Study on relationship between indoor radon concentration and air exchange rate for new residential buildings

Objective: To investigate the relationship between indoor radon concentration and air exchange rate for new residential building. Methods: The indoor radon concentration and air exchange rate were measured in two new roughcast houses in Guangzhou and Hefei, respectively. The radon concentration was measured using radon instrument. The air exchange rate was measured by using tracer gas dilution method. Results: The indoor radon concentrations measured in Guanzhou for two bedrooms in a 48-hour closed condition were 106 and 115 Bq/m³, the range of 17-181 and 6-224 Bq/m³. Air exchange rates were 0.16/h and 0.21/h. In Hefei, the twice measured values for one bedroom were 148 and 186 Bq/m³, the range of 8-224 and 14-290 Bq/m³, and air exchange rates were 0.14/h and 0.12/h. The indoor radon concentration exponentially decreased with the increase of air exchange rates. Conclusions: Attention should be paid to the indoor radon pollution issue that may arise in new residential buildings of energy-saving design due to low air exchange rate. (authors)