Natural radionuclides in fish species from surface water of Bagjata and Banduhurang uranium mining areas,East Singhbhum,Jharkhand, India

Purpose:?To study the natural radionuclides in the freshwater fish samples around the uranium mining areas of Bagjata and Banduhurang, East Singhbhum, Jharkhand, India

Materials and methods:?The naturally occurring radioisotopes of uranium, U(nat), consisting of ²³⁴U, ²³⁵U and ²³⁸U; ²²⁶Ra, ²³⁰Th and ²¹⁰Po were analysed in the fish samples from the surface water of Bagjata and Banduhurang mining areas after acid digestion. The ingestion dose, concentration factor and excess lifetime cancer risk of the radionuclides were estimated.

Results:?The geometric mean activity of U(nat), ²²⁶Ra, ²³⁰Th and ²¹⁰Po in the fish samples was found to be 0.05, 0.19, 0.29 and 0.95 Bq kg^?1_fresh (Becquerel per kilogram fresh fish), respectively, in the Bagjata mining area, while for Banduhurang mining area it was estimated to be 0.08, 0.41, 0.22 and 2.48 Bq kg^?1_fresh, respectively. The ingestion dose was computed to be 1.88 and 4.16?μSvY^?1, respectively, for both the areas which is much below the 1 mSv limit set in the new International Commission on Radiological Protection (ICRP) recommendations. The estimation of the Concentration Factors (CF) reveal that the CF from water is greater than 1 l/kg^?1in most of the cases while from sediment CF is less than 1. The excess individual lifetime cancer risk due to the consumption of fish was calculated to be 2.53?×?10^?5 and 6.48?×?10^?5, respectively, for Bagjata and Banduhurang areas, which is within the acceptable excess individual lifetime cancer risk value of 1?×?10^?4.

Conclusion:?The study confirms that current levels of radioactivity do not pose a significant radiological risk to freshwater fish consumers.