Chronic exposure even to extremely low specific radioactivity of natural uranium in groundwater results in kidney problems and potential toxicity in bones. This study was conducted to assess the potential health risk via intake of the groundwater containing uranium, based on the determination of the uranium occurrence in groundwater. The groundwater was investigated from a total of 4140 wells in Korea. Most of the groundwater samples showed neutral pH and (sub-)oxic condition that was influenced by the mixing with shallow groundwater due to long-screened (open) wells. High uranium contents exceeding the WHO guideline level of 30 μg L−1 were observed in the 160 wells located mainly in the plutonic bedrock regions. The statistical analysis suggested that the uranium component was present in groundwater by desorption and re-dissolution processes. Predominant uranium phases were estimated to uranyl carbonates under the Korean groundwater circumstances. These mobile forms of uranium and oxic condition facilitate the increase of potential health risk downgradient. In particular, long-term intake of groundwater containing >200 μg U L−1 may induce internal exposure to radiation as well as the effects of chemical toxicity. These high uranium concentrations were found in twenty four sampling wells of rural areas in this study, and they were mainly used for drinking. Therefore, the high-level uranium wells and neighboring areas must be properly managed and monitored to reduce the exposure risk for the residents by drinking groundwater.
Bibliographical noteFunding Information:
Authors appreciate valuable comments from anonymous reviewers. We gratefully acknowledge that this study work was supported by the project of the National Institute of Environmental Research ( NIER-SP2014-382 ) and the Korea Basic Science Institute (Grant no. C36701 ). This research project was partially supported by the R&D Convergence Program of NST ( National Research Council of Science & Technology ) and Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education ( NRF-2015R1D1A1A01058184 ).
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Environmental Chemistry
- Health, Toxicology and Mutagenesis