Toxicity, monitoring and biodegradation of organophosphate pesticides: A review

Organophosphates are one of the major constituent of herbicides, pesticides, insecticides and nerve gas. Azinophos-methyl, chlorpyrifos, diazinon, fonofos and disulfoton are well-known organophosphate pesticides (OPs) having extensive applications in agriculture, horticulture, pest control, plastic making, flame retardants and for several household applications. OPs are the ester forms of phosphoric acid, usually considered as safe for agriculture use due to their relatively fast degradation rates. Acute or chronic exposure to OPs can produce varying levels of toxicity in humans, animals, plants, and insects. These are known to inhibit acetylcholinesterase activity, not only in insects but also in aquatic and terrestrial organisms leading to respiratory, reproductive, nervous, hepatic and renal abnormalities. OPs disrupt the growth promoting mechanism by inhibiting various enzymes, transcuticular diffusion and permeability which is essential for the growth of plants. Regular use of OPs subside the microbial community and reduces soil fertility. Due to environmental concerns associated with the accumulation of OPs in food products and water supplies, there is an urgent need to develop rapid, reliable and economical method amenable to onsite applications. Here, we review different classes of organophosphate pesticides, their environmental issues, analytical techniques for estimation, and eco-friendly biodegradation approaches for its efficient bioremediation.