To investigate pesticide residues in agricultural water, this monitoring was conducted over fifty surface waters. The detected residue data carried out ecological risk assessment by using toxicity exposure ratio of fish, algae and Daphnia.
Method and Results
Fifty sampling site were selected through main stream in Korea and water smaples were collected two times, which one is non-peak season of using pesticides from April to May and another is peak season from August to September. After that water samples were collected, analyzed with 136 pesticides by using LC-MS/MS and GC/ECD. As a results, eleven pesticides were detected with two herbicides, three fungicides and six insecticides on non-peak season. Twenty eight pesticides were detected with three herbicides, fourteen fungicides and eleven insecticides at peak season. More than ten times of detected pesticides were azoxystrobin, butachlor, carbofuran, chlorantraniliprole, isoprothiolane and thiamethoxam. As a result of ecological risk assessments, butachlor, carbendazim and oxadiazon have been assessed to be hazardous to algae in accordance with EU regulations.
Pesticides in the surface water samples were associated with frequency and time of pesticide use especially for paddy rice. As a results of ecological risk assessment, five pesticides (butachlor, carbendazim, carbofuran, chlorantranilprole and oxadiazon) was evaluated to potencial risk and risk. So, this study suggests pesticide safety management on surface water to protect fish, algae and Daphnia.