Concentrations Of Radionuclides In Soil Research Articles

Allometric-kinetic model predictions of concentration ratios for anthropogenic radionuclides across animal classes and food selection

Protection of the environment from radiation fundamentally relies on dose assessments for non-human biota. Many of these dose assessments use measured or predicted concentrations of radionuclides in soil or water combined with Concentration Ratios (CRs) to estimate whole body concentrations in animals and plants, yet there is a paucity of CR data relative to the vast number of potential taxa and radioactive contaminants in the environment and their taxon-specific ecosystems. Because there are many taxa each having very different behaviors and biology, and there are many possible bioavailable radionuclides, CRs have the potential to vary by orders-of-magnitude, as often seen in published data. Given the diversity of taxa, the International Commission on Radiological Protection (ICRP) has selected 12 non-human biota as reference animals and plants (RAPs), while the U.S. Department of Energy (DOE) uses the non-taxon specific categories of terrestrial, riparian, and aquatic animals. The question we examine here, in part, is: are these RAPs and categorizations sufficient to adequately protect all species given the broad diversity of animals in a region? To explore this question, we utilize an Allometric-Kinetic (A-K) model to calculate radionuclide-specific CRs for common animal classes, which are then further subcategorized into herbivores, omnivores, carnivores, and invertebrate detritivores. Comparisons in CRs among animal classes exhibited only small differences, but there was order of magnitude differences between herbivores, carnivores, and especially detritivores, for many radionuclides of interest. These findings suggest that the ICRP RAPs and the DOE categories are reasonable, but their accuracy could be improved by including sub-categories related to animal dietary ecology and biology. Finally, comparisons of A-K model predicted CR values to published CRs show order-of-magnitude variations, providing justification for additional studies of animal assimilation across radionuclides, environmental conditions, and animal classes.

Evaluation of radon hazards at the rural settlements of Uzbekistan.

The "passive" sorption detectors based on the activated charcoal together with scintillation spectrometry were utilized to measure radon flux density from the soil surface as well as volumetric activity of indoor radon at the dwellings of rural areas of Uzbekistan. Additionally, gamma dose rates as well as concentrations of natural radionuclides in soil and building materials samples were determined. Based on the values of natural radionuclides, common radiological indices have been calculated. It was found that varying greatly, 94% radon flux density values did not exceed 80mBq/(m2·s), while volumetric activities of radon were in the range of 35-564Bq/m3. The radium equivalent activity for studied soil and building materials samples were below the allowed limit of 370Bq/kg. Computed gamma dose rates were in the range of 55.50-73.89 ƞGyh-1 below the limit of 80 ƞGyh-1 and annual effective dose rate 0.068-0.091 mSvy-1, the average value of which was higher than the standard limit > 0.47 mSvy-1. The gamma representative index range was 0.89-1.19 with an average of 1.002 which was higher than the standard limit of 1.0. The range of activity utilization index was equal to 0.70-0.86 with an average value 0.77 which was lower than the recommended level ≤ 2.0. And lastly, excess lifetime cancer risk index values were from 1.9 × 10-4 to 2.5 × 10-4 and were lower than the recommended value 2.9 × 10-4 indicating low radiological risk. The results are consistent with the research conducted by other authors earlier, implying suitability of employing the method for the assessment of residential areas.

Effect of Grain Size on Radionuclide Content in Sediment Samples from Kolo Creek, Bayelsa State, Nigeria

