A chronic Kidney Disease of unknown etiology (CKDu) has emerged with disproportionately high prevalence across dry lowland agricultural communities globally. Here we present the results of a prospective cohort of 293 patients with CKDu in the endemic region of Wilgamuwa, Sri Lanka, in whom we measured baseline kidney function and undertook quarterly follow up over 2 years. Well water was the primary historic drinking water source in the region, although a majority (68%) of participants reported switching to reverse osmosis water during study follow ups. Participants who reported ever drinking from well water had estimated glomerular filtration rates −6.7 (SD: 2.8) ml/min/1.73 m² lower than participants who did not drink from well water historically (p = 0.0184) during the study period. Geospatial analysis identifies a cluster within the region where CKDu progression is significantly higher than the surrounding area. Samples of household wells (n = 262) indicated 68% had detectable agrochemical compounds with concentration above global water quality standards. It is expected that the detected contaminants compounds are indicators of poor water quality and that there is likely additional agrochemical exposure including commercial additives that may contribute to CKDu onset and/or progression. Thus, our study finds that well water exposure during a person’s lifetime in this region is associated with kidney function decline and identifies and quantifies putative nephrotoxic agrochemicals above safe drinking water concentrations in these wells.

一种病因不明的慢性肾脏病 (CKDu) 已经出现，在全球干旱低地农业社区中的患病率高得不成比例。在这里，我们展示了斯里兰卡 Wilgamuwa 流行地区的 293 名 CKDu 患者的前瞻性队列的结果，我们测量了这些患者的基线肾功能并进行了 2 年的季度随访。井水是该地区历史上主要的饮用水源，尽管大多数 (68%) 的参与者报告在研究随访期间改用反渗透水。报告曾饮用井水的参与者估计肾小球滤过率 -6.7 (SD: 2.8) ml/min/1.73 m ²低于历史上不饮用井水的参与者 ( p = 0.0184) 在研究期间。地理空间分析确定了 CKDu 进展明显高于周边地区的区域内的集群。家庭水井样本 ( n  = 262) 表明 68% 的水井中含有可检测到的农药化合物，其浓度高于全球水质标准。预计检测到的污染物化合物是水质差的指标，并且可能存在额外的农用化学品暴露，包括可能导致 CKDu 发生和/或进展的商业添加剂。因此，我们的研究发现，一个人一生中在该地区接触井水与肾功能下降有关，并识别和量化这些井中高于安全饮用水浓度的推定肾毒性农用化学品。