Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, 060-0818, Japan.
Environ Sci Pollut Res Int. 2013 Dec;20(12):8663-71. doi: 10.1007/s11356-013-1821-8. Epub 2013 May 26.
Dichlorodiphenyltrichloroethanes (DDTs) and heavy metals are ubiquitous contaminants with high bioaccumulation and persistence in the environment, which can have adverse effects on humans and animals. Although applications of DDTs have been banned in many countries, developing countries like Ethiopia are still using these for agricultural and medicinal purposes. In addition, heavy metals are naturally present in the aquatic environment and distributed globally. In this study, the occurrence, distribution, and ecological risk of DDTs and heavy metals in surface sediments from one of the Ethiopian rift valley lakes were studied. Twenty-five surface sediment samples from Lake Awassa, Ethiopia were collected and analyzed for DDTs and heavy metals. Results showed that concentrations of total DDTs ranged from 3.64 to 40.2 ng/g dry weight. High levels of DDTs were observed in the vicinity of inflow river side and coastal areas with agricultural activities. The heavy metals content were followed the order Zn>Ni>Pb>Cu>Cr>Co>As>Cd>Hg. Correlation analysis and principal components analysis demonstrated that heavy metals were originated from both natural and anthropogenic inputs. The levels of DDE and DDD in surface sediments exceeded the sediment quality guideline values, indicating that adverse effects may occur to the lake. A method based on toxic-response factor for heavy metals revealed that the calculated potential ecological risk indices showed low ecological risk for the water body.
滴滴涕（DDTs）和重金属是在环境中具有高生物累积性和持久性的普遍污染物，它们可能对人类和动物产生不利影响。尽管滴滴涕在许多国家的应用已经被禁止，但像埃塞俄比亚这样的发展中国家仍在将其用于农业和医药用途。此外，重金属在水生环境中自然存在并在全球范围内分布。在这项研究中，研究了埃塞俄比亚裂谷湖之一的表层沉积物中滴滴涕和重金属的存在、分布和生态风险。从埃塞俄比亚的阿瓦萨湖采集了 25 个表层沉积物样本，并对滴滴涕和重金属进行了分析。结果表明，总滴滴涕浓度范围为 3.64 至 40.2ng/g 干重。在有农业活动的入流河侧和沿海地区观察到滴滴涕浓度较高。重金属含量的顺序为 Zn>Ni>Pb>Cu>Cr>Co>As>Cd>Hg。相关性分析和主成分分析表明，重金属既有自然来源也有人为来源。表层沉积物中 DDE 和 DDD 的含量超过了沉积物质量指导值，表明湖泊可能会受到不利影响。一种基于重金属毒性反应因子的方法表明，计算出的潜在生态风险指数表明水体的生态风险较低。