The effect of grain sizes on radionuclide concentration in soil and sediment samples from Kolo creek, Bayelsa State was investigated using gamma spectroscopy. Eight (8) samples of sediment were collected around the oil spill site of the creek. All the samples were separated into four different grain sizes, A (0.5mm), B (1mm), C (1.5mm) and D (2mm), making a total of 32 sediment. The activity concentration in sediment samples of grain sizes 0.5 mm, 1.0mm, 1.5mm and 2mm were determined. In sediment samples of grain sizes 0.5mm(A), the activity concentration of 226Ra , 232Th and 40K ranges from 2.24 to 20.032.43Bq/kg, 3.21 to 5.591.32 Bq/kg and 24.46 4.06 to 795.99 6.20 Bq/kg respectively. For grain size of 1.0mm (B) the activity concentration of 226Ra, 232Th and 40K varies from 2.661.30 to 26.64Bq/kg, 2.19 0.95 to 33.47 Bq/kg and 43.38 to 739.21Bq/kg respectively. For grain size of 1.5mm (C) the activity concentration of 226Ra, 232Th and 40K varies from 4.401.09 to 33.93± 3.65 Bq/kg, 2.14±1.72 to 26.15±5.3 Bq/kg and 39.90±3.54 to 471.36±6.12 Bq/kg respectively. For grain size of 2.0 mm (D) the activity concentration of 226Ra, 232Th and 40K varies from 4.81±1.84 to 40.29±2.50 Bq/kg, 2.19±1.40 to 83.20±3.90 Bq/kg and 39.01 ±4.00 to 497.56±5.87Bq/kg respectively. The result obtained shows there was no clear trend in variation of activity concentration with grain sizes. The mean values obtained are below the world average of 35, 30 and 400 Bq/kg for 226 Ra, 232Th and 40K for grain sizes of 0.5, 1.0, 1.5 and 2.0 mm respectively in all the communities except samples from Kolo that recorded 471.36±6.12 to 795.99±6.44 Bq/kg in all the grain sizes. Radiological risk parameters such as Absorbed Dose Rate, Annual Effective Dose Equivalent, Annual Gonadal Dose Equivalent, Annual Utility Index, Radioactivity Level Index, Hazard Indices and Excess Life Cancer Risk were estimated and values were found to be within the word average. From this study, the sediment of the given grain sizes will pose no radiological health risk if used in farming and in building construction.

Retrospective Detection Sensitivity for GPS-based Gamma Radiation Surveys.

A probabilistic method for a priori calculation of the expected minimum detectable concentration of a contaminant radionuclide in soil while scanning ("scan MDC") with a GPS-based gamma radiation survey system has previously been described. This paper presents supporting evidence for the validity of respective use of a statistical minimum detectable count rate (MDCR) as described in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) and builds on related concepts to develop a technical basis for a posteriori estimation of MDCR and scan MDC sensitivity metrics for geospatially rendered datasets. Nearest-neighbor averaging of multiple data points from a geospatial population of gamma survey data permits retrospective quantification of MDCR values based on statistical reductions in the variance in both background and source data distributions. A retrospective MDCR can be used to calculate a posteriori scan MDCs based on detection efficiencies modeled with the probabilistic method for various radionuclides, source dimensions, detector heights, and scan speeds.

Potential Airborne Releases and Deposition of Radionuclides from the Santa Susana Field Laboratory during the Woolsey Fire.

The Santa Susana Field Laboratory (SSFL), located in southern California, is a former research facility, and past activities have resulted in residual radioactive contamination in Area IV of the Site. The Woolsey Fire burned across the site, including some of the contaminated areas, on 8-11 November 2018. Atmospheric transport modeling was performed to determine where the smoke plume went while the fire burned across the SSFL and the deposition footprint of particulates in downwind communities. Any radionuclides on vegetation and in surface soil released by the fire were assumed to follow particulate matter transport path and deposition. The predicted deposition footprint was used to guide confirmatory soil sampling at 16 locations including background. Highest offsite deposition was determined to be northeast of the Oak Park community, which is located about 6 km southwest of SSFL. Depth-profile sampling was used to evaluate whether radionuclides of SSFL origin were potentially emitted and deposited during the Woolsey Fire. If radionuclides had been deposited from the Woolsey Fire at sufficient concentrations, then they would be detected in the surface layer and would be expected to be higher within the plume footprint than outside it. An upper bound estimate of the hypothetical effective dose to a person in Oak Park based on measured radionuclide concentrations in soil and vegetation on the SSFL was less than 0.0002 mSv. The occurrence of naturally occurring radionuclides at concentrations above the established background for the SSFL was attributed to natural variability in geologic formations and not SSFL. No anthropogenic radionuclides were measured at levels above those expected from global fallout. The soil sampling confirmed that no detectable levels of SSFL-derived radionuclides migrated from SSFL at the locations sampled because of the Woolsey Fire or from past operations of the SSFL.

