Ecotoxicology is a multidisciplinary field, which integrates toxicology and ecology. It is the field of science dealing with study of toxic chemicals and their effect on biological organisms, especially at the population, community and ecosystem state. It devoted to present fundamental advances on the effects of toxic chemicals on terrestrial, freshwater and marine ecosystems. Ecotoxicology differs from environmental toxicology in that it integrates the effects of stressors across all levels of biological organisation from the molecular to whole communities and ecosystems.