Measurement of 222Rn Exhalation Rate from Natural Rubber Latex Pillows Randomed from Online Market in Thailand

Radon is a natural radioactive gas, and it is increasingly interesting worldwide because it affects the human healthy and increases lung cancer risk when people receive high concentrations over extended periods of time by inhalation. The study was to measure the radon concentration, determine the radon exhalation rate, and estimate annual effective dose level in order to set up a policy on controlling the contamination of radon in the natural rubber latex products in Thailand, and the radon concentrations were measured from natural rubber latex pillows randomized from online market in Thailand by closed chamber system technique with ATMOS 12 DPX. The results showed that the equilibrium radon concentrations were ranged between 11 ± 2 and 43 ± 5 Bqm–3 with an average value of 17 ± 9 Bqm–3. All measured radon concentrations were well below the allowed maximum contamination level of radon concentration in collected samples of 148 and 300 Bqm–3, recommended by the USEPA and the ICRP, respectively. The exhalation rates from natural rubber latex pillows were ranged 12 ± 3 and 60 ± 7 mBq m–2 h–1 with an average value of 25.7 ± 14.4 mBq m–2 h–1. The annual effective doses calculated for inhalation were between 0.12 ± 0.03 and 0.43 ± 0.05 mSv y–1, and also well lower than the annual effective dose for general public (1.0 mSv y–1) recommended by the ICRP.