Activity Concentrations Of 226Ra Research Articles

Assessing the need for radiation protection measures in artisanal and small scale mining of tantalite in Oke-Ogun, Oyo State, Nigeria

There is concern that work scenarios on the tantalite mining sites in Oke-Ogun, Oyo State, Nigeria may cause occupational radiation exposure of workers due to enhanced concentrations of naturally occurring radionuclides in some process materials. A prior radiological assessment of the mining activities was carried out to determine if and which exposure scenarios may require radiation protection measures. Samples of the materials involved, comprising tantalite (tantalum ores), soil and waste rock were collected and analyzed for activity concentrations of 40K, 226Ra, 238U and 232Th using a hyper pure germanium detector gamma-ray spectrometer. Radon concentrations in the mines were also measured using a continuous radon monitor - Radon-Scout Plus (Sarad, GmbH). Activity concentrations of 40K are below 10 Bqg-1 in all the samples but all the tantalite samples contain more than 1 Bqg-1 of 226Ra and 238U. Hence tantalite is regarded as naturally occurring radioactive material (NORM) and the mining activity as a practice. The requirements for planned exposure situations apply to all the mining sites but, on the basis of graded approach, the optimum radiation protection measures vary from one mine to another, ranging from exemption to authorization. Exposures to radon in the underground mines pose the greatest radiological risks and portend the greatest need for regulatory control in the mining operations. The results further underscore the need to integrate radiation protection with the other health and safety measures in the mining sector.

Natural radiation of chemical fertilisers and radiological impact on agriculture soil

To investigate the radiological hazards indices of chemical fertilisers commonly used in agriculture soils of Arasbaran, Iran, the activity concentration of 226Ra, 232Th, and 40K in four types of chemical fertilisers were measured by gamma spectrometry system. The concentration range for 226Ra, 232Th, and 40K was obtained from 54 ± 2.2 to 1585 ± 29.4, 6 ± 0.1 to 157 ± 9.1, and 31 ± 1.5 to 1496 ± 32.8 Bq/kg, respectively. The obtained results showed that the fertiliser's average radiation hazard parameters were higher than the reference level. The outcomes give rise to more parameter values over the permissible limit, increasing the likelihood of adverse health consequences.

Natural Radioactivity and Metals in Pit Lakes in Sweden Analyzed by Principal Component and Cluster Analysis

The aim of this work was to determine which parameters are sufficient to measure in order to describe the water quality of a pit lake and to identify patterns in the data among different kind of pit lakes. The data consisted of ambient dose equivalent rate, elemental and radionuclide concentration, pH, and specific conductance in surface water and sediment samples collected from different types of mines. Data were tested for normality and log-normality and used in principal component analysis (PCA) and hierarchical cluster analysis (HCA). The normality tests indicated that only 40K was normally distributed, while only the 234,238U isotopes were log-normally distributed. HCA performed on parameters measured in surface water provided clusters that in most cases separated the elements according to their chemical groups. However, when HCA was performed on pit lakes, the clustering seemed to indicate that surface water might not be the preferred sample to differentiate between different types of pit lakes. PCA of surface water data resulted in three components that explained 72% of the variance when pH, SC, concentration of the elements Mg, K, Ca, Cu, Zn, Sr, Pb, activity concentration of 234,238U and 210Po, and ambient dose equivalent rate were included. For surface sediment data, the PCA resulted in three components explaining 83% of the variance when the concentration of Na, Mg, Al, P, K, Ca, Rb, Sr, Y, Tl, activity concentration of 234Th, 226Ra, 210Pb, 232Th (series average), and 40K, and ambient dose equivalent rate were included.

Assessment of natural radioactivity levels and radiological hazards in building materials commonly used in Ethiopian constructions

