Budd R, Bondarenko S, Haver D, Kabashima J, Gan J
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
J Environ Qual. 2007 May 25;36(4):1006-12. doi: 10.2134/jeq2006.0249. Print 2007 Jul-Aug.
The shift in land use patterns within many urban areas has the potential to influence the magnitude and nature of nonpoint-source pollution. The presence of pyrethroid insecticides in urban surface streams is of particular concern due to the broad spectrum toxicity of pyrethroids to aquatic organisms and the widespread use of pyrethroid products for agricultural and urban pest control. Sediment samples were collected throughout a mixed land use watershed in southern California during two sampling periods and analyzed for a suite of pyrethroids. Bifenthrin and fenpropathrin were found most frequently in the sediment samples, with the highest concentrations associated with sites adjacent to large commercial nurseries. Sediments from residential areas or residential-commercial mixed areas had fewer detections and significantly lower concentrations than the nursery runoff sediments. No apparent difference was found between wet and dry season concentrations, which may be attributed to the fact that the lack of flow under dry weather conditions rendered pyrethroid residues immobile. Organic carbon-normalized sediment concentrations were poorly correlated with the freely dissolved pore water concentrations measured by solid phase microextraction (SPME), suggesting factors other than sediment organic carbon content should be considered when relating concentrations to potential toxicities.
许多城市地区土地利用模式的转变有可能影响非点源污染的规模和性质。由于拟除虫菊酯类杀虫剂对水生生物具有广泛的毒性，且拟除虫菊酯类产品在农业和城市害虫防治中广泛使用，城市地表溪流中拟除虫菊酯类杀虫剂的存在尤其令人担忧。在两个采样期内，从南加州一个混合土地利用流域采集了沉积物样本，并对一系列拟除虫菊酯类进行了分析。联苯菊酯和甲氰菊酯在沉积物样本中出现的频率最高，最高浓度与大型商业苗圃附近的地点相关。来自居民区或住宅-商业混合区的沉积物检测到的次数较少，浓度也明显低于苗圃径流沉积物。湿季和干季浓度之间没有明显差异，这可能是由于干燥天气条件下缺乏水流，使拟除虫菊酯类残留物无法移动。有机碳归一化沉积物浓度与通过固相微萃取（SPME）测量的自由溶解孔隙水浓度相关性较差，这表明在将浓度与潜在毒性联系起来时，应考虑沉积物有机碳含量以外的其他因素。
