铀是一种肾脏毒物和放射性物质，在一些州的地下水中浓度较高。1991年，美国环境保护署（US Environment Protection Agency）提出饮用水中铀的最高污染物水平（MCL）为20 ug/L或30 pCi/L（1.1 Bq/L）。1992年，加利福尼亚州采用了20 pCi/L（0.74 Bq/L）的MCL。由于加州法规允许通过质量或放射化学技术对铀进行分析，因此需要一个将质量值转换为放射性值的可靠因素来确定是否符合加州MCL和任何未来的联邦MCL。 地下水的转换系数可能与天然地壳铀丰度的转换系数明显不同。本研究比较了三种质量测量技术和两种放射化学技术测定的值。建议使用0.79 pCi/ug的转换系数来确定是否符合加州MCL。包括16个参考文献、表格和图表。

Uranium, a kidney toxicant and a radioactive material, is present at elevated concentrations in groundwater in some states. In 1991 the US Environmental Protection Agency proposed a maximum contaminant level (MCL) for uranium in drinking water of 20 ug/L or 30 pCi/L (1.1 Bq/L). In 1992 California adopted an MCL of 20 pCi/L (0.74 Bq/L). Because California regulations permit analysis of uranium by either mass or radiochemical techniques, a reliable factor that converts values from mass to activity is required to determine compliance with the California MCL and any future federal MCL. The conversion factor for groundwater may differ markedly from that of the natural crustal abundance of uranium. This study compared values determined by three mass measurement techniques and two radiochemical techniques. It is suggested that a conversion factor of 0.79 pCi/ug be used to determine compliance with the California MCL. Includes 16 references, tables, figures.