Polychlorinated Biphenyl (PCB) in Environment: Contamination, Toxicity, and Carcinogenicity

Abstract

Polychlorinated Biphenyl (PCB) compounds which are widely used in industry have become a widespread and sustainable environmental problem for decades. PCB is chemically stable, low volatility, non-flammable, and high dielectric constant. Its main uses include heat exchange and dielectric fluids in transformers and capacitors, hydraulic fluids and lubricants, diffusion pump oils, plasticizers for plastics, and so on. PCBs are biologically magnified in the food chain and found in fish, wildlife, and human tissues. PCBs have been identified as contaminants in water, air, and soil, and are distributed up to the polar regions. According to epidemiological studies reporting blood levels of PCBs, the higher the level of exposure, the higher the blood concentration of PCBs, and the higher the environmental concentration or the longer the exposure period (or both), the longer the blood levels of PCBs remain elevated. PCB levels also correlate with race, place of residence (geographical), age, and dietary intake of fish in humans. PCBs have a very low potential to produce acute toxic effects. PCB exposure has been linked to having a particular skin rash commonly referred to as “chloracne”. Liver damage was the most consistent finding among the many laboratory animal species tested. Yusho refers to the epidemic of poisoning by consumption of cooking oil contaminated with PCBs and polychlorinated dibenzofuran. Mothers with Yusho experience stillbirth, abnormal skin pigmentation, or babies tend to be small when compared to the national average. Some PCB compounds are carcinogenic in a number of rodent bioassays, producing liver tumors. Based on the available animal data, PCBs should be considered potential carcinogens for humans. Keywords: Polychlorinated Biphenyl, pollution, contamination, toxicity, carcinogenicity.