These are compounds that were produced as industrial chemicals (man-made organic compounds, synthetic) and used in lubricating oils, paints, in carbonless copy paper (non-carbon copy paper – an alternative to carbon paper), in electrical insulators and in many other industrial and commercial products.
PCBs stand for polychlorinated biphenyls where chlorine atoms are attached to biphenyl. Biphenyl is a hydrocarbon that naturally occurs in oil and gas.
Due to toxicity, manufactures of PCBs were banned in 1979 in
Because of high stability, PCBs hardly degrade naturally. And as these compounds are hydrophobic (don’t like to stay with water), they are sorbed on sediments. Microorganisms like bacteria can breakdown the chlorine atoms from biphenyl (dechlorination) as a process of metabolism into ecologically safe molecules. The process is called bioremediation.
The following video shows the research works of Donna Fennell from