Some Facts About PCBs
PCBs were discovered during the 19th century. As gasoline was extracted from crude oil, great quantities of other chemicals, like benzene, were left over. Chemists started playing around with these chemicals, to see if something useful could be made.
If you heat benzene under the right conditions, you can glue two benzene rings together, creating diphenyl. If you then expose the diphenyl to chlorine gas under the right conditions, you can create chlorinated diphenyls, or 'biphenyls' as we call them today. Adding more or less chlorine creates compounds with differing properties, and thus PCBs (polychlorinated biphenyls, all 209 kinds of them) came into being.
PCBs aren't soluble in water (very much, at least), they don't burn except at very high temperatures, they don't conduct electricity, they do not degrade during use, and they conduct heat very well. PCBs were considered excellent candidates for a variety of uses in electric power equipment, electronics, the printing industry, and elsewhere.
Different mixtures of PCBs (called Aroclors) were marketed with varying levels of chlorine content. Most mixtures were contaminated with Furans, a related kind of chlorinated compound. PCBs and Furans are structurally very similar to Dioxins --- and certain kinds are equally toxic.
When PCBs or Furans (or other chlorine compounds) are burned at very high temperatures, the benzene rings and chlorine can recombine into Dioxin --- making incineration a serious risk.
PCBs, Furans and Dioxins are persistent once they are
dumped into the environment.
A Capsule History
By 1914, enough PCBs had already escaped into the environment to leave measurable amounts in the feathers of birds held in museums today.
By the mid-1930s, Monsanto was producing PCBs commercially (and licensing other companies to produce as well) and PCBs had created a public health problem sufficient to attract academic researchers, the U.S. Public Health Service, and several large industrial producers and users of PCBs.
In 1936, the U.S. Public Health Service described a wife and child, both of whom had developed chloracne, a combination of blackheads and 'pustules' merely from contact with a worker's clothes. In addition, they found symptoms of systemic poisoning among workers inhaling these fumes. Internal Monsanto memos documented workers who died of liver failure traced to PCB exposure.
In 1936, Harvard University researchers performed experiments with rats exposing them to chemicals at rates similar to those chemical plant workers were exposed to. They reported that "the chlorinated diphenyl [an early name for PCBs] is certainly capable of doing harm in very low concentrations and is probably the most dangerous of the chlorinated hydrocarbons studied. These experiments leave no doubt as to the possibility of systemic effects from the chlorinated naphthalenes and chlorinated diphenyls."
By 1947, Westinghouse's medical department wrote in a company memo that long-term exposure to PCB fumes "may produce internal bodily injury which may be disabling or could be fatal."
By 1959, the assistant director of Monsanto's Medical Department would write to the Administrator of Industrial Hygiene at Westinghouse saying, "... sufficient exposure, whether by inhalation of vapors or skin contact, can result in chloracne which I think we must assume could be an indication of a more systemic injury if the exposure were allowed to continue."
In 1966, PCBs were first recognized as an environmental problem when a Swedish researcher reported finding them in 200 pike from all over Sweden, in other fish and in an eagle. For the next decade, scientists accumulated information about PCBs, finding them disrupting food webs all over the planet.
In 1968, when 1,300 residents of Kyushu, Japan, fell ill after eating rice contaminated with PCBs, the world's public health establishment woke up from a long sleep and began to examine PCBs, which by this time were everywhere.
In late 1971, a group of Westinghouse staff met to discuss PCBs and they noted that PCBs concentrate in the food chain. A memo summarizing the meeting said, "It was generally concluded that ... there is sufficient evidence that PCBs can be deleterious to the health of animal and human life and that the risks of ignoring the evidence that does exist was inappropriate for Westinghouse." Yet the 1971 memo recommended continued use of PCBs.
Several industries made conscious decisions to continue manufacturing and using PCBs in spite of abundant information about the chemicals' toxicity.
Nearly 20 years later, in the late 1980s, researchers began to find that workers exposed to PCBs were dying of skin cancer and, perhaps, of brain cancer.
By 1976, the destruction wrought by PCBs was so obvious
and so well understood that even the U.S. Congress comprehended the danger
and took action, outlawing the manufacture, sale, and distribution of PCBs
except in 'totally enclosed' systems, such as electrical capacitors or
How Bad is the Contamination?
Between 1929 and 1989, total world production of PCBs (excluding the Soviet Union) was 3.4 billion pounds, or about 57 million pounds per year. Even after the U.S. banned PCBs in 1976, world production continued at 36 million pounds per year from 1980-84 and 22 million pounds per year from 1984-89. The end of PCB production is still not in sight.
The whereabouts of 30 percent of all PCBs (roughly a billion pounds) remains unknown. Another 30 percent reside in landfills, in storage, or in the sediments of lakes, rivers, and estuaries. Some 30 percent to 70 percent remain in use. A certain percentage of PCBs do volatilize (or evaporate) from soil and the surface of water bodies, which means that PCBs are now cycling through the atmosphere as well as our soil and water. The characteristics of PCBs (their stability and their solubility in fat) tend to move them into the oceans (and Great Lakes) as time passes. Nevertheless, it is estimated that only one percent of all PCBs have, so far, reached the oceans.
The one percent that have reached the water are already
causing major problems.
