Radionuclides In Soil Research Articles

Heavy metals concentrations and naturally occurring radionuclides in soils affected by and around a solid waste dumpsite in Osogbo metropolis, Nigeria.

The presence of heavy metals and naturally occurring radioactive materials (NORMs) in high concentrations in soils can be hazardous to exposed humans. This study is aimed at measuring the concentrations of heavy metals (Cu, Pb, Ni, Zn, Cd, Co, and Cr) and activity concentration of 232Th, 238U, and 40K in soils affected by and around a solid waste dumpsite in Osogbo metropolis, Nigeria. Atomic absorption spectrometry and gamma-ray spectrometric techniques were used to determine the concentrations of metals and NORMs, respectively. Possible environmental impact of the heavy metal content and the probable radiological hazard by the NORMs to the general public were assessed. The calculated pollution indices reported in this work for Co, Cr, Pb, and Ni show low pollution status. Geoaccumulation indices for Cu, Zn, and Cd indicated that the area under study is strongly contaminated by these metals. Evaluated ecological risk index narrowed down Cd as the poisonous metal with high concentration. The measured radionuclides' mean activity concentrations and the evaluated mean of radium equivalent and absorbed dose rate values are higher than the recommended safe limit, an indication of possible radiological hazard. The principal factor analysis results explained 76% of the collection of data and described chips of galvanized/chrome metals, scrap metals, waste from electronics, Cr, and Cd-containing waste as sources of the heavy metals. The practice of land cultivation around the dumpsite should be deterred to prevent the transportation of these vicious heavy metals into the food chain.

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.

Investigations of environmental radioactivity in the northern state of Sudan

Investigations have been carried out for naturally occurring radionuclides in surface soils in selected regions of the Northern State of Sudan, in response to widely spread rumours of elevated levels of radioactivity causing higher than normal incidence of cancer in that area. Eighty surface soil samples were collected from different regions in the Northern State and their activity concentrations were measured by a high-purity germanium detector gamma spectrometer system. From the data obtained the mean values and standard deviations of the radionuclide activities were calculated. From the activity concentrations of 226Ra, 232Th and 40K radionuclides the external absorbed dose rate in air and the annual effective dose were calculated.The radium equivalent activity and the external hazard index were applied for estimating the radiation hazards of soil used as building material. The mean activity concentrations of 226Ra, 232Th and 40K in different regions of the Northern State were found to be 82.6 + 6.8, 26.0 + 2.9 and 726.4 + 72.0 Bq/kg, respectively.The average outdoor gamma absorbed dose rate in air at 1meter above ground was calculated as 84.6 + 7.1 nGy/h. The average annual effective dose equivalent for population in the regions under study was found to be 103.7 + 8.7 Sv/y. The external hazard index was found to be 0.48 + 0.04.

Natural radionuclides in soils of the Novaya Zemlya Archipelago (Severny Island)

The article presents the results of a study of natural radionuclides (226Ra, 232Th and 40K) content in the soils of the Severny Island of the Novaya Zemlya archipelago that were sampled prior to the first nuclear tests. The humus content in the soils varies from 1.4 to 6.5%. Soil pH levels vary from moderately acidic (4.7) to neutral (6.5). Fine soils are characterized by a light particle size distribution with a predominance of 0.25-0.05 mm and 0.05-0.0.1 mm fractions. The total volume of these fractions reaches 81-94%, which indicates the predominance of primary minerals and a low content of secondary (basic sorbents of natural radionuclides) minerals in soil. The content of radionuclides in soils is as follows: 226Ra: 11.9 ±5.1 (5.7-19.8) Bq/kg; 232Th: 13.6 ± 7.4 (3.0-19.1) Bq/kg; 40K: 302 ± 100 (224–493) Bq/kg. No Caesium-137 has been observed in the analyzed soils.

Modes of Occurrence of Artificial Radionuclides in Soils in the Area of the Kola Nuclear Power Plant

Modes of Occurrence of Artificial Radionuclides in Soils in the Area of the Kola Nuclear Power Plant

Soil Radionuclide Concentration and Radiological Assessment in selected Tourist Centres in Southwest Nigeria

