| The relations between indoor radon and the incidence of lung cancer research is a hot topic in the world. As the soil radon exhalation have an important impact on the indoor radon concentration, the research of soil radon exhalation is caused by a new hotspot.Therefore, to study the importance of changes in atmospheric pressure on soil radon exhalation, outdoor data of those had simultaneously been measured on January 8, 2008 to January 13, 2008 (winter) and March 28, 2008 to April 1, 2008 (spring). At the same time, the effect of atmospheric pressure on soil radon exhalation had been analyzed, and a preliminary model of changes in atmospheric pressure and soil radon exhalation had been established. Finally, the model simulation results were compared with the measured data.The analysis of field data indicated that: the more evident factors on radon exhalation were temperature and humidity, but atmospheric pressure caused a short term changes on radon exhalation and fluctuations in that were negative correlation with the changes of radon exhalation. However, there existed certain limitations in the conclusion due to the short monitoring time.A pressure difference existed between the atmosphere and soil gas when fluctuations in atmospheric pressure, and through Darcy's law, we could know that the pressure difference was related with the convection speed of radon. Therefore, the simple model of molecular diffusion combined with pressure-induced transport in the soil was based on the instantaneous pressure on the diffusion equation, the soil gas velocity and soil radon exhalation were coupled by finite difference method. The modeling soil radon exhalations by applying the measured atmospheric pressure data into the model were compared with the measured one. And the comparing result appeared well initially.
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