BACKGROUND Accumulating evidence suggests that domestic water hardness is linked to health outcomes, but its association to all-cause and cause-specific cancers warrants investigation. OBJECTIVE The aim of this study was to investigate the association of domestic hard water with all-cause and cause-specific cancers. METHODS In the prospective cohort study, a total of 447,996 participants from UK Biobank who were free of cancer at baseline were included and followed up for 16 y. All-cause and 22 common cause-specific cancer diagnoses were ascertained using hospital inpatient records and self-reported data until 30 November 2022. Domestic water hardness, measured by CaCO3 concentrations, was obtained from the local water supply companies across England, Scotland, and Wales in 2005. Data were analyzed using Cox proportional hazard models, with adjustments for known measured confounders, including demographic, socioeconomic, clinical, biochemical, lifestyle, and environmental factors. RESULTS Over a median follow-up of 13.6 y (range: 12.7-14.4 y), 58,028 all-cause cancer events were documented. A U-shaped relationship between domestic water hardness and all-cause cancers was observed (p for nonlinearity <0.001). In comparison with individuals exposed to soft water (0-60mg/L), the hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause cancer were 1.00 (95% CI: 0.98, 1.02) for those exposed to moderate hard water (>60-120mg/L), 0.88 (95% CI: 0.84, 0.91) for those exposed to hard water (>120-180mg/L) and 1.06 (95% CI: 1.04, 1.08) for those exposed to very hard water (>180mg/L). Additionally, domestic water hardness was associated with 11 of 22 cause-specific cancers, including cancers of the esophagus, stomach, colorectal tract, lung, breast, prostate, and bladder, as well as non-Hodgkin lymphoma, multiple myeloma, malignant melanoma, and hematological malignancies. Moreover, we observed a positive linear relationship between water hardness and bladder cancer. DISCUSSION Our findings suggest that domestic water hardness was associated with all-cause and multiple cause-specific cancers. Findings from the UK Biobank support a potentially beneficial association between hard water and the incidence of all-cause cancer. However, very hard water may increase the risk of all-cause cancer. https://doi.org/10.1289/EHP13606.

中文翻译：

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生活用水硬度与全因和特定原因癌症的关联：来自 447,996 名英国生物银行参与者的证据。


背景越来越多的证据表明，生活用水硬度与健康结果相关，但其与全因和特定原因癌症的关联值得研究。目的 本研究的目的是调查生活硬水与全因癌症和特定原因癌症的关系。方法 在前瞻性队列研究中，共有 447,996 名来自英国生物银行的基线时未患癌症的参与者被纳入研究，并随访了 16 年。使用截至 2022 年 11 月 30 日的医院住院患者记录和自我报告数据确定了全因癌症和 22 种常见原因特异性癌症诊断。通过 CaCO3 浓度测量的生活水硬度是从英格兰、苏格兰和英国的当地供水公司获得的。威尔士，2005 年。使用 Cox 比例风险模型对数据进行分析，并对已知的测量混杂因素进行调整，包括人口、社会经济、临床、生化、生活方式和环境因素。结果 在中位随访 13.6 年（范围：12.7-14.4 年）中，记录了 58,028 起全因癌症事件。生活用水硬度与全因癌症之间存在 U 形关系（非线性 p <0 id=1>60-120mg/L），接触硬水的人为 0.88（95% CI：0.84，0.91）（ >120-180mg/L) 和 1.06 (95% CI: 1.04, 1.08) 对于那些接触极硬水 (>180mg/L) 的人。此外，生活用水硬度与 22 种特定癌症中的 11 种有关，包括食道癌、胃癌、结直肠癌、肺癌、乳腺癌、前列腺癌和膀胱癌，以及非霍奇金淋巴瘤、多发性骨髓瘤、恶性黑色素瘤、和血液系统恶性肿瘤。此外，我们观察到水硬度与膀胱癌之间存在正线性关系。 讨论 我们的研究结果表明，生活用水硬度与全因癌症和多因癌症相关。英国生物银行的研究结果支持硬水与全因癌症发病率之间存在潜在的有益关联。然而，非常硬的水可能会增加患全因癌症的风险。 https://doi.org/10.1289/EHP13606。