Radon exhalation rate from building materials used on the Garyounis University campus, Benghazi, Libya

Radon exhalation rates were measured from building materials on the Garyounis University campus by using the can technique, containing CR-39, to estimate the radiation exposure in the atmosphere. The radon concentration from brick walls, marble ledges, and ceramic floors was found to vary from 107.8 ± 3.6 to 277.9 ± 9.3 Bq m^−3 with a mean of 172 ± 5.8 Bq m^−3, 100.0 ± 3.3 to 298.7 ± 10.0 Bq m^−3 with a mean of 174.5 ± 5.8 Bq m^−3, and 87.0 ± 2.9 to 275.3 ± 9.2 Bq m^−3 with a mean of 145.1 ± 4.9 Bq m^−3, respectively. The average radon exhalation rate from the brick walls and marble ledges showed approximately the same value, which was higher than that of the ceramic floors by more than 15%. The levels of radon concentrations caused by these construction materials in 15 work places were found to be relatively low, giving an annual exposure dose within the internationally recommended range.