Effects of temperature difference between indoor air and concrete, and water content in concrete, on Rn-222 exhalation were investigated. In concrete with 0% water content, the heat generated due to temperature difference between concrete and indoor air could raise Rn-222 exhalation rate by 2.6 times. The Rn-222 exhalation rate rose initially, then declined as water content in concrete was increased. The maximum Rn-222 exhalation rate was 4.4 mBq m(-1) s(-1) in concrete with 10% water content. A grey prediction model was established for predicting Rn-222 exhalation rates and exposure doses of ...