Activity Concentrations of Natural Radionuclides in Soil and Water Around Some Quarries and Potential Human Health Effects

Activity Concentrations of Natural Radionuclides in Soil and Water Around Some Quarries and Potential Human Health Effects

Accumulation of lead radionuclides in 18 leaf vegetable types in Viet Nam

Studying the concentration of radioactive lead in soil and plants, and using plants for phytoremediation are important for the environment and human health protection. In this study, we used gamma spectrometry to determine activity concentration in soil - plants, transfer factor. The average activity concentration of lead radionuclides in soil and plants were in the following order of 210Pb > 214Pb > 212Pb. The average activity ratio of 214Pb and 212Pb to 210Pb in soil were 0.70 and 0.59 and in plants were 0.69 and 0.14, respectively. The results showed that there was not much difference between the ratio of radioactive 214Pb and 210Pb concentrations in vegetable and plant samples. Ming aralia (Polyscias fruticose) and lettuce (Lactuca sativa) contained the highest concentrations of 210Pb, and Malabar spinach (Basella alba) contained the lowest concentration. Ming aralia could be used for the radioactive decontamination of 210Pb. There vegetable samples from Ho Chi Minh City were considered safe for human consumption in the aspect of lead radionuclides.

Relationships between natural radionuclides activity concentration in soils of the State of Alagoas, Brazil and WRB/FAO soil classification, types of parental rocks and rainfall variability

Climate, soil type and geology that can influence the activity concentrations of natural radionuclides in soils. For this, 41 samples were collected in the first 25 cm of soil from the state of Alagoas, Northeast Brazil. This sample collection represents the mains soils classifications, parental rocks, and rainfall variability in this locality. The samples of soils were processed and analyzed by means of gamma-ray spectrometry for the 40K, 226Ra and 228Ra. The non-parametric Mann-Whitney U test was applied to perform the statistical inference on the differences in activity concentration for each soil class studied. There was a significant difference in the 40K activity distributions between the combination for most soil types. The results for 226Ra show no significant difference. However, Planosols differ significantly from Yellow Acrisols and Regosols for 228Ra. The strong relationship of the 40K concentration with the rock classes was shown. On the other hand, an association of the activity concentration of 226Ra and 228Ra with the rock type was not evidenced. There was a negative correlation between the 40K activity concentration and the rainfall index. 226/228Ra concentrations showed no correlation with the rainfall index.

Speciation of 137Cs, 90Sr, 241Am, and 239+240Pu artificial radionuclides in soils at the Semipalatinsk test site

This paper reports the speciation of 137Cs, 241Am, 90Sr and 239+240Pu in the soil samples of the Experimental Field (EF). The EF is a testing ground of the Semipalatinsk nuclear weapons test site used for surface and atmospheric tests. The study revealed low mobility of artificial radionuclides in the EF site soils.The revealed high radionuclide concentrations in soil mainly exist in tightly bound form. On average, the content of the tightly bound form of 137Cs was revealed to be below 98%, that of 90Sr - 94%, 241Am - 89%, and 239+240Pu - 98%.The radionuclides occurrence forms were analyzed in correlation with the physicochemical parameters of soils. Reliable relationships have been established between the content of carbonates and the content of the exchangeable, acid-soluble and strongly bound 90Sr forms in soils, as well as the content of the water-soluble salts and the content of the strongly bound 239+240Pu form in the soil.Similarly, we compared the distributions of the radionuclides speciation and their stable isotopes with their analogous elements in the soil. Unlike 137Cs and 90Sr, which are in a tightly bound form in the soils of the Experimental Field site, the main content of soil “competitors” of the 137Cs radionuclide – K and Cs is observed in an exchange form, less significantly in an acid-soluble form. The alkaline earth metals (analogous elements for 90Sr) are mainly observed as a composition of the exchangeable and acid-soluble forms. The results allow to conclude that there is no equilibrium distribution of the physicochemical forms of radionuclides introduced into the soil and the natural presence forms of their stable analogs in the soil. Such equilibrium distribution can only be achieved at a complete isotopic exchange in phases and soil components, which under the conditions of the Experimental Field is not possible in the near future.It can be concluded that the behavior of the studied radionuclides in soils is stipulated by the initial form delivered by the fallouts from tests at the EF site.

Investigation of Radionuclide Migration at Sites Adjacent to the 30-km Exclusion Zone of the Chernobyl Nuclear Power Plant.

