中文摘要：

通过研究大气颗粒物中222Rn子体活度比与颗粒物平均寿命之间的关系,建立了基于活度比估算大气颗粒物滞留时间（residence time of atmospheric aerosol,RTAA）的方法,并在相对理想条件下进行了实验验证.当氡室浓度稳定为1.816kBq/m3时,由214Bi/214Pb活度比计算出的RTAA为112.17min,与氡室的平均换气时间（104.17min）相当,表明大气颗粒物中同一衰变链上的放射性核素活度比（如214Bi/214Pb,210Bi/210Pb或210Po/210Pb）可以用于估算RTAA.

英文摘要：

A method of estimating residence time of atmospheric aerosol （ RTAA） is established based on the relationship between specific activity ratio of radon daughters in atmospheric particles and average life of the particles. The method is further testified in a standard radon chamber. When specific activity of radon is 1. 816 kBq /m3 in the chamber,the RTAA is estimated to be 112. 17 min,which is in agreement with the mean-ventilation time in the chamber,104. 17 min. Therefore,the residence time of the atmospheric aerosol can be estimated by using the specific activity ratios of radionuclide in the same decay chain,such as 214Bi /214Pb,210Bi /210Pb and 210Po /210Pb.