PCBs Explained

PCBs or polychlorinated biphenyls is a group of 209 man-made organic compounds. It has two benzene rings (biphenyl) to which are attached chlorine atoms. The different PCBs are distinguished by the number of chlorine atoms attached, which is anywhere from 1 to 10. About 130 of the 209 possible congeners have commercial applications, although in the US, 98% of commercially produced PCBs are confined to just seven congeners.

PCBs are extremely useful because they are heat resistant, non-conductive, and stable compounds. They are useful as coolant and insulating fluids. The most common industrial use for PCBs is in transformers and capacitors. PCBs are also added to paints, cements, electrical wiring, PVC coating, pesticides, flame retardants, hydraulic fluid, and sealants for a variety of reasons. The compound is produced under various trade names. Monsanto PCBs go by the name of Aroclor, and Monsanto Company is the only US producer of PCBs in the US.

PCBs are extremely useful across many industries, including paper production and medical equipment. It is unfortunate that the properties that make it so useful are the same properties that make it highly toxic to the environment, animal life, and humans.

PCBs do not exist in nature. Prior to its discovery in 1881 by German scientists, there was no PCB detectable in the environment. However, once it escapes into the soil, water, and air, it does not degrade on its own. The worst thing is it permeates into the tissue of fish and other animals, which then moves up the food chain. Studies have shown that it causes cancer in lab animals, and is probably carcinogenic to humans.

It is extremely difficult and expensive to manage PCB contamination. Wastes containing PCBs dumped in landfills and rivers in the 1930s are still detectable today despite massive efforts to eradicate them. Fish from certain rivers are no longer safe to eat, and residents near rivers and landfills are at high risk of developing health complications from PCB exposure by simply breathing.

The problem of PCB is on a global scale. The most badly hit cities in the US are currently struggling with clean up operations. It will take time and it will take money. It is hoped that there is enough of both to keep PCB levels down to manageable levels.

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