This paper reports the hydrochemistry and activity concentration of the natural radionuclides ²³⁸U, ²³⁴U, and ²¹⁰Po for three compartments of the hydrological/hydrogeological system in Araxá city, Minas Gerais State, Brazil: 1) mineral waters from the prominent springs Dona Beja (DBS) and Andrade Júnior (AJS), occurring at Barreiro area; 2) surface waters from Barreiro area and vicinity; and 3) rainwater. According to the Rule for Mineral Waters in Brazil (Register 7841) for temperature, the DBS water is cold (< 25 °C), while AJS is hypothermal (25–33 °C). The TDS (Total Dissolved Solids) concentration of DBS is low (70 mg/L), but high in AJS (2898 mg/L). The hydrogeochemical facies corresponded to sodium–(bi)carbonate for AJS and sodium/potassium–bicarbonate for DBS. The hydrochemical differences of DBS and AJS waters reflect the distinct characteristics of their respective aquifer systems. The DBS classification for TDS is the same of the Barreiro basin surface waters (mean TDS = 102 mg/L). Such value is somewhat higher than that of the rainwater and surface waters used for human consumption at Araxá city (TDS < 50 mg/L). The dataset reported in this paper indicated that fluoride and barium exceeded the WHO limits proposed in 2011 for drinking water. Among the natural radionuclides analyzed here that offer potential hazards for the human health is ²¹⁰Po, whose WHO’s limiting value of 100 mBq/L in drinking water was exceeded in rainwater, thus, restricting the use of this resource as a possible supply of drinking water for the local community.

本文报告了天然放射性核素²³⁸ U、²³⁴ U 和^{210的水化学和活度浓度}Po 用于巴西米纳斯吉拉斯州阿拉沙市水文/水文地质系统的三个部分：1) 来自 Barreiro 地区著名泉水 Dona Beja (DBS) 和 Andrade Júnior (AJS) 的矿泉水；2) 巴雷罗地区及附近的地表水；3) 雨水。根据巴西矿泉水规则（注册 7841）的温度，DBS 水是冷的（< 25 °C），而 AJS 是低温（25–33 °C）。DBS 的 TDS（总溶解固体）浓度较低（70 mg/L），但在 AJS 中较高（2898 mg/L）。水文地球化学相对应于 AJS 的钠-（氢）碳酸盐和 DBS 的钠/钾-碳酸氢盐。DBS 和 AJS 水的水化学差异反映了各自含水层系统的不同特征。TDS 的 DBS 分类与 Barreiro 盆地地表水相同（平均 TDS = 102 mg/L）。该值略高于阿拉沙市供人类消费的雨水和地表水（TDS < 50 mg/L）。本文报告的数据集表明，氟化物和钡超过了世界卫生组织 2011 年提出的饮用水限值。此处分析的对人体健康有潜在危害的天然放射性核素包括²¹⁰ Po，其世界卫生组织规定的饮用水中 100 mBq/L 的限值在雨水中被超过，因此，限制了将该资源用作当地社区可能的饮用水供应。