Occupational exposure to NORM in gold mining areas of northwestern Sudan

This study was carried out to evaluate the distribution of naturally occurring radioactive materials (NORM) and radiological hazard indices in the soil of a gold mine in northwestern Sudan using gamma ray spectrometry. The activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in the soil samples varies from 2.54 ± 1.70 to 50.67 ± 3.10 Bq/kg, 10.28 ± 4.20 to 39.91 ± 2.10 Bq/kg and 274.64 ± 0.98 to 1625.85 ± 54.40 Bq/kg, respectively. The average activity concentration of ⁴⁰K were found to be above the world average. The annual effective dose is 0.05 mSv/year which is lower than the 20 mSv/year recommended by the International Commission on Radiological Protection (ICRP) guidelines for occupational exposure.