韩江流域土壤中有机氯农药的特征分布

本文选取韩江流域作为研究对象,于2013年4月,沿韩江干流采集土壤样品17个,利用气相色谱(GC-ECD)检测13种有机氯农药的含量.并以此为依据,进一步分析土壤中该污染物的分布组成特征和污染来源,根据美国环境保护署(U. S.EPA)的计算标准,对当地居民做出健康风险影响评价.结果表明,13种有机氯农药的含量区间为2. 97～1 275. 79 ng·g~(-1),检出率为75%～100%.其中HCHs和DDTs的含量变化趋于一致,即上游中游下游,在国内外均属于较低水平.另外,根据比值法推断,该区域的HCHs主要来源于工业HCH的输入,且近期仍有DDTs的输入,主要为工业DDT和三氯杀螨醇的混合输入. DDTs与总有机碳有较显著的相关性.致癌风险值(10~(-12)～10~(-8))和非致癌风险值(10~(-6)～10~(-3))均低于阈值(10~(-6)和1),因而表明该流域土壤对当地居民无危害.

Characteristics of Organochlorine Pesticides (OCPs) in Soil Samples of Hanjiang River Basin, Southeast China

Seventeen soil samples were collected along the main stream of the Hanjiang River in April 2013. Thirteen types of organochlorine pesticides (OCPs) were detected in the samples by gas chromatography with a ⁶³Ni electron capture detector. The purpose of this study was to investigate the distribution, composition, and source of OCPs and assess the potential health risks for local residents. The 13 types of OCPs were all detected in this region, ranging from 2.97 ng·g^-1 to 1275.79 ng·g^-1, and the detection rates were 75%-100%. The contribution trends of both hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were upstream < midstream < downstream. Based on the ratio method, the HCHs were mainly from technical HCH input. Furthermore, there was DDT input recently, which contained industrial DDT and dicofol. The DDTs concentrations significantly correlated with total organic carbon. The values of cancer and non-cancer risks (10^-12-10^-8 and 10^-6-10^-3) were both lower than the corresponding thresholds (10^-6 and 1), which indicated that the soils in the Hanjiang River Basin had no harmful effects on local residents.