects on Ihe liver * In both Japanese quail and laboratory tats, dietary levels of 100 parts per mil lion (ppm) fed for two months resulted In enlarged livers, an increase in liver fats, and a sharply reduced liver content for as long as 40 days.* Anaerobic diges of vitamin A. In rats the decrease in tion in sewage sludge if one of the most liver vitamin A storage was 50 percent rigorous techniques Tor determining the that of untreated animals stability of a potential pollutant Other CuOtle physiological effects Another difficulty is that PCBs, have been observed in laboratory ani rather than being one specific chemical, mals fed various PCS compounds Inter are a mixture of a large number of close ference with the production of adeno ly related but different chemicals For example, a careful analysis of Aroelor 1254," a widely used commercial PCB sine triphosphatase (ATrase) in fish is a good example, A True is an enzyme which makes energy available for impor preparation showed that tt n actually tant biological reactions such as in Ihe composed of 69 different chemical structures. Nineteen of these structures production of proteins, muscle contrac tions, the conduction of nerve impulses, were considered major constituents of and flindular secretions.* At levels as the mixtura, while 50 were classified u low as 0.6 ppm, Aroelor 1242 inhibited minor constituents. For the most part, the ATPase system m bluegill tissue by analytical and toxteological studies have as much as 50 percent. been conducted with commercial PCB Still other effects that have been re preparations white little attention his ported include edema (ihe accumulation been given the individual chemicals that _ of fluids) of Ihe tissues surrounding the maka up these preparations, many of heart, porphyria (an abnormality of which may have unique toxicological blood pigment metabolism), thickening characteristics. of the skin, and a reduced resistance to Finally, while PCBa are not quite as certain kinds of parthogeme organisms poisonous at DDT when consumed oral When len-day-oid ducklings were fed ly. they do posseu similar ability to Aroelor 1254 at level* of 25, 50. and alter important biological functions. 100 ppm in their diet they suffered no Like DDT, pegs have been shown to be apparent clinical symptoms of poison potent inducers of liver enzymes in a ing, but five days later, when they were number of laboratory animals. That It, exposed to duck hepatitis vims, they when fed to laboratory animats in small suffered significantly higher rales of dose* they stimulate the liver to pro mortality than did birds that were given duce enzymes which then act on other the virus but wera not pre-exposed to body substrates. The dearest measure of PC BS.' . thu effect is that which occurs In PCB-treated rata when they are sub Food Coalaminatioo sequently given a barbiturate. A meas ured amount of phenobarbttol, for ex While a great deal of research is still ample, will produce a standard sleeping being conducted on the various sublethal tune in laboratory rats. The sleeping effect* of rcas on laboratory animals, time it a function of the rate at which the accidental presence of pcbi in liver enzymes break down the barbit human food and animal feeds remains urate to non-narcotic substances When Ihe most important aspect of thru dis rats are treated with a combination of tribution. Over the past few years a PCBs and barbiturates, sleeping time is number of incidents have been recorded greatly reduced becauie of the increased in which significant quantities of pc ds enzyme activity brought on by the have contaminated human food Most presence of Peat in the liver, ` of these incidents were preventable, but The metabolism of barbiturates is of In some eases it is still a mystery is lo no importance to laboratory animals, what was the source of contamination but the enzymes induced by this effect In December 1970 Ihe Campbell are the same ones that metabolize eer- Soup Company of Camden, New Jersey, tain hormones and thereby regulate through a routine monitoring program important physiological functions. Their discovered excessive PCB residues (up to overabundance in the liver at eertein 261 ppm) in chickens grown tn New times could cause serious disruptions of York Slat*. The state of New York emicenmeot, Vot is. No, I M0NS 208550 U!:-,'1 * * mm >i ret, *t>i iwa ia I IvtKeyt me clue amt m ttvttii citti at tn ra| Ml at tanlamlaatta lute. U \/J~ \Jl 1 placed a quarantine around a threecounty area and required