Measurement of radon exhalation from soil samples in various fault regions of Aizawl district, Mizoram, India

摘要

Radon is a highly radioactive, colourless, chemically unreactive and is produced from the natural decay of uranium. As it is being synthesized, it can be released into air or water-containing pores between soil and rock particles. Environmental radon is of great medical concern as it causes dangerous health problems such as lung cancer, and is classified as Group A carcinogen. Measurement of radon mass exhalation rate was performed on soil samples collected from 33 different sites within different fault regions of Aizawl district, Mizoram, India, using Smart RnDuo. The sampling sites are located within the region 23°22'39.5"N to 24° 09'30.16"N latitude and 92°39'49.03"E to 92°56'49.35"E longitude. Soil samples were collected from three different points in each selected fault with a minimum of 200 m from each other. The type of soil collected from these regions was identified using mechanical sieve shaker and the result obtained was found to be mostly sandy type of soil for all the soil samples. The radon mass exhalation rate in soil was found to be in the range of 11.2 mBq/kg/hr to 72.2 mBq/kg/hr, with an average of 39.92 mBq/kg/hr. It was observed that radon mass exhalation rate is higher in fault regions of Aizawl district as compared to other regions of India such as northern Rajasthan, Kangra District, Himachal Pradesh and Kathmandu Valley, Nepal.