This paper reports the study of the vertical migration of radionuclides in soils at test sites adjacent to the 30-km Chernobyl Exclusion Zone. The results of this effort demonstrate that the migration processes for studied pollution occur similarly to the fuel fallout behavior at the vicinity of the Chernobyl Nuclear Power Plant (ChNPP) Unit 4. It was also observed that the main fallout component, 137Cs, originated from aerosol fallout and was bound in the surface layer. The authors determined a significant increase of 60Co, 94Nb, and 241Am radionuclide concentrations in soils near the ChNPP Unit 4 and suggested their appearance due to the installation of the New Safe Confinement. Niobium-94 activity is proposed as a marker for monitoring the "fresh" fallout in the Chernobyl Exclusion Zone.

INVESTIGATION OF ENVIRONMENTAL RADIOACTIVITY AT A DECOMMISSIONED URANIUM MINE IN SOUTHERN CHINA.

An environmental radioactivity survey was performed on a uranium mine that has been decommissioned for >10 y. According to the characteristics of this uranium mine, the relevant parameters, such as the surface-absorbed dose rate in air, the radon and radon progeny concentrations in the air, the radon exhalation rate from the soil surface and the concentrations of natural radionuclides in soil and surface water, were measured. The results show that the maximum annual effective doses of residents and employees in the uranium mine caused by radon and radon progenies inhalation were 1.48 and 1.74mSv, respectively, and the maximum annual effective doses of residents and employees caused by gamma-ray external radiation were 1.16 and 1.32mSv, respectively.

ОСОБЕННОСТИ РАСПРЕДЕЛЕНИЯ РАДИОНУКЛИДОВ В НАЗЕМНЫХ ЭКОСИСТЕМАХ КАШТАНОВОЙ ЗОНЫ В УСЛОВИЯХ РОСТОВСКОЙ ОБЛАСТИ

The determination of the radioactivity of soils in settlements and natural territories is necessary to identify areas with an increased level of radionuclide content. The paper is devoted to studying the features of accumulation of natural radionuclides (226Ra, 232Th, 40K) and artificial 137Cs by plants in the conditions of semiarid steppes on the example of the chestnut zone of the Rostov region. Samples of soils and plants selected in the Tsimlyansky, Volgodonsky, Dubovsky and Orlovsky districts of the Rostov region during the 2014-2017 expeditions were used as objects of research. The activity concentration of radionuclides in soil and plants was measured by gamma spectrometric method of radionuclide analysis. It is shown that the distribution of artificial radionuclide 137Cs in the soil cover of the Rostov region, caused by the accident at the Chernobyl nuclear power plant, is extremely uneven and depends on the humus content. Biogenic element 40K accumulates in the surface horizon, also correlating with the humus content. The activity concentration of 137Cs content on 40K is most clearly displayed in the upper layer (0-10 cm). The lowest activity concentration of natural radionuclides is typical for alluvial-meadow soils and salt marshes of lightweight granulometric composition formed in floodplains of rivers and on coastal areas of lake Manych-Gudilo. In chestnut and dark-chestnut soils, the activity concentration of natural radionuclides is almost comparable, since variations in the activity concentration of these radionuclides in these soils are within the measurement error (10-15 %). The aggregated transfer factors from soil to plants for all radionuclides were generally less than 0.4 m2/kg. Variations in radionuclide aggregated transfer factors in the ecosystem are caused by climatic conditions during the selection period and, as a result, by mechanical contamination of soil particles and dust both during rains and during droughts, when the soil begins to dust.

Assessment of Activity Concentration of Radionuclides in Soil and Cassava Food Crop from Solid Mineral Mining Site in Ishiagu, Ivo L.G.A of Ebonyi State, Nigeria

The assessment of activity of concentration of radionuclides in soil and food crops from solid mineral mining sites at Ishiagu, in Ivo L.G.A of Ebonyi State was carried out using the necessary measuring instruments. Samples of soil and cassava crop collected from around the mining sites. The samples were analysed using gamma ray spectrometry. The average activity concentration of 226Ra, 232Th and 40K in soil samples were 12.37,16.08, and 144.29 Bqkg-1 while those for cassava were 2.81, 16.80, and 205.41 Bqkg-1. The soil/plant radionuclide transfer ratio estimated are 0.62, 2.43 and 2.51 for 226Ra, 232Th and 40K, respectively. All the radiological risk parameters estimated are relatively low. The result of this work showed that the obtained results for all samples were lower than the international accepted limit. Hence, from radiological health standpoint, the obtained values of effective doses may not pose significant threat to both human and the environment.

