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1.
Environ Geochem Health ; 46(6): 208, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806960

RESUMO

Concentrations of potentially toxic elements (PTEs) like arsenic, uranium, iron, and nitrate in the groundwater of the Majha Belt (including Tarn Taran, Amritsar, Gurdaspur, and Pathankot districts) in Punjab, India were measured to evaluate the health risks associated with its consumption and daily use. The average concentrations of these elements in some locations exceeded the WHO-recommended values. Arsenic and iron toxicity levels were found to be higher in the Amritsar district, while uranium toxicity was more prevalent in Tarn Taran. The Trace Element Evaluation Index suggests that Amritsar is one of the districts most affected by toxic elements. According to the US Environmental Protection Agency's (USEPA) guidelines, the HQ values of U, Fe, and nitrate were less than one, indicating that there is no non-carcinogenic health risk for adults and children. However, the hazard quotient (HQ) value for arsenic was greater than one, indicating a higher possibility of health risk due to arsenic in the study area. The total hazard index values of 44.10% of samples were greater than four for arsenic, indicating that people in the Majha Belt are at a very high health risk due to the usage of water for drinking and domestic purposes. The cancer risk assessment values for arsenic in children (5.69E + 0) and adults (4.07E + 0) were higher than the accepted limit of USEPA (10-4 to 10-6) in the Majha Belt. The average radiological cancer risk values of U for children and adults were 8.68E-07 and 9.45E-06, respectively, which are well below the permissible limit of 1.67 × 10-4 suggested by the Atomic Energy Regulatory Board of DAE, India. The results of this study confirm that the residents of the Majha Belt who use contaminated groundwater are at a serious risk of exposure to arsenic in the Amritsar district and uranium in Tarn Taran district.


Assuntos
Arsênio , Água Subterrânea , Poluentes Químicos da Água , Índia , Água Subterrânea/química , Medição de Risco , Arsênio/análise , Poluentes Químicos da Água/análise , Humanos , Urânio/análise , Nitratos/análise , Monitoramento Ambiental , Ferro/análise , Criança , Adulto
2.
Radiat Prot Dosimetry ; 200(8): 715-720, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38689537

RESUMO

This study used gamma ray spectrometry to determine the radiological safety of construction soil sampled randomly from Mbeere North region, Kenya. The mean activity concentration of 232Th, 238U, and 40K was 149.7 ± 2.8 Bqkg-1, 88.3 ± 2.4 Bqkg-1, and 490 ± 35 Bqkg-1, respectively. These averages exceed the world average for all the radionuclides. The radionuclides were non-uniformly distributed, with higher concentrations along the slopes and on the feet of the hills. The mean absorbed dose rate, indoor and outdoor annual effective dose, radium equivalent, external hazard index, and internal hazard index were 157.9 ± 4.4 nGh-1, 0.58 ± 0.02 mSvy-1, 0.39 ± 0.01 mSvy-1, 340.7 ± 9.2 Bqkg-1, 0.92 ± 0.02 and 1.14 ± 0.03, respectively. Among the radiation safety indicators, only the average internal hazard index exceeded slightly the acceptable safe limit. Therefore, soils of Mbeere North region are radiologically safe for use in brick making and construction of human habitats.


Assuntos
Radioisótopos de Potássio , Monitoramento de Radiação , Poluentes Radioativos do Solo , Espectrometria gama , Tório , Quênia , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Tório/análise , Radioisótopos de Potássio/análise , Humanos , Urânio/análise , Doses de Radiação , Raios gama
3.
Sci Total Environ ; 926: 171918, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38522553

RESUMO

The disposal of spent nuclear fuel in deep subsurface repositories using multi-barrier systems is considered to be the most promising method for preventing radionuclide leakage. However, the stability of the barriers can be affected by the activities of diverse microbes in subsurface environments. Therefore, this study investigated groundwater geochemistry and microbial populations, activities, and community structures at three potential spent nuclear fuel repository construction sites. The microbial analysis involved a multi-approach including both culture-dependent, culture-independent, and sequence-based methods for a comprehensive understanding of groundwater biogeochemistry. The results from all three sites showed that geochemical properties were closely related to microbial population and activities. Total number of cells estimates were strongly correlated to high dissolved organic carbon; while the ratio of adenosine-triphosphate:total number of cells indicated substantial activities of sulfate reducing bacteria. The 16S rRNA gene sequencing revealed that the microbial communities differed across the three sites, with each featuring microbes performing distinctive functions. In addition, our multi-approach provided some intriguing findings: a site with a low relative abundance of sulfate reducing bacteria based on the 16S rRNA gene sequencing showed high populations during most probable number incubation, implying that despite their low abundance, sulfate reducing bacteria still played an important role in sulfate reduction within the groundwater. Moreover, a redundancy analysis indicated a significant correlation between uranium concentrations and microbial community compositions, which suggests a potential impact of uranium on microbial community. These findings together highlight the importance of multi-methodological assessments in better characterizing groundwater biogeochemical properties for the selection of potential spent nuclear fuel disposal sites.


