Soil radioactivity levels, radiological maps and risk assessment for the state of Kuwait

Abstract

An evaluation of the radioactivity levels associated with naturally occurring radioactive materials has been undertaken as part of a systematic study to provide a surface radiological map of the State of Kuwait. Soil samples from across Kuwait were collected, measured and analysed in the current work. These evaluations provided soil activity concentration levels for primordial radionuclides, specifically members of the 238U and 232Th decay chains and 40K which. The 238U and 232Th chain radionuclides and 40K activity concentration values ranged between 5.9 ↔ 32.3, 3.5 ↔ 27.3, and 74 ↔ 698 Bq/kg respectively. The evaluated average specific activity concentrations of 238U, 232Th and 40K across all of the soil samples have mean values of 18, 15 and 385 Bq/kg respectively, all falling below the worldwide mean values of 35, 40 and 400 Bq/kg respectively. The radiological risk factors are associated with a mean of 33.16 ± 2.46 nG/h and 68.5 ± 5.09 Bq/kg for the external dose rate and Radium equivalent respectively. The measured annual dose rates for all samples gives rise to a mean value of 40.8 ± 3.0 μSv/y while the internal and internal hazard indices have been found to be 0.23 ± 0.02 and 0.19 ± 0.01 respectively.