Khalil F A, Amin Rafat M, El Fayoumi M A K
Ionizing Radiation Laboratory, National Institute for Standards, Egypt.
J Radiol Prot. 2009 Mar;29(1):105-12. doi: 10.1088/0952-4746/29/1/N01. Epub 2009 Feb 18.
Measurements of natural radioactivity in drinking water have been performed in many parts of the world, mostly for assessment of the doses and risk resulting from consuming water. A study of the radionuclide and chemical components in groundwater from Beni Suef Governate, Egypt has been carried out. Fifty water samples were analysed by gamma-ray spectroscopy to determine the (226)Ra, (232)Th and (40)K concentrations; major elements, pH, alkalinity and conductivity were also measured. The activity concentration values ranged from 0.008 to 0.040 Bq l(-1) for (226)Ra, from 0.003 to 0.019 Bq l(-1) for (232)Th and from 0.025 to 0.344 Bq l(-1) for (40)K. The annual ingestion of these radionuclides, using local consumption rates (averaged over the whole population) of 1.5 l d(-1), was estimated to be 8.59, 4.86 and 83.47 Bq y(-1) for (226)Ra, (232)Th and (40)K, respectively. The estimated effective doses from drinking water were found to be 2.4 microSv y(-1) ((226)Ra), 1.1 microSv y(-1) ((232)Th) and 0.5 microSv y(-1) ((40)K). The contribution of these radionuclides to the committed effective dose from a year's consumption of drinking water is therefore estimated to be only 4% of the WHO value (0.1 mSv y(-1)). The moderate pH value is the most important parameter, and there was no observed correlation between natural radioactivity and electrical conductivity or concentrations of major ions.
世界上许多地区都对饮用水中的天然放射性进行了测量，主要是为了评估饮水所导致的剂量和风险。埃及贝尼苏韦夫省对地下水中的放射性核素和化学成分进行了一项研究。通过伽马射线光谱法对50个水样进行了分析，以确定镭-226、钍-232和钾-40的浓度；同时还测量了主要元素、pH值、碱度和电导率。镭-226的活度浓度值范围为0.008至0.040贝克勒尔每升，钍-232为0.003至0.019贝克勒尔每升，钾-40为0.025至0.344贝克勒尔每升。利用当地每人每天1.5升的饮水消耗率（整个人口的平均值），估计这些放射性核素的年摄入量分别为：镭-226为8.59贝克勒尔每年，钍-232为4.86贝克勒尔每年，钾-40为83.47贝克勒尔每年。发现饮用水的估计有效剂量分别为：镭-226为2.4微希沃特每年，钍-232为1.1微希沃特每年，钾-40为0.5微希沃特每年。因此，估计这些放射性核素对一年饮用水所致的待积有效剂量的贡献仅为世界卫生组织值（0.1毫希沃特每年）的4%。适度的pH值是最重要的参数，且未观察到天然放射性与电导率或主要离子浓度之间存在相关性。