Assuntos
Desulfovibrio , Água Subterrânea , Urânio , Bactérias , Urânio/análise , RNA Ribossômico 16S/genética , Estudos Prospectivos , Água Subterrânea/química , Sulfatos/análise
4.
Radiat Prot Dosimetry ; 200(6): 554-563, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38453149

RESUMO

Monitoring radioactivity levels in the environment around nuclear power plants is of great significance to assessing environmental safety and impact. Shidaowan nuclear power plant is currently undergoing commissioning; however, the baseline soil radioactivity is unknown. The naturally occurring radionuclides 238U, 232Th, 226Ra and 40K, and artificial radionuclide (AR) 137Cs in soil samples around the Shidaowan nuclear power plant were measured to establish the baseline levels. Human health hazard indices such as external hazard indices (Hex), Radium equivalent (Raeq), outdoor absorbed dose rate (Dout), annual effective dose (AED) and excess lifetime cancer risk (ELCR) were estimated. The average concentration of 232Th, 40K, 137Cs, 238U and 226Ra were 42.6 ± 15, 581 ± 131, 0.68 ± 0.38, 40.13 ± 9.07 and 40.8 ± 12.8 Bq per kg, respectively. The average Hex, Raeq, Dout, AED and ELCR were 0.40, 146 Bq per kg, 68.8 nGy per h, 0.09 mSv per y and 3.29E-04, respectively. These data showed an acceptable level of risk to residents near the nuclear power plant and that the current radioactivity in the soil may not pose immediate harm to residents living close to the nuclear power plant. The observed lower AED and 40 K and 137Cs concentrations were comparable to other studies, whilst ELCR was higher than the world average of 2.9E-04. The commissioning of the Shidaowan nuclear power plant is potentially safe for the surrounding residents; further continuous monitoring is recommended.


Assuntos
Radioisótopos de Césio , Centrais Nucleares , Radioisótopos de Potássio , Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Tório , Poluentes Radioativos do Solo/análise , Medição de Risco/métodos , China , Monitoramento de Radiação/métodos , Humanos , Radioisótopos de Césio/análise , Rádio (Elemento)/análise , Tório/análise , Radioisótopos de Potássio/análise , Doses de Radiação , Urânio/análise
5.
Environ Sci Pollut Res Int ; 31(18): 27085-27098, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38503952

RESUMO

In Santa Quitéria City, part of the population uses surface water for potation. These waters do not undergo any treatment before consumption. As the region has a deposit of uranium, assessing water quality becomes important. In the present study, the uranium activity concentration (AC) in becquerels per liter was determined in water samples from six points. Univariate statistics showed differences between the soluble and the particulate fraction (soluble AC > particulate AC). The particulate fraction showed no variation in AC among the six points. On the other hand, the soluble fraction and the total fraction presented different ACs between them. The multivariate statistics allowed to separate the soluble from the particulate fraction of the points. The same tools applied to the total fraction made it possible to differentiate the sampling points, grouping them ((#1, #2); (#3, #4), and (#5, #6)). The maximum mean value of AC found was 0.177 Bq∙L-1, corresponding to 25% of the chemical toxicity limit (0.72 Bq∙L-1). The maximum mean dose rate, 2.25 µSv∙year-1, is lower than the considered negligible dose rate (> 10 µSv∙year-1). The excess lifetime cancer risk was 10-6, two orders of magnitude smaller than the threshold considered for taking action. The assessment parameters used in this work indicate that the risk due to the uranium intake by the local population is negligible.