The natural radioactivity in the soils ofselected tourist centres in Southwest Nigeria was determined using gamma-ray spectrometer comprising a 3” x 3”Nal(TI) detector coupled to a Camberra series 10 MCA. Twenty(20) soil samples were collected from the five tourist centres. Four soil samples each were collected from Idanre hills (ID) in OndoState, Ikogosi warmspring (IKG) in EkitiState, Erin-Ijesha (EI) waterfall in OsunState, Olumo rock (OL) in OgunState,and Old Oyo National Park (OONP) in Oyo State. The Activity Concentrations (AC) were measured in Bqkg -1 . The AC at ID ranged from below detection limit (BDL) to 41.93±4.74 for 226 Ra, BDL to 49.37±2.90 for 232 Th, and 643.27±33.36 to 2040.16±104.33 for 40 K with respective mean values of 17.55±2.01, 23.61±1.86, and 1221.90±62.9. At IKG, AC ranged from BDL to 70.43±7.76 for 226 Ra and 75.25±3.94 to 550.16±28.69 for 40 K with mean values of44.51±4.94 and 255.14±13.38 respectively while 232 Th was BDL. At EI, AC ranged from BDL to 35.32±4.18 for 226 Ra, 139.60±7.37 to 452.71±23.60 for 40 K with mean values of 10.64±0.94 and 285.55±8.81 respectively while 232 Th was BDL. At OL, AC ranged fromBDL to 87.78±10.47 for 226 Ra, 3.95±0.23 to 84.08±4.99 for 232 Th, and 528.49±27.68 to 2159.01±112.85 for 40 K with mean values of 21.94±2.57, 52.66±10.34 and 1533.63±79.82respectively. For OONP, AC ranged from BDL to 72.66±7.72 for 226 Ra, and 247.04±13.12 to 611.10±32.05 for 40 K with mean values of 22.11±2.40 and 450.93±23.33 respectively while 232 Th was BDL.The maximum and minimum Absorbed dose rate meanvalues were foundto be 111.40±10.74 in OL and 16.82±1.19 nGyh -1 in EI respectively while that of the outdoor Annual Effective Dose and the Radium equivalent values for all the study centreswere also estimated and comapared to the world limits.

Determination of radioactivity level of water supply network in Trabzon province, Turkey

ABSTRACT In the present study, the radioactivity levels of water samples collected from the main water supply network in Trabzon province and districts and soil samples taken from the vicinity of the water network were measured. An Alphaguard-PQ2000 radon gas detector was used to determine the seasonal radon gas level in the water samples. An HPGe detector was used to determine the level of radioactivity in soil and water samples. The average concentration of 222Rn in drinking water ranges from 0.56 ± 0.51 to 13.3 ± 5 Bq L–1. In water samples, average gross alpha and gross beta values were measured as 8 ± 1 and 43 ± 1 mBq L–1, respectively. The average concentrations of 238U, 232Th, 137Cs, 40K radionuclides in soil were measured as 51 ± 2, 21 ± 2, 16 ± 1, 28 ± 7 Bq m–3, respectively. The average concentrations of 238U, 232Th, 137Cs, 40K radionuclides in drinking water were measured as 147 ± 5, 25 ± 2, 77 ± 2, 12 ± 2 mBq L–1, respectively. When the radon concentrations for drinking water were examined, it was found that the radon concentration of the three samples was above the limit value (11 Bq L–1) allowed by the US-EPA for drinking water. All other results are below the limit values.

Transfer from soil to grass and statistical analysis of naturally occurring radionuclides in soil from phosphate mining and processing sites in Maritime Region of Togo

Natural radionuclides activity concentrations of 226Ra, 228Ra, and 40K in soil and grass samples, statistical analysis of these radionuclides, and transfer factors (TFs) from soil to the grass were carried out from phosphate mining and processing sites in southern areas of Togo using gamma-ray spectrometry-based high-purity germanium (HPGe) detector. The average activity concentrations of 226Ra, 228Ra, and 40K were found within the range usually measured worldwide. Statistical analysis was done by investigating the skewness, the kurtosis, and the density distribution of radionuclides in the study areas. Both skewness and kurtosis displayed that the activity concentrations of soil and grass samples in the discharge waste site (Kpémé) and mining site (Hahotoé) exhibited slightly positively skewed, negatively skewed, leptokurtic, and platykurtic distributions. The TFs for 226Ra, 228Ra, and 40K from discharge waste soil to grass were evaluated. The average transfer factors of 226Ra, 228Ra, and 40K in the phosphate processing area were found to be 0.16, 0.32, and 8.42, respectively. 226Ra and 228Ra TFs values were found to be within the limit of worldwide measure values, while that of 40K was found to be larger than the values measured in other countries. The average TF value of 8.42 for 40K was eight times higher than the average value of unity, showing its large intake by vegetables. The high TFs for 40K could be explained by the extensive application of phosphate fertilizers to soils when growing vegetables.

