Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism.[1] Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high.[2] Bioaccumulation, for example in fish, can be predicted by models.[3][4] Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data.[5]Biotransformation can strongly modify bioaccumulation of chemicals in an organism.[6]
Toxicity induced by metals is associated with bioaccumulation and biomagnification.[7] Storage or uptake of a metal faster than it is metabolized and excreted leads to the accumulation of that metal.[8] The presence of various chemicals and harmful substances in the environment can be analyzed and assessed with a proper knowledge on bioaccumulation helping with chemical control and usage.[9]
An organism can take up chemicals by breathing, absorbing through skin or swallowing.[7] When the concentration of a chemical is higher within the organism compared to its surroundings (air or water), it is referred to as bioconcentration.[1] Biomagnification is another process related to bioaccumulation as the concentration of the chemical or metal increases as it moves up from one trophic level to another.[1] Naturally, the process of bioaccumulation is necessary for an organism to grow and develop; however, the accumulation of harmful substances can also occur.[7]