Assuntos
Urânio , Urânio/análise , Brasil , Poluentes Radioativos da Água/análise , Humanos , Monitoramento de Radiação
6.
Sci Rep ; 14(1): 2530, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291175

RESUMO

The article summarizes the activity concentrations data of 226Ra and the sum of uranium isotopes (∑U) in samples of drinking underground water for different regions of Ukraine studied during 1998-2023 in the radiation monitoring laboratory of the State Institution "O.M. Marzieiev Institute of Public Health National Academy of Medical Sciences of Ukraine. Arithmetic mean and standard deviations, minimum and maximum values for 226Ra and ∑U activity concentrations are presented for the entire 1240 sample set and for each region separately. Collected data show that the established state permissible level for drinking water of 1.0 Bq/l is exceeded for 226Ra in 1.1% of the studied samples, and for ∑U-in 3.9% correspondingly. The detected high levels of 226Ra and ∑U activity concentrations correspond to certain regions belonging to the Ukrainian crystalline shield territory. A comparison of the current data with the data of previous studies held during of 1989-1991 indicates a significant difference: for the previous studies the average and standard deviations are much higher. We attribute this to the fact that the centralized sampling of previous studies was random, and it was related exclusively to communal water supply systems. At the same time, the current sample set covers a much larger number of regions, different water consumers; the data set includes the results of repeated studies for a large number of sources, in particular, sources with purified water. Hypothetical exposure doses caused by consumption of 226Ra and ∑U in water for the current sample set were estimated for different age groups for each sample studied, as is, without taking into account the pattern of water consumption. The corresponding dose exceeds the WHO recommended value of 0.1 mSv per year for children under the age of one year for 220 cases (17.7%). This dose limit excess for other age groups corresponds-for children: aged 12-17 years-13.1%, aged 1-2 years-7.4%, 7-12 years old-5.6%, 2-7 years old-3.9% and for adults-4.1%.


Assuntos
Água Potável , Monitoramento de Radiação , Rádio (Elemento) , Urânio , Poluentes Radioativos da Água , Adulto , Criança , Humanos , Pré-Escolar , Urânio/análise , Ucrânia , Monitoramento de Radiação/métodos , Poluentes Radioativos da Água/análise
7.
Radiat Prot Dosimetry ; 200(2): 201-205, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38044801

RESUMO

Natural radioactive materials in certain conditions can get to hazardous radiological level. The aim of the present work was to evaluate the natural activity concentration from sampled building materials collected from different locations in Babadogo Estate within Nairobi City County. The analysis done using gamma ray spectrometer, which was put into action for spectral data acquisition and then analysis. The activity concentration levels of 238U, 232Th and 40K for the selected samples of building materials was measured by the use of gamma ray spectrometry method. The analyzed data compared with the standard acceptable values. The activity concentration in 40K varied from 55 ± 3 to 2647 ± 132 Bq kg-1, giving an average (sum of all values divided by 33) value of 831 ± 42 Bq kg-1; 238U varied from 39 ± 2 to 3602 ± 180 Bq kg-1, giving average figures of 378 ± 19 Bq kg-1 and 232Th ranged from 5.000 ± 0.300 to 4213 ± 211 Bq kg-1, giving average figure of 290 ± 15 Bq kg-1. The calculated average figures for activity concentration surpassed the world average values of 420, 33 and 45 Bq kg-1 in 40K, 238U and 232Th, respectively.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Urânio , Tório/análise , Urânio/análise , Quênia , Materiais de Construção/análise , Espectrometria gama , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise
8.
Sci Total Environ ; 913: 169252, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38092210

RESUMO

Groundwater contributes to an average of 8 % of the total water source capacity in the Republic of Korea. Hence, private residential households in rural areas in Korea are still using groundwater for drinking without any regular water quality inspection. This can increase the risk of exposure to natural radionuclides like uranium through drinking groundwater. This study investigated the uranium level in drinking groundwater all over the country by analyzing 11,451 samples from private residential drinking groundwater facilities and compared the exposure amount and its associated carcinogenic and non-carcinogenic risk based on the geological characteristics of the aquifer. Results yield that although the average hazard quotient (HQ) and excess cancer risk (ECR) of exposure to natural uranium through drinking groundwater were respectively below 1 and 1 × 10-6 and do not indicate a potential health hazard, significantly high HQ and ECR up to respectively 70 and 4 × 10-4 in samples where the aquifer is the Jurassic granite observed. Accordingly, regular water quality investigation and onsite treatment methods are required to provide healthy drinking water in such areas.


