Evaluation of natural radioactivity levels in soil and various foodstuffs from Delta Abyan, Yemen

Assessing radioactivity levels in agricultural soil: a comparative study of traditional vs. modern fertilization techniques in Tunisian oases

To establish a radiological national reference for agricultural soil across Tunisian oases and assess the risk to human health associated with date consumption, with a focus on comparing the impact of traditional and modern fertilization, radiological parameters and activity levels of 22⁶Ra, 232Th, and 4⁰K were determined for 27 oases. These oases were located in three southern Tunisian governorates. The activity concentration of 22⁶Ra, 232Th, and 4⁰K was measured using a 3 × 3 inch NaI(Tl) scintillation detector, which was found to be 21.82 ± 1.0Bq kg - 1 , 26.51 ± 1.1Bq kg - 1 , and 559.21 ± 23.0Bq kg - 1 , respectively, for traditional oases and 26.56 ± 1.2Bq kg - 1 , 24.45 ± 1.1Bq kg - 1 , and 661.28 ± 26.3Bq kg - 1 , respectively, for modern oases. In addition, ambient dose equivalent rate was measured during sampling using a multipurpose hand-held radiation CsI(Tl) detector, which was found to be 0.075 µSv/h in traditional oases and 0.078 µSv/h in modern oases. The resulting radiological parameters and activity concentrations were then compared to results from neighboring countries and the average soil activity worldwide.

Study of activity concentrations of 40K, 238U and 232Th for assessment of radiation dose in agricultural soils of southwestern Nigeria

Gamma spectrometric measurement of natural radionuclides activity concentrations by HPGe detectors was conducted in 150 agricultural soil samples collected from six states of southwestern Nigeria. The overall activity concentrations of radionuclides ranged from 15.27 to 972.00 Bqkg-1 for 40K, 0.66 to 336.19 Bqkg-1 for 232Th and 1.32 to 123.01 Bqkg-1 for 238U, with mean values of 143.95, 17.02 and 22.92 Bqkg-1, respectively. The overall averages results from this study were generally lower than worldwide average value of 420, 33 and 45 Bqkg-1 for 40K, 238U and 232Th, respectively, thus minimal transfer to plant may be expected. The estimated radiation dose levels of the soil indicated acceptable limits for general public exposure. The radioactivity levels of 40K, 232Th and 238U in the investigated agricultural soil of southwestern Nigeria are within acceptable limits. Therefore, stochastic radiological health effects of radiation exposure by farmers may not be feasible at the current moment.

Evaluation of natural radioactivity in soils of Konya (Turkey) and estimation of radiological health hazards

Surface soil samples were collected from Konya, Turkey and natural activity concentrations were determined using the ɤ-ray spectroscopy system with HPGe detector. The activity concentrations of 226Ra, 232Th and 40K were found to vary from 14.07 ± 0.71 Bq kg-1 dw to 67.27 ± 1.62 Bq kg-1 dw, 10.19 ± 2.60 Bq kg-1 dw to 46.09 ± 0.76 Bq kg-1 dw and 107.87 ± 13.32 Bq kg-1 dw to 605.95 ± 11.34 Bq kg-1 dry weight (dw), respectively. The radiological hazard parameters such as Raeq, D, AEDE, ELCR, AGDE, Hex, Hin, and Iɤ evaluated the radiological risk for the public and environment. The mean values of D, AEDE and ELCR are lower than the world average value of 57 nGy h-1, 70 μSv y-1, 0.29 × 10-3 respectively. The activity concentration distribution maps of 226Ra, 232Th and 40K and the radiological maps of the radiological hazard parameters were plotted using the Surfer programme. Cluster analysis was carried out to indicate the similarity between the variables.

Gamma spectroscopy study of soil-plant transfer factor characteristics of 40K, 232Th and 226Ra in some crops cultivated in southwestern region of Nigeria

