Assessment of Indoor and Outdoor Radon Levels in South Lebanon

The presence of high indoor radon concentrations, C x , is a major concern of the public worldwide. Measurements of indoor radon in South Lebanon have been achieved using CR-39 detectors. C x values ranged between 30 and 122 Bq m −3 in one of the major towns in the area and are compared with measured atmospheric air Radon. Moderate seasonal variation of C x indoors has been observed, although 90 % of the obtained indoor C x measurements are below 100 Bq m −3 . Some homes produced C x readings above the permissible limit. Results showed that the ventilation effect played a major factor in reducing radon concentration levels indoors. Health assessment has been considered. Annual effective doses of radon varied from 1.01 ± 0.10 to 8.65 ± 0.50 mSv a −1 in six homes in one of the four cases studied. These dosage values are above the permitted limit of 2.5 mSv a −1 . Several types of granite contained in the studied homes were identified and their contributions to radon levels indoors were calculated.