SI Vault
Robert H. Boyle
September 01, 1975
Toxic chemical compounds called PCBs are being discharged into rivers and lakes, contaminating food fish, which are contaminating us
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September 01, 1975

Poisoned Fish, Troubled Waters

Toxic chemical compounds called PCBs are being discharged into rivers and lakes, contaminating food fish, which are contaminating us

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Dr. Ward Stone, a New York State wildlife pathologist, warned conservation department superiors for several years of the PCB crisis. He found his warnings "futile." Dr. Stone says, "No one really cared. In one memo I wrote, 'I hope the department begins to take some of these toxic problems seriously...because it is doubtful these problems can be put off. In fact, they have already been put off far too long.' " In autopsies Dr. Stone discerned excessive PCB levels in breast muscles of a number of greater scaup shot on Lake Ontario and Long Island Sound. He also found excessive PCB levels in white-winged scoter dying on Lake Ontario. Moreover, he found 30.16 ppm of PCBs in the liver of a great blue heron from Albany County; 11.05 ppm in the liver and 21.49 ppm in the muscles of a dead herring gull from Oneida Lake; 20.3 ppm in the liver of a porpoise washed ashore at Westhampton Beach, N.Y.; and 49.39 ppm in the brain of an otter from Twitchell Lake in Herkimer County.

But not just mammals, birds and fish are affected. The water is, too. In a review of PCBs in the Hudson, Dr. Gilman D. Veith of the Duluth lab reported that "the river for many miles downstream from the G.E. discharge has not been adequately tested. It could be contaminated with PCBs at levels 100 times over the 10-parts-per-trillion guideline set forth by EPA in 1972 and 1,000 times higher than the newly recommended water quality criteria [of one part per trillion]." Poughkeepsie and other river towns draw their drinking water from the Hudson. Water supplies for cities on the Great Lakes may also be endangered. Chicago and Milwaukee draw their water from Lake Michigan, and EPA reports indicate that PCB levels in certain areas of the lake range from four to 10 parts per trillion, well above the recommended one part per trillion.

PCBs have been manufactured in the U.S. since 1929 by one firm, Monsanto Industrial Chemicals Company. It is estimated that Monsanto has turned out about 400,000 tons of PCBs between 1948 and 1973. The company's output is about half the world production. PCBs have also been made in Great Britain, France, Germany, Italy, Spain, Czechoslovakia, the Soviet Union and Japan.

PCBs are a family of partially or wholly chlorinated isomers of biphenyls. Monsanto has marketed them under the trademark names of Aroclor 1016, 1221, 1232, 1242, 1248, 1254, 1260, 1262 and 1268. The last two digits indicate the chlorine percentage in the different formulations. Like DDT, PCBs are chlorinated hydrocarbons, but compared to DDT, which may persist up to 15 years, PCBs resemble the Rock of Gibraltar. After the use of DDT was restricted by the Great Lakes states in 1970, DDT residues in Lake Michigan fish dropped 87%. However, the more highly chlorinated of the PCBs are essentially unalterable by microbial or physical chemical action in the environment. Their molecular structure inhibits enzymes from shearing the bonding between the chlorine atom and the biphenyl structure. So far as is known, the only way in which PCBs can be destroyed is in a special incinerator at a temperature of 2,700� Fahrenheit.

The apparent indestructibility of PCBs horrifies ecologists and gladdens industrialists. Just a partial listing of products made with PCBs at one time or another includes hydraulic fluids, plasticizers, adhesives (brake linings and clutch faces), paints, sealants (asphalt and concrete) and printing products (carbonless carbon paper and paper coating). PCBs are still used as filling agents or impregnants in electrical transformers and capacitors. Imported or recycled PCBs are used in such products as heat-transfer fluids. Traces of PCBs have been found in toilet soaps, hard and soft wood pulps, coloring compounds, fish oil and Xerox toners. Ironically, waste paper claimed for recycling is one of the sources of the PCBs that flow into Wisconsin streams emptying into Lake Michigan. These PCBs come from the inks and papers.

In 1971, five years after scientists recognized PCBs as contaminants, Monsanto announced it would voluntarily restrict sales to "closed cycle" systems in transformers and capacitors. However, PCBs were already omnipresent.

Dr. George Harvey of the Woods Hole Oceanographic Institution says PCBs enter the environment from sewage outfalls, industrial and municipal wastes, leaching from dumps and the burning of refuse. PCBs occur in rain and snow. For example, measured snowmelt in Kenosha, Wis. contained .22 parts per billion of PCBs. "The atmosphere is the major pathway of global transport," Harvey has written. "PCBs have been found in all organisms analyzed from the North and South Atlantic oceans, even in animals living under 11,000 feet of water.... Based on available data it seems safe to conclude that PCBs are present in varying concentrations in every species of wildlife on the earth."

The concentrations do vary. Dr. Robert Risebrough of the University of California at Berkeley has found levels of from 300 to 1,000 ppm in cormorants and ospreys, and he suspects that deformities in terns born on Great Gull Island in Long Island Sound are caused by PCBs. Researchers in both the U.S. and Canada have discovered that ranch-raised mink suffer adverse reproductive effects when fed PCB-contaminated foods. At Michigan State University, R. K. Ringer, R. J. Aulerich and M. Zabik "confirmed the mink industry's observation that Lake Michigan coho salmon, when fed to breeder mink, resulted in either total cessation of mink reproduction (embryo toxicity) or kit mortality, the degree of complication being dependent upon the percentage of coho salmon fed and the duration of feeding."

Dr. Renate Kimbrough of the Center for Disease Control of the U.S. Public Health Service in Atlanta and a team of researchers have "concluded that the polychlorinated biphenyl Aroclor 1260 had a hepatocarcinogenic [liver cancer] effect in female Sherman Strain rats when fed in the diet." The Kimbrough study will be published in the Journal of the National Cancer Institute.

In 1968, more than 1,000 Japanese developed Yusho disease when they used rice oil containing an estimated 2,000 ppm of PCBs. The PCBs leaked from pinholes in a factory pipe during processing. Disease symptoms included eye discharges, severe acne, ulcers of the uterus and darkening of the skin. Pregnant women suffered miscarriages and stillbirths, and surviving infants suffered from abnormal pigmentation as the result of transplacental transmission of PCBs.

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