Soil-plant transfer factor (TF) is one of the vital variables employed in assessing plants uptake of radionuclides and their transfer to food chain for predictive ingestion dose and risk evaluation. To further this goal, the TF characteristics of natural 40K, 232Th and 226Ra were thus investigated in some crops (yam, cassava, rice, maize, groundnut, cowpea, okra, pumpkin leaf, banana and pawpaw) cultivated in southwestern part of Nigeria using HPGe gamma spectroscopy. The obtained results of activity concentration (AC) of the radionuclides across all the cultivated soil samples indicated average values that are less than the global average, whereas in the crops, average values of 226Ra and 232Th, were higher than reference values for different crops group. The overall range of the calculated TF of 40K, 232Th and 226Ra across all the crops was 0.05 (in maize and cowpea) to 15.01 (in banana), 0.01 (in pumpkin leaf and groundnut) to 19.80 (in pawpaw), and 0.04 (in cassava) to 21.30 (in cowpea), respectively. Overall arithmetic mean and geometric mean were estimated as 2.66 and 1.60, 1.11 and 0.43, and 1.10 and 0.54 for 40K, 232Th and 226Ra, respectively. TFs mostly correlated negatively with soil radionuclides, while positive correlation was mostly noticeable in the case of crop. Log normal transform of the TFs data indicated a near normal distribution as against the calculated data. The derived results of this study is here presented as a baseline data suggested for possible radiological risk assessment of food chain of the local population.

Advances in the management of radioactive wastes and radionuclide contamination in environmental compartments: a review

Several anthropogenic activities produce radioactive materials into the environment. According to reports, exposure to high concentrations of radioactive elements such as potassium (⁴⁰K), uranium (²³⁸U and ²³⁵U), and thorium (²³²Th) poses serious health concerns. The scarcity of reviews addressing the occurrence/sources, distribution, and remedial solutions of radioactive contamination in the ecosystems has fueled data collection for this bibliometric survey. In rivers and potable water, reports show that several parts of Europe and Asia have recorded radionuclide concentrations much higher than the permissible level of 1 Bq/L. According to various investigations, activity concentrations of gamma-emitting radioactive elements discovered in soils are higher than the global average crustal values, especially around mining activities. Adsorption technique is the most prevalent remedial method for decontaminating radiochemically polluted sites. However, there is a need to investigate integrated approaches/combination techniques. Although complete radionuclide decontamination utilizing the various technologies is feasible, future research should focus on cost-effectiveness, waste minimization, sustainability, and rapid radionuclide decontamination. Radioactive materials can be harnessed as fuel for nuclear power generation to meet worldwide energy demand. However, proper infrastructure must be put in place to prevent catastrophic disasters.

Activity concentrations and radiological hazard assessments of 226Ra, 232Th, and 40K in soil samples of oil-producing areas of South Africa

The specific activity of natural radionuclide in soil samples of the oil-producing areas of South Africa was measured using a High Purity Germanium detector. The activity of226Ra, 232Th, and 40K in the soil range from 16.5 ± 1.3 to 64.9 ± 3.1, 16.8 ± 1.5 to 88.6 ± 1.2, 135.2 ± 17.5 to 604.8 ± 13.4 Bqkg-1 for Mossel Bay; 14.3 ± 1.2 to 48.9 ± 8.2, 22.3 ± 1.4 to 45.1 ± 3.2, 237.7 ± 10.9 to 486.5 ± 40.1 Bqkg-1 for Cape Town; 10.5 ± 1.1 to 25.8 ± 3.2, 13.1 ± 1.9 to 44.3 ± 5.2, 140.2 ± 10.9 to 229.8 ± 12.8 Bqkg-1 for Nelson Mandela Bay and 5.6 ± 2.2 to 13.1 ± 2.9, 4.5 ± 2.5 to 14.1 ± 2.7, 62.7 ± 22.6 to 126.5 ± 21.2 Bqkg-1 for Msunduzi. Most soil samples' radiological hazards were within the world average.

Anthropogenic accumulation based on chemometrics of the radionuclide K-40 in tropical soils in the northeast Brazil

The continuous use of fertilizers can increase the radionuclides levels in soils, and their accumulation and concentration are related to their characteristics and the various processes of use and soil occupation. Analyzing data from radiometric and pedological measurements often demands the use of more robust tools for better integration of results. This work presents the results of a study to evaluate the accumulation of ⁴⁰K, in an area of the Zona da Mata region in Pernambuco, Northeastern Brazil, due to the contribution of natural or artificial sources. ⁴⁰K activity concentration was measured by high resolution gamma spectrometry in 108 soil samples, as well the organic matter content and particle size distribution. Results showed the ⁴⁰K activity ranged from 103 to 1843 Bq.Kg^-1, with the arable soils showing levels above the world average value (420 Bq.Kg^-1). A higher prevalence of ⁴⁰K was observed on arable soils, regardless of soil type, organic matter content, depth or texture. Agricultural activities increased of ⁴⁰K levels in different degrees, depending on the type of crop used, with an accumulation factor of up to 4 times greater compared to soils not impacted by agricultural activities. The radiochemometric diagnosis maded it possible to draw up a strategic management plan to improve the management practices of family farming in order to maximize production efficiency, and promote the conservation of natural resources and environmental preservation.

