Document XOYpQ5RQLxJOmVVVgzvjJQ0qK

CHEMICAL & ENGINEERING NEWS, Jan. 3, 1972 "science\ PCB's may be common in humans... ' Polychlorinated biphenyls (PCB's), known to be wide spread in fish and wildfowl, appear to be common in humans also, says Dr. Anne R. Yobs of the Environ mental Protection Agency. She told a federally sponsored meeting on PCB's last month that an EPA analysis of 593 human tissue samples collected from 38 hospitals in 17 states revealed that 33.6% of the samples contained greater than 1 p.p.m. PCB and another 30.1% contained detectable quantities of PCB. Dr. Harold A. Price of the Michigan department of public health told the meeting he found that more than 41% of 80 human adipose tissue samples collected in Michigan contain more than 1 p.p.m. PCB. . . . but levels decline elsewhere PCB levels in two Green Bay tributaries meanwhile have dropped sharply over the past year, says Univer sity of Wisconsin water chemist Gilman D. Veith. He notes that "PCB levels in Peshtigo and Oconto river . waters dropped from 0.31 and 0.45 p.p.b. respectively in November 1970 to less than 0.01 p.p.b. last summer." Dr. Veith believes that the decline is probably a direct result of Monsanto Co.'s restrictions on sales of PCB's. He adds, however, that waters of the Fox river, which flows through the city of Green Bay, have not yet shown a similar decline in PCB levels. Copies to: Cunningham Corey Papageorge Wheeler Stapleton Pickard Marsh--Brussels EJohn DSW 282231 STLCOPCB4063560  . by ELIZABETH N. LAYNE / N 1966 A SWEDISH SCIENTIST named Soren Jensen, 5with the Institute for Analytical Chemistry at the University of Stockholm, detected the man made chemical compounds known as polychlorinated biphenyls (PCBs) in fish taken from different parts of Sweden, in an eagle found dead in the Stockholm Archipelago, and in the hair of his wife, himself, and his baby daughter. Neither Jensen nor any other scientist had any idea what quantity of PCBs might be dangerous or possibly even fatal. He knew, however, that the compounds are a chlorinated hydrocarbon closely related to DDT, and that the high concentrations of PCBs in the dead eagle would have been close to a lethal dose if PCB toxicity were similar to that of DDT. Further, an examination of a sequence of eagle feathers from the Swedish National Museum of Natural History dating to 1830 revealed PCBs in one bird collected as far back as 1944. Since Jensen's initial discovery of PCBs in the environ ment, scientists have been dismayed to find the chemical virtually everywhere they have looked for it--in rainwater in England, mussels in the Netherlands, seals off the coast of Scotland, porpoises in Canada's Bay of Fundy, sea lions in California waters, cod in the Baltic Sea, Adelie penguin eggs in the Antarctic, brown pelican eggs in Panama, osprey eggs on' Long Island Sound, river water in Japan, coho salmon in the Great Lakes, tuna off the Galapagos and Hawaiian Islands, petrels and shearwaters from the Pacific Ocean, plankton far out in the North and South Atlantic, polar bears in Arctic Canada, trout in remote lak s in northern Quebec, in the air over cities in the United States, and in human milk samples and human fat. PCBs have joined DDT as a truly global pollutant. But while DDT was deliberately cast into tne environment. PCBs have leaked their way into the world's ecosystems. We. know only sketchily how it has come about. PCBs are not a single compound but a mixture of chemical compounds made up, like DDT, of chlorine, hydrogen, and carbon. They are available in this country--where they have been sold to industry for 40 years--as a colorless, odorless, 116 DSW 282232 AUDUBON STLCOPCB4063561 M fK l RAMUS syrupy liquid or as a resin. The sole manufacturer in the United States, Canada, and Britain is the Monsanto Indus trial Chemicals Company of St. Louis, which markets them under the trade name Aroclor. PCBs are also made in France, Germany, Italy, Japan, and the Soviet Union. Like DDT, PCBs are described as insoluble in water, and highly soluble in oils and fats. They can withstand incredibly high tempera tures (up to 1600F). and are exceedingly resistant both to biological and chemicai decomposition. The compounds are probably at least as stable as DDT and its long-lived breakdown product, DDE. In other words, PCBs have all the necessary characteristics for persistence and accumulation within the food chain. The very qualities that make the compounds a threat to the environment are those that make them of great value to industry. Since the 1930s PCBs have been used primarily as coolant-insulation fluids in power transformers located in populated areas, where the danger of explosion from the intense heat produced by voltage changeovers presents a special hazard; and in what are called heat-transfer systems, in which PCBs are circulated through coils or tubes to conduct heat from furnaces to ovens or radiators. They have long been used in those black boxes called capacitors that sit on poles and regulate the flow of electricity through transmission lines, and in capacitors in fluorescent lights and air conditioners. Theoretically PCBs cannot escape into the environment from these "closed system" uses, but systems can and do leak, and insulation fluids degrade and are discarded. To cite one recent example, a heat-transfer system leak in a fish meal plant last summer made it necessary to destroy 80,000 chickens and a like number of contaminated eggs. It was not until about 1960 that Monsanto encouraged the use of polychlorinated biphenyls for a wide variety of _ "open" applications--to prolong the kill life of some pesti cides, in sealants and synthetic adhesives, in paints, var nishes, and wax, in printing inks and carbonless copy paper, in automobile