Soil to Cassava Transfer Factors of Natural Radionuclides in Farms in Ini Local Government Area, Akwa Ibom State, Nigeria

Knowledge of activity concentration of radionuclides in soil of our farmlands and the consequent transfer factors of the radionuclide to plants are necessary to estimate the contamination level of the soil, plants and food. The activity concentration of 40K, 238U and 232Th in soils and cassava in Ini Local Government Area, Akwa Ibom State, Nigeria were measured using gamma spectrometry. Activity concentrations of radionuclides in soils in the locations ranged from BDL (below detectable limit) to 298.76 ± 21.40 Bq/Kg for 40K; BDL to 7.95 ± 1.88 Bq/Kg for 238U and 2.59 ± 0.25 to 16.56 ± 1.61 Bq/Kg for 232Th. Activity concentration of the radionuclides in cassava in all locations ranged from 213.96 ± 15.38 Bq/kg to 520.58 ± 37.25 Bq//Kg for 40K; BDL to 33.02 ± 8.91 Bg/Kg for 238U and BDL to 16.34 ± 1.59 Bq/kg for 232Th. The activity concentrations of all the radionuclides were lower than the world standard. Transfer factors obtained ranged between 3.21 to 4.18 for 40K; 0.93 to 12.64 for 238U and 0.75 to 1.01 for 232Th. Effective ingestion dose due to the consumption of cassava from the studied area obtained ranged between 1.31 to 1.74 mSv/yr and 3.52 to 4.69 mSv/yr for children and adult respectively. These values are above the 1.0 mSv/yr recommended dose limit for general public, therefore the consumption of this food stuff could pose a radiological health effect on humans. However the risk could be minimized when the cassava is cooked.

A study on leaching of primordial radionuclides 232Th and 40K to water bodies

India is one of the countries in the world having vast reserves of heavy minerals, especially thorium bearing minerals. Beach sands of the coastal territories of Kerala and Tamil Nadu in India are very rich in monazite containing 8–10.5% of thorium (as ThO2), 0.2–0.4% of uranium (as U3O8) and K-40, hence the water body can be contaminated by the leaching of radionuclides. In the present investigation, we have made an attempt to study the extent of leaching of surface soil-borne Thorium and Potassium into water in various pH conditions. To study the effect of pH on leaching, soil samples collected were allowed to remain in contact with acidified and alkaline water samples. From the measured concentrations of radionuclides in soil and water samples, the leaching efficiency of 232Th and 40K for most of the samples was calculated to be 20 and > 40%, respectively. It has been found that the degree of acidity or a lower pH largely influenced the migration/leaching of 232Th from soil/sand to water than the alkalinity of water. On the other hand, a reverse phenomenon, i.e., the degree of alkalinity show a greater influence on the leaching of 40K from soil to water samples compared to the degree of acidity. Overall, a weak but positive correlation was observed between the concentration of 232Th and 40K in the soil samples and the corresponding concentration in the water samples indicating the possible leaching of radionuclides from the soil to water under favorable conditions. Measured data on the leachability of radionuclides can be used for any future study on safety of human health due to the contamination of waterbodies.

Transfer of radionuclides from soil to selected tropical plants of Indian Subcontinent: A review

Soil to plant transfer factor (TF) of radionuclides is an important input parameter in dose assessment models. The wide range of TF for each radionuclide reported in the literature for a particular plant type indicates that radionuclide concentration in soil is not the only factor influencing its uptake by the plant. Different soil properties and agricultural practices may influence the TF and these are also a function of the climate. Considering the wide variation in TF data, here we attempt to review the available literature on TF of radionuclides in tropical countries of the Indian subcontinent (India, Bangladesh, and Sri Lanka). TF under equilibrium conditions are not available for all radionuclides, in such cases TF of naturally existing stable analogs elements were compiled. With an emphasis on, transfer of radionuclides from soil to the edible compartment of the plant; the TF data for 21 elements are compiled for 12 plant groups classified as per IAEA, Technical Reports Series No. 472. The article also presents the analysis and discussion of the extent and limitations of the compiled data. The compiled TF may be useful in assessing the food chain transfer of radionuclides when site-specific information is not available.

