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BY KEVIN P. SHEA !j .> The worldwide pollutant that nobody noticed. HWBIBlB THE POLYSTYRENE COFFEE cup you used this morning, plastic liners for baby bottles, frozen-food bags, bread wrappers, and many other products which come into contact with food contain rcis, or polychlor inated biphenyls. While recently issued federal standards restrict these toxic materials to much less than 1 part per million In most foods, PC* concentrations in the food containers just named have been measured at as 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 series 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 in 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 hae 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 which PCB might enter and spread throughout ecological systems. By the middle 1950s analytical techniques had been developed (gas chromatography) that 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 D DT with results obtained from chromatographic analysis of environmental samples. . In 1964 the Swedf-U Roval Commission on Natural Resources em- HONS 069035 2ft ployed Dr. Sorrn Jensen of the Univer sity of Stockholm to begin study ol chlorinated pesticides in the Swedish en vironment. It was during this study that Dr. Jensen and his colleague* began to see evidence on their chromatograms of several substances totally unknown to them hut apparently related to the chlo rinated pesticides.* At first It was thought that the compounds might be unidentified breakdown products of chlorinated pesticides. To cheek this idea. Dr. Jensen collected from the Swedish Museum of Natural History feathars from specimens of the white tailed eagle for each year dating back to 188$. By this technique it was learned that the unknown compounds first oc curred in feathers in 1942 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 ss 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 PC 8 compounds and one of the breakdown products of dot could easily be mistaken for each other. In Dr. Jeaaea'a opinion it is quite likvly that .many DDT analytes 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 PCSa, it has now been established that PCBs sre among the most abundant, persistent, and widely dispersed environ mental contaminants. A comparison of production figures for the U.S. alone sheds some light on the relative importance of DDT and PCBs. During the period I94S to 1968, UA production of DDT was about 933 million pounds.* It is 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 PCBs vu ap proximately one billion pounds, of which, it has bean estimated, 780 mil lion pounds has entered the environ ment via the atmosphere, water systems, and dumps.4 Add to these figures the production of PCBs In Europe, Russia, and Japan, and the total amount of PCBs entering the environment on a global basis msy approsch that of DDT. Japan, for instance, produced 114,660,000 pounds of PCBs between 1954 and 1971. Physiological Effects While the amounts of pcbs and DDT released to the environment may be elm- 26 ^ ilar, other information indicates that PCBs may be the most important In terms of ecological damage. Pint, PCBs seem to be far more stable - that is. because of their chemical structure they are leu susceptible to being broken down by sunlight, water, and micro biological action than are the chlorin ated pesticides. When DDT and pcbs are added to an activated sewage sludge and are digested anaerobically, DDT is broken down, mainly to DDD and other compounds, within e few days, pcb compounds, however, wilt remain intact for u long u 40 days.* Anaerobic diges tion in sewage sludge is one of the moat rigorous techniques for determining the stability of a potential pollutant. Another difficulty Is that PCBs, rather than being one specific chemical, are a mixture of a large number of close ly related but different chemicals. For example, a careful analysis of Aroclor 1254,* a widely used commercitl PCB preparation showed that it is actually ' composed of 69 different chemical structures. Nineteen of them structures were considered major constituents of the mixture, while 50 were classified as minor constituents. For the most part, analytical and toxicological studies have been conducted with commercial PCB preparations while little attention has been given the individual chemicals that make up these preparations, many of which may have unique toxicological characteristics. Finally, while pcbs sre not quite as poisonous at DDT when consumed oral ly. they do possess similar ability to alter important biological functions. Lika DDT, PCBs have been shown to be potent inducers of Uver enzymes in number of laboratory animals. That it, .when fed to laboratory animals in small dosea they stimulate the liver to pro duce enzymes which then act on other body substrates. The clearest measure of this effect it ttut which occurs in PCB-treated rets when they are sub sequently given a barbiturate. A meas ured amount of phenobsrbitol, for ex ample, will produce standard sleeping time in laboratory rata. The sleeping time is a function of the rate at which liver enzymes break down the barbit urate to non-narcotic substances. When rats are treated with e combination of pcbs and barbiturates, sleeping time is greatly reduced because of the increased enzyme activity brought on by the presence of PCBs in the liver. The metabolism of barbiturates is of no importance to laboratory animals, but the enzymes induced by this effect are the same ones that metabolize cer tain hormones end thereby regulate Importent physiological functions. Their overabundance in the liver at certain times could cause serious disruptions of HONS 069036 normal icthiljes such a reproduction. In the past, DDT has been implicated in the disruption of the reproductive cycle of some birds, and it is thought that the mechanism has something to do with hormonal imbalance brought about by the increased production of liver enzymes at the wrong tints. PCBs have other effects on the liver.