福建省东山湾生态环境中滴滴涕（DDTs）的分布特征及风险评价

摘要

An investigation into the residue, distribution, and composition of Dichloro-diphenyl-tricgloroethanes (DDTs) in sea water, sediment, and cultured shellfish in Dongshan Bay was carried out in spring(May) and sum-mer(August), 2011. We also evaluated the contamination status and ecological risks. The results were as follows:First, the DDT content in the sea surface layer varied from non-detectable(ND) to 25.7 ng/L in May and from ND to 36.7 ng/L in August, the average values were (6.08±3.02) ng/L and (16.30±4.78) ng/L, respectively; the DDT content in the bottom layer varied from ND to 30.6 ng/L and from ND to 36.7 ng/L, the average values were (7.75±2.07) ng/L and (13.30±5.12) ng/L in May and August, respectively. In general, the DDT concentration dis-tribution in Dongshan Bay declined from the inner to outer bay and from the near- to far-shore. DDT concentra-tions in summer were higher than those in spring. Compared with other bays in China, DDTs pollution in Dong-shan Bay was at a lower level status;however, it is likely that there has been a recent pollutant input in sites DS03 and DS11. Second, the DDT content in the sediment varied from 5.56?12.8 μg/kg, the average value was (9.00±5.34)μg/kg. The concentration declined from the inner to the outer bay. DDT residue in the sediment may have negative effects on organisms, the toxicity risk index varied from 25%to 75%. Third, the DDT content varied among different species of cultured shellfish from 1.68?26.60μg/kg and the average was 15.70μg/kg. The pollu-tion index varied from 0.007 to 2.660, the average was 1.580. This exceeded the standard rate by 71.4% and the highest value was 1.66 fold. These results show that some shellfish have been contaminated by DDTs. This prob-lem requires further attention and must be resolved.%根据2011年春季(5月)和夏季(8月)对东山湾生态环境的调查资料,初步探讨了东山湾海水、沉积物和养殖贝类体中滴滴涕(DDTs)残留水平、分布趋势和组成特征,并对东山湾生态环境中 DDTs 污染状况及其生态风险进行了评价。结果表明：(1)春季(5月)和夏季(8月)东山湾表层海水中 DDTs 质量浓度范围分别为 ND~25.7 ng/L 和ND~36.7 ng/L,平均值分别为(6.08±3.02) ng/L 和(16.30±4.78) ng/L；底层海水中 DDTs 质量浓度范围分别为ND~30.6 ng/L和ND~36.7ng/L,平均值分别为(7.75±2.07) ng/L和(13.30±5.12) ng/L,总体上,东山湾海水中DDTs浓度分布呈夏季高于春季、近岸高于远岸、由湾内向湾外下降的格局。与国内其他海湾相比,东山湾海水中D D Ts污染处于低水平状态,但邻近漳江入海口海域的DS03站和DS11站可能有新的污染源输入。(2)东山湾表层沉积物中DDTs含量范围5.56~12.80μg/kg,平均值为(9.00±5.34)μg/kg,总体上呈现由湾内向湾外下降之势,东山湾表层沉积物中DDTs残留可能对生物产生负效应,毒性风险为25%~75%。(3)东山湾海域养殖贝类DDTs的残留量在种类间存在一定的差异,其DDTs含量范围在1.68~26.60μg/kg,平均值为15.70μg/kg,污染指数范围在0.007~2.660,均值为1.580,超标率达到71.4%,超标倍数最高达1.66倍,说明东山湾部分贝类受到DDTs的污染。