Drinking water quality from rural handpump-boreholes in Africa
Drinking water quality from rural handpump-boreholes in Africa
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DOI：
10.1088/1748-9326/ab8031
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发表时间：
2020-06-01
影响因子：
6.7
通讯作者：
Casey, V
中科院分区：
文献类型：
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作者：
Lapworth, D. J.;MacDonald, A. M.;Casey, V
地下水为非洲许多地区的农村社区提供了重要的饮用水来源，特别是在旱季，因为几乎没有安全的替代水源。本文总结了一项研究(n=428)采用分层随机抽样设计在埃塞俄比亚高地(n=142)、马拉维(n=162)和乌干达(n=124)的手泵设备钻孔(HPB)中评估旱季水质(微生物和无机化学)的结果。这项研究试图通过在具有不同地质和气候的更大范围内随机抽样农村地下水供应来检查一般水质。接受调查的大多数(72%)HPBs提供符合世卫组织饮用水质量标准的优质旱季饮用水。在这一总体情况中，最显著的限制来自耐热大肠菌群(TTC)，在21%的地点(范围0-626 CFU/100毫升)超过了世卫组织饮用水零菌落形成单位(CFU/100毫升)的标准。三氯甲烷污染与年平均降雨量呈显著正相关(Rho=0.2，p=0.00003)。在所有三个国家中，有9%的地点超过了世卫组织基于健康的饮用水化学质量值，发现了锰(4%)、氟(2.6%)和硝酸盐(2.5%)；砷浓度低于10微克L(-1)的指导值(范围为0.5-7微克L(-1))。在乌干达饮用水水源中发现的锰超标率很高(14%+/-5.2%；400毫克L(-1))，这对世卫组织不将基于健康的锰指南正规化的决定构成了挑战。虽然HPB的微生物污染总体水平较低，但这项研究的结果有力地表明，在国家和区域层面上，微生物污染而不是化学污染将为实现联合国可持续发展目标6下为改善饮用水质量设定的目标提供更大的障碍。应努力确保井孔的适当选址和有效建造，以减少病原体污染。
Groundwater provides a vital source of drinking water for rural communities in many parts of Africa, particularly in the dry season when there are few safe alternative sources. This paper summarises results from a study (n = 428) assessing dry season water quality, both microbiological and inorganic chemistry, in handpump equipped boreholes (HPBs) across the Ethiopia Highlands (n = 142), Malawi (n = 162) and Uganda (n = 124) using a stratified, randomised sampling design. This study seeks to examine general water quality by randomly sampling rural groundwater supplies across larger areas with different geology and climate. The majority, 72%, of HPBs surveyed provide good quality dry season drinking water as defined by WHO drinking water quality criteria. Within this overall picture, the most notable constraints were from thermotolerant coliforms (TTCs), which exceeded the WHO drinking water guideline of zero colony forming units (cfu/100 ml) in 21% of sites (range 0-626 cfu/100 ml). TTC contamination was found to have a significant and positive correlation with annual average rainfall (rho = 0.2, p = 0.00003). Across all three countries, WHO health based chemical drinking water quality values were exceeded at 9% of sites and were found for manganese (4%), fluoride (2.6%) and nitrate (2.5%); arsenic concentrations were below the guideline value of 10 mu g l(-1)(range < 0.5-7 mu g l(-1)). The high percentage of Mn exceedances (14% +/- 5.2% >400 mu g l(-1)) found in drinking water sources in Uganda challenges the decision by WHO not to formalise a health-based guideline for Mn. While the overall level of microbiological contamination from HPBs is low, results from this study strongly suggest that at a national and regional level, microbiological contamination rather than chemical contamination will provide a greater barrier to achieving targets set for improved drinking water quality under the UN-SDG 6. Efforts should be made to ensure that boreholes are properly sited and constructed effectively to reduce pathogen contamination.