Biomagnification

accumulation of a substance by an animal which preys on other animals that have themselves already accumulated such substance in its tissue. This process can bring to accumulation of a remarkably high concentration of persistent chemicals or heavy metals in organisms of predators being at the end of trophic chains even if a tolerance level of such matter in the environment is rather low. A chemical burden accumulated within a lifetime can be also transferred to the younger animals through their eggs (in case of birds) or through the placenta and breast milk (among mammals).