广东省典型区域农业土壤中六六六(HCHs)和滴滴涕(DDTs)的残留及其分布特征

2002年10月—2005年11月采集广东省典型区域(汕头市、湛江市、东莞市、惠州市、中山市、珠海市和佛山市顺德区)的农业土壤表层(0～20 cm)样品444个，采用气相色谱方法对土壤中六六六(HCHs)和滴滴涕(DDTs)进行分析，初步揭示广东省农业土壤中有机氯农药的分布及残留情况. 结果表明:HCHs的检出率为95.9%，w(HCHs)为未检出～104.38 ng/g，平均值5.90 ng/g；DDTs的检出率为95.7%，w(DDTs)为未检出～157.75 ng/g，平均值为10.18ng/g. HCHs的4种异构体中，w(β-HCH)最高，平均值为2.96 ng/g，而p,p′-DDE是3种DDTs异构体中含量最高的，平均值为5.09 ng/g. 不同土壤利用类型中，有机氯农药残留总量为水稻田>菜地>香蕉地>旱坡果园地>甘蔗地，汕头市土壤中有机氯农药残留总量明显高于该研究区的其他地方. 与国内外其他地区农业土壤中的DDTs和HCHs含量和我国土壤环境质量标准(GB15618-1995)相比，广东省典型区域污染程度较低. 

Residues and Distribution Character of HCHs and DDTs in Agricultural Soils from the Typical Areas of Guangdong Province

444 samples of surface agricultural soils (0～20 cm depth)were collectedin the typical areas of Guangdong Province (Shantou, Zhanjiang, Dongguan, Huizhou, Zhongshan and Zhuhai Cities, and Shunde District of Fushan City) in October 2002—November 2005. The residues and distribution character of HCHs and DDTs insoil were analyzed with gas chromatography. The result showed that HCHs were found in 95.9% of the collected soil samples and ranged from nd to 104.38 ng/g with average contents of 5.90 ng/g; and DDTs were found in 95.7% and ranged from nd to 157.75 ng/g with average contents of 10.18 ng/g. The highest contents of β-HCH (with average contents of 2.96 ng/g) among 4 HCHs isomers and of p,p′-DDE(with average contents of 5.09 ng/g) among 3 DDTs isomers were observed. The contents of organochlorine pesticides in different soils were in the order as follows:paddy soils>vegetable soils> banana soils> orchard soils> sugarcane soils, and there were the higher concentrations of organochlorine pesticides in the collected samples of Shantou than those of remote sites. Compared with those in other regions and Soil Environment Quality Standard (GB15618-1995), the HCHs and DDTs of pollution were generally slight in agricultural soils from the typical areas of Guangdong Province.