As the scientific reassessment of dioxin unfolds inside EPA [U.S. Environmental Protection Agency], one of the stickiest issues is how to deal with PCBs (polychlorinated biphenyls). PCBs are a family of 209 separate chemicals, some of which have the same unpleasant characteristics as dioxins--they interfere in growth and reproduction, they damage the immune system, they cause cancer, and they cause these effects in fish, birds, mice, rats, mink, seals, sea lions, whales, humans and other forms of life. One key difference between PCBs and dioxins is that there are much larger quantities of PCBs in the environment, compared to dioxins. And many major industrial firms have a long track record of exposing their workers and their neighbors to PCBs. Therefore, the potential for PCB-related lawsuits and liability is large. And therefore the political visibility of PCBs inside EPA is also large.

There is now considerable evidence that humans WITHOUT OCCUPATIONAL EXPOSURES are being adversely affected by PCBs. Humans are exposed mainly through food, especially meat and most especially fish. Two groups of U.S. children have been studied from birth to age four, looking for effects from the PCBs we all carry in our bodies. In Michigan, 313 newborns have been studied; 242 of their mothers had eaten PCB-contaminated sportfish from Lake Michigan. Higher PCB levels in umbilical cords have been correlated with smaller birth size (including reduced head size, diminished girth in the chest) and shorter gestation, an effect also seen in children whose mothers had occupational exposure.[1] On standardized tests for infant development, higher PCB levels in the Michigan children were correlated with abnormally weak reflexes, less responsiveness to stimulation, more jerky, unbalanced movement, and more startles.

In North Carolina, 912 infants have been followed from birth. Their mothers had no unusual PCB exposures but, like all Americans, they carry PCBs in their body tissues. Among 866 North Carolina infants tested, higher PCBs in mother's milk was correlated with hypotonicity [loss of muscle tone] and more abnormally weak reflexes. Subsequent studies of 802 of the North Carolina children at ages 6 months and 12 months revealed those with higher levels of PCBs had poorer performance in tests requiring fine motor coordination. At seven months, a test of 123 of the Michigan children showed higher PCB levels were related to poorer visual memory. Researchers reviewing the history of these children conclude, "There is thus consistent evidence that prenatal exposure to levels of PCBs commonly encountered in the U.S. produce detectable effects on motor maturation and some evidence of impaired infant learning."[2] In North Carolina, about 5% of the children have so far shown measurable effects related to PCB exposure, and in Michigan somewhat more than 5% of the children are showing effects.

At age 4, children in the Michigan group with higher PCBs levels weighed 10% (4 pounds) less than children with lower PCB levels. The effect was particularly significant in girls. In addition, the Michigan children were ranked according to an "activity" index, and higher PCB levels were correlated with children who were unusually "quiet and inactive." These effects on growth and behavior were specifically correlated with exposure to PCBs before birth and not with exposure after birth. This leads researchers to conclude that PCBs attack the central nervous system more successfully during its earlier developmental stages.[3]

The Agency for Toxic Substances and Disease Registry (ATSDR) has identified human populations with potentially high exposures as: individuals exposed in the workplace, breast-fed infants of mothers who consume more than 6 pounds (12 meals) of fish per year, and "people who live in the vicinity of incinerators and PCB disposal facilities."[4]

How did this situation develop? The Westinghouse story helps us understand how we got where we are today.

In 1957 Westinghouse began operating a large transformer factory in Bloomington, Indiana, processing large quantities of PCBs, which they purchased from Monsanto, the inventor of PCBs. PCBs don't conduct electricity, but they conduct heat well, and they are very stable (they don't break down readily) so they make a nearly ideal fluid for insulating electrical transformers and capacitors.

PCBs came to the attention of the scientific world in 1966 when a Swedish scientist revealed that damage to birds that he had attributed to DDT was actually being caused by PCBs.

In 1968, PCBs came to public attention when it was reported that 1300 Japanese people had become ill from eating PCB-contaminated rice oil. Many of the PCB-exposed women subsequently gave birth to children with birth defects. Workers at the Westinghouse plant in Bloomington say they were never told of any health hazards from PCBs. On the contrary, when they began to ask questions after the mass poisoning in Japan, they say, Westinghouse officials led them to believe PCBs were entirely safe. Jason Morrow, a former union local president at the plant, recalls employee meetings in which then-plant manager Donald M. Sauter "washed his hands and face in what he told workers was liquid PCBs to convince them not to worry." A Westinghouse spokesman, Christopher C. Newton, confirmed for BUSINESS WEEK magazine that Sauter "dipped his hands" into PCBs at a meeting.

Westinghouse and Monsanto insist that they have always told the world what they knew about PCB toxicity as soon as they knew it. However, in a letter dated September 15, 1947, E.C. Barnes of Westinghouse's medical department wrote that long-term exposure to PCBs "may produce bodily injury which may be disabling or could be fatal." According to workers now suing Westinghouse for injuries they say are PCB-related, this information was never passed along to the people Westinghouse exposed to PCBs day in and day out for 25 years.

