Wildlife Exposure to Organophosphorus Insecticides

Abstract

Organophosphorus (OP) insecticides continue to be an important group of pesticides widely used worldwide in spite of the introduction of the modern synthetic pyrethroids. The success of this class of compounds as insecticides is due to three main characteristics: (1) they show a relatively low persistence in the environment in comparison with their predecessors, the organochlorine (OC) insecticides; (2) they show low accumulation by biota; and (3) they generally exhibit a high acute toxicity. OPs can be broken down by a large variety of physicochemical and biological processes, such as hydrolysis, photolysis, or microbial degradation. They present a wide range of half-lives in the environment, from a few days to several months. For instance, degradation half-lives of OPs on plant foliage ranged between 0.2 to 10.5 d while in soil the range was between 7 and 144 d, depending on the OP and soil type (Racke 1992). Half-lives in water ranged from a few hours—at high temperature or pH, or in the presence of light—to more than 6 mon (Lartiges and Garrigues 1995).KeywordsAChE ActivityEnviron ToxicolBrain AChEArch Environ Contam ToxicolBull Environ Contam ToxicolThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.