Quantification of the effect of temperature difference between concrete and indoor air, and water content in concrete on radon exhalation

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 residents due to different indoor temperature differences with concrete.

Automated summary

The study found that temperature difference and water content in concrete have significant effects on Rn-222 exhalation rate, with varying rates observed under different conditions.