Polychlorinated biphenyls (PCBs) are organic compounds with two to ten chlorine atoms. Thus there are 209 substances of high toxicity. These are used as coolant, insulating fluid in transformers, additive in PVC coated electrical wires and electronic components. These are also present in carbonless copy paper, adhesives and in paints. Most PCBs are toxic and so these were banned in 1970. But these groups are classified as persistent organic pollutants which bio accumulates in humans and animals even today.

PCBs are persistent organic pollutants and these were in the environment through use and waste. These were banned almost 40 years ago but we still found everywhere. Unfortunately these are still used in transformers. The very bad thing in our world is even if a toxic substance is banned in one country they produce this and sell to other countries, particularly to developing countries which may not have strict environmental laws and enough supervision in handling and disposal. But the wastes formed during production of organochlorines would be disposed in some poor countries. Tourism with industrial chemical wastes should not be allowed and the persons organizing this dirty business must be punished seriously.

PCBs have many negative adverse effects on our health. They include:

• Chloracne
• Rashes
• Yusho disease. PCBs contamination in rice bran oil caused a mass poisoning in Japan
• Irregular menstrual cycles
• Lowered immune response
• Fatigue
• Headache
• Cough
• Skin sores

The PCBs exposure could come from workplace contamination and consumption of contaminated fish or food. The exposed pregnant gave birth to babies who weighed less than babies born to the unexposed mothers. But problems with motor skills and a decrease in short-term memory lasted for several years. Immune system was affected also in children born to mothers exposed to PCBs. Infants are exposed through mother’s milk.

PCBs can alter estrogens level and the result may be reproduction problems. Intersex and feminization in the womb are reported. This pollution is so strong that polar bears and whales are there with both male and female sex organs and males incapable for reproduction.

There are cancer risks due to PCBs. These are associated with liver and biliary tract cancer.

PCBs are chemically inert compounds and they have a high thermal stability. They are resistant to chemical oxidation, photodegradation, acid-base reactions and hydrolysis. Therefore, it is difficult for natural systems to metabolize PCBs. The estimated half life period of PCBs is approximately 8 to 15 years.

It is not advisable to eat fishes from unknown waters. However, fish from the commercial food supply may be eaten. Never burn painted or treated wood. Burning materials that contain PCBs produce dioxins and furans which are more toxic.

Appropriate safety measures must be available in workplace.