ABSTRACT Natural radionuclide activity concentrations were measured in ceramic, gypsum, and brick samples from manufacturers, dealers, and construction sites in and around Addis Ababa, Ethiopia, using an HPGe detector. The study’s main aim is to assess the activity concentration of building materials and their health impacts. Average activity concentrations (Bq kg−1) for 226Ra in ceramic, gypsum, and brick samples were obtained as 81 ± 1, 1.34 ± 0.17, and 39 ± 1, respectively. In ceramic, gypsum, and brick, concentrations of 232Th were obtained as 166 ± 4, 0.68 ± 0.18, and 103 ± 3, respectively, while concentrations of 40K were found to be 755 ± 16,15 ± 1, and 921 ± 24, respectively. Some of the materials that were tested, especially the ceramic samples, had slightly higher concentrations of radionuclides in comparison to other analysed samples. In all samples except ceramic, Raeq was < 370 Bq kg−1, which is the recommended limiting dose for bulk medium. Furthermore, the corresponding radiological parameters, such as absorbed dose, annual effective dose equivalent, excess lifetime cancer risk (ELCR), internal (Hin) and external (Hex) hazard indexes, gamma index (Iγ), and alpha index (Iα) were determined. The ELCR average values in this study are slightly higher than the global average, and the indoor and outdoor absorbed dose rates are greater than the limiting criteria of 84 and 59 n Gy h−1, respectively. Therefore, it is important to assess the potential radiation risk of ceramic samples, which should be used in a controlled manner to reduce gamma exposure to residents. Finally, the computed data could be used as a baseline to assess any future radiation exposure from construction materials.

Soil to tobacco component transfer factors for natural radionuclides 40K, 226Ra, and 232Th and the risk assessment of tobacco leaf in smoking

This study determined the activity concentrations and corresponding transfer factors (TF) of 40K, 226Ra, and 232Th in three tobacco components (root, stem, and leaf). The radiation hazard index parameters were assessed for the tobacco leaf. The activity concentrations in the soil were 589–762, 32–43, and 49–59 Bq kg-dw−1 (dry weight) for 40K, 226Ra, and 232Th, respectively. The average activity concentrations of 40K, 226Ra, and 232Th were 447, 5.41 and 5.69 Bq/kg-dw for the root, 670, 9.64 and 7.61 Bq kg-dw−1 for the stem, and 793, 6.79 and 6.15 Bq kg-dw−1 for the leaf, respectively. The TF values were 0.42–1.42, 0.10–0.49 and 0.06–0.23 for 40K, 226Ra, and 232Th, respectively. The stem and leaf 40K TF values were significantly higher than the root values. The stem 226Ra TF values were significantly higher than the root values. The 226Ra and 232Th activity concentrations and TFs of tobacco components had a significant positive correlation. Based on the activity concentrations of the tobacco leaves, the annual inhalation effective dose to the lungs for an adult smoker was 0.32–0.81 mSv y−1 (average 0.60 mSv y−1). The Excess Lifetime Cancer Risk (ELCR) caused by smoking was an average of 2.39 × 10−3.

Assessment of the Naturally Occurring Radioactive Materials (Norm) In Jos North, Nigeria. A Case Study of the Utan Artisanal Tin Mining Sites

Tin mining and milling can be an avenue for economic and technological development. Mining of this mineral contributes significantly to the distortion of the natural distribution of radioisotopes in the environment. This study assesses the concentration of natural radioactivity due to radioactive elements such as 40K, 238U and 232Th. Soil samples were taken from 20 distinct locations within the Utan mining sites, Jos North, Plateau State, Nigeria. Potassium, radium, and thorium in soil samples from mining sites were determined by measuring their concentration activities using the gamma-ray spectroscopy method. Activity concentrations of potassium, radium and thorium were determined. In soil samples, activity concentrations of 40K, 226Ra and 232Th were established. 40K 196.07±4.91 to 608.07±1.44 with an average of 386.48, 226Ra 0.71±0.02 to 5.11±0.07 with an average of 2.35 and 232Th 14.91±0.74 to 63.71±0.97 with average activity concentrations of 54.78. The average concentration activity of potassium and thorium was slightly above the world recommended average of 370.00 and 40.00 respectively, while radium was below the recommended average. The mines mean absorbed and annual effective dose rates were 14.27-nGy h−1and 18.62 μSvy-1, respectively. This average calculated absorbed dose rate in the air was found to be much less, than the global average of 57-nGy h−1. The absorbed dose is considered low compared to the external natural radiation of about 2000 μSv.y-1, to which no harmful effect is expected directly. However, the mean measured dose rate and calculated dose parameters for the mine were higher than the regulatory limit for public exposure.

Radiological hazard assessment of natural radioactivity in Avcilar region, Turkey: a case of Istanbul University-Cerrahpasa Avcilar Campus

ABSTRACT Radionuclides 226Ra, 232Th, and 40K can be found in various concentrations in the surface soil. High concentrations of radionuclides in the surface soil may cause radiological risks. This study investigated natural radioactivity levels and artificial radionuclide (137Cs) levels in the Istanbul University-Cerrahpasa, Avcilar region, Istanbul, Turkey. Radioactivity concentrations were analyzed using the gamma-ray spectrometer. The mean activity concentration of 226Ra, 232Th, 40K, and 137Cs is 28.55, 29.57, 385.72, and 3.09 Bq kg−1, respectively. Radiological parameters radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, and excess lifetime cancer risk were calculated using activity concentrations. The radiological parameters values were lower than UNSCEAR values, except for the annual gonadal dose equivalent (approximately 10% higher). There is a strong correlation between radiological parameters and radionuclides. Generally, the activities of radionuclides in the region fall within the recommended limits, thus Istanbul-Avcilar region can be considered safe for settlement.

