Measurement of Radium Concentration and Radon Exhalation Rates of Soil Samples Collected from Selected Area of Aden Governorate, Yemen, Using Plastic Track Detectors

Abstract

Radon exhalation rate from soil is one of the most important factors for evaluation of the environmental radon level. Solid State Nuclear Track Detectors (CR-39) has been widely used for the study of different aspects of radon emission from soil and others. In this paper, we are presenting the results of radon concentration, its exhalation rate and radium content in soil samples collected from different locations of northern part of Aden governorate, south of Yemen. The outdoor radon levels concentrations were found to vary from 264.59Bq m-3 to 539.72Bq m-3 with a mean value of 369.29Bq m-3. The radon exhalation rate in terms of area and in terms of mass were found to vary from 460.08 mBq.m-2.h-1to 938.47mBq.m-2.h-1with a mean value of 642.12mBq.m-2.h-1 and from 25.99mBq.m-2.h-1 to 53.02mBqkg-1.h-1 with a mean value of 36.28 mBqkg-1.h-1. The results of effective radium concentrations in these sites were found to vary from 3.44 Bqkg-1 to 7.01 Bqkg-1 with a mean value of 4.80Bqkg-1. The working level varied from 4.54mWL to 9.26mWL with a mean value of 6.34mWL. The radon annual effective dose was varied from 0.049mSvy-1 to 0.100mSvy-1 with a mean value of (0.068±0.18) mSvy-1 for outdoor and from 0.20mSvy-1 to 0.40mSvy-1 with a mean value of 0.27mSvy-1 for indoor. The results indicate that the soil is quite safe for occupancies and to be used as building materials.