Environmental Radon and Thoron Progeny Concentrations in Fujan Province of China

Abstract

Surveys of environmental radon and thoron progeny concentrations were carried out with the filter method in Fujian Province of China, where very high concentrations of ²³⁸U and ²³²Th in soil had been reported. The mean values of equilibrium-equivalent radon and thoron concentrations (EEC_Rn and EEC_Tn) were 12.9 Bq.m^-3 and 0.87 Bq.m^-3 indoors, 9.7 Bq.m^-3 and 0.39 Bq.m^-3 outdoors in the general living environment. Very high concentrations of both radon and thoron progeny were observed in underground places and railway tunnels. The mean additional effective doses due to the inhalation of radon and thoron and their progeny were estimated to be 7.75 mSv.a^-1 and 22.2 mSv.a^-1 for workers in those places mentioned above. Furthermore, the diurnal/seasonal variations and height distributions of radon and thoron progeny were also studied.