Radionuclide contamination and nutritional evaluation of the wheat mostly used in the Republic of North Macedonia

Wheat is one of the world’s most commonly consumed cereal grains. It originates from a type of grass (Triticum) that is grown in countless varieties worldwide. Bread wheat or common wheat is a primary species. Several other closely related species include durum, spelt, emmer, einkorn, and Khorasan wheat. In addition to being a major source of starch and energy, wheat also provides substantial amounts of a number of components which are essential or beneficial for health, notably proteins, vitamins (notably B vitamins), dietary fibres, and phytochemicals. Wheat is a basic food product of Macedonian population. This study is mainly focused on measuring the concentration of radioactivity due to natural radioactive nuclides (226Ra, 232Th, 40K) in wheat grain samples, as well as on determining the quality of wheat used in daily diet. In addition, in this study we calculated radiation hazard indices (radium equivalent activity and internal hazard index) in the wheat sample. Average activity concentrations of 226Ra, 232Th, and 40K in the wheat samples were 0.57±0.14; 0.39±0.11; 96.55±0.86 (Bq·kg-1), respectively. The radiation hazard indices were calculated for all samples in this study where mean values ​​did not exceed safety limits, pointing out to negligible radiation hazard arising from terrestrial radionuclides that are naturally present in wheat. In terms of quality, we confirmed that all tested samples meet the requirements regarding quality in accordance with the laws in our country.

Annual effective dose associated with radioactivity in drinking water from tin mining areas in North-western Nigeria

Mining of minerals increases the risk of exposure to natural radionuclides by exposing them to the outer surface of the earth. The risk increases when these radionuclides are migrated into the bodies of water that have been used for drinking purposes. This work was carried out to assess the radionuclides concentration in drinking water from tin mining areas in North-western Nigeria. Water samples were collected and the activity concentration of 40K, 232Th, 226Ra, and 222Ra were analyzed using a high-purity germanium detector and a liquid scintillation counter respectively. The mean activity concentrations were found to be 3.57 ± 2.1, 4.0 ± 2.2, 7.6 ± 3.7 and 5.8 ± 3.3, 4.4 ± 2.7, 6.2 ± 4.2 Bq/l in surface and groundwater for 226Ra, 232Th, 40K respectively. These values exceeded the recommended value of 1.00 Bq/l in drinking water set by the International Atomic Energy Agency. The activity concentrations of radon varied from 0.75 to 17.08 Bq/L with a mean value of 12.50 Bq/l. The obtained mean value exceeded the recommended value of 11 Bq/l set by the United State Environmental Protection Agency as the level of radon in drinking water. The calculated annual effective dose due to radon and 226Ra, 232Th 40K from the studied water are 2.66 μSv/y and 3.30 μSv/y respectively. These values are lower than the maximum allowable value of 100 μSv/y as a radiation dose received from drinking water set by the World Health Organisation and the United Nations Scientific Committee on the Effect of Atomic Radiations. Therefore, both the surface and groundwater from the study areas can be used for drinking and other domestic purposes as it could pose no significant radiological health hazards.

Measuring of natural and artificial radioactivity in Al-Dakhiliya governorate, Sultanate of Oman

Soil and sand samples were collected from eight different locations in the Al-Dakhiliya governorate, Sultanate of Oman to determine and evaluate the natural and artificial radioactivity levels. The activity concentrations of radionuclides 137Cs, 226Ra, 40K, 235U and 228Ac were measured using high resolution gamma-ray spectroscopy detectors (HPGe detectors). In addition, radiation hazard indexes were evaluated in order to measure radioactive risk for human beings and the environment. The activity concentrations of 137Cs, 226Ra, 40K, 235U and 228Ac were found as 0.82 ± 0.04, 29.01 ± 1.37, 290.14 ±2.79, 5.88 ± 0.65 and 39.57 ± 3.85 Bq/Kg respectively. Radium-equivalent activity Raeq was obtained and varied in the range from 340 to 43 Bq/Kg with a mean value of 108.3 Bq/Kg. The study found that the gamma indexes, external indexes and internal indexes in most sites were less than 1, which indicates a low radioactive dose. The study concludes that seven sites contain relatively low radioactivity, whereas one site requires more investigation in future as the results show a sort of rise in the radioactivity rate on its samples.

