Radon-222 measurements in a uranium-prospecting area in Brazil

Radon-222 concentrations were determined in about 100 measuring points in a uranium-prospecting area in the eastern part of Brazil. The single measurement data in open areas, identified as environmental points, present values between 4 ± 2 Bq m−3 and 404 ± 16 Bq m−3, with a mean value of 69 ± 6 Bq m−3. Comparing the mean values for each measuring site, the values obtained are between 15 ± 2 Bq m−3 in the store room for mineral samples and 245 ± 7 Bq m−3 for the central point AN08 of the prospective mine. Makrofol SSNTD was used for the measurements and exposed for 120 day-alternated periods from May 1992 to May 1994.