ABSTRACT
Inhalation of indoor radon has been recognized as one of the health hazards. Building materials, natural gas and underground-derived water supply are considered the major sources of indoor radon and its daughters. In this work a set of radon measurements was carried out, using CR-39 solid state nuclear track detector, in different compartments of dwellings in Cairo built of the same type of building materials. The results showed that the radon concentrations and exhalation rates in these houses varied from 47.94 to 84.32 Bqm-3 and 2.59 to 4.04 mBqm-2 h-2 respectively. The mean values of radon concentrations in living rooms, bedrooms, bathrooms and kitchens were 50.98 +/- 1.94, 53.18 +/- 3.69, 79.36 +/- 2.96, and 81.29 +/- 1.93 Bqm-3, respectively. The mean values of exhalation rates were 2.68 +/- 0.11, 2.79 +/- 0.19, 4.01 +/- 0.18, and 4.22 +/- 0.12 mBqm-2 h-1, respectively. This data show that bathrooms and kitchens have significantly higher radon concentrations and exhalation rates compared with other compartments and the outdoor levels