Distributions and Risk Assessment of the Natural Radionuclides in the Soil of Shoubra El Kheima, South Nile Delta, Egypt

Due to heightening concern about radiation hazards protection, activity concentrations of 226Ra, 232Th, 40K in forty soil samples collected from Shoubra El Kheima in the South Nile Delta were measured using gamma-ray spectrometry. The mean activity concentrations of 226Ra and 40K were higher in 20% of the considered samples than the world average values. A comprehensive comparison with up-to-date data was carried out. Spatial distribution maps of the measured radionuclides and radiological parameters were generated. The distributions of natural radionuclides were influenced by the soil organic matter, clay content, and scavenger metals oxides, as well as differences in the physical and chemical attributes and solubility of these radionuclides. The results revealed that industrial activity and agricultural practices in the study area caused an incremental increase in 226Ra and 40K activity concentrations. It can be deduced that although there are intensive industrial activities in this area, the natural radiation that comes from the soil is normal and does not pose a significant radiological hazard to the public. The natural radioactivity of soil in this area needs to be monitored periodically to prevent unnecessary radiation exposure to inhabitants.

Determination of natural radioactivity material concentrations consumed widely during Corona pandemic in Thi Qar province

The present study was carried out to assess the potential radiation hazards to the public, especially the persons who consumed onion and garlic plants widely during coronavirus disease in Thi Qar province South of Iraq. Nine samples collected from the market (5 samples onion and 4 sample Garlic), which classified according to their origin. Using 3″x3″ NaI (Tl) gamma ray spectroscopy system, the radioactivity concentrations of the natural radionuclides radium-226, thorium-232 and potassium-40 were determined. The results obtained showed that the average concentration of radioactivity of radium-226, thorium-232 and potassium-40 is 3.398 Bqkg^-1, 4.667 Bqkg^-1 and 216.738 Bqkg^-1, respectively, for onion and 2.808 Bqkg^-1, 3.524 Bqkg^-1, and 172.064 Bqkg^-1 for garlic. The results also showed that the average annual total effective dose of the three nuclides is 122.955 μ S v . y - 1 for onion and 97.231 μ S v . y - 1 for garlic. Other relevant risk parameters were also calculated, such as equivalent activity concentrations, absorbed dose, excess lifetime cancer risks, and other health risk parameters. One of the most important conclusions reached by this study is that the natural radioactive elements in onions and garlic do not pose a great danger to their consumers, especially those infected with the COVID-19. Because the concentrations of these radioactive elements do not exceed the permissible limits recommended by recognized scientific organizations and agencies such as International Commission on Radiological Protection (ICRP), United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and World Health Organization (WHO).

Natural and anthropogenic radioactivity in some vegetables and fruits commonly consumed in the Western Black Sea region of Turkey

In this study, the activity concentration of 226Ra, 232Th, 40K, and 137Cs in some vegetable and fruit samples frequently consumed in Kastamonu province located in the West Black Sea region of Turkey were determined using a gamma-ray spectrometer. The activity concentrations of 226Ra, 232Th and 40K varied from 0.8 ± 0.1 to 32.8 ± 1.3, 0.7 ± 0.1 to 41.3 ± 21 and 391.8 ± 18.3 to 4679.0 ± 311.4 Bq kg−1 (dw), respectively, in twenty-eight vegetables and 1.3 ± 0.1 to 12.6 ± 0.4, 1.4 ± 0.1 to 15.0 ± 0.5 and 133.0 ± 84 to 777.0 ± 69.4 Bq kg−1 (dw), respectively, in seven fruit samples. The highest activity concentration of 226Ra and 232Th was measured in the garlic sample, while the highest activity concentration of 40K was measured in the spinach sample. Artificial radionuclide 137Cs was measured only in four vegetable samples; its activity concentration in garlic, eggplant, cucumber and carrot samples was determined as 9.6 ± 0.3, 3.1 ± 0.1, 3.1 ± 0.1 and 2.2 ± 0.1 Bq kg−1 (dw), respectively. The results obtained were compared with the results of similar studies in the literature. Annual effective radiation dose to adults due to the internal irradiation caused by ingestion of the investigated vegetable and fruit samples, and the corresponding excess lifetime cancer risk were estimated as 201 µSv and 8.9 × 10−5, respectively. The contribution of 40K to the total annual effective radiation dose was found as approximately 70%.

