The effect of some soil characteristics on soil radon concentration and radon exhalation from soil surface

To find out the impacts of soil characters on radon concentrations in soil and radon exhalation from soil, field measurements on soil radon concentrations (60 cm under the soil surface) and radon exhalation rate from soil surface were carried out in totally 31 points with different types of soil in three cities in both South and North China. Soil radium contents, water contents, soil porosity and grain size were concretely analyzed in our laboratory. The linear simulation was used to analyze the above data. The results showed that radon exhalation rate from soil and radon concentrations in soil have direct proportion to soil radium contents. Rather high radium content and radon exhalation rate were measured in Guiyang area, 67+/-28 Bq/kg and 40+/-59 mBq/m(2).s, however no high soil radon concentration was found due to the difficulties in the measurements on clay soils with high water saturation. Compared with soil radium contents, radon exhalation rate from soil and soil radon concentrations are more easily impacted by soil characters and change in a rather large range.