pretesting be fore daughter of all chickens originating from that area. As an interim guideline the Federal Food and Drug Administra tion (FRA) agreed to allow normal mar keting of all chickens containing less than S ppm fcb. On the bant of the pretesting program 140.450 chickens were slaughtered and buned. The source of contamination in this case was thought to be ptashc wrappers on stale bakery goods that were ground, wrapper and all, for use as s feed In July of 197], Holly Firms of Wilkesboro, North Carolina, notified personnel of the Melt tnd Poultry In spection branch of the U.S. Department of Agriculture that (hey had been alerted lo a fcb problem by a decrease in egg hatchability (a typical rc8-poi soning symptom) id their poultry opera tion The sourt-c of Hie contamination was traced to a fish meal pasteurization plant in Wilmington, North Carolina, where a leaky heating system was drip ping Aroclor 1242 into the finished product. The leak began in April 1971 and continued through July. A total of 12,000 tons of feed wen contaminated, and more than 2,000 tons were recalled by (he company. In the meantime, broiler and egg producers suffered tre mendous losses as a result of contamin ated meat and eggs. A single producer was forced lo destroy 66,000 broilers, and 123.750 pounds of eggs were re moved from |lie market. In Augusl 1971, Swift and Company and I he Department of Agriculture noti fied the FRA of excessive levels of rci found in turkeys in Minnesota. Over 100 flocks m Minnesola. North Dakota, and South Dakota were tested, but only the flock In which the original discovery was made showed high residues (20 ppm). In (his esse, over one million tur keys approaching market weight were held off the market until the residue levels were reduced to less than 5 ppm. The source of the eonlaminant was not determined. In a routine food surveillance pro gram, Baltimore health authorities dis covered excessive rce levels in milk, and (he dairy farms Involved were taken out of production by state officials. An Investigation revealed that the source was spent transformer fluid (a major use of FCBs) used as a carrier for a herbicide sprayed on a power line nght-of-way near Martinaburg, West Virgtnia, Finally in Ohio, Florida, and Georgia, contamination of milk was iraeed to a FCB-containing sealant used to seal the inside of silos. The silo coat ing was composed of 11 percent FCB, soma of which hed migrated into tne silage and was subsequently consumed by dairy cattle. Yusho Disease While North Americans have so fsr avoided a massive outbreak of human poisoning from FCB-conlaminated food, Japan has not been so lucky In October 1966 s number of reports of a skin disease similar in appearance to chloracne (a disease often observed in work ers who handle FCBs and other chlorin ated aromatic compounda) began to appear in Fukuoka perfecture in west ern Japan. It wasn't long before twenty other perfectures in the same general ares also began reporting similar eases, and it was soon apparent that a full blown epidemic was underway.' Aside from the symptoms of chloracna, which include acne-tlke skin eruptions and ex restive pigmentation of the skin, patients afflicted with the disease suffer ed from increased eye discharges, swelling of the upper eyelids, headaches, vomiting, diarrhea, fever, visual distur bances, and a number of other un pleasant effects A learn of specialists in medicine, pharmacology, agriculture, and engineering was quickly assembled faculties of (he University of and the cause of (he massive [1,057 patients had been re- 1971) was soon discovered carefully interviewing hnth in `; suffering from the disease and number of healthy individ- was found Ihsl of 60 personal traits used lo compare healthy and affected individuals only one (ran. (hat of eating fried foods or tempura daily, differed greatly between healthy and stricken people It was also discovered that 96 pereenl of the diseased individ uals eame from households where a nce-bran oil produced by s company in Kitakyushu City ind known as K rice oil was used regularly. Further investiga tion showed that 143 of 1SS patients who had used the oil purchased it from a lot (hit had been produced and shipped between February 5 and IS. 1966. Finally, analysis of some of the recovered K nee oil showed that it con tained from 2,000 to 3,000 ppm of Kanechtor 400, a Japanese produced FCB that was used in the heating system at the K rice oil production plant in Kitakyushu City Since the cause of the