Poor drinking water quality in household wells is hypothesised as being a potential contributor to the high prevalence of chronic kidney disease of uncertain aetiology (CKDu) among the farming communities of the Medawachchiya area, Anuradhapura, Sri Lanka. One of the natural processes that can affect water quality is the dissolution of minerals contained within an aquifer by water–rock interactions (WRIs). Here we present a comprehensive assessment of WRIs and their influence on the water chemistry in household wells and spring waters in the Medawachchiya area by combining measurements of environmental isotopes, such as strontium, lithium and stable carbon isotopes and inorganic chemistry parameters, and modelling geochemical mass balance reactions between rainfall and groundwater samples. Our results reveal the presence of strontium, dissolved from both silicate and carbonate minerals, with high isotopic (⁸⁷Sr/⁸⁶Sr) ratios of up to 0.7316. Geochemical mass balance modelling and prior ⁸⁷Sr/⁸⁶Sr studies on the Wanni Complex bedrock suggest these strontium values may be the result of biotite dissolution. We also identify lithium and uranium contributed from the dissolution of silicates, albeit at concentrations too low to constitute a known health risk. In contrast, the levels of magnesium and calcium in our samples are high and demonstrate that, despite the felsic bedrock, well water chemistry in the Medawachchiya area is dominated by carbonate dissolution.

据推测，家庭水井中的饮用水质量差是导致斯里兰卡阿努拉德普勒（Anuradhapura）Medawachchiya地区农业社区中病因不明的慢性肾脏疾病（CKDu）患病率高的潜在原因。可能影响水质的自然过程之一是通过水-岩相互作用（WRI）溶解含水层中的矿物质。在这里，我们结合对锶，锂和稳定碳同位素等环境同位素和无机化学参数的测量，并对地球化学质量进行建模，从而对WRI及其对Medawachchiya地区家庭水井和泉水中水化学的影响进行了全面评估。平衡降雨和地下水样品之间的反应。我们的结果表明存在锶，⁸⁷ Sr / ⁸⁶ Sr）的比率最高为0.7316。地球化学质量平衡模型和先前在Wanni复杂基岩上进行的⁸⁷ Sr / ⁸⁶ Sr研究表明，这些锶值可能是黑云母溶解的结果。我们还确定了由于硅酸盐溶解而产生的锂和铀，尽管其浓度太低而不会构成已知的健康风险。相比之下，我们样品中的镁和钙含量很高，这表明尽管有长英质基岩，但Medawachchiya地区的井水化学主要是碳酸盐溶解。