Chemical behavior and risk assessment of four pesticidesin soil and water

The degradation of pesticides in the environment is a very important index in evaluation the ecologi- cal risk of pesticides , the degradation of pesticides varies with their physico - chemical properties. In this pa-per , four pesticides including rnethyl - ISP (N - isopropyl - o - methyl - o -(2- isopropyl oxo - carbonyl) phenylphosphorthia midoate] ; rnonocarboxoldehyde N -(2 , 4- dimethylbenzyl - N - methyl amidine) hydrochloride] :pyrirnyxthion o , o diethenyl - o -( 2- methoxy -4- methyl pyrimidine -6-)phosphorothioate] which are three ef-fective insecticides used to control many pests of paddy field and cotton field and propachlor 2- ethenyl - N -(ethongmethyl]-2- monochloroacetamide] which is an effective herbicide used to control annual weeds , wereselected and their degradation dynamics in soil and water under different conditions were studied.