Assessment of radiological hazards from soil samples in the Northeastern area of Burkina Faso

Abstract

The activity concentrations of main naturally occurring radionuclides were determined with the aim of assessing the radiation hazards in the Northeastern part of Burkina Faso. Soil samples were taken and analyzed by the gamma-ray spectrometry method. The ranges of specific activity of 238U, 232Th and40K are $$15.25 \pm 2.59 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 15.25 ± 2.59 Bq · kg - 1 to $$109.57 \pm 3.21 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 109.57 ± 3.21 Bq · kg - 1 , $$19.56 \pm 1.65 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 19.56 ± 1.65 Bq · kg - 1 to $$44.88 \pm 2.49 \text{Bq} \cdot {\text{kg}^{-1}}$$ 44.88 ± 2.49 Bq · kg - 1 and $$125.74 \pm 4.40 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 125.74 ± 4.40 Bq · kg - 1 to $$705.85 \pm 10.79 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 705.85 ± 10.79 Bq · kg - 1 respectively. Three high background radioactivity areas have been identified for Uranium, Thorium and Potassium on different places in the study area. The radiological hazards indices vary from $$62.87 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 62.87 Bq · kg - 1 to $$189.47 \, \text{Bq} \cdot {\text{kg}^{-1}}$$ 189.47 Bq · kg - 1 for the Radium equivalent activity ($$Ra_{eq}$$ R a eq ), $$29.5 \, \eta \text{Gy} \cdot {\text{h}^{-1}}$$ 29.5 η Gy · h - 1 to $$86.65 \, \eta \text{Gy} \cdot {\text{h}^{-1}}$$ 86.65 η Gy · h - 1 for the absorbed dose rate ($$D_R$$ D R ), $$0.18 \, \text{mSv} \cdot {\text{y}^{-1}}$$ 0.18 mSv · y - 1 to $$0.53 \, \text{mSv} \cdot {\text{y}^{-1}}$$ 0.53 mSv · y - 1 for the annual effective dose rate (AEDE), 0.21 to 0.81 for the internal hazard index ($$H_{in}$$ H in ), 0.17 to 0.51 for the external hazard index ($$H_{ex}$$ H ex ), $$1.27 \times 10^{-4}$$ 1.27 × 10 - 4 to $$3.73 \times 10^{-4}$$ 3.73 × 10 - 4 for the Excess Lifetime Cancer Risk (ELCR) and $$209.01{\mkern 1mu} \mu \, 0.18{\mkern 1mu} Sv \cdot y^{{ - 1}}$$ 209.01 μ 0.18 S v · y - 1 to $$594.21 \, \mu \text{Sv} \cdot {\text{y}^{-1}}$$ 594.21 μ Sv · y - 1 for the annual gonadal dose equivalent. The average values of indices are well below their permissible limit. However, at Niapsi the obtained values for absorbed dose rate, annual effective dose rate and excess lifetime cancer risk are little above their permissible limit.

Assessment of Radiation Levels and Potential Radiological Hazards in the Soils of Riruwai Mining Area, North-Western Nigeria

“…The activity of 238 U was computed as the mean of the activities obtained from the gamma-ray lines 214 Pb (295.30 and 352.00 keV) and 212 Bi (609.50, 1120.20, and 1764.5 keV) isotopes. The activity of 232 Th was obtained by the gamma-ray lines of 228 Ac (911.1 and 968.80 keV), and the activity of 40 K was obtained from the gamma-ray line of 1460.80 keV.…”

“…Where: CU-238, CTh-232 and CK-40 are the activity concentrations of 238 U, 232 Th and 40 K respectively in soils [4].…”

“…Where, CU, CTh and CK are the measured concentrations of 238 U, 232 Th and 40 K respectively in Bq/kg [4] External Hazard Index (Hex)…”

“…Radioactivity is a natural phenomenon evidenced by the release of ionizing radiation that can be found in various quantities throughout the environment [1]. Radioactivity has become an important environmental concern around the world and has become a topic of great concern over the years due to its significant adverse effects on human health [2,3].…”

“…Radionuclides are responsible for around 86 % of the effective human dosage [3,4]. These radionuclides consist predominately of the 238 U series, the 232 Th series, and the 40 K series, together with their decay products [5,6]. Radiations emitted by radioactive materials and associated progenies are one of the most significant external sources of radiation exposure for human beings [7,8].…”