Calculation of natural external radiation dose rate for environmental impact assessment, case study: Abu Zenima area, Southwestern Sinai, Egypt

Abstract

ABSTRACT The present article aims to assess environmental impact coming from terrestrial natural radionuclides, external gamma exposure dose radiation and the average effective annual dose value. The obtained data can be used to provide technical support for the social communication of nuclear energy bodies to understand the natural radiation background of the study area. To achieve the aim, 11271 measurements of 238U, 232Th and 40K were carried out using airborne gamma ray spectrometry for the study area. These measurements were used and converted in to specific activity for calculating the absorbed dose rate (D) and the annual effective dose (E) to infer the average annual effective dose value for the population of Abu Zenima area. The calculated specific activity of U238, Th232 and K40, absorbed dose rate, annual effective dose rate, collective dose and annual effective dose value for the population were mapped through Geographic Information System (GIS) using Arc map software version 10.5. The specific activity concentration of U238 ranged from 1 to 400 Bq/kg, Th232 ranged from 1 to 650 Bq/kg and K40 ranges from 1 to 4000 Bq/kg. The absorbed dose rate values ranged from 3.25nGy/h to 261 nGy/h. Annual effective dose rate values, varying from 21 to 9867 µSv y−1 with an average value of 172µSv y−1which is higher than the worldwide average value of 70µSv y−1 (for outdoor exposures from terrestrial radiation sources).The collective effective average dose (S), varied from 1.16 to 424.31 with an average value of 20.77 man mSv. Finally, average total population effective dose of Abu Zenima area ranged from 0.0013 to 0.0375 with an average value of 0.0129mSv. From all these results, it was concluded that Al Sahu, Al Nasb, Serabit El Khadim and Al Lehianlocalities have high background radiation.