Persistent Organic Pollutants (POPs) have been identified as chemical substances which are not only bio accumulative but also persistent posing risk to health and the environment.
They are branched chain, chain or ring organic compounds that are noted for their resistance to biological, chemical, or photolytic degradation or breakdown. Persistent Organic Pollutants, also mentioned Persistent Toxic Substances (PTS) are also characterized by their property to accumulate in lipid as a result of their very limited solubility in water.
Although many different forms of POPs may exist, bolt natural and anthropogenic, persistent organic pollutants wich are much noted for their persistence and bio accumulative characteristics include many of the first generation organochlorine insecticides such as aldrin, dieldrin, tocaphene, chlordane and DDT an several industrial chemical products or by products including PCBs, dioxins and furan, in total 12 POPs and also called “The Dirty Dozen”. These compounds when used in large quantities have the ability to bio accumulate and bio magnify, as a result of their environmental persistence.
Some of these compunds such as PCBs may persist in the environment for periods of decades and may bio concentrate by factor up to 70.000 fold!
Fish, predatory birds, mammals and humans are high up the food chain and so absorb the greatest concentrations. When they travel the POPs travel with them.