Assessment of terrestrial gamma radiation in Sudan

Calculations of the external exposure due to γ radiation from the ground have been made from the results of the measurements of radionuclide activity concentrations in the soil at various locations in Sudan. The average exposure was found to be 45 nGy.h-1, corresponding to the annual dose equivalent of 278 μSv.y-1. With the exception of the Arkuri and Dumper areas in the western part of the country, the calculated exposure falls within the global wide range of outdoor radiation exposure given in the UNSCEAR publications. The nationwide average concentrations of 226Ra, 238U, 232Th, 40K and 137Cs determined were 31.62, 20.11, 19.10, 280.29 and 4.12 Bq.kg-1, respectively. This shows that there is little contamination due to fallout radioactivity at survey sites. (author)