广东清远电子垃圾处理地沉积物对伸展摇蚊的慢性毒性效应

电子垃圾拆解引起的环境污染和生态风险已成为全球关注的热点问题,不适当的电子垃圾拆解过程造成处理区水体沉积物受到多类有机化合物和重金属污染,直接威胁生活在沉积物中的底栖动物。在典型电子垃圾处理地广东清远采集沉积物,测定样品中以烃类为主的色谱难分离混合物(unresolved complex mixture,UCM)的含量,开展伸展摇蚊全生命周期慢性毒性测试。结果表明,清远沉积物中的UCM浓度(0.08±0.01)%接近于这类污染物对伸展摇蚊的慢性半致死性效应浓度(0.073±0.022)%。同时发现清远沉积物对以摇蚊为代表的底栖无脊椎动物具有显著慢性毒性效应,且可通过测定UCM含量初步估算。这为开展以电子垃圾处理地沉积物为代表的,受到以麻醉作用为主要致毒机制的混合物污染的沉积物的毒性评价提供了一种有效方法。

Chronic Toxicity of Sediment Collected from an E-waste Recycling Site in Qingyuan, Guangdong to Chironomus dilutus

Environmental pollution and ecological risk caused by e-waste recycling have become a great concern. Improper e-waste recycling activities may cause sediment contamination by organic pollutants and heavy metals, posing a potential threat to benthic organisms. Sediment samples which were collected from Qingyuan, a representative e-waste recycling site, were analyzed for unresolved complex mixture (UCM) and evaluated for the toxicity using a life-cycle toxicity testing with a benthic invertebrate, Chironomus dilutus. The concentration of UCM in Qingyuan sediment was (0.08±0.01)% (g oil?g-1 dry sediment) and it was close to the chronic median lethal concentration of UCM to C. dilutus (0.073±0.022)%. In addition, the sediments from Qingyuan e-waste recycling site exhibited significant chronic toxicity to C. dilutus, and the toxicity could be estimated by measuring UCM contents in sediment. This study provided a valuable method for assessing chronic toxicity of sediments which were contaminated by a mixture of chemicals with narcotic mode of action, such as sediments in e-waste recycling sites.