Published online by Cambridge University Press: 10 June 2010
Ingestion of radionuclides through food intake accounts for a substantial part ofradiation doses and vegetables constitute essential components of the diet, bycontributing protein, vitamins, iron, calcium and other nutrients. Radionuclides can beapprehended in the ecosystem of the East Singhbhum region which is known for its viablegrades of uranium. In the present study, vegetables were collected from the villagesaround the proposed Bagjata mining area and analysed for U(nat), 226Ra,230Th and 210Po. The geometric mean concentration of U(nat),226Ra, 230Th, and 210Po were 0.05, 0.09, 0.17 and 1.12Bq kg-1 fresh weight, respectively. The intake of the radionuclides fromvegetables was found to be 49.58 Bq y-1while the ingestion dose was calculatedto be 11.51 µSv y-1, respectively. The estimated doses are reflecting thenatural background dose via the route of ingestion, which is much belowthe 1 mSv limit set in the new ICRP recommendations. It is lower than the global averageannual radiation dose of 2 400 µSv to man from the natural radiation sources as proposedby UNSCEAR. The total cancer risk due to the consumption of vegetables was calculated tobe 6.65 × 10-9 which is negligible and much lower than the threshold risk valueof 10-6. The study also reveals that water is more conducive forhigh radioactivity occurrence in vegetables compared to soil systems.