Determination of the natural radioactivity in the mineral water distributed in the Salutaris Park, Paraíba do Sul, Brazil

Humans are daily exposed to the natural radioactivity present in rocks, soils, and water. The distribution of these elements in the surface is not uniform, being influenced by the variation of the physical, geological, and meteorological parameters. The concentration activities of natural radionuclides 238U, 226Ra, 228Ra, and 222Rn were determined in the groundwater supplying the Salutaris Mineral Waters Park, in Paraíba do Sul, in the state of Rio de Janeiro. The concentrations of 238U varied from 0.95 to 2.70 μg L−1 with a mean concentration of 1.96 μg L−1, 226Ra ranged from 1.50 to 12.6 mBq L−1 with an average of 5.03 mBq L−1, 228Ra presented levels between 1.80 and 2.80 mBq L−1, with an average of 2.40 mBq L−1, and 222Rn, with levels of 5.90–1.94 × 104 mBq L−1 with an average concentration of 7.50 Bq L−1. The contribution of the consumption of these radionuclides dissolved in the water distributed in the Park to the effective annual dose ranged from 0.03 to 0.10 mSv year−1, with an average of 0.08 mSv year−1. The results showed that all effective annual dose values per ingestion of these mineral waters were below the individual dose limit of 0.10 mSv year−1 recommended by the World Health Organization (WHO).