Grapentine Lee, Rochfort Quintin, Marsalek Jiri
Water Science and Technology Branch, Environment Canada, Burlington, Ontario, Canada L7R 4A6.
Water Sci Technol. 2008;57(9):1375-81. doi: 10.2166/wst.2008.261.
The quality of aquatic habitat in a stormwater management facility located in Toronto, Ontario, was assessed by examining ecotoxicological responses of benthic invertebrates exposed to sediment and water from this system. Besides residential stormwater, the facility receives highway runoff contaminated with trace metals, polycyclic aromatic hydrocarbons (PAHs), and road salt. The combined flow passes through two extended detention ponds (in series) and a vegetated outlet channel. Toxicity of surficial sediment collected from 14 longitudinally arrayed locations was assessed based on 10 acute and chronic endpoints from laboratory tests with four benthic organisms. Greatest overall toxicity was observed in sediment from sites in the upstream pond, where mortality to amphipods and mayflies reached up to 100%. Downstream pond sediment was less toxic on average than the upstream pond sediment, but not the outlet channel sediment where untreated stormwater discharges provided additional sources of contamination. Macroinvertebrate communities in sediment cores were depauperate and dominated by oligochaetes and chironomids, with minimum densities and diversity at the deeper central pond sites. While sediment toxicity was associated with high concentrations of trace metals and high-molecular weight PAHs, benthic community impoverishment appeared related to high water column salinity.
通过检测暴露于安大略省多伦多市一个雨水管理设施的沉积物和水中的底栖无脊椎动物的生态毒理学反应，对该设施的水生栖息地质量进行了评估。除了住宅雨水外，该设施还接收受到痕量金属、多环芳烃（PAHs）和道路盐分污染的公路径流。混合水流经过两个串联的延长滞留池和一条植被丰富的出水渠道。基于对四种底栖生物进行实验室测试得出的10个急性和慢性终点，评估了从14个纵向排列位置采集的表层沉积物的毒性。在上游池塘各点位的沉积物中观察到总体毒性最大，其中双壳类动物和蜉蝣的死亡率高达100%。下游池塘沉积物的平均毒性低于上游池塘沉积物，但未经处理的雨水排放提供额外污染源的出水渠道沉积物并非如此。沉积物岩芯中的大型无脊椎动物群落数量稀少，以寡毛纲动物和摇蚊为主，在较深的中央池塘点位密度和多样性最低。虽然沉积物毒性与痕量金属的高浓度和高分子量多环芳烃有关，但底栖生物群落的贫瘠似乎与水柱高盐度有关。
