Borrell A, Aguilar A
Department of Animal Biology, University of Barcelona, C/Diagonal 645 6a planta, 08071 Barcelona, Spain.
Chemosphere. 2007 Jan;66(2):347-52. doi: 10.1016/j.chemosphere.2006.04.074. Epub 2006 Jun 12.
We collected blubber samples from bottlenose dolphins stranded on Spain's Mediterranean coasts over a 25-year period (1978-2002). Samples were analyzed to determine time trends in levels of: HCB (hexachlorobenzene), PCB (polychlorinated biphenyls) and tDDT (dichlorodiphenyltrichloroethane and its metabolites). Overall, levels were high relative to other areas. This reflects both the ubiquity of organochlorine pollution in the western Mediterranean and the sampled species' coastal habit. There was a significant decline over the study period in the concentrations of all the compounds analyzed. However, the DDE/tDDT, which is indicative of DDT ageing, significantly increased. This suggests there has been no significant use of HCB, DDT or PCB in the region for a long time. It also indicates that the pollutant loads in the environment are gradually being reduced; either by degradation or by migration of the compounds to other regions. A comparison with dolphin species that have an oceanic distribution suggests that PCB decline at a comparable pace in coastal and offshore water bodies. However, the decline of tDDT is faster near the coast.
在25年期间（1978 - 2002年），我们从搁浅在西班牙地中海沿岸的宽吻海豚身上采集了鲸脂样本。对样本进行分析，以确定六氯苯（HCB）、多氯联苯（PCB）和总滴滴涕（tDDT，即二氯二苯三氯乙烷及其代谢物）水平的时间趋势。总体而言，相对于其他地区，这些物质的水平较高。这既反映了西地中海有机氯污染的普遍性，也反映了所采样物种的沿海习性。在研究期间，所有分析化合物的浓度均显著下降。然而，指示滴滴涕老化程度的DDE/tDDT显著增加。这表明该地区长期以来未大量使用六氯苯、滴滴涕或多氯联苯。这也表明环境中的污染物负荷正在逐渐减少，要么是通过化合物的降解，要么是通过其向其他地区的迁移。与具有海洋分布的海豚物种进行比较表明，沿海和近海水体中多氯联苯的下降速度相当。然而，海岸附近总滴滴涕的下降速度更快。