Assuntos
Água Potável , Água Subterrânea , Urânio , Poluentes Químicos da Água , Urânio/análise , República da Coreia , Radioisótopos , Medição de Risco , Poluentes Químicos da Água/análise , Monitoramento Ambiental
9.
Environ Sci Pollut Res Int ; 31(5): 7227-7245, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38157180

RESUMO

Characterizing uranium (U) mine water is necessary to understand and design an effective bioremediation strategy. In this study, water samples from two former U-mines in East Germany were analysed. The U and sulphate (SO42-) concentrations of Schlema-Alberoda mine water (U: 1 mg/L; SO42-: 335 mg/L) were 2 and 3 order of magnitude higher than those of the Pöhla sample (U: 0.01 mg/L; SO42-: 0.5 mg/L). U and SO42- seemed to influence the microbial diversity of the two water samples. Microbial diversity analysis identified U(VI)-reducing bacteria (e.g. Desulfurivibrio) and wood-degrading fungi (e.g. Cadophora) providing as electron donors for the growth of U-reducers. U-bioreduction experiments were performed to screen electron donors (glycerol, vanillic acid, and gluconic acid) for Schlema-Alberoda U-mine water bioremediation purpose. Thermodynamic speciation calculations show that under experimental conditions, U(VI) is not coordinated to the amended electron donors. Glycerol was the best-studied electron donor as it effectively removed 99% of soluble U, 95% of Fe, and 58% of SO42- from the mine water, probably by biostimulation of indigenous microbes. Vanillic acid removed 90% of U, and no U removal occurred using gluconic acid.


Assuntos
Gluconatos , Urânio , Urânio/análise , Água/análise , Biodegradação Ambiental , Glicerol , Ácido Vanílico , Oxirredução
10.
Radiat Prot Dosimetry ; 199(18): 2218-2223, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37934993

RESUMO

Phosphate ore is the starting raw material for production of all phosphate products including fertilisers phosphate waste. It can be of sedimentary, volcanic or biological origin. Like any other geological material found in nature, it contains various amounts of naturally occurring primordial radionuclides, such as 238U series, 232Th series and 40K. Gamma-ray spectrometry was used to assess natural radioactivity levels and radiological hazard indices in phosphate samples. In this paper, the specific activity concentrations of 226Ra, 232Th and 40K of phosphate ores, merchant and mine waste samples were determined. Based on the activity concentrations, the radiation hazard indices (Raeq, Hex, Hin and I𝛾𝑟), and the radiation doses (D, AED and ELCR) were calculated. The results were discussed and compared with those from other studies as well as recommended safety limit values.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Urânio , Rádio (Elemento)/análise , Tório/análise , Urânio/análise , Fosfatos/análise , Argélia , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos
11.
J Environ Radioact ; 268-269: 107246, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37506478

RESUMO

In this study, we present an assessment of the uranium ore tailings impact on groundwater and surface water contamination. The radioactive materials were deposited in the tailings storage facility "Dniprovske" (the city of Kamianske, Ukraine) from 1954 to 1968; now it contains about 5.85·106 m3 of hazardous waste on the area of about 76 ha in the floodplain of the Dnipro river. The lack of a proper waterproof screen below deposited tailings and in the earthen dam led to permanent watering of radioactive materials, their leaching and migration in groundwater into the nearest small Konoplianka river. We used the reports on previous site-specific studies conducted in 1999-2016, monitoring results, and the field studies conducted in 2022 with the authors' team participation. The calculations performed with the advection-dispersion model to simulate transport of radionuclides 238U, 230Th, 226Ra and 210Pb through the embankment to the Konoplianka river and dilution relations were compared to the monitoring data of the surface water quality. Among four radionuclides, uranium poses the greatest risks today; the subsurface runoff increases its concentration in the Konoplianka river water by several times over the background value. It is estimated that due to much more intensive sorption in the shallow aquifer, the contribution of 226Ra and 210Pb to the increase in radioactivity of Konoplianka river water is insignificant compared to uranium, whereas the migration front of 230Th has probably not yet reached the riverbank. In the next 50 years the radionuclide fluxes will increase by 1.3-3.7 times for different isotopes, with the uranium subsurface runoff growing at a slower rate than nowadays. These results are of high significance for improving hydrological, hydrogeological, and geotechnical monitoring on this hazardous facility to maintain its radiation safety.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Urânio , Poluentes Radioativos da Água , Urânio/análise , Ucrânia , Chumbo , Poluentes Radioativos do Solo/análise , Radioisótopos/análise , Poluentes Radioativos da Água/análise
12.
Arch Environ Contam Toxicol ; 85(3): 302-313, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37233742

