福建漳江口水环境中滴滴涕(DDTs)的分布与溯源

Distribution characteristics and source apportionment of dichloro-diphenyl-tricgloroethanes in Zhangjiang River Estuary of Fujian,China

采用气相色谱（GC-ECD）方法分析了漳江口水环境中表层水、沉积物和水生生物体内滴滴涕（DDTs）的污染水平,初步研究了其在多介质中的含量、转移分配规律,并根据其沿江分布规律、组成特征,结合三氯杀螨醇同步调查结果进行了溯源分析.结果表明：漳江口表层水中的DDTs平均含量为枯水期10.5 ng·L^-1（未检出~20.1 ng·L^-1）、丰水期28.3ng·L^-1（未检出~45.2 ng·L^-1）、平水期5.03 ng·L^-1（未检出~18.8 ng·L^-1）;表层沉积物中DDTs含量（以干质量计）为1.87~144 ng·g^-1,平均17.3 ng·g^-1;11种水生生物中DDTs的含量范围为1.09~432 ng·g^-1,平均37.0 ng·g^-1.与其他地区相比,漳江口表层水和沉积物中的DDTs残留属于中等水平.DDT在沉积物中的富集因子为1185;在生物体中的富集因子平均为2534,富集能力依次为水生植物〈虾类〈贝类〈鱼类.DDTs沿江分布基本呈下降趋势,推断其残留与船舶防污剂释放关系不大,主要来源于陆源性污染.组成特征分析显示,漳江口DDTs主要来源于环境中的早期残留,而Y8站（江心岛后）近期有新的DDTs输入,可能与三氯杀螨醇的使用有关.同步调查结果显示,Y8站表层水和沉积物中均检出三氯杀螨醇,且含量最高,近期存在三氯杀螨醇的施用.

The concentration, distribution and transfer of dichloro-diphenyl-tricgloroethanes （DDTs） in the surface layer water, sediments and aquatic organisms from the Zhangjiang River Estuary were investigated using GC-ECD method. The possible sources were assessed based on the distribution and composition characteristics of DDTs together with the investigation results of dicofol. The results showed that the concentration of DDTs in surface layer water ranged from ND （not detected） to 20.1 ng · L^-1 with an average of 10.5 ng· L^-1 in dry period, from ND to 45.2 ng · L^-1 with an aver- age of 28.3 ng· L^-1 in wet period, and from ND to 18.8 ng · L^-1 with an average of 5.03 ng · L^-1 in level period. Concentration of DDTs in surface sediment （dry mass） ranged from 1.87 ng · g^-1 to 144 ng ~ g-I with an average of 17.3 ng · g^-1, and that in 11 species of aquatic organisms ranged from 1.09 ng ·g^-1 to 432 ng · g^-1 with an average of 37.0 ng · g^-1 Compared to other areas, the resi- dues of DDTs in the Zhangjiang River Estuary were at the medium level. The accumulation factors of DDTs in sediment and aquatic organisms were 1185 and 2534, respectively. The capacities for DDTs accumulation were in the order of fish〉shellfish〉shrimp〉aquatic plants. The concentrations of DDTs showed downtrend along the Zhangjiang River, indicating that the residues of DDTs mainly came from terrigenous pollution rather than from the release of antifouling agent of ships, Based on the composition profile, DDTs mainly came from the early residues. However, the highest value of di- cofol was recently detected both in the water and sediment of Ys station, which suggested that new DDTs inputs at the Y8 station might be related to the recent usage of dicofol.