| QUESTIONS | ANSWERS |
|---|---|
| What is this chemical? | Polychlorinated biphenyls (PCBs) are mixtures of up to 209 individual chlorinated compounds, which are composed of two benzene rings.
Polychlorinated biphenyls (PCBs) are no longer produced in the United States, but are still found in the environment. |
| What is its purpose? | PCBs were widely used for many applications, especially as dielectric fluids in transformers, capacitors, and coolants.
Due to PCB’s toxicity and classification as a persistent organic pollutant, PCB production was banned by the United States Congress in 1979 and by the Stockholm Convention on Persistent Organic Pollutants in 2001. |
| Where is it found? |
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HEALTH CONCERNS Is this chemical a carcinogen? Recent research by the National Toxicology Program has confirmed that PCBs are carcinogens. PCBs were associated with specific kinds of cancer in humans, such as cancer of the liver and biliary tract. Polychlorinated biphenyls (PCBs) have been shown to mimic the action of oestrogen in breast cancer cells and can enhance breast carcinogenesis.
How can it affect me? You can be exposed to PCBs by:
- Using old fluorescent lighting fixtures and electrical devices and appliances, such as television sets and refrigerators, that were made 30 or more years ago. These items may leak small amounts of PCBs into the air when they get hot during operation, and could be a source of skin exposure.
- Eating contaminated food. The main dietary sources of PCBs are fish (especially sportfish caught in contaminated lakes or rivers), meat, and dairy products.
- Breathing air near hazardous waste sites and drinking contaminated well water.
- In the workplace during repair and maintenance of PCB transformers; accidents, fires or spills involving transformers, fluorescent lights, and other old electrical devices; and disposal of PCB materials.
You can reduce the risk of exposure to polychlorinated biphenyls (PCBs) by:
- You and your children may be exposed to PCBs by eating fish or wildlife caught from contaminated locations. Certain states, Native American tribes, and U.S. territories have issued advisories to warn people about PCB-contaminated fish and fish-eating wildlife. You can reduce your family’s exposure to PCBs by obeying these advisories.
- Children should be told not play with old appliances, electrical equipment, or transformers, since they may contain PCBs.
- Children should be discouraged from playing in the dirt near hazardous waste sites and in areas where there was a transformer fire. Children should also be discouraged from eating dirt and putting dirty hands, toys or other objects in their mouths, and should wash hands frequently.
- If you are exposed to PCBs in the workplace it is possible to carry them home on your clothes, body, or tools. If this is the case, you should shower and change clothing before leaving work, and your work clothes should be kept separate from other clothes and laundered separately.
PCBs readily penetrate skin, PVC (polyvinyl chloride), and latex (natural rubber). The most commonly observed health effects in people exposed to extremely high levels of PCBs are skin conditions such as chloracne and rashes, but these were known to be symptoms of acute systemic poisoning dating back to 1922. Studies in workers exposed to PCBs have shown changes in blood and urine that may indicate liver damage.
In Japan, 1968, PCB contaminated rice bran oil used as chicken feed resulted in a mass poisoning known as Yushō Disease in over 14,000 people. Common symptoms included dermal and ocular lesions, irregular menstrual cycles and a lowered immune response. Other symptoms included fatigue, headache, cough, and unusual skin sores. Additionally, in children, there were reports of poor cognitive development.
There have also been studies of the health effects of PCBs in the general population and in children of mothers who were exposed to PCBs.
Are there controversial issues? No. The toxicity of PCBs had been known since before its first production through researches done by producing companies themselves back in the 1930s, however these conclusions were dismissed as neglectable.
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