No abstract

The presence of large quantities of TENORM contaminated soil produced during the extraction and processing of crude oil at oil extraction sites exceeds the radiological reference levels assigned by the international organizations [1] TENORM may cause the exposure of workers at these sites to unusual radiation hazards. This is of a great importance for assessing the dose to the workers at these sites, which plays a vital rule in exploring the radiation health risks due to radiation exposure. This study aims to assess the TENORM activity concentration of the contaminated soil in some oil and gas production fields in Egypt. The assessment of the radiological hazards for the workers by estimating the annual doses and the radiation hazard indices were also studied. The obtained data show that the activity concentration of 238 U, 232 Th and 40 K ranged from166 to 42567 Bq/Kg, 88 to 8358 Bq/Kg and 52.22 to 440 Bq/Kg respectively. The calculated absorbed dose rate ranged from 132.39-24732.67 nGy/h, and the calculated Annual Effective Dose Equivalent ranged from 0.16-30.33 mSv/y (depending on the activity concentration of NORM contamination). The radiation hazard indices were calculated and found to be much higher than the international values. From the obtained results, it has been concluded that the remediation/decontamination of the contaminated soils in the production sites that have activity concentration higher than 400 Bq/Kg is highly recommended. In addition, Egyptian regulations should be coherent to force companies to decontaminate NORM contamination to reduce as much as possible the radiation worker exposure.