Pesticide contamination is a threat to many aquatic habitats, and runoff from residential homes is a major contributor of these chemicals in urban surface streams and estuaries. Improved understanding of their fate and transport can help identify areas of concern for monitoring and management. In many urban areas, runoff water congregates in numerous underground catch basins before draining into the open environment; however, at present essentially no information is available on pesticide presence in these systems. In this study, we collected water samples from a large number of underground urban catch basins in different regions of California during the active pest management season to determine the occurrence and profile of the widely used pyrethroid insecticides. Detectable levels of pyrethroids were found in 98% of the samples, and the detection frequency of individual pyrethroids ranged from no detection for fenpropathrin to 97% for bifenthrin. In the aqueous phase, total pyrethroid concentrations ranged from 3 to 726 ng/L, with a median value of 32 ng/L. Pyrethroids were found to be enriched on suspended solids, with total concentrations ranging from 42 to 93,600 ng/g and a median value of 2,350 ng/g. In approximately 89% of the samples, whole water concentrations of bifenthrin were predicted to have toxic units >1 for sensitive aquatic invertebrates. The high detection frequency of bifenthrin and overall pyrethroid concentrations, especially for particle-bound residues, suggest that underground urban catch basins constitute an important secondary source for extended and widespread contamination of downstream surface waters by pesticides such as pyrethroids in urban regions.

农药污染对许多水生栖息地构成威胁，住宅径流是城市地表河流和河口中这些化学物质的主要来源。更好地了解它们的命运和运输有助于确定监测和管理的关注领域。在许多城市地区，径流水在排入开放环境之前聚集在许多地下集水池中；然而，目前基本上没有关于这些系统中存在杀虫剂的信息。在这项研究中，我们在害虫管理活跃季节从加利福尼亚州不同地区的大量地下城市集水盆地收集了水样，以确定广泛使用的拟除虫菊酯杀虫剂的发生情况和概况。在 98% 的样品中发现了可检测水平的拟除虫菊酯，单个拟除虫菊酯的检测频率从未检测到甲氰菊酯到检测到 97% 的联苯菊酯不等。在水相中，总拟除虫菊酯浓度范围为 3 至 726 ng/L，中值为 32 ng/L。发现拟除虫菊酯富含悬浮固体，总浓度范围为 42 至 93,600 纳克/克，中值为 2,350 纳克/克。在大约 89% 的样本中，预计联苯菊酯的全水浓度对敏感的水生无脊椎动物具有 >1 的毒性单位。联苯菊酯和总拟除虫菊酯浓度的高检测频率，尤其是对于颗粒结合残留物，