Study on the pore structure and radon emission characteristics of typical rocks in the Lintong area

Radon is found in various rocks as a naturally occurring radioactive gas. It is crucial to estimate the radon emission characteristics of different in situ rocks in the pre-mountain fracture zone of the northern foot of the Qinling Mountains in China for radiation risk prevention, as several inhabitants occupy the area. This paper analyzes the pore structure and radon gas emission characteristics of granite, gneiss, limestone, and sandstone by low-temperature nitrogen adsorption (LTNA) test, nuclear magnetic resonance (NMR) test, scanning electron microscope (SEM) test, and radon gas (Rn-222) measurements. Based on the findings of the study, the order of radon emission rate from high to low is granite, gneiss, limestone, and sandstone, and the volume of micropores ( r