Estimation of annual effective dose due to ingestion of natural radionuclides in foodstuffs and water at a proposed uranium mining site in India

摘要

Purpose: To study the distribution of 210Po, 226Ra, 230Th and U(nat) (naturally occurring radioisotopes of uranium [ 234U, 235U and 238U]) in food and water around the Bagjata uranium mining area in India. Materials and methods: Radionuclides were analyzed in food samples of plant and animal origin after acid digestion. Intake and ingestion dose of the radionuclides were estimated. Results: 210Po, 226Ra, 230Th and U(nat) in all the dietary components ranged widely from 0.2-36, 0.02-1.58, 0.01-2.8 and 0.017-0.39 Bqkg-1, respectively. The range of 226Ra and U(nat) in water was 3.5-206 and 12.6-693 mBql-1, respectively. The intake of radionuclides considering food and water was calculated to be 760 BqY-1 while the ingestion dose was 601 μSvY-1. The estimated doses reflect the natural background dose via route of ingestion, which is below the 1 mSvY-1 limit set by the International Commission on Radiological Protection (ICRP). However, the doses are more than the dose constraint of 300 μSvY-1 as suggested by the ICRP for members of the public for planned disposal of long-lived radioactive waste. Conclusion: The study confirms that current levels of radionuclides do not pose significant radiological risk to the local inhabitants, but they need close investigation in the near future.