tires and brake linings, and in plasticizers, which is presumably why PCBs appear in many consumer plastics. All these new uses accelerated the release of PCBs into the environment through factory waste, abrasion, and trash incineration. Not long ago the federal Food and Drug Administration discovered PCBs in a variety of cardboard boxes used to package dried foods such as cereal. In addition, they found PCBs in some samples of shredded wheat and noodles packed in those boxes. Carbonless copy paper that went into the recycled paper from which the cardboard boxes were made is believed to be the source ' of contamination. In response to mounting evidence of PCB pollution of ( the environment, Monsanto stopped selling the compounds for these "open" uses last year. And the Department of Agriculture has canceled registration for pesticides mixed with PCBs. What portion of total sales these uses represent ed is not known because Monsanto has not come forth with such information. However, the company did release some figures in November, under pressure from the scientific community and the government, that show production in the U. S. reached a high of 42,527 tons in 1970, more than double what it had been in 1960. How directly lethal to life are PCBs? In Japan in 1968, more than 1,000 people suffered a severe skin acne and liver damage as a resuit of consuming a commercial rice oil used for cooking. In addition, there were two still births out of nine pregnancies among the women affected. The rice oil had been heavily contaminated with PCBs used as a heat-transfer fluid in the food processing equipment. Recent studies in the Netherlands indicate the culprit in such cases is probably a highly poisonous contaminant, chlorinated dibenzofurans, found in some PCBs manufac tured putside the United States, rather than the PCBs themseFves.^Chlorinated dibenzofurans are "among the most poisonous compounds known," says Dr. Robert Risebrough, this country's foremost authority on PCBs in wildlife. The presence of these contaminants explains the high toxicity of German and French PCBs compared to those manufactured here. Studies thus far indicate that American-made PCBs, free of chlorinated dibenzofurans, have a relatively low acute toxicity compared to DDT and to dieldrin. Interestingly enough, they are not highly toxic to insects but do have a synergistic effect with DDT and dieldrin. It is the shellfish that have been found to be more sensitive to PCBs than other forms of life thus far tested. However, it is perhaps significant that all testing in the United States and Canada is done with PCBs supplied by Monsanto. And an incident in 1963 suggests that at least some past batches of Ameri can-made PCBs may have carried the lethal contaminants. Professor E.L. McCune at the University of Missouri discov ered his chickens were dying because of PCBs (Aroclor) used as a binder in an epoxy paint that had been freshly applied to parts of their feeding house. The symptoms shown by his chickens are now known to be characteristic of poisoning from chlorinated dibenzofurans. UT AS WITH SO MANY environmental pollutants, the 9possible long-term, sublethal effects of PCBs are what frighten scientists. Three separate tests in recent months-- with rabbits, with mink, and with ring doves--have all had disturbing results. In the two studies using mammals, the animals were fed food saturated with American PCB concen trations of 10 to 15 parts per million, a level commonly found these days in Lake Michigan coho salmon. (The mink in fact were fed on salmon.) The first generations of both mink and rabbits failed to produce young. The speond generation of ring doves, which had been fed the lowest dose of PCBs, produced an extremely high rate of embryonic deaths. In the light of these results, it is not unreasonable to surmise that PCBs pose a considerable .long-range hazard to all animal life. The extreme concern among scientists is that there is no clear evidence that the PCB contaminant, the highly poisonous chlorinated dibenzofurans, is not produced from the PCBs after they have entered the environment--or has not been widely present in batches produced in the past that now lie buried in dumps or in lake or river sediments. ^ Dr. Risebrough, who suspects PCBs to be the cause of macabre birth defects and feather loss in young terns in a nesting colony in Long Island Sound, conjectures in a recent article in Natural History that the contaminants may be the agent causing the defects. Such speculation is prompted by recent experiments with chlorinated dioxins, a close chemical ally of the chlorinated dibenzofurans, which produced similar birth defects in birds in the laboratory. Risebrough grimly concludes that "these contaminants may, someday soon, result in an increase in the numbers of human defects as they work up through the food chain to the ultimate consumer." Until it is known how much polychlorinated biphenyl has been produced and the major sources for release into trie environment, we will be hindered in efforts to assess or reduce the potential hazards. Dr. Ian Nisbet of the joint scientific staff of the National Audubon Society and Mas- JANUARY 1972 DSW 282233 117 STLCOPCB4063562 sachusetts Audubon, and Dr. Adel Sarofim of MIT, who read a paper on PCBs at a December seminar of the National Institutes of Health, estimate that about one-half to threequarters of all PCBs so far produced have escaped into the environment. Since dumping by industry must account for a large part of that quantity, Nisbet and Sarofim guess that a good many PCBs are still in dumps and landfills, where they have not yet come into circulation. Most of the remain ing loose PCBs, they believe, lie in the shallows of estuaries, bays, and rivers. Here there