Indoor radon concentrations caused by construction materials in 23 workplaces

The aim of this study was to compare the measured and the calculated concentrations of indoorradon caused by building materials at 23 workplaces. The measured concentrations of radon wereclearly higher than the calculated radon concentrations from the building materials indicating thatthe main source of indoor radon was the soil under and around the buildings. The highest means ofcontinuously (933 Bq m-3) and integrated (169 Bq m-3) measured and calculated (from 70 to 169Bq m-3) concentrations of radon were found in hillside locations. On the other hand, the median (27and 43 Bq m-3) and maximum (626 and 1002 Bq m-3) values of calculated indoor radonconcentrations exhaled from construction materials were the highest at the ground level places. Onthe average only from seven to nineteen percent of the radon seemed to originate from theconstruction materials.