Indoor and soil radon measurements in Swaziland by track detectors

Indoor radon in dwellings of Jeddah city, Saudi Arabia and its correlations with the radium and radon exhalation rates from soil

“…The average background track density for the unexposed detector was subtracted from the observed values. The value of soil radon concentration (Bq m −3 ) has been obtained from equation (1) 3,6,23,24,30,33 where ρ is the background corrected track density (tracks cm −2 ) and T is the total time of exposure (d). K is the sensitivity factor and its value is calculated by different literatures 3,23,24,30,33 which is 0.2315 tracks cm −2 d −1 (Bq m −3 ) −1 .…”

“…Solid state nuclear track detectors (SSNTDs) have been used successfully by many researchers for indoor radon measurements in dwellings. In the present work, CR-39 plastic track detector films (Pershore Mouldings Ltd, England) and the 'cup with membrane mode' technique [23][24][25][26] were employed to measure the concentration of radon inside the dwellings. For measuring the 222 Rn concentration, the detector (2.5 Â 2.5 cm 2 ) was exposed in a plastic cup with the mouth covered by a semipermeable membrane.…”

“…This configuration also prevents radon daughters from entering the cup and is a 'radon only' device. 23,24,27 After exposing to indoor air for 90 days, the detector was removed and etched for 9 h in 6 N NaOH solution at 70 C. The tracks were then counted microscopically. The average background track density for the unexposed detector was subtracted from the observed values.…”

“…The resulting track density was then converted into 222 Rn concentration in Bq m À3 by appropriate calibration factor of 0.22 tracks cm À2 d À1 ¼ 1 Bq m À3 . [23][24][25][26] The calculations for annual exposure, the annual effective dose and lifetime fatality risk were made using the conversion factor given elsewhere. 9,26,[28][29][30]…”

“…Soil samples (1 kg) were collected under the depth 30 cm within 1.5 m of the foundations of the dwelling in selected locations. 23,26,35 This distance of 1.5 m from the foundations of the dwelling is recommended by Brookins. 35 The samples were dried in an oven at about 105 C for 1-2 h to remove the moisture content.…”