College of Geology and Environment, Xi'an University of Science and Technology, Xi'an, Shaanxi 710054, China.
College of Geology and Environment, Xi'an University of Science and Technology, Xi'an, Shaanxi 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, 710054, China; Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, Ministry of Land and Resources, China.
Sci Total Environ. 2022 Nov 25;849:157935. doi: 10.1016/j.scitotenv.2022.157935. Epub 2022 Aug 7.
The inhalation of a high concentration of radon gas increases the risk of cancer. Therefore, it is of utmost necessity to pay due attention to the problem of environmental radon pollution. The high radioactivity above the coal slab causes serious radon radiation contamination on the mining grounds in coal mining areas such as the northern part of China and the western part of the United States. At present, there is a lack of research on radon exhalation in different lithologies. In this study, the differences in the radon exhalation of different lithologies at various depths and their controlling factors were studied by NMR and radon measurement. The results highlighted that the radon exhalation rates in different rocks varied from 0.3 to 0.6 Bq/m·s. The average radon exhalation rate of the soil was 0.7 Bq/m·s, and the radon exhalation rates of different lithologies followed the pattern red clay > loess > sandstone > mudstone > coal. The radon exhalation rate increased initially, followed by a decrease, and the radon exhalation rate was the highest at the boundary between the soil and rock layers. The radon exhalation rates of different lithologies have a strong correlation with the small pores (<0.1 μm), which govern the changes in the porous structure with depth. The results of this study are important from the perspective evaluation of environmental radon pollution.
吸入高浓度的氡气会增加患癌症的风险。因此，必须高度重视环境氡污染问题。在中国北方和美国西部等采煤区，煤板上方的高放射性导致了严重的氡辐射污染。目前，对于不同岩性的氡逸出研究还比较缺乏。在这项研究中，通过 NMR 和氡测量研究了不同岩性在不同深度的氡逸出差异及其控制因素。结果表明，不同岩石的氡逸出率在 0.3 到 0.6 Bq/m·s 之间变化。土壤的平均氡逸出率为 0.7 Bq/m·s，不同岩性的氡逸出率依次为红粘土>黄土>砂岩>泥岩>煤。氡逸出率最初增加，随后减少，在土壤和岩层边界处氡逸出率最高。不同岩性的氡逸出率与小于 0.1 μm 的小孔（微孔）有很强的相关性，微孔控制着多孔结构随深度的变化。从环境氡污染评价的角度来看，这项研究的结果非常重要。
