五指山地区水和沉积物中HCHs、DDTs和PCBs分布特征及生态风险

Distribution and Risk Assessment of DDTs,HCHs and PCBs in Waters and Surface Sediments of Wuzhishan Area

使用GC/ECD分别对海南五指山地区11个采样点水中和表层沉积物中的六六六(HCHs)、滴滴涕(DDTs)和多氯联苯(PCBs)进行了分析测定,获得了3种持久性有机氯污染物其在该地区的含量与分布特征。有机氯农药组分分布特征研究表明,五指山地区水环境中HCHs和DDTs主要来自于早期残留和历史积累,尽管个别采样点DDTs仍有新的污染源输入,而该地区水环境中的PCBs可能是由大气长距离输送而来的。与世界其他地区相比较,五指山地区水体中的持久性有机氯污染物的含量还处于一个较低的水平,生态风险不大。

Persistent organic pollutants （POPs） in the region of south Asia are now receiving serious concern because the climate in tropics makes POPs easier to disperse and transport to other regions of the world. Wuzhishan area is located in the center of Hainan Island with tropical monsoon climate. But little is known about the concentrations and distributions of POPs in aquatic environment of this area. In this paper the concentrations of HCHs, DDTs and polychlorinated biphenyls （PCBs） in waters and surface sediments at 11 sites in Wuzhishan area were determined by the method of GC-ECD. The distributions of HCHs, DDTs and PCBs in this area were therefore obtained. Distributions of HCHs and DDTs components indicate that HCHs and DDTs in aquatic environment of Wuzhishan may be derived from the aged and weathered agricultural soils, though new inputs of DDTs at a few sites still exist. And since the local industrial pollutions are few, PCBs in this area may be probably brought into through long-distance transportation of atmosphere from other regions. Although the concentrations of PCBs are higher than those of HCHs and DDTs in water and surface sediments, the ecological risk is still low based on the comparison of ERL and ERM value. Compared with the corresponding results in other areas throughout the world, the concentrations of persistent organochlorine pollutants in Wuzhishan area are much lower and the risk is low in general. However, new input of pollutants especially DDTs still needs to be monitored and controlled.