Goshu Goraw, Koelmans A A, de Klein J J M
Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University &Research, P.O. Box, 47,6700AA, Wageningen, the Netherlands; College of Agriculture and Environmental Sciences and Blue Nile Water Institute, Bahir Dar University, P.O. Box 1701, Bahir Dar, Ethiopia.
Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University &Research, P.O. Box, 47,6700AA, Wageningen, the Netherlands.
Environ Pollut. 2021 May 1;276:116693. doi: 10.1016/j.envpol.2021.116693. Epub 2021 Feb 9.
Faecal indicator bacteria (FIB) are used for the assessment of faecal pollution and possible water quality deterioration. There is growing evidence that FIB used in temperate regions are not adequate and reliable to detect faecal pollution in tropical regions. Hence, this study evaluated the adequacy of FIB, including total coliforms (TC), Escherichia coli (EC), Enterococci (IEC), and Clostridium perfringens (CP) in the high-altitude, tropical country of Ethiopia. In addition to FIB, for microbial source tracking (MST), a ruminant-associated molecular marker was applied at different water types and altitudes, and faecal pollution risk mapping was conducted based on consensus FIB. The performances of the indicators were evaluated at 22 sites from different water types. The results indicate that EC cell enumeration and CP spore determination perform well for faecal contamination monitoring. Most of the sub-basins of Lake Tana were found to be moderately to highly polluted, and the levels of pollution were demonstrated to be higher in the rainy season than in the post-rainy season. Markers associated with ruminants (BacR) were identified in more than three quarters of the sites. A bacterial pollution risk map was developed for sub-basins of Lake Tana, including the un-gauged sub-basins. We demonstrate how bacterial pollution risk mapping can aid in improvements to water quality testing and reduce risk to the general population from stream bacteria.
粪便指示菌（FIB）用于评估粪便污染及可能的水质恶化情况。越来越多的证据表明，在温带地区使用的FIB不足以可靠地检测热带地区的粪便污染。因此，本研究评估了FIB（包括总大肠菌群（TC）、大肠杆菌（EC）、肠球菌（IEC）和产气荚膜梭菌（CP））在埃塞俄比亚这个热带高海拔国家的适用性。除了FIB，为了进行微生物源追踪（MST），在不同水型和海拔高度应用了一种与反刍动物相关的分子标记，并基于共识FIB进行了粪便污染风险绘图。在22个不同水型的站点评估了这些指标的性能。结果表明，EC细胞计数和CP孢子测定在粪便污染监测方面表现良好。塔纳湖的大部分子流域被发现受到中度至高度污染，且雨季的污染水平高于雨后季节。在超过四分之三的站点中鉴定出了与反刍动物相关的标记（BacR）。为塔纳湖的子流域绘制了细菌污染风险图，包括未测量的子流域。我们展示了细菌污染风险绘图如何有助于改进水质检测并降低溪流细菌对普通人群的风险。
