Study on Characteristics of Pyrethroid Pesticides Residues in Dianchi Lakeshed

To investigate the pollution of pyrethroid pesticides of soil in Dianchi lakeshed,soil samples were collected from cultivated fields and pyrethroid pesticides residues represented with Cyhalothrin,Cypermethrin,Fenvalerate,Cyfluthrin and Deltamethrin,were analyzed by gas chromatography ECD detector.The results showed that among 5 pyrethroid pesticides the detection rates of Cyhalothrin and Cypermethrin were higher than others pesticides in soil samples from cultivated vegetables and flowers,and it ranged from 66.7 % to 100 %,from 52.9 % to 100 %,respectively.And the average level of Cyfluthrin was the highest with 44.9 μg/kg in vegetables fields.However,the residues level were different in seasons,the Deltamethrin were only detected in soils collected in autumn.The residues in flower fields were higher than those in vegetables fields of spring and autumn;the situation was contrary in summer and winter.Comparing the pyrethroid pesticides residues in greenhouse with open fields,the residues in greenhouse were higher than those in open field.The difference of 5 pyrethroid pesticides residues amount in different soil layers was not significant except for Cypermethrin.The issue of pyrethroid pesticides pollution was discussed,because there was not soil environmental quality standards of pyrethroid pesticide residues in soil,the exceeded rate of residues in soils could not be determined.But the environment problems of pyrethroid pesticides residues in soils should be paid more attention.