Distribution of Radionuclides in Surface Soil and Bottom Sediment in the District of Jessore, Bangladesh and Evaluation of Radiation Hazard

Radionuclides transfer from soil-to-tea leaves and concomitant doses to the Malaysian populace

One of the most well-liked energizing drinks is now tea, which is primarily used in Malaysia. The natural radioactivity in the associated soils where tea plants are cultivated plays a major role in determining the presence of radionuclides in tea leaves. The present study assesses the transfer of radionuclides from soil-to-tea leaves and then estimates the committed effective doses through tea consumption. Tea leaves and the associated soils were obtained from the largest tea plantation area, which is located in the Cameron Highlands, Malaysia. The marketed tea leaves in powdered form were obtained from the supermarkets in Kuala Lumpur. HPGe gamma-ray spectrometry was used to determine the prevailing concentrations of long-lived radioactive materials in tea leaves. Activity concentrations of 226Ra, 232Th, and 40K in tea soils ranged from 49 to 101.7 Bq kg-1, 74.5-124.1 Bq kg-1 and 79.6-423.2 Bq kg-1, respectively, while the respective values in tea leaves are 14.4-23.8 Bq kg-1, 12.9-29.5 Bq kg-1 and 297-387.5 Bq kg-1. Transfer factors of radionuclides showed typical values (<1.0) except for the 40K. The threshold tea consumption rates suggest that one should not consume more than 67 g of tea leaves per day (around 4 g of tea leaves are needed for making 1 cup of tea, so 17 cups per day) to avoid negative health effects. Committed effective doses due to tea consumption are found to be lower (5.18-6.08 μSv y-1) than the United Nations Scientific Committee on the Effects of Atomic Radiation (2000) reference dose guidance limit of 290 μSv y-1 for foodstuffs; however, it should be noted that the guidance limit is recommended for all foodstuffs collectively. Providing data on natural radioactivity in tea leaves grown in Malaysia, this study may help people manage a healthy lifestyle.

Assessment of natural radioactivity levels in soil samples from Dejen district, Ethiopia

Gamma ray spectrometry was used to determine the activity concentrations of naturally occurring radionuclides in 12 soil samples collected at random from Dejen district, Ethiopia. In agricultural soils, the calculated mean activity concentrations of 226Ra, 232Th and 40K were 33.44 ± 2.01, 66.02 ± 4.54 and 214.16 ± 8.90 Bq kg-1, respectively, and in virgin soils, they were 38.05 ± 2.48, 61.78 ± 4.76 and 240.32 ± 10.79 Bq kg-1, respectively. The findings were discussed and compared to other studies' findings. The mean values of absorbed dose rate, annual effective dose rate and radium equivalent activity in agricultural land soils are 67.24 nGyh-1, 0.083 mSvy-1 and 144.57 Bq kg-1, and in virgin land soils are 67.53 nGyh-1, 0.082 mSvy-1 and 144.90 Bq kg-1, respectively. These findings were discussed and compared to the internationally recommended value. As a result, it is possible to conclude that the soil samples are safe for residents and those involved in agricultural activities.

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

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.

γ-Spectroscopy measurement of natural radioactivity and assessment of radiation hazard indices in soil samples from oil fields environment of Delta State, Nigeria

The analysis of naturally occurring radionuclides ((226)Ra, (232)Th and (40)K) has been carried out in soil samples collected from oil and gas field environment of Delta state, using gamma spectroscopy operated on a Canberra vertical high purity 2″×2″ NaI(TI) detector. The activity concentration of the samples ranges from 19.2 ± 5.6Bqkg(-1) to 94.2 ± 7.7Bqkg(-1) with mean value of 41.0 ± 5.0Bqkg(-1) for (226)Ra, 17.1 ± 3.0Bqkg(-1) to 47.5 ± 5.3Bqkg(-1) with mean value of 29.7 ± 4Bqkg(-1) for (232)Th and 107.0 ± 10.2Bqkg(-1) to 712.4 ± 38.9Bqkg(-1) with a mean value of 412.5 ± 20.0Bqkg(-1) for (40)K. These values obtained are well within the world range and values reported elsewhere in other countries, but are little above some countries reported average values and some part of Nigeria. The study also examined some radiation hazard indices, the mean values obtained are, 98.5 ± 12.3Bq.kg(-1), 0.8Bqkg(-1), 54.6ηGyh(-1), 0.07μSvy(-1), 0.3 and 0.4 for Radium equivalent activity (Ra(eq)), Representative level index (Iγ), Absorbed Dose rates (D), Annual Effective Dose Rates (E(ff) Dose), External Hazard Index (H(ex)) and Internal Hazard Index (H(in)) respectively. These calculated hazard indices to estimate the potential radiological health risk in soil and the dose rate associated with it are well below their permissible limit. The soil and sediments from the study area provide no excessive exposures for inhabitants and can be use as construction materials without posing any immediate radiological threat to the public. However, oil workers in the fields and host communities are cautioned against excess exposure to avoid future accumulative dose of these radiations from sludge and sediment of this area.