outbreak was discovered the disease has been known as "Yusho" or oil disease Ihe effects of this outbreak are still evident tn Japan. By the summer of 1970 half of a closely studied popula tion of 159 individuals seemed to be improving, while the other half showed no improvement, and 10 percent teemed to be worsening There is also soma evidence lhat babies born lo women who had consumed the contam inated oil while pregnant exhibit some of Ihe symptoms of Yusho. Thirteen women, eleven of them suffering from Yusho, and two who had no symptoms but had consumed some K oil. gave birth to ten live born and |wo stillborn children between February and Decem ber of 1966 Nine of the len children showed positive signs of Yusho. and Japanese authorities plan cxlensivc fol low-up studies of ihe children to delect any physical or menial impairment (hat may develop in Islet years Ironically, six months prior lo Ihe outbreak of Yusho, Japanese health authorities hid s dear warning (hat such an epidemic was possible. Beginning in Februwy an epidemic of chick edema ntovamber leys HONS 208551 27 disease occurred in the umt western Japan perfecture. More than I wo million chicken* were involved and over 400,000 died. The cause of the disease proved (o be PCB-conlammated feeds made by two feed manufacturers that had purchased "dark oil" for use as an Ingredient in (heir producta. The "dark oil" was produced by the same com pany (hat produced the poisonous K rice oil implicated in the outbreak of Y uslio. Regulating PCUs Since the repeated episodes of food con tamination and the outbreak of Yusho in Japan, a number of actions have been taken both by government agencies and (he major manufacturer of rCBs in the U.S., the Monsanto Chemical Company, to prevent further incidents Before 1971. about 40 percent of (he PCS compounds produced in the ll.S. were used In applications where losses to the environment were probable These included plasticiser*, lubricants, hydraulic fluids, carbonless carbon paper, and adhesives.1 Since that lime, however, Monsanto has agreed (o sell rCB compounds for use only in closed systems from which spent reus are theoretically recoverable The company has also constructed a htgb-lempcrature Incinerator, in which Monsanto will destroy spent PCBs for customers that purchase large amounts of the materials for use In electrical transformers and capacitors The expense of shipping (he materials (o the company and (he cost of incineration must be paid for by (he customer. In January 1973 (he National Elec trical Manufacturers Association pub lished (heir "official guidelines" for handling end disposing of capacitor and transformer grade rcB compounds. In the guidelines seven different locidons for disposal of pcb compounds were listed, two of which have high-temperalure incinerators. The other five are described as having "scientific landfills*' for PC B disposal. In ons facility at Shef field, Illinois, the disposal system was described in a telephone conversation as an open pit into which contained hagardous chemicals are placed and then covered with soil. 'While placing spent PCBs in landfill* is far cheaper than in cineration at high temperatures, the security of materials handled in this way is open to question In 1970 slone, 36 million pounds of I't'os were disposed of in dumps and landfills, and in 1972, sales of pcos for use in transformers and capacitors were expected to be an additional 50 to eO million pounds. Since high temperature incineration is expensive and limited ((he Monsanto inctnerstor has an annual maximum 28 - capacity of one million pounds) it is likely that much of this production will eventually be disposed of in landfills To prevent further contamination of food and animal feeds, the fda recent ly (July 6) issued regulations placing restriction of the use of pens in the manufacture of food and feeds and also issued tolerance limits On the amount of pcos that are acceptable in food as un avoidable contaminants' * The new regulations forbid the use of PCBs for use in new equipment in food processing plants and require PCBs used in old equipment to be replaced with non-PCB-contatning materials PCBs are also to be eliminated from surface coat ings and lubricants used for handling or processing food Similar regulations were to go into effeet by September 4, 1973, for plant* processing or handling animal feed*. Restrictions were also placed on equipment used to manufacture paper food containers and a tolerance limit of 10 ppm was placed on