the study of how chemicals affect entire ecosystems.

The science of poisons and toxic substances occurring in the environment and their effects.

Study of the toxic effects of chemical and physical agents on all living organisms, especially on populations and communities within defined ecosystems; it includes transfer pathways of these agents and their interactions with the environment

The term "ecotoxicology" was coined by Truhaut in 1969, who defined it as "the branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animal (including human), vegetable and microbial, in an integral context” (Truhaut, 1977). Ecotoxicology is alleged to be the integration of toxicology and ecology or, as Chapman (2002) suggested “ecology in the presence of toxicants”. It aims to predict the effects upon natural communities - ‘the ecosystem’- of stressors, be they anthropogenic in origin or otherwise.