Document 10K16M2k4LpE3YpqM5DLOa55K

MOMS 0 6 6 7 2 3 dentist tad any idee what quantity of PCD* might be dangerous or possibly even fatal. Ha knaw, howavar, that ttacompounds ara a chlorinated hydrocaroon closely ralatad to DOT, and that the high concentrations of PCBs in tta doad eagle would have been close to a lethal dose if PCS toxicity were similar to that of DOT. Further, an examination of a sequence of eagle feathers from the Swedish National Museum of Nature! History dating to I860 revealed pCBs . In one bird collected as far pack at 1944. . Since Jensen's initial discovery of PCBs in the environ* ment, scientists heve been dismayed to find the chemical virtually everywhere they have iooved for it--in rainwater Ocean, plankton iar out in the North and South Atlantic, polar bears in Arctic Canada, trout in ramota lakes in northern . Quebec, in tta air over cities in the United States, and in human milk samples vnd human fat. PCBs have joined DOT as a truly global pollutant. But while DDT was delibei ateiy east into the environment. PCBs have leaked their way into the work)*! ecosystems. We know only sketchily how it has come about. - PCBs are not a single compound but mixture ol chemical compounds made up. like DOT, of chlorine, hydrogen, end carbon. Thoy are available in this country--where they have been sold to industry for 40 years--ea a colorless, odorless. r 1472n \!iitJ /'I .' M'OUIOH syrupy liquid or as a resin. The sola manufacturer in tho United States. Canada, and Britain is the Monsanto Indus trial Chemicals Company of St. Louis, which markets them under the trade name Aroclor PCHs are also made in France, Germany. Italy. Japon. and th* Soviet Union, like OOT. PCBs re described as insoluble n water, and highly soluble in oMs and tats. They can withstand incredibly high tempera- 4ures (up to 1600*F), and are exceedingly resistant both to biological and chemical decomposition. The compounds are probably at least as stable as DDT and its long-lived breakdown produet. ODE. In other words. PCDs have all the necessary characteristics lor persistence and accumulation within Ihc 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 s coolant-insulation fluids in power transformers located In populated areas, where the danger of explosion from the Intense heal produced by voltage changeover* presents a special hazard; and in what are called heat-teansfor systems, m which PCBs arecircutated through coils or tubes to conduct heat from furnaces toovens or radiators. They have long been used in those black boxes called capacitors .that sit on poles and regutata the How ot electricity through transmission lines, andm capacitors in fluorescent lights and air conditioners. Theoretically PCBs cannot escape into the environment from these "closed system" uses, but systems can and do teak, and insulation fluids degrade and are discarded. To die one recent example, a heat-transfer system leak in a fish meat plant last summer made it necessary to destroy 0.000 chickens end a like number ot contaminated eggs. ft was net until about 1900 that Monsanto encouraged the use of polychlorinated otphenyts lor a wide variety of "open" applications--to prolong the kiH life of some pesti- ` cidet, in sealants and synthetic adhesives, in paints, var nishes. and wax. in printing mbs and carbonless copy paper. Hi automobile tires and brake linings, and in plasticizers, which is presumably why PCBs appear in many consumer ptasUes. All these new uses accelerated the release of PCBs Into the environment through factory waste, abrasion, and trash Incinaration. Not long ago the federal Food and Drug Administration discovered PCBs in e variety of cardboard boxes used to package dried foods such as cereal. In addition, they found PCBs in some samples of shredded wheel and noodles packed in those boxes. Carbonless copy paper that went into the recycled paper frc-m which the cardboard boxes were made is believed to be the source of contamination. In response lo 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 rcgisfrati'm for pextirirffi mixed with PCBs. What portion of total Hw ........ d is not known because Mnnt.mit. ims nui unit- lottli will* such information. However, the company did release some1 ffgures in Novombcr, under pressure from the scientific community and the government, that show production in the U. S. reached a high of *2.527 tons in 1070. more than double what it had been in 1960. How directly lethal to life are PCBs? In Jepen in 1908, more than 1,000 people suffered a severe skin acne and liver damage as result 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 (he culprit in such cases is probably a highly poisonous contaminant, chlorinated dibenzolurans. found in some PCBs manufac tured outside the United Slates, rather than the PCBs themselves. Chlorinated dibenzolurans are "among the most poisonous compounds known." says Dr. Robert Rise- brough. this country's foremost euthonty on PCBs in wildkfe. The presence of these contaminants explains the high toxicily of German and French PCBs compared to those manufactured here. Studies thus far indicate that American-made PCBs. tree of chlorinated dibenzolurans. have a relatively low acute toxicity compared to 00? and to dieldnn. Interestingly enough, they are not highly toxic to insects but do have a synergistic effect with DDT and dieldnn. It is the shellfish that have been found to be more sensitive to PCBs than other forms ol life thus far tested. However, it is perhaps Significant that all testing in the United Stales and Canada rs done with PCBs supplied by Monsanto. And an incident in 1963 suggests that at least soma past batches of Ameri can-made PCBs may have carried lire lethal contaminants. Professor E.l. McCunc at the University of Missouri discov ered his chickens were dying Decause of PCBs (Aroclor) used as binder in an epoxy paint that had bean freshly applied to parts ol their feeding house. The symptoms shown by his chickens ere now known to be characteristic of poisoning from chlorinated dibenzolurans. , UT AS WITH SO MANY environmental pollutants, tho Bpossible tong-term, subiethai effects ot PCBs are what frighten scientists. Three seoarate tests m recent months-- with rabbits, with mink, and with ring doves--have aM had ' disturbing results. In the Iwo studies using mammals, tho