海南省瓜菜田土壤中有机氯农药残留及生态风险分析

采用气相色谱法检测了海南瓜菜田的33个表层土壤样品中18种有机氯(OCPs)农药残留,并对其进行污染来源分析和初步生态风险评价。结果表明:(1)土壤中的OCPs检出率为90.9%,最高残留量为17.37 ng·g-1,平均值为2.30 ng·g-1;(2)18种OCPs均有检出,六六六(HCHs)、滴滴涕(DDTs)、硫丹类农药的检出率较高,分别为63.6%、57.6%、54.5%;(3)DDTs是主要残留物质,占总OCPs残留量的54.6%,18.2%的土样可能有DDTs新的输入,土壤中HCHs主要来源于过去使用的林丹;(4)与国内其他地区土壤和国家《土壤环境质量标准》(GB 15618—1995)一级标准相比,海南省瓜菜田土壤DDTs和HCHs残留量处于较低水平,生态风险也较低。

Residues and Eco-risk Evaluation of Organochlorine Pesticides in Agricultural Soils from Typical Vegetable Produce Areas of Hainan Province,China

To determine current levels of organochlorine pesticides (OCPs) and assess their sources, ecological risk in agricultural soils from typical vegetable produce areas of Hainan Province, 33 soil samples were collected and detected by the GC method. The results showed that OCPs were found in 90.9% of the collected soil samples and ranged from Not Dedected (ND) to 17.37 ng·g-1, with a mean of 2.30 ng·g-1. The DDTs、HCHs、endosulfan and endosulfan sulfate were found over 54% in the collected soil samples. Also, the DDTs were the main components, and their contribution to the residues of OCPs was over 54.6%. Analysis of the sources of contamination showed that HCHs in the area were mainly derived from lindane. DDTs, which were suspected to have recent application to 18.2% soil, were derived mainly from technical DDTs or dicofol containing DDT impurities. Comparing with various studies and the‘National Environmental Quality Standard for Soils of China'(GB 15618—1995), OCP pollutions were generally slight in present study, and the ecological risk of HCHs and DDTs residue in agricultural soils of Hainan Province was lower.