Bonotto Daniel Marcos
Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Câmpus de Rio Claro, Av. 24-A No.1515, C.P. 178, CEP 13506-900, Rio Claro, São Paulo, Brazil.
Heliyon. 2019 May 8;5(5):e01563. doi: 10.1016/j.heliyon.2019.e01563. eCollection 2019 May.
Gross alpha and gross beta activities have been determined in thermal and non-thermal spas groundwaters (75) occurring at São Paulo and Minas Gerais states in Brazil as they are ingested in public places, bottled and used for bathing purposes, among other. The samples provided from springs and pumped tubular wells drilled at different aquifer systems inserted in Paraná and Southeastern Shield hydrogeological provinces. The WHO guideline reference value proposed in 2011 for the drinking water quality was never reached for the gross alpha activity (0.5 Bq/L) but it was exceeded in 13 groundwater samples for the gross beta activity (1 Bq/L). Available activity concentration data of the natural radionuclides K, Ra (Th-daughter), U and descendants (U, Ra, Rn, Pb, Po) allowed calculate the total Committed Effective Dose (CED) based on a drinking water ingestion rate of 2 L/day. The WHO reference level of 0.1 mSv per year for the CED was surpassed in a high number of water sources (62 (83%) or 41 (55%), disregarding radon), denoting the relevance of the radiological surveys detailing as much as possible the dissolved radionuclides present in potable waters, despite the analytical difficulties and costs involved.
已对巴西圣保罗州和米纳斯吉拉斯州温泉及非温泉地下水（75处）中的总α和总β活度进行了测定，这些地下水在公共场所被饮用、装瓶并用于沐浴等用途。样本取自不同含水层系统中钻探的泉水和抽水井，这些含水层系统位于巴拉那和东南地盾水文地质省份。2011年提出的饮用水水质世卫组织指导参考值中，总α活度（0.5 Bq/L）从未达到，但在13个地下水样本中总β活度（1 Bq/L）超过了该值。天然放射性核素K、镭（钍子体）、铀及其子体（铀、镭、氡、铅、钋）的可用活度浓度数据，使得能够根据每天2升的饮用水摄入量计算总待积有效剂量（CED）。大量水源（62个（83%）或41个（55%），不考虑氡）超过了世卫组织规定的每年0.1 mSv的CED参考水平，这表明尽管存在分析困难和成本，但详细说明饮用水中溶解的放射性核素的放射学调查具有重要意义。