* In both Japanese quail snd laboratory rats, dietary levela of 100 parts per mri- lion (ppm) fed for two months resulted in enlarged livers, an increase in liver fats, and a sharply reduced liver content of vitamin A. In rats the decrease in Uver vitamin A storage was 50 percent that of untreated animals. Other subtle physiologies! effects have been observed in laboratory ani mals fed various PCB compounds. Inter ference with the production of adeno sine triphosphatase (ATPase) in fish is a good example. ATPase is an enzyme which makes energy available for impor tant biological reactions such as in the production of proteins, muscle contrac tions, the conduction of nerve impulses, and glandular secretions/ At levels ss low as 0.6 ppm, Arodor 1242 inhibited the ATPase system in blucpll tissue by as much as 50 percent. Still other effects that have been r* ported include edema (the accumulation of fluids) of the tissue* surrounding the hesrt, porphyria (an abnormality of Mood pigment metabolism), thickening of the skin, and a reduced resistance to certain kinds of parthogenic organisms. When ten-day-old ducklings were fed Aroclor 1254 at levela of 2S, 50, and 100 ppm in their diet they suffered no apparent clinical symptoms of poison ing, but five days later, when they were exposed to duck hepatitis virus, they suffered significantly higher rates of mortality than did birds that were given the virus but were not prewxpoaed to PCBS.' . Food Contamination While a great deal of research is still being conducted on the various sublctha! effects of PCBs on laboratory animals, the accidental presence of pcb* in human food and animal feed* remains the most important aspect of their dis tribution. Over the past few years a number of incidents have been recorded in which significant quantities of PCBs have contaminated human food. Most of these incidents were preventable, but in some cases it is still a mystery ss to what was the source of contamination. In December 1970 the Campbell Soup Company of Camden, New Jersey, through a routine monitoring program discovered excessive pcb residues (up to 268 ppm) in chickens grown in New York State. The state of New York ' Imlrcmmnl, Voi IS, No. lull ff MndmiMtH line placed a quarantine around a three* county area and required pretesting be* (oat slaughter of all chickens originating from that area. As an interim guideline the Federal Food and Drug Administra tion (FDA) agreed to allow normal mar keting of all chickens containing leu than 5 ppm PC>. On the basis of the pretesting program 140.4S0 chickens were slaughtered and buried. The source of contamination in this case was thought to be plastic wrappers on stale bakery goods that were ground, wrapper and all, for use as a feed. In July of 1971, Holly Farms of WUkesboro, North Carolina, notified penonnel of the Meat and Poultry In fection branch of the U.S. Department of Agriculture that they hed been alerted to a pcs problem by a decrease in egg hitchability (a typical PCB-poi- toning symptom) in their poultry opera tion. The source of the contamination was traced to a fish meal pasteurisation plant in Wilmington, North Carolina, where a leaky heating system wss drip ping Arodor 1242 into the finished product. The leak began in April 1971 and continued through July. A total of 12,000 tons of feed were contaminated, and mora than 2,000 tons were recalled by the 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 to destroy Sg,000 broilers, and 123,'750 pounds of eggs were re moved from the market. In August 1971, Swift and Company and the Department of Agriculture noti fied the PDA of excessive levels of pea found in turkeys in Minnesota. Over 100 flocks in Minnesota, North Dakota, and South Dakota were tested, but only the flock in which the originel discovery keys approaching market weight were held off the market until the residue levels were reduced to less then 5 ppm. The source of the contaminant was not determined. In a routine food surveillance pro gram, Baltimore health authorities dis covered excessive PCI levels in milk, and the dairy farms involved were taken out of production by etate officials. An investigation revealed that the source was spent transformer fluid (a major use of pens) used as a carrier for a herbicide sprayed on a power line right-of-way near Martinsburg.West Virginia. Finally, in Ohio, Florida, and Georgia, contamination of milk was traced to a PCb-containing sealant used to seal the inside of silos. The silo coat ing was composed of 11 percent pci, some of which had migrated into the silage and was subsequently consumed by dairy cattle. Yusho Disease While North Americans have so far avoided a massive outbreak of human poisoning from PCB-contsminated food, Japan has not been so lucky. In October 1968 a number of reports of a skin disease similar in appearance to chloracne (a disease often observed in work ers who handle pens and other chlorin ated aromatic compounds) begsn to appear in Fukuoka perfecture tn west ern Japan. It wasn't long before twenty other perfectures in the same general area alto began reporting similar cases, end It was soon apparent that a full blown epidemic was underway.