Radon availability from the ground of the Brazilian state of Rio Grande do Norte

The radon availability for soils of 51 towns in the Brazilian state of Rio Grande do Norte was assessed by measuring the radon emanation rates of the soils together with their radon diffusion coefficients. The mean emanation rate and the mean diffusion coefficient were 7.2±4.8 atoms.kg-1.s-1 and (5.7 ± 0.6) x 10-6 m2.s-1, respectively. Radon flux densities were also computed by assuming, for the radon emanation ratio, a conservative value of 0.25. The resulting flux densities ranged from 0.011 to 0.17 Bq.m-2.s-1 with a mean value of 0.035 ± 0.024 Bq.m-2.s-1. (Author)