"Radioactivity Concentration and Radionuclide Transfer Factor Assessment in Afang Leaves (Gnetum africanum) Cultivated in Akwa Ibom State, Nigeria"

Activity concentration of radionuclides present in soil and transfer factor (TF) in plants are very useful parameters in accessing the level of radioactive contamination in farmlands and in plants cultivated in such farmlands. In this research work the activity concentration of naturally occurring radionuclides in farm soil and Afang leaves planted in the soil were measured using high purity Germanium (HPGe) detector. In soil the mean activity concentration of 238U was58.34±3.41Bq/kg,226Ra had mean value of 26.98±1.39Bq/kg, 232Th had 45.06±2.38Bq/kg, while that of 40K was30.91±1.71Bq/kg. The mean activity concentration of 238U, 226Ra, 232Th and 40Kin Afang leaves were 13.29±1.28Bq/kg, 4.85±0.79Bq/kg, 6.80±0.45Bq/kg and 459.65±25.64Bq/kg respectively.Transfer factors of 238U, 226Ra, 232Th and 40K were 0.22, 0.22, 0.17 and 31.21 respectively from soil to Afang leaves. In soil mean activity concentration of226Ra and 40K were within recommended limits while themean values obtained for activity concentration of 238U and 232Th in soil from most sampling locations were observed to be above world recommended values.Mean activity concentration of 238U, 226Ra and 232Th in afang leaves were within permissible values except for 40K.High values of TF were also obtained for 40K in all afang leaves samples, however 40K is known to be naturally abundant in soil and plants.Values of transfer factor obtained for 238U, 226Ra and 232Th in all afang samples were all below unity, which is within the recommended limits and therefore safe for consumption

Radiation Hazard Index in Around NPP Candidate Site in West Kalimantan, Indonesia

Before the construction of nuclear power plant (NPP), several documents must be prepared, including environmental and site permit documents. Environmental radiation monitoring is also necessary to ensure public safety and security. The purpose of this research is to obtain data on 238U, 226Ra, 232Th, and 40K which will be used for the preparation of site permit documents and environmental documents for NPP in West Kalimantan. In addition, it also determines the radiation hazard index (considering that there are 3 coal thermal power plants in the vicinity) by calculating the Radium equivalent index (Raeq), Representative Level Index (Iγ ), Absorbed Dose rate (D), and Annual effective Dose Rate (Deff ) to estimate the potential radiological health risk. Based on this, the measurement of environmental radioactivity around the prospective site of NPP at West Kalimantan was carried out. Measurement of radionuclides using a Gamma Spectrometer an ORTEC P-type coaxial high-purity germanium (HPGe) detector for 24 hours, and for spectrum analysis it was used Personal Computer-based 4096-channel analyzer and processed using Maestro software gamma. The activity concentrations of 238U, 226Ra, 232Th, and 40K in the soil were 23.18 ± 11.97; 24.03 ± 15.95; 12.18 ± 13.81; 113.80 ± 122.45 and 0.19 ± 0.18 respectively, lower than the world average and levels reported by several other countries (Malaysia, Thailand, China, and Japan). The hazard index values as Radium Equivalent Activity (Raeq), Representative Level Index (Iγ ), Absorbed Dose Rate (D), and Annual Effective Dose Rate (Deff) were 68.51 ± 41.43 Bq.kg-1, 0.49 ± 0.30; 124.14 ± 66.16 nGy.h-1 and 0.93 ± 0.50 mSv.y-1 respectively. These values are below the permissible limits and in the safe zone category

Cancer risk (ELCR) and annual gonadotropin equivalent dose (AGED) in macaroni

Natural radioactivity has attracted a lot of attention in the world due to its crucial role in human safety. macaroni (Macaroni) is a dry, hollow pastry, made from cereals such as wheat, rice and barley. Macaroni is one of the basic and important for human beings, as well as its proven usefulness to the general health of human beings. Therefore, the measurement of natural radioactivity is a critical because of its direct impact on human safety. In this research, quantification has been made of natural radionuclide concentrations using NaI(Tl) gamma-ray spectrometry. The analyses of samples reveal the mean activity concentrations of 226Ra, 232Th, 40K% are found to 4.5E-01±0.071, 4.46±0.163 and 2.14±0.021, respectively. RLI,AUI,IC and Iα were also calculated the values ​​were less than one also estimated annual gonadal equivalent dose (AGED) resulting with an average 302.98±07.59 mSv.y-1 where was higher than globally limits. Consumption of macaroni for adult was found (0.035±0.0015) mSv.y-1 which less than global studies , while the average value of cancer risk ( 1.21E-04±0.000005*10-3 mSv.y-1 Below the international permissible limits. The study can be considered as a basis for future studies on this basic substance in food.