animals were fed food saturated with American PCB concen trations ot 10 to 15 parts per million, a level commonly found f these days in Lake Michigan coho salmon. (The mink in loci were fed on salmon.) The first generations of both mink and rabbits failed to produce young. The second generation of ring doves, which had been fed the lowest dose of PCBs. produced an extremely high rale ot embryonic deaths. In the light of these results, it is not unreasonable to surmise that PCBs pose a considerable long-range hazard to all animalHit. The extreme concern among scientists is that there is no clear evidence that the PCB contaminant, the nighty poisonous chlorinated dibenzolurans. is not produced from the PCBs after the'/ have entered tne 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. RisebfOugh. who suspects PCBs to bo the cause ot 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 delects. Such speculation is prompted by recent experiments with chlorinated dioxins. nmici ally of the chlorinated dibenzolurans. which produced similar birth delects Hi birds in the laboratory, Risebrough grimly concludes that "these contaminants may. someday soon, result m an increase in the numbers of human delects 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 rnapr sources for release into (he environment, we will be hindered in eilerts to assess or reduce the potential hazards. Dr. lan Kisbct of the joint scientific stall ol Ihe National Audubon Society and Mas- HONS 0 6 6 7 2 * JANUARY 2972 . .\ sachusetts Audubon, and Or. Adel Sarolim of MIT. who rend paper on PC8* at a December seminar ol the National Institutes of Health, estimate that about one-half to thineQuarter! ol all PCBs so far produced have escaped into the environment. Smco dumping by industry must account lor a large part ol that quantity. Nisbet and Sarolim guess th.it a good many PC8s ore stilt in dumps and landfills, whe*** they have not yet come into circulation. Most ol the remaminf 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, whera they pose a special threat to the thousands ol aquatic organisms that use these waters as leading and spawning grounds. It is expected that the PCBs will be released slowly over a period ol decades as the sediments in the dumps end In the shallows tra turned over and leached out. The highest concentrations ol the chemical so far found are in the waters in industrial, urban areas. Researchers in Creat Britain last 'year discovered that approximately one ton of PCBs e year is being dumped in the oeeen with the sludge from Glasgow sewage treatment plants. A similar amount enters the Irish Sea from Mandtcster's sewwe and the Thames from sewage in London. Tests at one outl.wi in Los Angeles revealed an annual (low of 10 tons of PCBs. It is hardly surprising to learn that the main source ol 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 PCS 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 PCS 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 tar worked their wey down to the coasts. Despite curtailments of production or sales. Nisbet and Sarolim expect that much more will find its way down the rivers, into the estuaries, and out to saa. Tht situation wilt Inevitably get a lot worsa than it is now.a discuss in the hearing. His statements, of course, have bean 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 ail pesticides, fertilisers, and other chemicals, as ha asserts. Nor have environ mentalists attempted, through anti-DOT litigation, to stop tha export of DDT to developing nations that cannot afford attar-' 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 nd ROBERT VAN DEN BOSCH Dr. Borlsug. 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 Ms integrated control because it disrupts the beneficial balance own speelelty. being drawn into fields where he has ' of insect communities, often creates greater pest problems no expartisa-and exploited by forces he does not under- than it solves, is destructive to wildlife, and is a human ilantMs tregedy of modern scitnee. This occupational health hazard. In short, most of the benefits Dr. Borlaug hazard is particularly acute for some scientists with Nobel 1 envisions are not attainable with DOT. But they can be Prices. achieved by safer means. Dr. Norman E. Borlaug. a plant ganeticist. won a Nobel When a broadly toxic insecticide such as DDT is sprayed Price 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 tittle 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 resurgenct of the plant-eating pests. Last Oetober 7th Dr. Borlaug testified at DDT cancellation Often this leads to greater pest abundance than before haarmgs in Washington upon invitation of tha U.S. Depart spraying. And the development of pesticide-resistant strains ment of Agriculture. Under the rules ol evidence, a witness of the pest insects makes matters still worse. The farmer, must qualify as an expert in a subject before he can testify faced with nightmarish insect problems, finds himself ad about It. When the USDA attorney asked Or. Borlaug his dicted to more and heavier insecticide treatments, oftan at opinion on tha effects of DDT on wildlife, the hearing the urging of pesticide salesmen. With rising pesticide biHs examiner barred the answer on the ground that Dr. Borlaug and failing crop yields, he is on a treadmill to economic( was not an expert in that subject. Dr. Borlaug testified that disaster. ' hs 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 ol Mexico, near Or- Borlaug's own labor*lories, was irrelevant to the issues of the hearing. ` severe insect problems creatod by insecticides caused aban From that hearing. Dr. Borlaug went directly to a press donment ot the cotton industry and collapse ol the associat conference arranged by Montrose Chemical Corporation, the world's largest DOT maker. Without rules Of evidence to ed economies. Excessive pesticide use could destroy the "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 advica for ha has made unsupporteble assertions about DDT and other a starving world. ' pesticides, witdlile, cancer, insect control, hysterical environ - Entomologists have developed effective, economical, and' mentalists, and other subjects he wes not competent to ecologically sound integrated control programs for a number . .' /' -/ na At mi IRON