Nuclear Science Research Institute (NSRI), King Abdulaziz City for Science and Technology (KACST), P·O.Box 6086, Riyadh, 11441, Saudi Arabia; Department of Soil Sciences, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia.
Physics Dept., Faculty of Science, Yarmouk University, Irbid, 211-63, Jordan; College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Al-Ahsa, Saudi Arabia.
Chemosphere. 2020 Mar;242:125181. doi: 10.1016/j.chemosphere.2019.125181. Epub 2019 Oct 23.
Recognizing the vast uses of water in human life, the presence of α and β particles emitting radionuclides in groundwater of northern Saudi Arabia has been evaluated as a means of water quality assessment of the region. A liquid scintillation counting technique was used to determine the gross α/β, and Ra radioactivities in water samples, while the radioactivity concentrations of U and Ra were determined using alpha spectrometry after the separation process. Present results show that all water samples contain a higher level of gross α and β radioactivity than the WHO recommended limits; the average gross α activity is about 7 times greater than the limit value of 0.5 Bq L, while the average gross β activity value is about 3.5 times greater than the limit value of 1 Bq L. Correlations of TDS and pH with gross α and β radioactivity in the studied samples were investigated. The activity ratio of the measured U and Ra alpha emitters to the gross α radioactivity and the ratio of the measured β emitters to gross β radioactivity were also discussed. Furthermore, interesting information on thorium abundance and radioactive disequilibrium in U series were observed by studying the activity ratio of Ra/Ra, Ra/U, and U/U. Although these samples are not directly used for human being drinking, and mainly used in irrigation, the higher gross α/β radioactivity may cause health risks to humans, since these radionuclides may enter the food chain through irrigation water. Thus, further radioactive risk assessment is highly recommended.
鉴于水在人类生活中的广泛用途，评估了沙特阿拉伯北部地下水的α和β粒子放射性核素的存在情况，将其作为该地区水质评估的一种手段。采用液体闪烁计数技术测定水样的总α/β和 Ra 放射性活度，而 U 和 Ra 的放射性活度浓度则采用分离后进行的α谱法测定。目前的结果表明，所有水样的总α和β放射性活度均高于世界卫生组织建议的限值；总α活度的平均值约为限值的 7 倍，而总β活度的平均值约为限值的 3.5 倍。研究了 TDS 和 pH 值与所研究样品中总α和β放射性之间的相关性。还讨论了测量的 U 和 Raα发射体与总α放射性的活度比以及测量的β发射体与总β放射性的活度比。此外，通过研究 Ra/Ra、Ra/U 和 U/U 的活度比，观察到了钍丰度和 U 系放射性不平衡的有趣信息。尽管这些样品不直接用于人类饮用，主要用于灌溉，但较高的总α/β放射性可能会对人类健康造成风险，因为这些放射性核素可能会通过灌溉水进入食物链。因此，强烈建议进行进一步的放射性风险评估。
