Teklehaimanot Giorgis Z, Coetzee Martie A A, Momba Maggy N B
Water Care Unit, Department of Environmental, Water and Earth Sciences, TUT, Private Bag X680, 175 Nelson Mandela Drive, Arcadia Campus, Pretoria, 0001, South Africa.
Environ Sci Pollut Res Int. 2014;21(16):9589-603. doi: 10.1007/s11356-014-2980-y. Epub 2014 May 17.
The discharge of untreated or inadequately treated effluents has been identified among the activities responsible for the spread of a wide range of potentially infectious agents. The aim of this study was to determine whether inadequate treatment of wastewater and the faecal pollution load of effluents and receiving water bodies in Sedibeng District and Soshanguve peri-urban area of the Tshwane Metropolitan Municipality could be a potential threat to the health of the surrounding communities. Variations in the counts of faecal indicator bacteria and pathogenic microorganisms and compliance of the effluents and receiving water bodies with South African and World Health Organization standards were assessed between August 2011 and May 2012 using culture-based methods and molecular techniques. The overall quality of effluents did not comply with the South African special standard of no risk for unrestricted irrigation (zero Escherichia coli/100 ml). The quality of the receiving water bodies did not comply with South African regulatory limits set for domestic purposes (zero E. coli/100 ml, <30 faecal enterococci/100 ml and <1 somatic coliphages/100 ml), for full contact recreation (<20 somatic coliphages/100 ml) and aquaculture (<10 E. coli/100 ml) and WHO standards for full and intermediate contact recreational use (<1 E. coli/100 ml and <40 faecal enterococci/100 ml, respectively). The PCR results revealed the prevalence of pathogenic microorganisms; between 0 and 60 % of samples tested positive for Salmonella Typhimurium and Shigella dysenteriae, and between 20 and 60% of samples tested positive for Vibrio cholerae. These findings demonstrated that potential health risks might be associated with the use of the target river waters for domestic, recreational and irrigation purposes. This study calls for a prompt intervention to improve wastewater management.
未经处理或处理不当的废水排放已被确定为导致多种潜在传染源传播的活动之一。本研究的目的是确定茨瓦内都会市塞迪本地区和索尚古韦城郊地区废水处理不当以及废水和受纳水体的粪便污染负荷是否会对周边社区居民的健康构成潜在威胁。2011年8月至2012年5月期间，采用基于培养的方法和分子技术，评估了粪便指示菌和致病微生物数量的变化以及废水和受纳水体是否符合南非和世界卫生组织的标准。废水的总体质量不符合南非无限制灌溉无风险的特殊标准（每100毫升零大肠杆菌）。受纳水体的质量不符合南非为家庭用途设定的监管限值（每100毫升零大肠杆菌、每100毫升<30个粪肠球菌和每100毫升<1个体细胞噬菌体）、完全接触式娱乐的标准（每100毫升<20个体细胞噬菌体）和水产养殖的标准（每100毫升<10个大肠杆菌），也不符合世界卫生组织关于完全和中级接触式娱乐用途的标准（分别为每100毫升<1个大肠杆菌和每100毫升<40个粪肠球菌）。聚合酶链反应结果显示了致病微生物的流行情况；0%至60%的样本检测出鼠伤寒沙门氏菌和痢疾志贺氏菌呈阳性，20%至60%的样本检测出霍乱弧菌呈阳性。这些发现表明，将目标河流水用于家庭、娱乐和灌溉目的可能会带来潜在的健康风险。本研究呼吁迅速采取干预措施以改善废水管理。
