title: A long-term investigation of the atmospheric radon concentration in Beijing, China.
abstract: To investigate the levels and behaviour of the atmospheric radon concentration in Beijing, a continuous measurement was carried out and recorded hourly over a five-year period from January 2003 to December 2007. Levels and variations were studied on the basis of 36,731 data points, and the trends of diurnal and yearly variations were also analysed. The range of average concentration of atmospheric radon each year was from 11.2 to 13.0 Bq m(-3), while the average concentration over the five years was 12.1 +/- 4.9 Bq m(-3). The average diurnal pattern of radon concentration showed that the daily maximum appears between 6:00 and 8:00 in the early morning, and the daily minimum appears between 16:00 and 18:00 in the late afternoon. The frequencies of both the maximum and minimum during this period were 30% overall. The yearly pattern features a maximum around October and November and a minimum around April and May.
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Liguo
authors.initials: L
authors.lastname: Zhang
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Guo
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D000398:Air Pollution, Radioactive / Q000032:analysis* / Q000706:statistics & numerical data*; D001272:Atmosphere / Q000032:analysis*; D002681:China; D002947:Cities / Q000706:statistics & numerical data*; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D011886:Radon / Q000032:analysis*
chemical_list: D000396:Air Pollutants, Radioactive; D011886:Radon