paper materials intended for use in packaging both human and animal foods Manufacturers of plasttc food containers were also in cluded in the regulations excluding pens from use in equipment used to manufacture food wrappings, but no tolerance on plastic wraps was set The regulations specifically point out that no PCBS whatever are allowable in plastic food wraps either by purposeful or accidental introduction. The new FDA regulations. If strictly enforced, will almost certainly reduce human exposure to PCBs from accident al contamination, but they are unlikely to have an immediate effect on unavoid able contamination from environmental sources. For that reason the FDA has also established tolerance limits for foods and animal feeds in which s cer tain amount of PCB contamination Is inevitable because of the elready existing amounts of PCBs in the environment. The tolerance limits are- milk, 2.5 ppm (fit), finished dairy products, 2 5 ppm (fat), poultry, 5 ppm (fat); eggs, 0.5 ppm; finished animal feeds, 0.2 ppm; animal feed components, 2.0 ppm (fish meal, and so on); fish and shell fish, 5 ppm. One area the regulation! do not cover, however, is containers and wraps for home use. Whether or not there is widespread contamination of these materials is not known, but an analysis'1 3of a number of such items in 197) indicates that it is quite likely The following levels were found in various plastic containers other than commercial food wraps' a plastic bag, 2.4 ppm; a plastic bottle used to contain an eyewash, 3.7 ppm; a polystyrene cup, 6.6 ppm, a baby-bottle liner, 2,7 ppm; e froien-food bag, 4 8 ppm; e .ad wrap, 3 2 ppm, a sheet plj-ilie wrap, 3,7 ppm. None of these items are included in the regulations covering food wraps, and since none of the materials are actually plasticircd with PCBs it is likely that the contamination is a result of various rcu uses in the processing machinery, A further complication in tracking down all sources of human exposure is the fact thal Fens are now manu factured in Great Britain. France. Ger many, (ha Soviet Union, Japan. Spain, Italy, Czechoslovakia, and the United States. It it virtually impossible at this time to determine whether or not fin ished eoftsumer items that might lead (o human exposure are being imported into the ll.S., but (he FriA plans to investigate this possibility in the future While both regulatory and voluntary actions were tong in coming, they wilt quite likely reduce (he immediate hasards associated with PC us both to human beings and ecological systems On the other hand, because of the enor mous amounts of PCBs already cir culating in the environment, it w,u be some time before they will be con sidered insignificant contaminants. n NOTES I ''RiKd of i Ntm Chemical Nitr4," Ne# Scientist, Doc. 1$. I9(. 2. J*ncen. S . "To* PCS Story," Ambit, vot. I, no i. 1*72. 3. Mclnfirv, G., "SooOed bv Succtii,4*S. * * * * * * 12 fnv+renment, vet 14. no 4, 19*2 Frost, Juttln. A*rp Willf." Cftvtroomonl. vol. II. no. I. 19(9. 4 Nlibel. t. C. T., |fl0 A. F SiroMm/'Riln end Route* of Tfintpojl oi PCB'i In the en. ylrenment " environment*! Health Pertoee* live*. eaparimenui litue no I. Apr 1972. 5 SUion. O. end D wane, "Slruciu'ai iden ttriqjlion of Polychlorinated Biphenyls in Commercial Miniurei by Cat LJovid Cnrome* loyrapny, Nuclear Magnetic Resonance and Man Spectrometry, 1 Jowrnif of Cnromatof* rephy, (0 13-32, 1971 t. Bitman, J., M. C. Cecil, end S J Harrti, *'BlolQflcet Meet* of Potychto<lnel*d Biphenyl* in Rati and Quail," Environmental Ha aftn Fartoeatwt, Aor 1972 p |4 7 7. Cutfcamp, L. K., H H Yap, D Oemah, and R. B. Koch, "The Sentll*vly ol Fish ATPimi le PolyChlortntled Bphenyig " Cntrirenmental Health Penoective*. Apr |97Z. p. 1(5- S. Fiaund, M., and D. O. Trainer. "Poly* chlorinated Biphenyl ini'*citon wim Dvcn Hopaltiuf Vlrui," Science. UO till I97Q. 9. Kuretwne, M., T. Voinimura, J Mario*. ah, end A. Yamagucht, "Ei>0em*oio9`cei Study of Yusho, a Poltcminy Caused by inyei lion el Rice Oil Contaminated vrUh e com merclal Brand of Polychlorinated 0oftenyit,ia Environmental HiiUn r^tpictlvti, pen* mental iwu no l,Ar 19 72. |0 "PCB't and |he environment.*' an inter department Taut Force Report on PCS i, report no ITF-PCB 7? 1. NTiS, Oeoi o Commerce, Waihlnyton, DC. 1972 Jl. Federal HefUter. Jury 6, 1*73. p 1109* 12, Ptepp, Frederick, perion** com. munlcettoft, Teeet ASM univerilty, Co in?* Sullen. From an addreii lo me emomcn lepicet (octet* or America, LoAneia* Dec, 1*71. CMkanmen* voi 1 i No, * HONS 206552