Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA; Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Environ Pollut. 2024 Jan 1;340(Pt 1):122733. doi: 10.1016/j.envpol.2023.122733. Epub 2023 Oct 22.
Surface water runoff can transport contaminants offsite to downstream aquatic ecosystems. The prevalence of impervious surfaces in urban areas enhances surface runoff and contributes to contamination of urban surface streams. Urban areas have complex drainage systems for the conveyance of drainage water, however, there is a dearth of information on the distribution of contaminants within storm drain system structures. Pyrethroid insecticides are among the most used insecticides in urban areas, and trace levels of pyrethroids are known to exert toxicity to aquatic invertebrates. To investigate pyrethroid occurrence and distribution throughout an urban drainage system, samples of water, sediment, algae, and biofilm were collected from catch basins, open channels, and outfalls in Los Angeles County, California, during the dry season. From 3 catch basins, 7 open channels, and 7 outfalls, a total of 28 water samples, 4 sediment samples, 8 algae samples, and 4 biofilm samples were collected and analyzed. Pyrethroid concentrations above the reporting limit were detected in 89% of water samples and all sediment, algae, and biofilm samples, with bifenthrin and cyfluthrin being the most frequently detected compounds. The median total pyrethroid concentrations in water, sediments, algae, and biofilms were 27 ng/L, 88 ng/g, 356 ng/g, and 3556 ng/g, respectively. Bifenthrin concentrations in catch basins were found to be significantly higher than those in open channels or outfalls. Significant correlations were found for various metrics, including between pyrethroid partitioning in water samples and total suspended solids. These findings highlight the role of underground catch basins as a sink as well as a secondary source for contaminants such as pyrethroid insecticides. Prevention of the input of these urban originated contaminants to catch basins is crucial for protecting the water quality of urban surface waters.
地表径流可将污染物输送到下游水生生态系统。城市地区不透水表面的普遍存在增加了地表径流，并导致城市地表溪流受到污染。城市地区有复杂的排水系统来输送排水，但关于雨水系统结构内污染物分布的信息却很少。拟除虫菊酯类杀虫剂是城市地区使用最广泛的杀虫剂之一，痕量水平的拟除虫菊酯已知对水生无脊椎动物具有毒性。为了调查整个城市排水系统中拟除虫菊酯的发生和分布情况，在加利福尼亚州洛杉矶县的旱季，从雨水口、明渠和出水口收集了水样、沉积物、藻类和生物膜样本。从 3 个雨水口、7 个明渠和 7 个出水口共采集和分析了 28 个水样、4 个沉积物样本、8 个藻类样本和 4 个生物膜样本。在 89%的水样以及所有沉积物、藻类和生物膜样本中都检测到超过报告限值的拟除虫菊酯浓度，其中联苯菊酯和氯氟氰菊酯是最常检测到的化合物。水样、沉积物、藻类和生物膜中的总拟除虫菊酯浓度中位数分别为 27ng/L、88ng/g、356ng/g 和 3556ng/g。雨水口的联苯菊酯浓度明显高于明渠或出水口。发现各种指标之间存在显著相关性，包括水样中拟除虫菊酯的分配与总悬浮固体之间的关系。这些发现强调了地下雨水口作为污染物（如拟除虫菊酯类杀虫剂）汇和次生源的作用。防止这些源自城市的污染物输入雨水口对于保护城市地表水质至关重要。