NATURAL RADIATION ABSORBED DOSE RATE AND RADIATION TRANSFER FACTOR FROM SOIL TO VEGETABLE IN SOME SELECTED AREAS OF CHITTAGONG, BANGLADESH

The study aimed to investigate natural radioactivity levels and Transfer Factors of natural radionuclides from soil to some plants in Chittagong, Bangladesh. The concentrations of naturally occurring and anthropogenic radionuclides in soil and plants were measured in this work to determine the absorbed dose rate and the transfer factors of radionuclides from soil to plant. Plants (Spinach and Vegetables) and corresponding soil samples were collected from three different locations in Chittagong (Nasirabad, Sitakunda, and Halda Agrotechnology), and the concentrations of activity of natural radionuclides were measured using gamma-ray spectrometry. The average absorbed dose rate in the soil of Nasirabad, Sitakunda, and Halda Agrotechnology are 49.84 nGyh-1, 37.4 nGyh-1, and 45.6 nGyh-1. The average transfer factor from soil to plants, recorded for 238U, 232Th, and 40K of these study areas, are 0.461, 0.400, and 3.10, respectively. The ratio of soil to plant transfer factor for the present study compared with some previous work. The Transfer Factor of 40K gives some high value but does not exceed the limit of the different published values. Because there are no existing databases for the natural radioactivity in soil and plants from Chittagong, Bangladesh, our results are establishing a database for the Chittagong, Bangladesh soil and plants. This data may be used as a database for further investigation for the betterment of public health.

Evaluation of naturally occurring radionuclides (K, Th and U) in volcanic soils from Fogo Island, Cape Verde

Evaluation of naturally occurring radionuclides (K, Th and U) in volcanic soils from Fogo Island, Cape Verde

Natural Radionuclides in Rice Soils in the Mekong Delta Region, Vietnam: Health Risk, Transfer to Rice, and Long-Term Accumulation in Topsoil

Natural Radionuclides in Rice Soils in the Mekong Delta Region, Vietnam: Health Risk, Transfer to Rice, and Long-Term Accumulation in Topsoil

Assessment of residual radionuclide levels at the Bokak and Bikar Atolls in the northern Marshall Islands

The Bikar and Bokak Atolls, located in the northern Marshall Islands, are extremely isolated and consist of pristine marine and terrestrial ecosystems. Both atolls may have experienced significant radioactive deposition following the nuclear weapon testing conducted at Bikini and Enewetak proving grounds. Here we report activity concentrations of artificial radionuclides (239Pu, 240Pu, 241Pu, 241Am, 137Cs and 90Sr) in marine and terrestrial samples collected from Bikar and Bokak Atolls. Artificial radionuclides in soil from the Majuro Atoll are also reported and form a radiological baseline against which the levels at the other atolls can be compared. We observed low levels of artificial radionuclides in soil from Majuro and Bokak, but significantly higher levels in soil from Bikar. The residual radioactivity in the Bikar environment is comparable to the levels previously reported for other nearby atolls, including Taka and Utrik, but lower than for Rongerik, Rongelap, Bikini and Enewetak. An analysis of 240Pu/239Pu isotope ratios and estimations of the dates of contamination from 241Am/241Pu activity ratios both indicated that the Bikar Atoll was contaminated mainly by radioactive fallout from the Castle Bravo test in 1954. We compare the results of our measurements at Bikar and Bokak to data from other atolls in the Marshall Islands and to regions of the world affected by both global and regional fallout from atmospheric nuclear weapons testing and nuclear accidents.

Valorization of rare earth processing byproducts for agriculture usage

Sandy texture soil, a major problem for agriculture requires structure and capacity improvements. However, utilization of soil conditioner may arrest this problem. This research was carried out to investigate the accumulated levels of metal ions and radionuclides in water, soil and plants following phosphogypsum organic (PG organic) added to a sandy soil for 23-month in 3 cropping seasons. The condition in the field was simulated in the laboratory using an open leaching column for 30-day under constant but different pH of leachant. More ions were released at pH < 4.6 and decreases greatly at pH > 5.6. The metal ions measured in the surface and borehole water, and soils were below the target values for respective standard raw drinking water. The metal ions did not accumulate in soil, plant and grain, and water as indicated by biological accumulation coefficients, contamination factors, I-geo index and pollution load index in a sandy soil that received the PG organic. Naturally occurring radionuclide concentrations, such as 226Ra, 228Ra, and 40K, in soil and plant tissue were found to be lower than the average value reported by several earlier studies. Under field condition the pH of water (i.e., rainfall) was greater than pH 5.6, thus renders PG organic became less soluble. There was no leaching of natural occurring radionuclides to the groundwater. Therefore, the application of PG organic to the studied soil had no impact on the soil, plants, and water and suitable as a soil conditioner in sandy texture soils.

Evaluation of Migration Radiological Equivalence for Dual Component Nuclear Waste in a Deep Geological Repository.