A review of 137Cs and 40K soil-to-plant transfer factors in tropical plants

In this work we critically assess the soil-to-plant transfer factors (TF) for 137Cs and 40K in edible fleshy organs of tropical plants that are often components of the human diet. Radionuclide concentrations in soil and plants were obtained from previous investigations developed in Brazil, after the Goiânia radiological accident occurred in 1987. Transfer factors were determined in specific plant compartments (main root, main stem, bark, old and new branches, twig, old and new leaves, mature and green edible organs) of tropical species such as lemon (Citrus aurantifolia), orange (Citrus sinensis), guava (Psidium guajava), chili pepper (Capsicum frutescens), pomegranate (Punica granatum), papaya (Carica papaya), banana (Musa paradisíaca), and manioc (Manihot esculenta). For 137Cs, soil-to-fruit transfer factor ranged from 0.80 × 10−2 (banana) to 3.65 × 10−1 (pomegranate); for 40K, this factor was from 4.42 × 10−1 (orange) to 1.74 (chili pepper). Considering all the plant compartments analysed, the transfer factors for 40K are between 24.5 (guava) and 90.5 (papaya) times higher than for 137Cs. For both radionuclides, considerable differences in soil-to-plant transfer were found when new growing parts of the plant (green edible organ, leaf, and twig) are considered with respect to those older parts (mature edible organ, old leaf and branches). Considering all the species analyzed, the relationship TF(40K)/TF(137Cs) does not seem to follow a characteristic pattern. However, if we compare the value of this relationship for two organs of the same plant, the result is approximately constant, regardless of the species considered. This confirms earlier evidence that both radionuclides are similarly distributed in the different organs of the studied species.The differences in the transfer factors according to the ripening status of edible organs must be particularly considered when estimating the dose from ingestion of fruits and their derivatives in dose assessment models.

Element and radionuclide concentrations in soils and wildlife from forests in north-eastern England with a focus on species representative of the ICRP's Reference Animals and Plants

Abstract. There are international recommendations that the environment (i.e. wildlife) is assessed for the potential impact of releases of ionizing radiation. The transfer of radionuclides to wildlife from media (e.g. soil, water) is usually described using the whole-organism concentration ratio (CRwo-media), and a number of assessment models use these values to estimate radiation exposure and risk to wildlife; however, there are many gaps in knowledge. This paper describes a study conducted in 2015–2016 to sample terrestrial wildlife, soil and water from two forests in north-eastern England. Sampling was targeted towards species representative of the International Commission on Radiological Protection's (ICRP) terrestrial Reference Animals and Plants (RAPs): Wild Grass (Poaceae family), Pine Tree (Pinaceae family), Earthworm (Lumbricidae family), Bee (Apidae family), Rat (Muridae family), Deer (Cervidae family) and Frog (Ranidae family); opportunistic sampling of plant and fungi species was also conducted. The dataset comprises stable-element concentrations for 30 elements, radionuclide activity concentrations for K-40 and Cs-137, and radionuclide and stable-element concentration ratios. These data have significantly increased the number of CRwo-media values available for the ICRP RAPs and will contribute to the development of the databases underpinning the ICRP's environmental protection framework. Data will be included in the international database of wildlife transfer parameters for radioecological models and hence are likely to contribute to model developments in the future. All data and supporting documentation are freely available from the Environmental Information Data Centre (EIDC; https://eidc.ac.uk/, last access: 13 November 2020) under the terms and conditions of the Open Government Licence (Barnett et al., 2020 https://doi.org/10.5285/8f85c188-a915-46ac-966a-95fcb1491be6).

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.

ELEMENTAL CONCENTRATIONS AND SOIL-TO-MOSS TRANSFER FACTORS OF RADIONUCLIDES IN THE ENVIRONMENT OF NORTH KOSOVO AND METOHIJA

This paper deals with investigations of elemental concentrations and soil-to-moss transfer factors of radionuclides in area of municipalities Kosovska Mitrovica and Zubin Potok. Twelve samples of soil and moss Hypnum cupressiforme Hedw. were collected during May 2018. Transfer factors of radionuclides: 226Ra, 232Th, 40Kand 137Cs were calculated with regard to elemental concentrations of radionuclides in soil and moss samples. Analysis was done in order to indicate the different ways of adopting radionuclides by mosses. According to calculated transfer factors and analysis, authors concluded that the soil is dominant source of natural radionuclides and their concentration in moss occurred due to resuspension of soil particles, while artificial 137Cs is present in soil and moss samples as a consequence of atmospheric dry and wet deposition.