What are they and where are they found?
Polychlorinated biphenyls (PCBs) are a group of chemicals that have extremely high boiling points and are practically nonflammable. Because of this, they have been used in hundreds of industrial and commercial products, including electrical, heat transfer and hydraulic equipment.
In 1979 the manufacture and importation of PCBs was banned in the United States, based on evidence that they are toxic to humans and wildlife. Today PCBs are classified as probable human carcinogens and are listed in the top 10 percent of EPA’s most toxic chemicals. PCBs stay in the environment for a long time and do not degrade easily.
Other products that may contain PCBs include:
- Transformers and capacitors
- Electrical equipment including voltage regulators, switches, reclosers, bushings, and electromagnets
- Oil used in motors and hydraulic systems
- Old electrical devices or appliances containing PCB capacitors
- Fluorescent light ballasts (a ballast is an electrical component used with a fluorescent blub to conduct electricity at each end of the tube)
- Cable insulation
- Thermal insulation material including fiberglass, felt, foam, and cork
- Adhesives and tapes
- Oil-based paint
- Carbonless copy paper
- Floor finish
How do people come into contact with it?
Today, the main way people come into contact with PCBs is from eating fish that are caught from contaminated water bodies. This is because once PCBs leak or are dumped into the environment they stay there for a long time. PCBs do not flush out in water, so if they leaked into or were dumped into rivers and lakes, that contamination remains there today.
Little sediment-dwelling creatures that live in the bottom of rivers, lakes and streams accumulate PCBs in their bodies. When small fish eat the little creatures they become contaminated. Big fish eat the small fish, and the accumulation of PCBs continues all the way up the food chain until the largest, longest living fish have the most PCB contamination of all.
Older, bigger, and fatter fish have the most PCBs, which store in the fatty tissues. Meat and dairy are other dietary sources of PCBs, although these sources have not been studied thoroughly.
What are the health concerns?
PCBs have been shown to cause a number of health problems. They are called a “probable carcinogen,” meaning there is a strong possibility they cause cancer.
Other serious health concerns include immune system disorders, low birth weight, learning disabilities and impaired growth and development in children. PCBs are also linked to skin, eye, liver, and heart disorders. Some evidence suggests that different health effects from PCBs may be related because when one bodily system is affected, it can in turn affect others.
What can I do to protect myself, my family, or my employees?
Knowing about fish consumption advisories is an important way to keep from being exposed to PCBs. Since PCBs build up in the fatty tissues of fish, follow these guidelines for cleaning and cooking fish.
What’s being done to protect public health?
Due to health concerns, U.S. companies stopped making PCBs in 1977 and the U.S. Environmental Protection Agency banned most uses of them in 1979.
Where can I get more information?