Radioactivity of soil in Croatia II: 137Cs, 40K, and absorbed dose rate

We took samples of uncultivated soil from the surface layer (0–10 cm) at 138 sites from all over Croatia and measured their radionuclide activity concentrations with high-resolution gamma-ray spectrometry. This second part of our report brings the results on ⁴⁰K and ¹³⁷Cs to complement those on the ²³²Th and ²³⁸U decay chains addressed in the first part. Together they give the most complete picture of radioactivity of Croatian soil so far. Activity concentrations of ⁴⁰K were the highest in the Pannonian region, and there was an opposite trend for ¹³⁷Cs. We found that the concentrations of ¹³⁷Cs tended to increase with altitude, annual precipitation, and vegetation density. The concentration ratio of ¹³⁷Cs and K in soil, which indicates the potential for ¹³⁷Cs entering food chains via uptake by plants, was the lowest in agriculturally important areas in the east of the Pannonian region. In addition, we used the obtained results on activity concentrations to calculate the related absorbed dose rate as a measure of external exposure to ionising radiation from soil. The sum of the absorbed dose rates for naturally occurring radionuclides and ¹³⁷Cs showed that external exposure was generally the highest in the Dinaric region and Istrian Peninsula.

Radioactivity of soil in Croatia I: naturally occurring decay chains

The assessment of environmental radioactivity much relies on radionuclide content in soil. This stems from the significant contribution of soil to both external and internal exposure to ionising radiation via direct emission of gamma radiation and soil-to-plant radionuclide transfer, respectively. This motivated us to carry out a systematic research on the radioactivity of soil in Croatia to obtain relevant data that can be used as a basis for understanding the related effects of geomorphological, biogeographical, and climatological properties of the environment. We collected samples of the surface layer of uncultivated soil (0–10 cm) at 138 sites from all over the country and measured them for radionuclide activity concentrations by means of high-resolution gamma-ray spectrometry. This resulted in radioactivity maps containing data on activity concentrations of representative radionuclides in the environment. In this paper, which is the first in our two-part presentation, we focus on the naturally occurring ²³²Th and ²³⁸U decay chains and their correlations with the diversity of Croatian regions. For both of the chains, activity concentrations were the highest in the Dinaric region, the lowest in the Pannonian region, and intermediate in the Adriatic region. Relatively high concentrations of ²²⁶Ra in the soil of the Dinaric region implied a possibility of an enhanced emanation of its progeny ²²²Rn into the air. Activity concentrations of ²¹⁰Pb were additionally elevated in areas with dense vegetation, most probably due to an atmospheric deposition of airborne ²¹⁰Pb onto the surface of plants and their eventual decomposition on the ground.

Soil-to-crop transfer of natural radionuclides in farm soil of South Africa

The activity concentration of natural radionuclides in farm soil and most common indigenous food crops (maize, potato, cowpea) in oil-producing (Philippi, Uitenhage, and Hertenbos farms) and non-oil-producing (Ukulinga farm) areas of South Africa was measured using a Hyper Pure Germanium detector. Consequently, the transfer of these radionuclides from soil-to-crops was estimated. The mean activity concentration of ²²⁶Ra, ²³²Th, and ⁴⁰K for farm soil samples are 30.71 ± 11.77, 31.97 ± 8.90, 345.97 ± 98.62 Bq.kg^-1 for Philippi; 18.67 ± 6.70, 31.55 ± 11.48, 191.93 ± 33.39 Bq.kg^-1 for Uitenhage; 38.03 ± 17.44, 41.18 ± 31.54, 381.89 ± 163.40 Bq.kg^-1 for Hartenbos; and 8.47 ± 2.87, 8.65 ± 3.52, 94.22 ± 25.97 ± 25.97 Bq.kg^-1 for Ukulinga. The mean activity concentration of ²²⁶Ra, ²³²Th, and ⁴⁰K for crop samples are 4.54 ± 1.47, 4.87 ± 1.69, 140.18 ± 35.38 Bq.kg^-1 for Philippi; 9.17 ± 4.79, 3.85 ± 1.87, 136.75 ± 22.04 Bq.kg^-1 for Uitenhage; 7.97 ± 2.91, 4.62 ± 2.40, 105.97 ± 48.65 Bq.kg^-1 for Hartenbos; and 4.23 ± 1.63, 2.72 ± 1.19, 48.36 ± 15.55 Bq.kg^-1 for Ukulinga. The activity concentration and soil-to-crop transfer factors for ⁴⁰K were found to be much higher, possibly because this element is critical in crop growth. The results showed that the crop samples' transfer factor is in the order cowpea>potato>maize. This study showed that activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in crops and the corresponding transfer factors depend on activity concentrations of the same radionuclides in soil.