POLYCHLORINATED BIPHENYLS (PCBs)
This pamphlet provides answers to frequently
asked questions about polychlorinated biphenyls (PCBs). It describes PCBs,
where they can be found, how they can affect your health, and what you can do
to prevent or reduce exposure to them.
While on vacation, a family decided to
charter a boat to fish Lake Michigan. They were advised not to eat any chinook
salmon longer than 32 inches because of possible contamination from PCBs. They
were also told that children and women of childbearing age should not eat
chinook salmon that are 21 to 32 inches long.
WHAT ARE PCBs?
PCBs are a group of more than 200 similar
manmade chemicals. They are oily liquids or solids, clear to yellow in color,
with no smell or taste. PCBs are found as mixtures, and are very stable and
resistant to extreme temperature and pressure. They were manufactured in the
U.S., mainly under the trade name Aroclor, by Monsanto Inc.
PCBs were used widely in electrical equipment
like capacitors and transformers. They also were used in hydraulic fluids, heat
transfer fluids, lubricants, plasticizers, and as components of surface
coatings and inks. More than 1 billion pounds of PCBs were manufactured in the
U.S. since they were first commercially produced in 1929. Commercial production
of PCBs ended in 1977 because of health effects associated with exposure. In
1979, the U.S. Environmental Protection Agency (USEPA) banned the use of PCBs,
but the agency did not require the chemcials be removed from commerce. So, PCBs
are still present in many products made before 1979.
HOW DO PCBs GET INTO THE
PCBs have been released into the environment
through spills, leaks from electrical and other equipment, and improper
disposal and storage. It is estimated that more than half of the PCBs produced
have been released into the environment. Once in the environment, PCBs can be
transported long distances. They have been detected in air, water, soil, and
sediments throughout the world.
PCBs last a long time in the environment before
breaking down and may find their way into the food chain. Low levels of PCBs
can be found in fish, shellfish, meat, poultry, milk, dairy products, and other
foods. Since PCBs have not been made since 1977, the levels in the environment
have been declining over the past several years. Predators at or near the top
of the food chain (e.g. birds, fish) have the highest levels of PCBs in their
HOW CAN I BE EXPOSED TO PCBs?
Since PCBs are found throughout the
environment, it is likely that everyone has been exposed to them. Persons
living near a hazardous waste site with PCB contamination may be exposed to
higher levels. PCBs can enter the body by eating or drinking contaminated food,
through the air we breathe, or by skin contact. PCBs are easily absorbed by the
body and are stored in fatty tissue. PCBs are not eliminated well, so they can
accumulate in the body.
Most people are exposed to PCBs by eating
contaminated fish, meat, and dairy products. Some bottom-feeding, freshwater
fish may eat sediments containing PCBs while scavenging. Catfish, buffalo, and
carp usually have the highest PCB levels. Plants take up only small amounts of
PCBs from the soil, so amounts in grazing animals and dairy products are
generally lower than in fish. Dust contaminated with very small levels of PCBs
may be found on the outer surfaces of fruits and vegetables.
PCBs do not dissolve well, so exposure to them
from water is usually not a concern. Some private wells may use old submersible
pumps that contain PCB oil. If the pump seal fails, PCBs can leak into the well
and contaminate the drinking water. People are generally not exposed to PCBs in
surface waters unless they contact contaminated sediments.
Older fluorescent lights found in schools,
offices, and homes may still contain transformers or ballasts that contain
PCBs. If the ballasts fail, PCBs can leak out and contaminate exposed surfaces
and the air. PCB levels measured in the air after a light ballast failure can
In the Workplace
The workplace may also be a source of PCB
exposure. Industrial accidents have been responsible for most cases of PCB
poisoning in humans. Firefighters and cleanup crews responding to electrical
system fires and hazardous waste accidents also may be exposed to PCBs.
HOW CAN PCBs AFFECT MY HEALTH?
Coming in contact with PCBs does not mean you
will get sick or have health problems. Getting sick from being exposed to PCBs
depends on the following:
- the amount of PCBs that entered your body,
- how long you were exposed to PCBs,
- how sensitive your body is to PCBs, and
- whether the PCBs were combined with other
The health effects associated with exposure to
PCBs have been studied in both humans and animals. Several factors have
complicated the evaluation of health effects. Some PCB mixtures have a greater
ability than others to harm your body. Impurities in PCB mixtures, like furans
and dioxins, may be more toxic than PCBs at lower concentrations.
In people, PCBs can affect the skin and may
cause chloracne--small, pale, yellow skin lesions that may last from
weeks to years. PCBs also can cause short-term changes in the activity of the
liver, but without any noticeable symptoms. These liver changes are similar to
those resulting from the consumption of alcoholic beverages or smoking
cigarettes. Animal studies also have suggested that PCBs can affect the immune,
endocrine, and reproductive systems, but these effects are uncertain in
Large amounts of PCBs given to laboratory
animals over a short time can cause cancer. Studies of human workers exposed to
high levels of PCBs for long periods have not consistently shown that PCBs
cause cancer in humans. USEPA has classified PCBs as probable human
carcinogens (cancer-causing chemicals), but there is no evidence that PCBs
cause cancer at the low levels normally found in the environment.
IS THERE A MEDICAL TEST FOR PCBs?
Most people have a measurable amount of PCBs in
their bodies. Tests are available to measure PCBs in the blood, body fat, and
breast milk. A blood test is the best method for measuring exposure to large
amounts of PCBs. Although measuring PCBs in the body is possible, the analysis
is expensive, time-consuming, and not generally recommended because the results
do not predict health effects or treatment.
HOW CAN I REDUCE OR PREVENT MY EXPOSURE TO
Avoiding contact with contaminated soils and
sediments can reduce your exposure to PCBs. Exposure can be further reduced by
following the Guide to Eating Illinois Sport Fish, available from the
Illinois Environmental Protection Agency (copies are available by calling
217-782-3362). This guide recommends what fish you should and should not eat
and how to properly prepare fish for eating. Because PCBs accumulate in fish
fat, people can reduce their intake of PCBs by removing the skin and fatty
areas from fish fillets. Do not fry fish. Instead, barbecue, broil, or bake
fish on an elevated rack that allows fat to drip away. You can also poach fish
if you discard the broth.
Another way to avoid exposure to PCBs is to
wash fruits and vegetables before eating them. Old fluorescent lights
containing PCBs should be replaced and discarded before they fail and leak. If
PCBs leak, contact the Illinois Department of Public Health (IDPH) for
instructions on how to clean the area. If an oily film or fuel odor is noticed
in your well water and you have a submersible pump, check to see if the pump
has failed. If it has, replace it and contact IDPH for instructions on how to
clean the well.
WHERE CAN I GET MORE INFORMATION?
Illinois Department of Public Health
Division of Environmental Health
525 W. Jefferson St.
Springfield, IL 62761
TTY (hearing impaired use only) 800-547-0466
This pamphlet was supported in part by funds
from the Comprehensive Environmental Response, Compensation, and Liability Act
trust fund through a cooperative agreement with the Agency for Toxic Substances
and Disease Registry, Public Health Service, U.S. Department of Health and