Radiological Safety Assessment of Quarry Processing Site in Keffi, Nigeria

Disposal of large quantities of certain minerals (mining) containing 40K, 232Th and 226Ra and other radionuclides in the decay series of Th and U from the earth crust results in increase in the radionuclides concentrations. This research looks at the radiological safety assessment of quarry Processing Site in Keffi, Nigeria. The activity concentration of 226Ra, 232Th and 40K in the five (5) different Soil samples, varied widely as 10.54±3.040 Bq/ kg, 2.61±1.170 Bq/kg and 36.99 ± 7.490 Bq/kg respectively. Ungwan Tanko (UTN) has the highest activity concentration of 14.90 ± 2.30 Bq/kg for 226Ra while Pyanku (PYK) has the highest activity concentration of 4.52 ± 0.32 Bq/kg for 232Th. Activity concentration of 40K was highest (57.32 ± 2.530 Bq/kg) in Ungwan Kwara (UKW). It was also observed that Yalwa (YLW) had the lowest activity concentration of 02.20 ± 1.31 Bq/kg for 226Ra, while Ungwan Tanko (UTN) had the lowest activity concentration values of 1.03 ± 1.74 Bq/kg for 232Th and Attab Fueling Station (AFS) had the lowest activity concentration values of 13.67 ± 15.73 Bq/kg for 40K. Radium equivalent activity Raeq (Bq/kg), alpha index, internal hazard index, and total cancer risk 17.52 Bq/kg 0.055, 0.077 and 6.82 x 10-7 respectively. Based on the results presented, the present quarry processing sites in Keffi has less effect on ingestion rate of Soil and may poses no radiological risk to the population.

Measurement of activity concentrations of rock samples from rocks- surrounded town in Igbeti, Oyo State, Nigeria

Rocks are known to contain radionuclides that emit radiation continuously. The assessment of activity concentrations of rock samples from Igbeti, Oke-Ogun has been investigated. Twenty (20) rock samples were randomly collected from different rock sites. The rock samples were pulverized at the laboratory of the Department of Geology, University of Ibadan. 200g of each collected sample was allowed to attain secular equilibrium by enclosing it in a plastic container for twenty-eight (28) days. Radiometric analysis of the samples was carried out at the radiation laboratory of the Physics Department of the Federal University of Agriculture, Abeokuta using a thallium doped Sodium Iodide detector. Standard equations were used to estimate the radiological parameters associated with exposure to ionizing radiation from the natural radionuclides in the rock samples. The study revealed that the activity concentrations of 226Ra, 232Th, and 40K lie between 14 ̶ 487 (Bq/kg), 210 ̶ 3680 (Bq/kg), and 242 ̶ 1580 (Bq/kg) respectively. The absorbed dose rate (nGy/h), annual effective dose equivalent (μSv/y), (radium equivalent (Bq/kg), external and internal indices, activity utilization index and estimated excess lifetime cancer risks lie between from (180 ̶ 2700) nGy/h, (0.10 ̶ 14), 400 ̶ 6300 (Bq/kg), 1 ̶ 17, 1 ̶ 19, 2 ̶ 41, and 0.6 ̶ 9.5 × 10−6 respectively. The values of the absorbed dose rates value are greater than the world average of 60 nGy/h while annual effective dose equivalent values are less than the world’s average value of 1000 μSv/y respectively. The external and internal indices are greater than the permissible limit of (1) and likewise, the radium equivalent value is also greater than the acceptable limit of 370 Bq/kg. The estimated excess lifetime cancer risk for the study is below the permissible limit of 2.9 × 10−4 . Most of the estimated radiological parameters for the study are all greater than the permissible limit. This suggests that further exposure of dwellers to ionizing radiation may be possible and this calls for further investigation.

