Chronic effects of organic pesticides on the aquatic environment and human health: A review

Aquatic environment could be termed as the intercommunicating arrangement of water, sediment and biota that provide food for humanity. Aquatic environments have deteriorated substantially due to the accumulation of toxic inorganic and organic pollutants that cause potentially adverse, widespread and detrimental effects on human health. Among the toxic pollutants, pesticides are among the most concerning compounds. Pesticides are applied broadly to restrict insect infestation in agricultural crops as well as to eradicate a variety of pests and disease bearing organisms such as mice, rats, ticks and mosquitoes from human habitats and environments. Among the top ten pesticide-using countries of the world, more than 30 % are in South-Asia. Organochlorine pesticides (OCPs) such as dichloro-diphenyl-trichloroethane (DDT), aldrin, dieldrin and polychlorinated biphenyls (PCBs) are among the most environmentally detrimental pesticides. OCPs can persist for more than 40 years among components of the environment such as soil, water, fish tissues, and other aquatic biotas. Environmental integrity and human health are threatened by over 500,000 tons of OCPs in numerous countries. About 1–5 million cases of intense pesticide toxicity happen annually worldwide, causing approximately 200,000 deaths annually, in part because of bio-accumulation and bio-magnification of persistent pesticides. In aquatic environments, pesticide toxicity causes mortality, reproductive failure, egg shell thinning, suppression of the immune system, and other fish health complications such as excessive slime on fish scales and gills, cancers, tumors and lesions. In humans, pesticide toxicity causes short-term diseases such as skin and eye irritation, nausea, dizziness, headaches, and also chronic impacts such as diabetes, asthma and cancer. This review provides the historical overview with regard to the levels and distribution of organic pesticides in a range of environmental compartments of the Asian region as well as a worldwide perspective. It also presents a comprehensive consideration of chronic effects of pesticides on human health.