Biomagnification

Biomagnification (or bioaccumulation) refers to the ability of living organisms to accumulate certain chemicals to a concentration larger than that occurring in their inorganic, non-living environment, or in the case of animals, in the food that they eat. Of course, organisms accumulate any chemical needed for their nutrition. In environmental science, however, the major focus of biomagnification is the accumulation of certain nonessential chemicals, especially certain chlorinated hydrocarbons that are persistent in the environment, insoluble in water, but highly soluble in fats. Because almost all fats within ecosystems occur in the living bodies of organisms, chlorinated hydrocarbons such as DDT and PCBs tend to selectively accumulate in organisms. This can lead to ecotoxicological problems, especially for top predators at the summit of ecological food webs.