Distribution of Natural Uranium in Surface and Groundwater Resources: A Review

Keeping in view the toxicity of uranium and to reduce exposure to uranium and avoid high doses, it is essential to examine on routine bases the concentration of natural radionuclide uranium (U) in surface and groundwater resources. In this approach, the concentrations of U (total U) were summarized in worldwide surface and groundwater resources. U(+6) is the major form of U in oxic surface waters, while U(+4) is the major form in anoxic waters. An efficient way of uranium measurement in all water sources must be utilized to obtain reliable results. For this purpose a summary of available analytical techniques for U determination has also been presented. On the basis of the available data, the chemical exposures from these contaminated water sources were specified and some important epidemiological cross-sectional, ecological, and case-control studies and influence of heavy metal mining on water quality were also included. The literature review results revealed that the concentrations of natural U are higher in many parts of the world than the prescribed limit of World Health Organization. Ground and surface water in different areas of the world is contaminated with U and available data is not enough regarding water-related diseases possibly due to the lack of diagnostic facilities. Regular surveys need to be conducted in various parts of the world to obtain a clear picture of water-linked diseases.