Dissipation Of Carbendazim, Chlorothalonil And Chlorpyrifos In Cucumber And Soil Inside The Greenhouse And Soil Genotoxicity Induced By The Pesticides

Greenhouse production of vegetables has been developed quickly in China, but fast reproduction of fungal disease and pest is frequently observed duo to the high temperature and humidity inside the greenhouse, which result in extensive and frequent applications of different pesticides. Increasing concern has been expressed regarding food safety and soil health under greenhouse condition. Two fungicides (carbendazim and chlorothalonil) and one insecticide (chlorpyrfos) were selected as target pesticides in this study to investigate the dissipation characteristics of these pesticides in cucumber and soil inside the greenhouse. The accumulation possibility of these pesticides in soil after successive applications and genotoxicity of soil polluted by these pesticides were also examined. The results were summarized as follows:1) The dissipation of carbendazim, chlorothalonil and chlorpyrfos in cucumber and the dissipation of carbendazim, chlorothalonil in soil were fitted to the fist-order model. The half-lives (DT50) of carbendazim, chlorothalonil and chlorpyrfos in cucumber at the recommendation dose and the double recommendation dose were2.83and2.67d,2.24and2.02d,5.26and3.64d, respectively. The DT50of carbendazim and chlorothalonil in soil at the recommendation dose and the double recommendation dose were13.28and9.84d,8.52and6.11A, respectively.2) The residual amount of the three pesticides in soil increased with their increasing application concentrations and frequency, and obvious accumulation of pesticidesin soil of all treatments except for the recommendation dose of chlorpyrfos were observed. The level of carbendazim, chlorothalonil and chlorpyrfos measured on ninth day after its seventh application at the recommendation dose and the double recommendation dose was about2.83and2.40times,8.74and4.37times,2.07and4.95times of that measured ninth day after its first application, respectively.3)High frequency of micronucleus was induced by the three pesticides. Micronucleus frequency of Vicia faba, treated with carbendazim, chlorothalonil, chlorpyrfos at3,2,3mg/L, was significant difference with that of control, respectively.4) Genotoxicity of the soils contaminated by the three pesticides was monitored with micronucleus frequency of Vicia faba.Soil genotoxity increased with carbendazim, chlorothalonil and chlorpyrfosconcentration. Moreover, soil genotoxity was obviously enhanced when carbendazim combined with chlorothalonil or chlorpyrfos.