Estimation of natural radioactive and heavy metals concentration in underground water

Abstract

Estimation of contaminated groundwater containing human-made radionuclides, among which the transuranic elements are the most toxic, is an essential task for obtaining pure drinking water. Concentrations of natural nuclides (226 Ra, 232 Th and 40 K) and some heavy metals (Cu, Fe. Ni, Pb and As) were measured in groundwater collected from different locations in Makkah region in Saudi Arabia. In the radioactivity measurement, a high purity germanium detector system was used. In addition, chemical analysis was performed by an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The average measured activity concentrations of the nuclides 238 U, 232 Th and 40 K were 0.558, 0.204 and 4.581 BqL -1 , respectively. The total annual effective doses for ingestion of radionuclides in the water samples were 0.472 mSv for children and 0.169 mSv for adults. These results were lower than the recommended value (1.0 mSvy −1), as reported by WHO. The chemical analysis results showed that these water samples contain (Ca, Mg, Cu, Fe. Ni, Pb and As) elements. The concentration values were evaluated and compared with the internationally verified values. This study provides essential information for consumers and authorities; those at exposure risk from mineral water intake.