Assessment of age and sex dependent radiation dose and toxicity risk from exposure to ²³⁸U and ²³²Th in groundwater from Bathinda district of Punjab

HR-ICP-MS technique has been used for the microanalysis of ²³⁸U and ²³²Th concentrations in groundwater samples collected from Bathinda district of Punjab, India. ²³⁸U and ²³²Th concentrations ranged from 4 to 163 µg l^-1 and 0.41 to 1.79 µg l^-1 with mean values of 65 µg l^-1 and 0.93 µg l^-1, respectively. ²³⁸U concentration in water samples collected from villages exceeded the permissible limit of 30 µg l^-1 prescribed by World Health Organization and United States Environmental Protection Agency, while the samples collected from towns have ²³⁸U concentration well within the permissible limit. The estimated annual effective doses due to intake of ²³⁸U and ²³²Th through drinking water for various age groups ranged from 2 to 201 µSv y^-1 and 0.4 to 9.8 µSv y^-1, respectively. About 80% of the analyzed samples showed hazard quotient greater than unity indicating significant risk due to chemical toxicity of ²³⁸U in groundwater. ²³⁸U and ²³²Th concentrations were found to be correlated with the physicochemical properties of the water samples. (author)