University of Victoria, Department of Civil Engineering, Engineering and Computer Science (ECS) 304, PO Box 1700 STN CSC, Victoria BC V8W 2Y2, Canada.
University of Malawi, The Polytechnic, Private Bag 303, Blantyre 3, Malawi; Eawag: Swiss Federal Institute Of Aquatic Science And Technology, Überlandstr. 133, 8600 Dübendorf, Switzerland.
Water Res. 2021 Feb 1;189:116607. doi: 10.1016/j.watres.2020.116607. Epub 2020 Nov 5.
Lack of access to safe drinking water on premises remains widespread in low- and middle-income countries. Interventions to improve access to safe water at the point of collection are essential, but water safety at the point of consumption is also an important consideration. This research aimed to 1) improve understanding of household practices in collecting water with respect to seasonality, and 2) to further assess risk associated with post-collection contamination from the point of collection to the point of consumption. A seasonal cohort study, including 115 households, was conducted in Malawi. Along with household surveys and observations, samples of water were tested for microbial water quality at four different stages of water collection: water source, collection container, storage container, cup of drinking water. Using E. coli as an indicator of contamination (cfu/100 ml), the risk of post-collection contamination was assessed. The results indicate that most water sources were free from contamination; contamination was proportionally lower in the dry season when more sources were found to be classified as having a very low risk of contamination. However, the level of risk of contamination was more likely to increase following collection in water sources that were initially free from contamination. Results show that the degradation in water quality from the point of collection to the point of consumption was more important in the rainy season, which is likely to be driven by the effect of seasonality on the household environment. Filling the collection container at the point of collection and storage at the point of consumption were found to be critical stages for an increased risk of E. coli contamination. Understanding household practices in accessing and handling water during both rainy and dry season is necessary to target appropriate interventions to reduce post-collection contamination.
在中低收入国家,供水设施缺乏安全饮用水的情况仍然普遍存在。改善收集点获取安全用水的干预措施至关重要,但消费点的水安全也是一个重要的考虑因素。本研究旨在:1)增进对家庭在季节性方面收集水的做法的了解;2)进一步评估从收集点到消费点的收集后污染与风险的相关性。在马拉维开展了一项季节性队列研究,涉及 115 户家庭。除了家庭调查和观察外,还对水样本进行了微生物水质测试,测试在水收集的四个不同阶段进行:水源、收集容器、储存容器、饮用水杯。使用大肠杆菌作为污染的指示物(cfu/100 ml),评估了收集后污染的风险。结果表明,大多数水源没有受到污染;在旱季,污染比例较低,当时发现更多的水源被归类为具有极低污染风险。然而,在最初没有受到污染的水源中,收集后污染的风险更有可能增加。结果表明,从收集点到消费点的水质恶化在雨季更为重要,这可能是季节性对家庭环境影响的结果。在收集点灌装收集容器和在消费点储存被发现是大肠杆菌污染风险增加的关键阶段。了解雨季和旱季家庭获取和处理水的做法,对于针对收集后污染采取适当干预措施是必要的。