* Aside from the symptoms of chloraene, which include acne-like skin eruptions and ex cessive 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 team of specialists in medicine, pharmacology, agriculture, and engineering was quickly assembled from the faculties of the University of Kyushu, and the cause of the massive outbreak (1,057 patients had been re ported by 1971) was soon discovered. By carefully interviewing both in dividuals suffering from the disease and a matched number of healthy individ uals, it was found that of 60 personal traits used to compere healthy and affected individuals only one trait, that of eating fried foods or tempura daily, differed greatly between healthy end stricken people. It was also discovered that 96 percent of the diseased individ uals came from households where a rice-bran oil produced by a company in Kitakyuahu City and 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 that had been produced and shipped between February 5 end 15, 1968. Finally, analysis of some of the recovered K rice oil showed that it con tained from 2,000 to 3,000 ppm of Kanechlor 400, a Japanese-produced res that was used in the heating system at the K rice oil production plant in Kitakyushu City. Since the eause of the outbreak was discovered the disease has been known as "Yusho" or oil disease. The effects of this outbreak are still evident in 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 seemed to be worsening. There is also some evidence that babies born to women who had consumed the contam inated oil while pregnant exhibit some of the 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 two stillborn children between February and Decem ber of 1968. Nine of the ten children showed positive signs of Yusho, and Japanese authorities plan extensive fol low-up studies of the children to detect any physical or mental impairment that may develop in later years. Ironically, six months prior to the outbreak of Yusho, Japanese health authorities had a clear warning that such an epidemic was possible. Beginning in February an epidemic of chick edema Nevemier 1C7I HONS 069031 27  occurred in (he tame western capacity of one million pounds) It la Jtpan pcrfcclutc. More than two million likely (tut muck of tkif production will chickens were invoiced end over eventually be disposed of in landfills. 400,000 died. The cause of the disease To prevent further contamination of prowd to Ire fCKontaminaled feeds food and animal feeds, (he fda recent mads by two feed manufacturers that ly (July 6) issued regulations placing had purchased "dark oil" for use as an ingredient in their products. The **drk restriction of the use of Peas in the manufacture of food and feeds and also otT wu produced by the same com* peny that produced the poisonous K issued tolerance limits on the amount of PCBs that are acceptable in food as un rice oil implicated in the outbreak of avoidable contaminants.11 Ytuho. The new regulations forbid the use of PCBs for use in new equipment in food Rffolatinj PCBs processing plants and require PCBs used in old equipment to be replaced with Since the repeated episodes of food con non-PCB-contiining materials. PCBa are tamination and the outbreak of Yusho also to be eliminated from surface coat in Japan, a number of actions have been ings and lubricants used for handling or taken kotyoLJMBtBMnt agencies and processing food. Similar regulations the *40 |BfflHrf*l>t`1,*2>*o4f*p*e7n*s*i1n0t1h1e12 were to go into effect by September 4, U.S., tfa Hopunto Chemical Company, 1973, for plants processing or handling to prevent further incidents. animal feeds. . afore 1971, about 40 percent of the Restrictions were also placed on PCS compound* produced in the U.S. equipment used to manufacture paper ware used in applications where losses food containers and a tolerance limit of to the environment were probable. 10 ppm was placed on paper materials These included plasticizers, lubricants, intended for use in packaging both hydraulic fluids, carbonless carbon human and animal foods. Manufacturers paper, and adhesives.1 * Since that time, of plastic food containers were also in however, Monsanto has agreed to sell cluded in the regulations excluding PCI compounds for use only in dgvA PCBs from use in equipment used to ysterns from which spent Peas are manufacture food wrappings, but no fheorehcaily recoverable. The company tolerance on plastic wraps wss set. The has also constructed a high-temperature regulations specifically point out that hdntttljM, In which Monsanto will no PCBs whatever are allowable in destroy tpent pens for customers that plastic food wraps either by purposeful porches* large amounts of the materials or accidental introduction. for use in electrical