Sun J, Chen B, Yao P
Institute of Occupational Medicine, Chinese Academy of Preventive Medicine, Beijing 100050, China.
Wei Sheng Yan Jiu. 2000 Mar 30;29(2):65-8.
The acute oral toxicity (LD50) of two pesticides combined from 3 categories of insecticides, i.e. organophosphates(OPs), pyrethroids and carbamates, was evaluated by Harris method on equal toxicity doses. The OPs compounds studied included: methylparathion, omethoate, methamidophos, phoxim, dichlorvos, profenofos, isocarbophos and malathion; the pyrethroids: alpha-cypermethrin, deltamethrin, fenvalerate and fenpropathrin; the carbamates: methomyl, isoprocarb and metolcarb. The mixtures of two OPs on the combination of dichlorvos plus omethoate and methamidophos plus profenofos showed additive effects, but methylparathion plus phoxim showed antagonistic effect. Most of the combination of OPs with pyrethroids showed synergistic effects, such as the mixtures of phoxim plus deltamethrin, phoxim plus alpha-cypermethrin, methlyparathion plus alpha-cypermethrin and ioscoarbphos plus fenpropthrin, with the exception of two mixtures showed additive effects: phoxim plus fenvalerate resulting in 1.5 times higher toxicity than expected, while dichlorvos plus deltamethrin resulting in less toxicity than expected. The effects of the mixtures of OPs and carbamates: phoxim plus methomyl and methamidophos plus metolcarb, were all additive, but the mixtures of he methylparathion plus methomyl showed antagonistic effect and malathion plus isoprocarb were synergistic. The biochemical mechanisms of changed toxicity of pesticides mixtures were discussed based on their toxicokinetics and toxicodynamics. It was concluded that the combined effects of insecticide mixtures were additive for OPs plus OPs or plus carbamates in most cased, but synergistic for OPs plus pyrethroids.
采用哈里斯法，以等毒性剂量评估了3类杀虫剂（即有机磷类、拟除虫菊酯类和氨基甲酸酯类）中两种农药组合的急性经口毒性（半数致死剂量，LD50）。所研究的有机磷化合物包括：甲基对硫磷、氧乐果、甲胺磷、辛硫磷、敌敌畏、丙溴磷、水胺硫磷和马拉硫磷；拟除虫菊酯类包括：高效氯氰菊酯、溴氰菊酯、氰戊菊酯和甲氰菊酯；氨基甲酸酯类包括：灭多威、异丙威和速灭威。两种有机磷组合中，敌敌畏加氧乐果以及甲胺磷加丙溴磷表现出相加作用，但甲基对硫磷加辛硫磷表现出拮抗作用。大多数有机磷与拟除虫菊酯的组合表现出协同作用，如辛硫磷加溴氰菊酯、辛硫磷加高效氯氰菊酯、甲基对硫磷加高效氯氰菊酯以及水胺硫磷加甲氰菊酯，但有两种组合表现出相加作用：辛硫磷加氰戊菊酯的毒性比预期高1.5倍，而敌敌畏加溴氰菊酯的毒性比预期低。有机磷与氨基甲酸酯的组合效果：辛硫磷加灭多威以及甲胺磷加速灭威均表现为相加作用，但甲基对硫磷加灭多威表现出拮抗作用，马拉硫磷加异丙威表现为协同作用。基于农药混合物的毒代动力学和毒效动力学，讨论了其毒性变化的生化机制。得出的结论是，在大多数情况下，杀虫剂混合物的联合效应在有机磷加有机磷或加氨基甲酸酯时为相加作用，但在有机磷加拟除虫菊酯时为协同作用。
