Department of Environmental Toxicology, College of Agricultural and Environmental Sciences, University of California, Davis, CA 95616-8588, USA.
Rev Environ Contam Toxicol. 2013;222:93-109. doi: 10.1007/978-1-4614-4717-7_3.
The insecticide methomyl, an oxime carbamate, was first introduced in 1968 for broad spectrum control of several insect classes, including Lepidoptera, Hemiptera, Homoptera, Diptera, and Coleoptera. Like other carbamates, it inhibits AChE activity, resulting in nerve and/or tissue failure and possibly death. Considered highly toxic to insects (larval and adult stages), methomyl is thought to be metabolically degraded via mixed-function oxidase(s). Methomyl has both a low vapor pressure and Henry's law constant; hence, volatilization is not a major dissipation route from either water or moist or dry soils. Photolysis represents a minor dissipation pathway; however, under catalytic conditions, degradation via photolysis does occur. Methomyl possesses a moderate-to-high water solubility; thus hydrolysis, under alkaline conditions, represents a major degradation pathway. Methomyl has a low-to-moderate sorption capacity to soil. Although results may vary with soil type and organic matter content, methomyl is unlikely to persist in complex soils. Methomyl is more rapidly degraded by microbes, and bacterial species have been identified that are capable of using methomyl as a carbon and/or nitrogen source. The main degradation products of methomyl from both abiotic and biotic processes are methomyl oxime, acetonitrile, and CO₂. Methomyl is moderately to highly toxic to fishes and very highly toxic to aquatic invertebrates. Methomyl is highly toxic orally to birds and mammals. Methomyl is classed as being highly toxic to humans via oral exposures, moderately toxic via inhalation, and slightly toxic via dermal exposure. At relatively high doses, it can be fatal to humans. Although methomyl has been widely used to treat field crops and has high water solubility, it has only infrequently been detected as a contaminant of water bodies in the USA. It is classified as a restricted-use insecticide because of its toxicity to multiple nontarget species. To prevent nontarget species toxicity or the possibility of contamination, as with all pesticides, great care should be taken when applying methomyl-containing products for agricultural, residential, or other uses.
杀虫剂灭多威，肟基氨基甲酸酯类，于 1968 年首次引入，用于广泛控制几类昆虫，包括鳞翅目、半翅目、同翅目、双翅目和鞘翅目。与其他氨基甲酸酯类一样，它抑制乙酰胆碱酯酶的活性，导致神经和/或组织衰竭，甚至死亡。由于对昆虫（幼虫和成虫阶段）具有高毒性，因此认为灭多威通过混合功能氧化酶代谢降解。灭多威具有较低的蒸气压和亨利定律常数；因此，挥发不是水或潮湿或干燥土壤中主要的消散途径。光解代表一个较小的消散途径；但是，在催化条件下，确实会通过光解进行降解。灭多威具有中等至高的水溶性；因此，在碱性条件下，水解是主要的降解途径。灭多威对土壤的吸附能力低至中等。尽管结果可能因土壤类型和有机质含量而异，但灭多威不太可能在复杂土壤中持久存在。灭多威被微生物更快地降解，并且已经鉴定出能够将灭多威用作碳和/或氮源的细菌物种。灭多威的主要降解产物无论是来自非生物还是生物过程，都是灭多威肟、乙腈和 CO₂。灭多威对鱼类具有中等至高毒性，对水生无脊椎动物具有极高毒性。灭多威对鸟类和哺乳动物具有高度经口毒性。灭多威通过口服暴露对人类属于高度毒性，通过吸入暴露属于中度毒性，通过皮肤暴露属于轻度毒性。在相对较高的剂量下，它可能对人类致命。尽管灭多威已被广泛用于处理田间作物，并且具有高水溶性，但在美国，它很少被检测为水体污染物。由于其对多种非目标物种的毒性，它被归类为限制使用的杀虫剂。为了防止非目标物种毒性或污染的可能性，与所有农药一样，在农业、住宅或其他用途中使用含灭多威的产品时应格外小心。