transformers and The new FDA regulations, if strictly capacitors. The expanse of shipping the enforced, will almost certainly reduce materials to the company and the cost human exposure to PCBs from accident of incineration must be paid for by the al contamination, but they are unlikely customw In January 1973 the National EJec- to have an immediate effect on unavoid able contamination from environmental Meal Manufacturers Association pub- sources. For that reason the fda has ttehed their "official guidelines'* for also established tolerance limits for handling and disposing of capacitor and foods and animal feeds in which a cer transformer grade PC a compounds. In tain amount of PCB contamination is , the guidelines seven different locations inevitable because of the already existing for disposal of PCa compounds were amounts of PCBs in the environment. listed, two of which have high-tempere- The tolerance limits are: milk, 2.5 ppm tore Incinerators. The other five are (fat); finished dairy products, 2.5 ppm described as having "scientific landfills" (fat); poultry, 5 ppm (fat); eggs, 0.5 for PCS disposal. In one facility at Shef ppm; finished animal feeds, 0.2 ppm; field. Illinois, the disposal system was tnimal feed components, 2.0 ppm (fish described in a telephone conversation as meal, and so on); fish and shell fish, S an open pit into which contained haz ppm. ardous chemicals are placed and then One area the regulations do not eovered with soil. While placing spent cover, however, is containers and wraps PC9S in landfills is far cheaper than in- for home use. Whether or not there is einsration at high temperatures, the widespread contamination of these security of materials handled in this way materials is not known, but an .k open Co question. In 1970 alone, 36 analysis1' of l number of such items in million pounds of pcds were disposed 1971 indicates that it is quite likely. of in dumps and landfills, and in 1972, . The following levels were found in sales of Pda for use in transformers various plastic containers other than end capacitors were expected to be an commercial food wraps: a plastic bag, additional SO to 60 million pounds. 2.4 ppm; a plastic bottle used to contain Since high temperature incineration is expensive and limited (the Monsanto In^dnentor has an annual maximum an eyewash. 3.7 ppm; a polystyrene cup, 6.6 ppm; a baby-bottle liner, 2.7 ppm; a frozen-food bag, 4.8 ppm; a bread wrap. 3.2 ppm; a sheet plastic wnp, 3.7 ppm. None of (hex items art included in the regulations covering food wraps, and since none of the materials are actually ptaticired with FCBa U is likely that the contamination is a result of varioua FCB uses in the processing machinery. A further complication in tracking down all aources of human exposure it the fact that rest are now manu factured in Great Britain, France, Ger many, the Soviet Union, Japan, Spain, Italy, Czechoslovakia, and the United States. It is virtually impossible at this time to determine whether or not fin ished consumer items that might lead to human exposure are being imported Into the U.S., but the FDA plans to investigate this possibility in the future. White both regulatory and voluntary actions were long in coming, they will quite likely reduce the immediate haz ards iMociaied with FOBS both to human beings and ecological systems. On the other hand, because of the enor mous amounts of rest already cir culating in the environment, it will bo some time before they wUI be con sidered inrigniflcaat contaminants. O NOTES 1. "Report et a Now Chemical Meter*," Mew Setenttat. Dee. 18, ISM. 2. Jenaen, S., "The PCS Story," Ample. vet. I. no. 4,1072. S. Mclnttro, O., "tootled ty Suceoa*," environment, voi. 14, no. I, 10?2. Free*. Artttn, "Cirlft, Air, wefor," ImimmeM, vet. II. no.e. ms. 4. NltMt, I. C. T,, an* A, F. Serofkn, "Rotee and Route* of Tronaeort of FCO'l in the Km vkonmorit," Environment*! Health Rum Uve*. experimental issue no. ], Apr. 1973. . SlMon, one O. won*. ``Structural idon. tltlcetlon of Rotyehtorinetee Sloiienyi* M Commercial Mixture* by OaoLleutd Chtono tovrephy, Nuclear MevnetW Rotonance ane Man Spectrometry." Journal of Chroir lop> mohy. eOtlS-32. 1071. 0. Pitmen, A. M. C. Caen, an* S. J. Hern*, "Ololoolcel Effect* of hoiycniorinete* Mphtnyli In Rat* ene QuaH," environments Health Pcrtpoethro*. Apr. 1072, p. 147. .7. Cutkamp. L. K., H. M. Yep, D. Ooaoien. end R. 0 Koch, "Th* Sensitivity or x*n ATPawt to Polychlorinated Biphenyl*," Eo- vtronmoatal Health Rnaerlhei, Apr. 1072. p. ies. 0, Freund, M. end O. O. Trainer, "PolyChlorlnaiod Biphenyl: Interaction with OucM Hcpatltut Virus," Sctanao, 170:1314, 1070. 0. Kuratwne, T, Yothimura, j. Mottua- aka, and A. Vemayuchi, "Cmdamioioe'cai Study of Yu*ho, a Poisonlny Cawtad oy inyeo Ikon ol Rice Oil Contaminated with a Com. mercial Brand Of Poiycntormaiad pipnony**." Environmental Health PfrtpeeUv. exoart- mental iaawe no. 1. Aar. 1072. 10. "PCB'i and the Environment," an inter department Tath Force Report on FCB't, report no. ITF-FCR-72.1, MTIS. Cteot. ot Commerce, Wathinoton, O.C., 1072. 11. Federal Rapitar. July 4. 1073. . 14004. 12. Flaop, Frederick, pertonal com- muntcMIon, Toxat AAM UntvorUly. Conoo Station. From an addrow to lha CiMamo lootcai Society of America, Lo* Arieoioa, Dee. 1071. a ** HONS 069038 Environment, Vot. 19, No. 9