Unfortunately, like many other chlorinated chemicals, PCBs are soluble in fat, so they tend to accumulate in living things and to enter the food webs, where they concentrate. The higher you are on a food chain, the greater the concentration of PCBs. Large fish and creatures that eat large fish, tend to accumulate in their flesh thousands, even millions of times the background levels of PCBs. Furthermore, by a cruel twist of fate, large birds and marine mammals (seals, sea lions, whales, and some dolphins) lack enzyme systems to efficiently detoxify PCBs. As a result, PCBs build up in the bodies of these predators and are passed to their offspring through eggs (in the case of fish and birds) and milk (in the case of mammals). PCBs mimic hormones and are a powerful disrupter of the endocrine system that governs reproduction. Marine mammals are already having trouble reproducing. It is entirely possible that, as more PCBs reach the oceans, all large mammals will disappear.
All humans, too, are now contaminated by PCBs and are passing these powerful toxins to their infant children through the placenta and breast milk. In the U.S. and other industrialized countries, PCBs are present in breast milk at an average of 1 part per million (ppm) in the milk fat. An infant drinking milk contaminated at this level will take in a quantity of PCBs that is 5 times as high as the recommended 'allowable daily intake' for an adult, as established by the World Health Organization. Babies of local fish-eating mothers would get much higher doses of PCBs.
PCBs are so persistent in our bodies that scientists estimate it would require 7 generations of women breastfeeding their daughters, with no further PCB exposures, before the final daughter would be free of PCBs.
Children exposed in the womb to PCBs at levels considered 'background levels' in the U.S. have been found to experience hypotonia (loss of muscle tone) and hyporeflexia (weakened reflexes) at birth, delays in psychomotor development at ages 6 and 12 months, and diminished visual recognition memory at 7 months. Follow-up studies show that these deficiencies continue as the children age. An entire generation of children could be affected right now.
PCB exposure has been correlated with liver, skin, brain,
and breast cancers. In the last 40 years, the overall U.S. incidence of
liver cancer increased 89%, skin cancer increased 336%, brain cancer increased
74%, and breast cancer increased 52%, according to the National Cancer
Institute (after adjusting for an aging population). These increases could
be, at least partially, related to PCBs.
What is the Local Situation?
All wildlife and humans in the Great Lakes region are contaminated with PCBs and many other chemicals. 16 species of Great Lakes wildlife (including fish, birds, mammals, reptiles, amphibians, insects and even micro-organisms) have shown similar symptoms of poisoning --- birth defects, thyroid and liver dysfunction, immune suppression, cancers, behavioral changes, reproductive failures, etc. Some effects are linked to PCBs.
Scientists believe several kinds of Great Lakes fish may have gone extinct in the 1950s due to reproductive failure from chlorinated compounds like PCBs. The Lake Trout was saved in hatcheries, but after a decade of stocking efforts, natural reproduction of Lake Trout in the Great Lakes is still uncertain. These fish are highly sensitive to PCBs and dioxin.
On the Fox River and Green Bay, several valuable species of sport and commercial fish carry warnings against human consumption, and ducks also carry warnings. Though turtles also carry high burdens of PCBs, the government has yet to issue warnings against eating them.
The health standards for consumption warnings have been greatly tightened over the past 10 years, as more information about PCB dangers became available.
The U.S. EPA estimates that Great Lakes fish consumption will result in 38,255 extra cancers in the Great Lakes region over the coming 70 years (based on 5 chemicals --- but primarily PCBs). This estimate may be low. The Wisconsin DNR estimates that anglers eating fish from Little Lake Butte des Morts (a flowage at the upper end of the Fox River) face a 1 in 250 risk of cancer over their lifetime. This risk likely extends down the Fox River into Green Bay, because many downstream fish are at least as contaminated.
Approximately 250 tons of PCBs were dumped into the Fox River from 1957 to the present by paper recycling industries. Fox River sediments are now the largest waterborne source of PCBs to all of Lake Michigan, and are a significant airborne PCB source as well. Most of the dumping occurred in the 1960s and 1970s. PCBs were used in coatings on the back of carbonless copy paper, and when the used paper entered the paper recycling process, the mill discharges and papers became contaminated with PCBs.
Congress and the Wisconsin Legislature modified federal and state laws to exempt products containing PCBs, in order to promote recycling. Many paper products, including food containers and female supplies, have carried large amounts of PCBs [and Dioxins and Furans] over the past 30 years.
The U.S. Fish and Wildlife Service has identified five key recyclers as the 'Potentially Responsible Parties' for dumping the bulk of PCBs --- Fort Howard Corporation, P.H. Glatfelter Company, U.S. Paper Mills, Riverside Paper Corporation, and Wisconsin Tissue Mills.
Though most mills ceased PCB releases by 1980, one recycler,
Fort Howard Corporation, continued to release significant quantities until
around 1990. Fort Howard Corporation has also found a new method of releasing
PCBs, by sending their contaminated sludges to Granulation Technologies,
Inc. where the sludge is dried and turned into pellets to be used as a
carrier for fertilizers and pesticides. The drying puts up to 10 pounds
of PCBs into the air each year, and releases at least 1,200 pounds per
year through land-spreading of the final product.
This factsheet prepared by Clean Water Action
Council of N.E. Wis.,
2220 Deckner Avenue, Green Bay, WI 54302 --- Sept. 13, 1995
(From information supplied by Environmental Research Foundation)