Physicochemical and spatial distribution patterns of radon and its parent radionuclides in the uranium-mineralized Singhbhum Region, India

This study examined the distributions of radon and its parent radionuclides ²²⁶Ra and ²³⁸U in groundwater samples from the Singhbhum region, Jharkhand, India. Radon showed a heterogeneous spatial distribution pattern, with a lognormal distribution. A good correlation between radon bubbler-Lucas cells and liquid scintillation counting techniques was observed for radon monitoring. ²²²Rn and ²²⁶Ra were negatively correlated with pH, suggesting the mobilization of radionuclides at low pH. Uranium was positively correlated with common ions (e.g., Ca, Mg, and SO₄²⁻). The activity ratios among the radionuclides indicated disequilibrium, with ²²²Rn origin controlled by parent radionuclide activity in bedrock. The ²²⁶Ra and ²³⁸U concentrations in groundwater were lower than the limits recommended by the WHO.