多年来，公共和私人饮用水中天然存在的镭（Ra）浓度一直是研究的主题。这些研究表明，通常只有在井水中才能发现高浓度。据报道，美国最大的单一镭浓度高的地区位于五个州的范围内，包括明尼苏达州、威斯康星州、爱荷华州、伊利诺伊州和密苏里州。这项研究总结了从1950年至1978年间收集的1961份水样中获得的结果。177个美国社区的总人口为1442000人，其平均镭226浓度为3 pCi/L或更高。 其中，91个社区的59.9万人接触的镭226浓度超过5 pCi/L。本研究的一个目标是开发一种方法，根据油井位置、施工细节和穿透的地质结构预测井水中的镭浓度；然而，数据表明，这些变量并不能准确预测水中的镭226浓度。因为在镭226浓度较低的地区发现了高浓度的镭228，而镭228未被总量检测到- 在阿尔法分析中，似乎需要对水中的镭228进行大规模调查。包括33个参考文献、表格和图表。

The naturally occurring concentrations of radium (Ra) in public and private potable water supplies have been the subject of study for many years. These studies have shown that high concentrations are usually found only in well waters. The largest single area in the United States where significant radium concentrations have been reported is within a five-state area that includes Minnesota, Wisconsin, Iowa, Illinois, and Missouri. This study summarizes the results obtained from 1,961 water samples collected between 1950 and 1978. 177 U.S. communities, with a total population of 1,442,000 people, were identified as having mean radium 226 concentrations of 3 pCi/L or greater. Of these, 599,000 people in 91 communities are exposed to radium 226 concentrations exceeding 5 pCi/L. One objective of this study was to develop a method for predicting the concentration of radium in well waters based on the well's location, the details of its construction, and the geological structures it penetrates; however, the data suggest that these variables are not accurate predictors of radium 226 concentration in water. Because high concentrations of radium 228 have been found in areas with low radium 226 concentrations and radium 228 is not detected by gross-alpha analysis, it appears that a largescale survey of radium 228 in water is needed. Includes 33 references, tables, figure.