PCBs are Polychlorinated biphenyls, which are aromatic compounds consisting of biphenyl molecules (two bonded benzene rings), where the hydrogen atom in the biphenyl is replaced by two to 10 chlorine atoms (Cl). There are 203 congeners of PCBs, of which 130 are already used commercially, as dielectric coolants and electrical insulators in electrical equipment, particularly in transformers and electrical capacitors. This is because Polychlorinated biphenyls have a high flash point (3800C) so they are one of the most stable compounds.
Because they are very stable, PCBs are widely used as additives in equipment used in sensitive locations, such as underground mines, hospitals, schools and others. The goal is to reduce the risk of overheating and burning the electrical equipment. More than 60% PCBs are used in transformers and capacitors. PCBs are very useful. However, after being used, PCBs turned out to be very toxic and dangerous because they can cause various diseases and trigger cancer. PCBs become more dangerous because they are persistent, bioaccumulative, and transboundary. This means that PCBs that are released into the environment (soil and water) will not be easily destroyed naturally (because they are very stable).
PCBs are fat soluble, so they will accumulate in the body of living things, and move through the food chain. In various parts of the world, and in Indonesia, PCBs have been found in vegetables, fruits, and fish consumption. Because they are not easily destroyed when released in nature and remain in the body, PCBs can migrate globally through water and wind cycles, and through migration of migratory species. It is not surprising that PCBs have been found in whales and polar bears, in places where there is no human activity at all!
Source: ecoverse.id