Residual characteristics of HCHs and DDTs in agricultural soils from Guangzhou

One hundred and eighteen samples of surface agricultural soils (0～20 cm depth)were collected from Guangzhou ,The residues and distribution character of HCHS and DDTS in soil were analyzed by GC/ECD (Gas chromatography with electrochemical detection), The underlying risk were assessed with risk evaluation criterion. The results showed that HCHs were found in 95.8% of the collected soil samples and ranged from ND to 17.96 ng·g-1 with average contents of 2.10 ng·g-1, and DDTs were found in 92.4% and ranged from ND to 327.87 ng·g-1 with average contents of 18.97 ng·g-1. The highest contents of β-HCH with average con- tents of 0.86 ng·g-1 among 4 HCHs isomers and of p,p′-DDE with average contents of 11.89 ng·g-1 among 4 DDTs isomers were observed. The cultivated land contents of organochlorine pesticides in different soils were obvious higher than woodland and orchard land. Compared with those in other regions and China’s Soil Environment Quality Standard (GB15618-1995), the HCHs and DDTs of pollution were generally slight in agricultural soils from Guangzhou.