汕头地区农业生态系统中有机氯农药的研究

有机氯农药（Organochlorine Pesticides，OCPs）是一类由人工合成的杀虫广谱、毒性较低、残效期长的化学杀虫剂。本文以汕头市为研究区域，探讨了土壤OCPs的残留现状和特征，并对该区的土壤进行了环境质量评价和初步的生态风险评价。结果表明：（1）汕头地区土壤中OCPs的检出率高达99.13％，OCPs残留量的平均值是113.37 ng·g^-1，主要的OCPs污染物为DDTs和硫丹类；南澳县OCPs残留量平均值最高（174.68 ng·g^-1），其次为龙湖区，濠江区含量平均值最低（69.24 ng·g^-1）；（2）与国内外一些地区土壤中OCPs的残留量对比，本研究区域土壤中的OCPs处于中等污染残留水平；与美国马里兰州标准、纽约州可容许的土壤浓度标准和我国的土壤环境质量标准相比较，OCPs基本没有超标；（3）本研究地区土壤存在较高的生态风险，OCPs可能对环境造成一定的危害，其中生态风险最高的是DDTs，BHCs的生态风险较低。

Organochlorine Pesticides in Agro-ecosystem in Shantou City,China

Organochlorine pesticides（OCPs）is a kind of synthetic pesticides with broad-spectrum, low toxicity and long residual phase. In this paper, we selected Shantou City as the study area and explored the status and characteristics of residual OCPs in soil. Meanwhile, we also made an assessment about the environmental quality and the preliminary ecological risk of the soil in this city. The results were shown as fol-lows：（1）The detection rate of OCPs was as high as 99.13%, and the average concentration of OCPs was 113.37 ng·g^-1. The main OCPs contam-inants in soil were DDTs and endosulfan. The levels of average concentrations of OCPs in different places in Shantou were：Nan′ao County （174.68 ng·g^-1）＆gt;Dragon Lake area〉Haojiang area（69.24 ng·g^-1）.（2）In addition, the average concentration of OCPs in soil in this study area was at the middle level compared with that in domestic and overseas. Compared with some related standards such as Maryland′s, the permis-sible concentration in soil in New York State and the domestic soil environmental quality, the level of the average concentration of OCPs in Shantou was within the limit of the standards.（3）The soil in Shantou City had a high ecological risk. The OCPs in the soil could be harmful to environment. Thereinto, DDTs showed the highest ecological risk and BHCs showed the lowest.