Characterization of radon concentration and annual effective dose of soil surrounding a refinery area, Ras Tanura, Saudi Arabia

Abstract

Background and Objective: Oil refineries process and shipping of petroleum contaminate the environment due to leakage of waste materials containing naturally occurring radionuclides. Radon decays from radium which may content in the waste. Therefore, the present work dealt with measuring soil gas radon concentration, surface and mass exhalation rates from soil samples surrounding a refinery area in Ras Tanura city, Saudi Arabia. Materials and Methods: The measurements were carried out using CR-39 detectors. After etching process, all detectors were automatically counted using scanning and readout system and theoretical calculations were done to find the radon concentration, radon surface and mass exhalation rates and Dose estimation. Results: The soil gas radon concentration ranged from 6.02±0.8 to 927±101 Bq m–3 with an average value of 120±14 Bq m–3. The surface and mass exhalation rates were found to be ranging from 2.65-409 mBq m–2 h and from 0.04-8.31 mBq kg–1 h with an average of 53.4 mBq m–2 h and 1.08 mBq kg–1 h, respectively and the effective dose rate ranged from 0.15-23.4 mSv/y with an average of 3.02 mSv/y. A good positive correlation coefficients were observed between radon concentration and surface and mass radon exhalation rate of soil samples. The obtained results compared with other findings from local and worldwide locations. Conclusion: The obtained results were found to be within the recommended limits. This study could be useful as a baseline data for monitoring and evaluation radon exposure in soil around the residential area nearby refinery area in Arabian Gulf region.