ABSTRACT
Ecotoxicology is primarily concerned with the effects of chemicals expressed at the levels of population, community, or ecosystem. That said, effects at the level of population and above are usually the consequence of effects upon individuals. Thus, lethal and sublethal effects of pollutants on individuals of a species can lead to population decline if they are severe enough. Such effects can be measured upon live animals and plants in the laboratory. This issue will be discussed further in Chapter 4.
