Polychlorinated biphenyls ecological effects

In its broadest sense, environmental chemistry might be considered to include the chemistry of everything outside of the synthetic chemist s flask The moment that a chemical substance is released to the environment, its physico-chemical properties may have an enormous impact on ecological systems, including humans. Researchers have identified 51 synthetic chemicals that disrupt the endocrine system. Hormone disrupters include some of the 209 polychlorinated biphenyls (PCBs), and some of the 75 dioxins and 135 furans that have a myriad of documented effects (1). The latter half of the twentieth century has witnessed more synthetic chemical production than any other period in world history. Between 1940 and 1982, the production of synthetic chemicals increased about 350 times. Billions of pounds of synthetic materials were released into the environment during this period. United States production of carbon-based synthetic chemicals topped 435 billion pounds in 1992 or 1600 pounds per capita (2). 

The undesirable ecological effects have also restricted the applications of polychlorinated biphenyls (PCBs), the substances which are used in the cooling of high voltage electrical transformers. The main disadvantage of the use of PCB s is their slow rate of degradation after use. Dichlorodiphenyltrichloroethane (DDT) is a very efficient insecticide, but its use is restricted due to its carcinogenic and neurotoxic effects. 

---