Definition of bioaccumulation?

Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost. Thus, the longer the biological half-life of the substance the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation explains why chronic poisoning is a common aspect of environmental science in the workplace. Repeated exposure to very low levels of toxins in these environments can be lethal over time.