How do aldrin, dieldrin, and PCBs accumulate in fish?
Dieldrin and PCBs have been found in soil, ground and surface water, air, sediment, plants, and animals in all regions of the world. These contaminants break down very slowly in the environment and accumulate in fatty tissue, skin, and internal organs of fish and other animals. Levels of these contaminants in fish may be hundreds to a million times higher than the concentrations found in water or sediments. The amount of aldrin, dieldrin, and PCBs found in fish varies with species, age, size, fat content, diet, and surface water and sediment concentrations. Generally, larger, older fish such as catfish species and smallmouth buffalo may contain higher levels of aldrin, dieldrin, and PCBs than lean fish such as the black bass species and crappie.
