土壤物理性质对土壤氡浓度及地表氡析出率的影响

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

目的 探讨土壤性质对土壤氡浓度及地表氡析出率的影响。方法 在北京、贵阳、呼和浩特的 31个测量点进行土壤氡浓度及析出率的现场实测。采集土壤样品 ,在实验室进行土壤镭含量、含水量、孔隙度和粒径分布等物理性质测量。用线性拟合方法分析了实测土壤氡、析出率数据之间的相关性 ,以及它们与土壤镭含量的关系。结果 地表氡析出率与土壤氡浓度和土壤镭含量有正相关关系 ;土壤含水饱和度过高或过低均会使析出率和土壤氡浓度降低 ;贵阳地区土壤镭含量较高 ,但其粉砂黏土壤的特性使土壤氡浓度很难准确采样 ,导致结果偏低。结论 地表氡析出率和土壤氡浓度虽然与土壤镭含量有正相关关系 ,但在实际环境中易受含水量等多因素影响 ,而且土壤氡浓度的准确测量受土壤特性限制较大。

Objective To analyse the impacts of soil characters on radon concentration in soil and radon exhalation from soil. Methods Field measurements on soil radon concentration(60 cm under the soil surface) and radon exhalation rate from soil were carried out in totally 31 different types of soil samples collected from three cities in both South and North China.Soil radium contents,water contents,soil porosity and grain size were concretely analysed in our laboratory.The linear simulation was used to analyse the measurement data. Results Radon exhalation rate from soil and radon concentrations in soil had direct proportion to soil radium contents.No high soil radon concentration was gotten as expected in Guiyang area where soil radium content was high. Conclusion Compared with soil radium contents,radon exhalation rate from soil and soil radon concentration are more easily impacted by soil characters and changes in a rather large range.\;