MEASUREMENT OF RADON EXHALATION RATE AND ANNUAL EFFECTIVE DOSE FROM MARINE SEDIMENTS, RAS TANURA, SAUDI ARABIA, USING CR-39 DETECTORS

The behavior of radon in marine sediments collected from the beach of Ras Tanura, Arabian Gulf, Saudi Arabia was studied by using radon monitoring system consists of two tightly coupled cup-type plastic containers technique containing SSNTDs of type CR-39 to estimate the radon contribution and to calculate the annual effective dose to inhabitants of the study area. The activity concentration of radon in the sediments was found to be ranging from 13.5. +/- 1.4 to 140 +/- 11 Bq m(-3) with an average of 33 +/- 2.1 Bq m(-3). The calculated values of surface and mass exhalation rates of radon ranged from 5.97 to 61.8 mBq m(-2) h(-1) and from 0.11 to 1.47 mBq kg(-1) h(-1), with an averages of 14.6 mBq m(-2) h(-1) and 0.30 mBq kg(-1) h(-1), respectively, for the studied samples of marine sediments. The annual effective dose was found to be ranging from 0.34 to 3.54 mSv y(-1), with an average of 0.83 mSv y(-1). Average value of radon concentrations from marine sediments samples were compared with other literature values.