Radon/ thoron Exhalation Rates of Building Materials Collected from Kanyakumari district, Tamil Nadu
Radon (Rn222) and thoron (Rn220) are carcinogenic gases. According to WHO (2023) radon gas is estimated to cause 3% to 14 % of all lung cancers in a country. Building material used for construction is one of the reasons for elevated indoor radon and thoron concentrations. In this study, exhalation rate of radon and thoron from building materials used for construction in Kanyakumari District were analyzed. The materials collected were crushed into pieces, dried, weighed and subjected to exhalation analysis using RAD 7. The radon mass exhalation rate of the samples ranged from BDL to 15 ± 1 mBq/kg/h with the geometric mean of 4 mBq/kg/h and the thoron surface exhalation rates ranged from BDL to 5003.27 ± 36.73 Bq/m2/h, with the geometric mean of 237 Bq/m2/h. This study confirmed that Radon mass exhalation rate was high in gypsum, followed by clay, granite, and cement-based materials compared to ceramic tiles, bricks, marbles, m-sand etc.