A Study of Radium Content and Radon Exhalation Rates in Soil Samples from Abi-Adi Town, Ethiopia, Using LR-115 Type-II.

Abstract: In the present study, we are presenting the results of radium content, radon concentration, and radon exhalation rates (both mass and area) for 32 soil samples collected from different locations of Abi-Adi Town, Ethiopia, by using the sealed can technique containing a LR-115 Type-II plastic detector. The values of radium content from soil samples were found to vary from 35.26 Bq kg -1 to 101.78 Bq kg -1 , with a mean value of 70.25 Bq kg -1 . The mass and area exhalation rates of radon were found to be from 2.72 × 10 -6 Bq kg -1 d -1 to 7.87 × 10 -6 Bq kg -1 d -1 and from 0.76 × 10 -4 Bq m -2 d -1 to 2.20 × 10 -4 Bq m -2 d -1 , with a mean value of 5.43 × 10 -6 Bq kg -1 d -1 and 1.52 × 10 -4 Bq m -2 d -1 , respectively. The outdoor and indoor annual effective dose equivalent varied from 0.24 mSv y -1 to 0.68 mSv y -1 and from 0.06 mSv y -1 to 0.17 mSv y -1 with a mean value of 0.37 mSv y -1 and 0.09 mSv y -1 , respectively. The working level varied from 2.50 mWL to 7.21 mWL with a mean value of 3.94 mWL. From the results of this study, we found that there was a positive correlation between radium content and radon exhalation rates in soil samples. The radium content values determined in soil samples are less than the permissible value of 370 Bq kg -1 recommended by Organization for Economic Cooperation and Developments as acceptable for safe use. Thus, results reveal that the area under investigation is safe as far as the health hazards of radon are concerned.