Study On Measuring Method In Laboratory Of Radon Exhalation Rate Of Soil Samples

Radon is the only radioactive gas in natural. Radon and its progeny can be easily trapped into human respiratory system. When radon decay in human respiratory sys-tem, a particles it produced irradiate the respiratory tract, damage body cells, and in-duce lung cancer. Therefore, the control of indoor radon levels has very important im-plications to public health. Exhalation of radon is a main source of indoor radon, so study on measuring methods and influencing factors of soil radon exhalation rate has very important impact on protecting public health and reducing irradiation dose.In this paper, a new method for measuring radon exhalation rate measurement in the laboratory has been established. This method solves time-consuming problems of field work, eliminates the influence of thoron on measurement results, and achieves accurate measurement of samples of low radon exhalation rate.Depend on this method,21 soil samples of different moisture content from Shenzhen, Zhongshan have been measured. Radium content and physical parameters of soil samples are also measured.The results show that:1、Soil radon exhalation rate shows a good linearity with soil radium content when soil moisture content are almost the same. While soil ra-dium content increases, radon exhalation rate also increases.2、Effects of moisture content in soil samples on the radon exhalation rate have two aspects:One is to en-hance, the other is to inhibit. When enhancement is stronger than inhibition, radon exhalation rate is correspondingly increased; 3、For the same samples, changing trend of radon exhalation rate with moisture content is more complex. Analysis is needed depending on specific sample; 4、Soil particle density also shows some impact on the radon exhalation rate of soil samples. When soil particle density of sample with ra-dium content in a certain range is larger, the radon exhalation rate is relatively small; and vice versa.Through this study, measuring method available of radon exhalation rate has been improved; relationship between soil physical parameters and radon exhalation rate is obtained, which have some certain help for inducing theoretical formula of ra-don exhalation rate and radon potential map.