Radon ( 222 Rn) accounts for approximately 60% of natural radiation (2.4 mSv y -1 ) and is a well -documented concern as the primary contributor to indoor exposure. Radon itself is inert, but its decay products ( 218 Po, 214 Pb, 214 Bi, and 214 Po) are reactive and tend to attach to airborne aerosol particles, lodging in the respiratory tract (bronchi, bronchioles, and lungs). During the decay process, they deposit a large amount of radiation, emitting alpha particles into surrounding tissues, ultimately causing biological damage. While radon is most commonly released from soil or rocks, building materials are another potential source of indoor atmospheric pollution. The rate at which radon escapes from a solid substance or diffuses into the surrounding air is known as the solid’s “radon exhalation rate.” Accurately knowing the exhalation rate plays a crucial role in determining the radon source power in building materials and soil. This study aimed to determine the 222 Rn exhalation rate and assess radiological risks in some marble and granite samples commonly used in the Van Province of Turkey. The study employed an LR-115 type II plastic film detector and a closed-box technique. After chemical etching and alpha track counting on the detector, the following parameters were calculated: C Rn (radon concentration), C Ra (radium concentration), E A (surface exhalation rate), E M (mass exhalation rate), D eff (annual effective dose), WLM (annual exposure), F (%) (radon emission coefficient), A Rn (indoor radon concentration contribution), and ELCR (excess lifetime cancer risk). The average E A and E M values calculated for marbles were found to be 313.45 ± 10.90 mBq m -2 h -1 and 12.05 ± 0.41 mBq kg -1 h -1 , respectively. The average E A and E M values for granites were found to be 313.66 ± 11.24 mBq m -2 h -1 and 12.06 ± 0.42 mBq kg -1 h -1 , respectively. The highest values were obtained in sample M2. While the calculated radon concentrations were above the international limit value and the global average, radiological risk values were calculated based on data on indoor radon concentration contributions. It was determined that the use of both marble and granite samples in the construction sector did not pose any risk to human health.
Yildiz et al. (Wed,) studied this question.