Radiological impact of NORM generated by oil and gas industries in the kingdom of Bahrain

A study of the external background radiation in areas affected by NORM generated by oil and gas industrial activities has been performed in the Kingdom of Bahrain. In this framework, two experimental residential areas, Awali and Riffa Views, were selected due to the presence of extensive oil and gas exploration and transportation. Additionally, two control residential areas, Isa Town and Al-Budaiya Village, were selected as they lack any industrial activities that would disrupt the radiation profile. The radiation dose rates were measured using Colibri Very Low Dose radiation survey meter with a built-in GPS. A total of 317 dose rates with their GPS coordinates were acquired. The lowest dose rate was 0.02 μSv/h acquired in Isa Town while the highest dose rate was 0.37 μSv/h acquired in Awali. Since there were no studies performed in the Kingdom to measure the average background radiation, the average external background radiation calculated from the control areas was used in this study which is 0.75 ± 0.31 mSv/y. The measured mean annual equivalent doses above the background radiation levels in Isa Town, Al-Budaiya, Riffa Views and Awali were −0.05 ± 0.05 mSv/y, 0.04 ± 0.04 mSv/y, 0.62 ± 0.13 mSv/y and 1.32 ± 0.35 mSv/y respectively. In other words, the radiation measurements were notably higher in the experimental areas. This was particularly true in south and southwestern Awali where the annual equivalent dose in some areas reached 2.49 mSv/y above average background levels. The geological constituent of the earth crust could be one source that contribute to overall background radiation. However, presence of NORM generated by extensive oil and gas operations and transportation is stronger justification for the higher radiation readings in the experimental areas than geological characteristic factor. Such high radiation values were found only near oil and gas installations and not in other locations of the same areas. - Highlights: • The oil and gas industrial activities enhance the naturally occurring radioactive materials (NORM). • Experimental areas exhibit higher radiation levels compared to average radiation in the Kingdom of Bahrain. • Presence of industrial NORM is the major justification for higher radiation levels in the experimental areas. • Guidelines to monitor and control NORM related to industrial activities should be issued in the Kingdom.