The paper is concerned with the issue of achieving the radiological equivalence (the equivalence of radiation risks) of radioactive waste of nuclear reactors and corresponding mass of natural uranium, taking into account the different migration ability of radionuclides in geological formations and soil. This migration radiological equivalence is being investigated for the deep burial of radioactive waste in the case of the development of a two-component nuclear power system with the concurrent use of thermal neutron reactors and fast neutron reactors. Calculations were performed of radiation doses and radiation risks of cancer death arising from consumption of drinking water from a well above a disposal site. The radiation risk relating to a two-component nuclear power system is lower than that from natural uranium; i.e., after reaching the radiological equivalence (100 y of storage) over the timescale of 109 y, the principle of migration radiological equivalence is satisfied. It would take 106 y after radioactive waste disposal to reach the migration radiological equivalence if only thermal reactors were operated. As regards consumption of well drinking water, the radiation risk does not exceed 10-5 y-1 for a two-component nuclear power system, while being 10-3 y-1 (socially unacceptable level) for a power system using only thermal reactors. Radionuclides 241Am, 239Pu, and 240Pu in drinking water make the main contribution to the doses and radiation risks of people for 104 y after the disposal of radioactive waste.

Detection of Activity Concentration, Dose Rate, Absorbed Dose and Effective Annual Dose of Radionuclide's Around Fertilizer and Pesticide Stores, Al-Jazeera Project in Sudan

This paper demonstrates the evaluation of radiological risk factors due to terrestrial radionuclides in soil, about the stores of pesticides and fertilizers for Al-Jazeera agricultural project in Al-Hasahisa, Sudan, to address the issue of the natural radioactivity of this area. Hence, levels of 226Ra, 232Th, 228Ra, 40K and 137Ci in the soil were calculated (by using germanium detector), and then the radiation risk parameters were calculated. its including radioactivity concentration Bq/kg, absorbed dose D, and effective annual dose E, its due to inhalation of radon (222Rn) and consumption of potassium (40K), radium (226Ra), radium (228Ra), thorium (232Th) and mean activity concentrations±deviation The norms for the five primitive radionuclides were, respectively, 268.98±5.22, 14.54±0.2, 15.31±1.54, 20.45±0.96, and 0.34±0.19 Bq kg-1. This results somewhat normal distribution of the United Nations Scientific Committee on the Effects of Atomic Radiation. The results obtained indicate that some radiation risk factors appear to be unfavorable. The mean average absorbed dose±standard deviation (30.54±2.71) nGyh-1 was a slightly normal distribution of the average value of 30.54 nGy/ h, and the Average annual effective dose E (µSVyear-1)±standard deviation (37.48±3.32).) SVyear-1 was a slightly normalized distribution of the value of SVyear-1 its compared with the data of the United Nations Scientific Committee on the Effects of Atomic Radiation. The study focuses light on the demand to develop a comprehensive program for radiation protection in Sudan and in agricultural projects that constantly use pesticides and fertilizers for regulatory oversight.

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.

A preliminary survey of natural radionuclides in soil and indoor radon in the town of Niš, Serbia

A preliminary survey of natural radionuclides in soil and indoor radon in the town of Niš, Serbia

Characteristics of radionuclides in soil and tea plant (Camellia sinensis) in Hoa Binh, Vietnam

Characteristics of radionuclides in soil and tea plant (Camellia sinensis) in Hoa Binh, Vietnam

Natural and artificial gamma-emitting radionuclides in volcanic soils of the Western Canary Islands

Terrestrial gamma absorbed dose rates as well as spatial distribution of gamma-emitting radionuclides 40K, 226Ra and 232Th and 137Cs in soils, are provided in detail for the first time in the Western Canary Islands.The distribution of terrestrial gamma absorbed dose rates and the activity concentrations of 40K, 226Ra and 232Th are discussed with respect to the main lithologies and geological features of each island. The average terrestrial absorbed dose rate (71.4 nGy·h−1) reported here was slightly higher to previously reported values for the Eastern islands of this archipelago (43 nGy·h−1) and close to the world's average (59 nGy·h−1).Relatively high 137Cs activity concentrations, up to 100 Bq·kg−1, were measured in some of the collected samples. To understand the origin of these activities, we compared the results from two different field surveys performed in 1991 and in 2013. The activity concentrations were found to be rather similar despite the 22 years gap between the measurements. Complementary radiometric data from aerosol samples collected at this site show that there are additional contributions of 137Cs to this site produced by the deposition of dust particles brought by Saharan dust storms.In terms of radiological risk, the gamma absorbed doses reported (external exposure) pose no risk to the local population. However, the contribution of the soil 137Cs activity concentrations to the gamma absorbed dose were as high as 50% in some few locations.

Принципы и критерии экологического нормирования качества окружающей среды по уровням радиоактивности

Methodology for the ecological regulation of environmental quality by radioactivity levels is presented. Reference levels of radionuclides in surface waters and soil are determined to ensure the radiation safety of ecosystems. The developed criteria were tested using the data of long-term (2000-2018) radiation monitoring in the observation areas of nuclear power facilities like radiochemical plants, nuclear power plants with VVER, RBMK, and BN reactors. It is shown that the activity of the considered nuclear power facilities did not lead to the exceeding of ecologically safe levels of radionuclides in environmental components during the study period.