Abstract

Pesticides have played a very important role in enhancing the world food production for decades. However, their continuous and indiscriminate use has resulted in various ecological problems. Apart from creating environmental problems, pesticides and their metabolites have entered various natural ecosystems, viz., aquatic, terrestrial, soil, etc. Several groups of organochlorine pesticides such as Dichlorodiphenyltrichloroethylene (DDT), endosulfan, and chlorinated phenoxy acetic acid used as herbicides, and fungicides such as hexachlorobenzene and pentachlorophenol are major pollutants polluting various water bodies and affecting the aquatic fauna. Extensive use of pesticides have resulted in outbreaks of many serious pests, viz., codling moth, leafrollers, aphids, scales, and tetranychid mites, and in the decline of the population of pollinators and natural enemies. Herbicides, viz., atrazine, have been found to feminize frogs, leading to sterility in males and many adverse affects on humans. Human health is at risk when chemical residues are present in much of our food supplies. Integrated pest management emphasizes the need for simpler and ecologically safer measures for pest control to reduce environmental pollution. Preference may be given to organic produce grown without toxic pesticides. The objective of this entry is to provide basic knowledge on pesticide exposure and to understand issues on residues in the natural ecosystem.