is a danger they may be released into the food chain, where they pose a special threat to the thousands of aquatic organisms that use these waters as feeding and spawning grounds. It is expected that the PCBs will be released slowly over a period of decades as the sediments in the dumps and in the shallows are turned over and leached out. The highest concentrations of the chemical so far found are in the waters in industrial, urban areas. Researchers in Great Britain last year discovered that approximately one ton of PCBs a year is being dumped in the ocean with the sludge from Glasgow sewage treatment plants. A similar amount enters the Irish Sea from Manchester's sewage and the Thames from sewage in London. Tests at one outfall in Los Angeles revealed an annual flow of 10 tons of PCBs. It is hardly surprising to learn that the main source of PCBs in the human diet is fish, or that a recent report to the Environmental Protec tion Agency noted: "It appears that the most serious chronic PCB contamination is in fish and fish-eating birds . . . which are the terminal carnivores of a complex mesh of food chains in the sea." Ospreys nesting in the vicinity of Long Island Sound have been elevated to the dread distinction of being "more contaminated with PCB than any other wildlife in North America." The eggs of the ospreys were found to contain levels three times higher than those that caused massive embryonic deaths in ring dove eggs. Probably relatively few PCBs have so far worked their way down to the coasts. Despite curtailments of production or sales, Nisbet and Sarofim expect that much more will find its way down the rivers, into the estuaries, and out to sea. The * situation will ' inevitably - g_et a lot - worse than it is now.H - discuss in the hearing. His statements, of course, have been exploited for publicity purposes by the pesticide industry. Dr. Borlaug does not understand the objectives of the environmental scientists he so vehemently attacks. No responsible scientist stands against all pesticides, fertilizers, and other chemicals, as he asserts. Nor have environ mentalists attempted, through anti-DDT litigation, to stop the export of DDT to developing nations that cannot afford alter natives for malaria control. by CHARLES F. WURSTER The issue is which pesticides for which purposes. Excessive dependence on pesticides for insect control, espoused by and ROBERT VAN DEN BOSCH Dr. Borlaug, is an ineffective, costly, and destructive method that is rapidly being replaced by sophisticated and effective integrated control techniques. DDT is incompatible with THE SPECTACLE OF a SCIENTIST, competent in his integrated control because it disrupts the beneficial balance own specialty, being drawn into fields where he has of insect communities, often creates greater pest problems no expertise--and exploited by forces he does not under than it solves, is destructive to wildlife, and is a human stand--is a tragedy of modern science. This occupational health hazard. In short, most of the benefits Dr. Borlaug hazard is particularly acute for some scientists with Nobel envisions are not attainable with DDT. But they can be Prizes. achieved by safer means. Dr. Norman E. Borlaug, a plant geneticist, won a Nobel When a broadly toxic insecticide such as DDT is sprayed Prize for his work in developing high-yield grains. Now, into the complex machinery of an interrelated insect com however, Dr. Borlaug is enmeshed in controversies where munity, most insects are killed. The field is stripped of its his splendid achievements are of little relevance and his predatory insects and other natural controls, and is thus expertise is nonexistent or 25 years out-of-date. vulnerable to the rapid resurgence of the plant-eating pests. Last October 7th Dr. Borlaug testified at DDT cancellation Often this leads to greater pest abundance than before hearings in Washington upon invitation of the U.S. Depart ment of Agriculture. Under the rules of evidence, a witness spraying. And the development of pesticide-resistant strains of the pest insects makes matters still worse. The farmer, must qualify as an expert in a subject before he can testify about it. When the USDA attorney asked Dr. Borlaug his faced with nightmarish insect problems, finds himself ad dicted to more and heavier insecticide treatments, often at opinion on the effects of DDT on wildlife, the hearing the urging of pesticide salesmen. With rising pesticide bills examiner barred the answer on the ground that Dr. Borlaug and falling crop yields, he is on a treadmill to economic was not an expert in that subject. Dr. Borlaug testified that disaster. he last studied pesticides in 1944, when he was employed This sequence has occurred in many countries. In two by a pesticide manufacturer. Most of his other testimony regions of Mexico, near Dr. Borlaug's own laboratories, was irrelevant to the issues of the hearing. severe insect problems created by insecticides caused aban From that hearing, Dr. Borlaug went directly to a press donment of the cotton industry and collapse of the associat conference arranged by Montrose Chemical Corporation, the ed economies. Excessive, pesticide use could destroy the world's largest DDT maker. Without rules of evidence to "green revolution" Dr. Borlaug himself has helped develop: inhibit him at the press conference, and at other forums, his advocacy of this discredited approach is poor advice for he has made unsupportable assertions about DDT and other a starving world. pesticides, wildlife, cancer, insect control, hysterical environ Entomologists have developed effective, economical, and mentalists, and other subjects he was not competent to ecologically sound integrated control program? ` 'a number 118 DSW 282234 AUDUBON STLCOPCB4063563