Assessment of absorbed dose rate in air over plowed arable lands in Sinnar State, central Sudan

Abstract

The absorbed gamma-dose rate in air at a height of 1 m above ground level was calculated from activity concentrations of gamma-emitting radionuclides in arable soil samples collected from eight locations within Sinnar State using the published Dose Rate Conversion Factors. Measurements were carried out using high-resolution gamma-spectrometry. On average, the activity concentrations obtained were 38 +/- 8 ((232)Th), 17 +/- 2 ((226)Ra), 174 +/- 19 ((40)K) and 0.9 +/- 0.2 Bq kg(-1) for the fallout radionuclide (137)Cs. The average value obtained here for (232)Th is slightly higher than the corresponding world-average. The calculated absorbed dose rate in air at a height of 1 m for all sampled locations ranges from 31 to 47 nGy h(-1) with an average value of 39 +/- 7 nGy h(-1) which is characteristic of normal background radiation areas. The corresponding annual effective dose was 47.8 +/- 6 microSv y(-1). The major contribution to the total absorbed dose rate comes from (232)Th, which amounts to 61%. Recalculation of the absorbed dose rate-based gamma-energies of individual nuclides from uranium and thorium decay series and (40)K showed that the greater part of the absorbed dose from the uranium series is due to (214)Bi, whereas for the (232)Th series it is equally attributed to (228)Ac and (208)Tl.

Investigations of the Radioactive Presence and Heavy Metallic Materials in Merowe Dam Area

“…In additions, in Sinnar State, measurements were carried out using high-resolution gamma-spectrometry; on average, the activity concentrations obtained were 38 ± 8 (232Th), 17 ± 2 (226Ra), 174 ± 19 (40K) and 0.9 ± 0.2 Bq·kg −1 for the fallout radionuclide 137Cs. The average value obtained here for 232Th is slightly higher than the corresponding world-average [12].…”

“…Table 2 shows the present organic compound found in the buried hole near the dam, the existence revere to the human activity Mechanical workshop, car fuel, and construction martial like epoxide. [12]. The Result in Figure 1 indicates that, the percentage of the radiation dose in different location around the dam to the main value range reading 0.09 µSv/h according overall Sudan measurement were within the normal range.…”