In 1971, fearing lawsuits, Monsanto began requiring its customers like Westinghouse to sign a waiver relieving it of financial liability for improper uses of the chemical, thus putting buyers on notice of possible dangers. That same year a Westinghouse biochemist named Thomas O. Munson says he received instructions directly from then-chief executive officer Donald C. Burnham to study PCB contamination around four Westinghouse plants. In 1972 Munson submitted his report to Westinghouse officials, urging them to tell the local communities of the massive contamination he had found and to take remedial action. Instead Westinghouse kept the Munson report secret and continued to dump liquid PCBs directly into the local environments, Munson says.[5]

What does the future hold?

Between 1929 and today, Monsanto made, or licensed someone else to make, a total of 1.2 million tons of PCBs.[6] Of this total, 31% (370,000 tons) has so far escaped into the general environment. An estimated 4% of original production has been fed into incinerators, in hopes of destroying it. However, 780,000 tons of PCBs are still in use in transformers and capacitors, or have been sent to landfills where they are waiting patiently to escape. Thus the amount waiting to be released into the environment is approximately twice as large as the amount that has already been released.

Almost all PCBs released into the environment end up in the oceans eventually. Because PCBs are not water-soluble but are fat soluble, they have a marked tendency to accumulate in living organisms. Marine mammals at the top of the oceanic food chain are likely to have up to 10 million times more PCBs in their fat, compared to the concentration of PCBs in the water they live in.

Once they enter the oceans, PCBs build up in the bodies of fish and then in fish-eating birds and mam-mals. Fish-eating birds and mammals (seals, sea lions, some whales, and dolphins) have a distinct inability to metabolize PCBs--they lack certain enzyme systems that land-based mammals (such as humans) have that speed the breakdown of PCBs. As a consequence, ocean birds and mammals accumulate unusually high levels of PCBs in their bodies and pass the PCBs to their offspring via eggs (birds) and milk (mammals). Since PCBs released into the environment move into the oceans readily, in coming decades ocean birds and mammals seem likely to experience a continuing buildup of PCBs in their flesh. There is good evidence that PCBs in marine mammals and birds are already causing major reproductive failure.[7] Therefore, it seems likely that ocean mammals (whales, seals, sea lions, and dolphins) will experience increasing reproductive failure and will become extinct unless substantial efforts are made to prevent the release of PCBs that are still in use or are stored in landfills. (See RHWN #144.) At present, no such efforts are under way or even under discussion.
--Peter Montague, Ph.D.

===============
[1] Hugh A. Tilson and others, "Polychlorinated Biphenyls and the Developing Nervous System: Cross-Species Comparisons," NEUROTOXICOLOGY AND TERATOLOGY Vol. 12 (1990), pgs. 239-248.

[2] Tilson, cited above, pg. 245. Some of the human data are also reviewed on pgs. 53-54 of Syracuse Research Corporation, DRAFT TOXICOLOGICAL PROFILE FOR POLYCHLORINATED BIPHENYLS (Atlanta, GA: Division of Toxicology, Agency for Toxic Substances and Disease Registry, Public Health Service, U.S. Department of Health and Human Services, October, 1991.) See also, Anthony B. Miller and others, ENVIRONMENTAL EPIDEMIOLOGY. VOL. 1. PUBLIC HEALTH AND HAZARDOUS WASTES (Washington, DC: National Academy Press, 1991). pgs. 204-205, [207,] 208-210; and see Joseph L. Jacobson and others, "Effects of in utero exposure to polychlorinated biphenyls and related contaminants on cognitive functioning in young children," JOURNAL OF PEDIATRICS Vol. 116 (January, 1990), pgs. 38-45.

[3] Joseph L. Jacobson and others, "Effects of Exposure to PCBs and Related Compounds on Growth and Activity in Children," NEUROTOXICOLOGY AND TERATOLOGY Vol. 12 (1990), pgs. [319-326.]319-326.

[4] Syracuse Research Corporation, cited above, pg. 140.

[5] Michael Schroeder, "Did Westinghouse Keep Mum on PCBs?" BUSINESS WEEK August 12, 1991, pgs. 68-70.

[6] Shinsuke Tanabe, "PCB Problems in the Future: Foresight from Current Knowledge," ENVIRONMENTAL POLLUTION Vol. 50 (1988), pgs. 5-28.

[7] See, for example, Robert L. DeLong and others, "Premature Births in California Sea Lions: Association With High Organochlorine Pollutant Residue Levels," SCIENCE Vol. 181 (Sept. 21, 1973), pgs. 1168-1170; and Peter J. H. Reijnders, "Reproductive failure in common seals feeding on fish from polluted coastal waters," NATURE Vol. 304 (Dec. 4, 1986), pgs. [456-457.]456-457.

Descriptor terms: pcbs; epa; lake michigan; nc; prenatal exposure; atsdr; westinghouse; donald suater; monsanto; munson report; ocean mammals; bioaccumulation; mi; health; studies;