Movement of these pollutants involves two main processes:
- Bioaccumulation
refers to how pollutants enter a food chain. there is an increase in concentration of a pollutant from the environment to the first organism in a food chain.
- Biomagnification
refers to the tendency of pollutants to concentrate as they move from one trophic level to the next. there is an increase in concentration of a pollutant from one link in a food chain to another.
In order for biomagnification to occur, the pollutant must be: long-lived, mobile, soluble in fats, biologically active.
If a pollutant is not active biologically, it may biomagnify, but we really don’t worry about it much, since it probably won’t cause any problems Examples : DDT.