Polychlorinated byphenyls (PCBs)

Polychlorinated byphenyls (PCBs) were manufactured as a man-made chemical beginning in the 1920s and are part of a group of compounds called congeners. (1)

Produced globally for use in various industrial and commercial applications, they were favored for their unique characteristics.  Non-flammability, stability, and electrical insulating properties, PCBs were included for use in electrical manufacturing, hydraulics, plastics, paint, and rubbers. (2)

After several decades of use, it was discovered that PCBs aggressively enter the food chain during their manufacture and use, as well as spills and leaks from industrial accidents, or from damage or destruction of the material they were used in.   The high capacity for bioaccumulation in lower reaches of the food chain, made them extraordinarily hazardous to humans.  Typically collecting in sediments, they are ingested by fish, their prey, and so on, until finally entering the human food supply. (1)

Health effects associated with exposure to PCBs are primarily concerned with damages to prenatal conditions; predominantly, the disruption of thyroid hormone systems, which can complete stop, alter or inhibit human brain development.  Excessive exposure to PCBs in postnatal situations can affect brain, eye, heart, immune, kidney, liver, skin, reproductive systems, and could lead to cancer. (1)

1. Polychlorinated biphenyls (PCBS):  Detox Campaign Fact Sheet. [article online] 2005.  Available from http://assets.panda.org/downloads/fact_sheet___pcbs_food.pdf .  Accessed 2009 Nov 21.
2. PCBs (Polychlorinated Biphenyls).  Pollution Issues.  [article online]  2009.  Available from http://www.pollutionissues.com/Na-Ph/PCBs-Polychlorinated-Biphenyls.html .  Accessed 2009 Nov 21.