岳阳市地下水有机氯农药浓度水平与污染特征分析

Analysis of organochlorine pesticide concentrations and pollution characteristics in groundwater of Yueyang City

为进一步了解岳阳市地下水有机氯农药(OCPs)污染状况,利用2008年地下水污染现状调查数据,对地下水OCPs的浓度水平与污染特征进行了分析。结果表明:OCPs总检出率为72.2%,其中六六六(HCHs)和滴滴涕(DDTs)的检出率分别为72.2%和22.2%,七氯、六氯苯(HCB)和五氯酚(PCP)未检出,ρ(OCPs)的平均值为0.035 2μg/L,其中ρ(HCHs)为0.023 2μg/L,占65.9%,ρ(HCHs)和ρ(DDTs)的最大值分别为0.080 9μg/L和0.159 0μg/L,均明显低于GB 5749—2006《生活饮用水卫生标准》限值;OCPs污染状况呈现出水田与城区污染水平大于旱地大于林地、岗地污染水平大于平原大于低丘、潜水污染水平大于承压水的特征。尽管岳阳市地下水OCPs污染程度较轻,但考虑到OCPs的难降解性和毒性在生物体内的逐步累积放大性,应对今后岳阳市OCPs的污染趋势加以重视,加强地下水环境质量监测。

In order to study the pollution status of organochlorine pesticides （OCPs） in the groundwater of Yueyang City, we analyzed the OCP concentrations and OCP pollution characteristics in the groundwater based on the groundwater pollution status survey data of 2008. The results show that the total detection ratio of OCPs was 72.2% , and the detection ratios of HCHs and DDTs were 72.2% and 22.2% , respectively, while heptachlor, HCB, and PCP were not detected. The average value of p （OCPs） was 0. 035 2 μg/L, and the average value of p（HCHs） was 0. 023 2 μg/L, accounting for 65.9% of that of p （OCPs）. The maximum detectable values of p（HCHs） and p（DDTs） were 0.080 9 μg/L and 0. 159 μg/L, respectively, which were substantially lower than the limit values of the Standards for Drinking Water Quality （ GB 5749-2006）. According to the pollution status of OCPs, the OCP pollution was more serious in the paddy field and urban land than in the dry land and woodland, more serious in lowlands than in the plain, followed by low hillocks, and more serious in phreatic water than in confined water. Although the groundwater of Yueyang City was slightly polluted by OCPs, considering that the difficult degradation of OCPs and their harm can be magnified by gradual accumulation in organisms, we must pay attention to the trend of OCP pollution in the future and strengthen groundwater environmental quality monitoring in Yueyang City.