Bioaccumulation

Bioaccumulation is the net buildup of a substance in an organism over time when uptake from water and food outpaces metabolism and excretion. Lipophilic and persistent contaminants such as PCBs, DDT, and methylmercury accumulate most. It is quantified by the bioconcentration factor (organism-to-water ratio). When the accumulated load increases at each step up the food chain, the related process is biomagnification, which exposes top predators and seafood consumers.