Department of Civil and Environmental Engineering, Environmental Engineering and Science, Stanford University, 94305-4020, USA.
San Francisco Public Utilities Commission, Water Quality Laboratory, 1000 El Camino Real, Millbrae, CA 94030, USA and EPA Region 10 Laboratory, 7411 Beach Dr E, Port Orchard, WA 98366, USA.
Environ Sci Process Impacts. 2018 Mar 1;20(3):480-492. doi: 10.1039/c7em00594f. Epub 2018 Feb 6.
Fecal pollution of surface waters presents a global human health threat. New molecular indicators of fecal pollution have been developed to address shortcomings of traditional culturable fecal indicators. However, there is still little information on their fate and transport in the environment. The present study uses spatially and temporally extensive data on traditional (culturable enterococci, cENT) and molecular (qPCR-enterococci, qENT and human-associated marker, HF183/BacR287) indicator concentrations in marine water surrounding highly-urbanized San Francisco, California, USA to investigate environmental and anthropogenic processes that impact fecal pollution. We constructed multivariable regression models for fecal indicator bacteria at 14 sampling stations. The human marker was detected more frequently in our study than in many other published studies, with detection frequency at some stations as high as 97%. The odds of cENT, qENT, and HF183/BacR287 exceeding health-relevant thresholds were statistically elevated immediately following discharges of partially treated combined sewage, and cENT levels dissipated after approximately 1 day. However, combined sewer discharges were not important predictors of indicator levels typically measured in weekly monitoring samples. Instead, precipitation and solar insolation were important predictors of cENT in weekly samples, while precipitation and water temperature were important predictors of HF183/BacR287 and qENT. The importance of precipitation highlights the significance of untreated storm water as a source of fecal pollution to the urban ocean, even for a city served by a combined sewage system. Sunlight and water temperature likely control persistence of the indicators via photoinactivation and dark decay processes, respectively.
地表水污染对全球人类健康构成威胁。新的粪便污染分子指标已经被开发出来，以解决传统可培养粪便指标的缺点。然而，关于它们在环境中的命运和迁移的信息仍然很少。本研究利用美国加利福尼亚州旧金山高度城市化地区海水周围传统（可培养肠球菌，cENT）和分子（qPCR-肠球菌，qENT 和人类相关标记物，HF183/BacR287）指标浓度的广泛时空数据，研究影响粪便污染的环境和人为过程。我们在 14 个采样站建立了多变量回归模型，用于粪便指示菌。在本研究中，人类标记物的检测频率比许多其他已发表的研究都高，有些站点的检测频率高达 97%。cENT、qENT 和 HF183/BacR287 超过健康相关阈值的几率在部分处理后的合流污水排放后立即显著升高，并且 cENT 水平在大约 1 天后消散。然而，合流污水排放并不是每周监测样本中通常测量的指示物水平的重要预测因子。相反，降水和太阳辐射是每周样本中 cENT 的重要预测因子，而降水和水温是 HF183/BacR287 和 qENT 的重要预测因子。降水的重要性突出表明，即使对于一个使用合流污水系统的城市，未经处理的雨水也是城市海洋中粪便污染的重要来源。阳光和水温可能分别通过光失活和暗衰减过程控制指示物的持久性。
