A subnationwide survey of outdoor and indoor ~(222)Rn concentrations in China by passive method

摘要

Survey of outdoor and indoor ~(222)Rn concentrations in China were made with 2-month integrating times from Nov. 1988 to Jan. 1990, and from Feb. 1991 to Mar. 1993. In the first survey, the annual mean outdoor ~(222)Rn concentrations at Beijing, Xi'an, Nanjing, Shanghai, Fuzhou, and Guiyang were 8.0, 11.2, 6.4, 4.8, 9.5, and 12.2 Bq·m~(-3), respectively. The results of the second survey at Changchun, Huhehaote, Shanghai, Wuhan, Fuzhou and Guiyang were 10.1, 8.6, 4.3, 14.6, 10.2, and 11.8 Bq·m~(-3), respectively. The annual mean indoor ~(222)Rn concentration was 21.8 Bq·m~(-3) in typical buildings constructed with concrete and brick. The highest indoor ~(222)Rn concentration of 38.1 Bq·m~(-3) was observed at Guiyang, and the lowest of 11.3 Bq·m~(-3) was at Huhehaote. The annual effective dose equivalent resulted from outdoor and indoor ~(222)Rn and its daughter products was estimated to about 0.67 mSv·a~(-1) in China.