Polychlorinated biphenyls, or PCB’s, are part of a family of man-made organic chemicals called chlorinated hydrocarbons. PCB’s are composed of a variety of chlorinated biphenyl components. They vary in toxicity as well as consistency, are non-flammable, chemically stable, have a high boiling point, and are a good electrical insulator. They are odorless, tasteless and are generally invisible or very light yellow in color.
PCB’s were manufactured between 1929 and 1979 for both commercial and industrial uses. During this time, PCB’s were used in electrical and hydraulic equipment, paint, plastic, rubber, pigments, dyes, carbonless copy paper, and other products. PCB’s were also sprayed on dirt roads to keep the dust from rising. Approximately 1.5 billion pounds of PCB’s were manufactured while effects were not known.
The harmful effects of PCB’s began to be discovered in 1960, when traces of PCB’s, which had entered the environment through manufacturing spills and leaks, and traces were found in people and animals across the world. PCB’s were eventually banned in 1979.
Despite the fact that PCB’s are no longer being manufactured, they can still be found in some products manufactured before 1979, including transformers, capacitors, some electrical equipment, motor oil, oil used in hydraulic systems, fluorescent light ballasts, cable insulation, thermal insulation material, adhesives, tape, oil-based paint, caulking, and floor finishes.
PCB’s are a public health concern, as well as an environmental concern. They are known to cause cancer and to adversely affect the immune system, reproductive system, nervous system, and endocrine system. PCB’s do not easily break down, and therefore remain in the environment for a long time. They cycle between air, water, and soil, and can accumulate in small organisms as well as plants and food crops. PCB’s can also be carried a long way from the source of the contamination, and therefore, are found all over the world.
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