Radiological Impact of Building Material: Characterization of a Village Entirely Built out of Stone in Tuscany, Italy

Tuscany, with its mixed geology, offers a great variety of stones that are used to build entire villages. In this paper, two of these building materials are considered: Rosso Ammonitco and Pietra Serena. In particular, the activity concentration of 226Ra, 232Th and 40K have been analysed in order to estimate the value of the gamma index. In addition to this, the X-ray fluorescence spectroscopy has been carried out to obtain a chemical characterization of the stones. Although these kind of stones are not subjected to radiological characterization, the approach used was the one reported in Radiation Protection 112, also implemented in the Italian Legislative Decree 101/2020, because of their lithographical peculiarity and their employment in construction.

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.

Natural radionuclide concentration and associated health hazard indices in coal samples from Okobo Coal Mine, Nigeria

Background: Mining activities of coal have the capacity to raise the level of natural radionuclide concentration in our environment. This exposes human population to ionizing radiations with their associated health hazards. This study was aimed at measuring natural radionuclide concentration of 226Ra, 232Th and 40K, and their associated health hazard indices in coal samples from Okobo coal mine. Materials and Methods: The survey design adopted for this study was the cross sectional type. Coal samples totaling ten (10) in number, were randomly collected from the coal mine. The sampled coal was analyzed at the University of Ibadan, in the laboratory of the National Institute of Radiation Protection and Research (NIRPR), using high resolution spectrometry technique, with high purity germanium (HPGe) detectors. Results: The obtained results revealed that the radionucide concentration of 226Ra in the sampled coal recorded slightly higher value (21.34±7.94 Bq/kg) than global average of 20 Bq/Kg. However, the recorded values for 232Th (13.61±5.08 Bq/kg) and 40K (20.91±15.77 Bq/kg) fall below the global average value of 20 and 50 Bq/Kg respectively. All calculated radiological hazard parameters recorded lower values than the global permissible value but for annual gonadal dose equivalent (AGDE) which recorded significantly higher value (407.74 mSv/yr) than the world acceptable limit of 300 mSv/yr. Conclusion: The activity concentration of 226Ra for Okobo coal sample recorded a unit mean value higher than the global average, however the recorded values for 232Th and 40K fall below global permissible values. All radiological health hazards recorded lower values than the precautionary safe limit but for annual gonadal equivalent dose which recorded significantly higher value than the global permissible limit. This implies that both staff and residents of the community could be exposed to radiological threat, which might affect the functionality of their sensitive organs if prolonged and cumulative exposure is not avoided.

Radiological hazard assessment and sensitivity analysis for soil samples in Taghdoua area of Ranyah, Saudi Arabia

In this study, twenty-two samples of soil were studied for 222Rn, 226Ra, 232Th and 40K using hyper-pure Germanium (HPGe) detector. The soil samples were collected from an inhabited area surrounding the small mountain in Taghdoua area of Ranyah. The measured activity concentrations of 226Ra, 232Th and 40K in the soil were found to vary from 6 to 54, 7 to 52 and 299–761 Bq kg−1, respectively. The radiological risk parameters including excess lifetime cancer risks and other relevant parameters were also evaluated. Furthermore, the effect of ventilation changes on both external and internal doses over a protracted exposure duration were studied through sensitivity analysis using RESRAD-BUILD computer code. The external doses were observed to be insensitive to ventilation while a considerable change was detected in the internal doses with ventilation. Hence, the investigated radiological risk parameters including the results from RESRAD were all below the recommended limit.

Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean

The vertical activity concentration distributions of the radium isotopes, 226Ra and 228Ra, which are useful as radiotracers, were obtained for the first time in the western Subarctic Pacific Gyre (WSAG). It was possible to detect short-lived 228Ra present from the surface to 400 m depth by analyzing large seawater samples. Low 228Ra and high 226Ra activity concentrations in the surface layer in the WSAG were strongly influenced by upwelled deeper water with nutrients. The activity concentration distribution of 226Ra especially was in good agreement with the silicate concentration distribution, which was consistent with previous reported findings. These distributions were uniform from the surface to 100 m of the dichothermal layer due to vertical mixing in winter. 228Ra activity concentration decreased with water depth below the pycnocline and reached the undetectable level at 600 m which was within the oxygen minimum layer. Estimations of vertical fluxes of 228Ra and nitrate according to 228Ra decay indicated that the vertical transport by eddy diffusion was a minor process for the 228Ra and nitrate fluxes, and lateral transport mainly affected 228Ra in the intermediate warm water, that is, the mesothermal layer below the main pycnocline. Vertical mixing or submarine underground water and lateral transport to the WSAG could yield this 228Ra in the intermediate depth.