bioaccumulate

Bioaccumulate refers to the process by which an organism accumulates a chemical from its environment or diet at a rate faster than it can eliminate it, leading to increasing body burdens over time. Substances commonly involved include persistent organic pollutants, heavy metals, pesticides, and pharmaceuticals, and the phenomenon affects plants, invertebrates, fish, and terrestrial animals.

Uptake occurs through gills, skin, or roots, and through food. Once inside, the chemical may be stored in fat, liver, or bone, or bound to proteins; metabolism and excretion determine the clearance rate. Lipophilic, persistent compounds tend to build up, particularly if exposure is continuous and elimination is slow. Quantitative terms such as bioaccumulation factor (BAF) or bioconcentration factor (BCF) are used to describe the tendency of a chemical to accumulate in an organism relative to environmental exposure.

Bioaccumulation is distinct from biomagnification, which describes increasing concentrations at higher trophic levels along a food chain. Notable examples include methylmercury in fish, and polychlorinated biphenyls (PCBs) and DDT in various wildlife. Plants can also accumulate metals from soil, a process exploited in phytoremediation, though it is still a form of bioaccumulation when discussing uptake into plant tissues.

Implications and management: bioaccumulation can pose risks to wildlife and human health through consumption of contaminated organisms. Risk assessment, environmental monitoring, and regulatory limits aim to minimize exposure, while pollution reduction and site remediation seek to limit ongoing accumulation in ecosystems.