RESUMO

The Red River is one of the largest rivers that plays an important role in the economic development of North Vietnam. There are many radionuclides bearing rare earth, uranium ore mines, mining industrial zones and magma intrusive formations along this river. The contamination and accumulation of radionuclides could exist at high concentration in surface sediments of this river. Thus, the present investigation aims to study the activity concentrations of 226Ra, 232Th (228Ra), 40K, and 137Cs in Red River surface sediments. Thirty sediment samples were collected, and their activity concentration was calculated using high-purity germanium gamma-ray detector. The observed results ranged from 51.0 ± 2.1 to 73.6 ± 3.7 for 226Ra, 71.4 ± 3.6 to 103 ± 5.2 for 232Th, 507 ± 24.0 to 846 ± 42.3 for 40K, and ND (not detected) to 1.33 ± 0.06 Bq/kg for 137Cs, respectively. In general, the natural radionuclides concentration of 226Ra, 232Th (228Ra), and 40K is higher than the average world average values. This indicated that the natural radionuclides could contribute from similar and principal sources surrounding the upstream of Lao Cai where distributed uranium ore mines, radionuclide bearing rare earth mines, mining industrial zones and intrusive formations. Regarding the radiological hazard assessment, results of the indices computed such as absorbed gamma dose rate (D), the excess lifetime cancer risk (ELCR), and the annual effective dose equivalent (AEDE) were nearly two times higher than world average values.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Urânio , Vietnã , Urânio/análise , Monitoramento de Radiação/métodos , Radioisótopos de Césio , Poluentes Radioativos do Solo/análise
13.
Environ Monit Assess ; 195(6): 673, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37188758

RESUMO

The objective of this research is to assess the impact of radon concentration on workers at certain construction material industries in Erbil, Kurdistan Region of Iraq. The CR-39 solid-state track detector was used in this experiment to monitor radon levels and their daughters. For this purpose, as a case study group, 70 workers were divided into seven subgroups (gypsum, cement plant, lightweight block, marble, red brick 1, crusher stone, and concrete block 2), and 20 healthy volunteers were selected as a control group. The findings demonstrate that the mean concentrations of radon, radium, uranium, and radon daughters deposited on the detector face (POS) and chamber walls (POW) for the case study group were 9.61 ± 1.52 Bq/m3, 0.33 ± 0.05 Bq/Kg, 5.39 ± 0.86 mBq/Kg, 4 ± 0.63, and 16.62 ± 2.64 mBq/m3, whereas for the control group, they were 3.39 ± 0.58 Bq/m3, 0.117 ± 0.03 Bq/Kg, 1.91 ± 0.32 mBq/Kg, 1.41 ± 0.24, and 5.88 ± 1 mBq/m3, respectively. The statistical analysis revealed that radon, radium, uranium, and POW and POS concentrations were statistically significant (p ≤ 0.001) in the samples for the case study groups of cement, lightweight block, red brick 1, marble, and crusher stone factories in comparison to the control group; however, the results for gypsum and concrete block 2 factories were not statistically significant in comparison to the control group. Intriguingly, the radon levels in every blood sample examined were far lower than the 200 Bq/m3 limit established by the International Atomic Energy Agency. Hence, it may be argued that the blood is devoid of contaminants. These results are crucial for determining whether or not an individual is exposed to substantial quantities of radiation and for demonstrating a link between radon, its daughter, uranium, and the prevalence of cancer among workers in the Kurdish region of Iraq.


Assuntos
Poluentes Radioativos do Ar , Monitoramento de Radiação , Rádio (Elemento) , Radônio , Urânio , Humanos , Rádio (Elemento)/análise , Urânio/análise , Sulfato de Cálcio/análise , Monitoramento Ambiental , Radônio/análise , Poluentes Radioativos do Ar/análise , Materiais de Construção/análise , Carbonato de Cálcio/análise , Monitoramento de Radiação/métodos
14.
J Radiol Prot ; 43(2)2023 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-37257439

RESUMO

The outdoor222Rn and220Rn concentrations at 320 sampling points at 1 m above the ground in different sites surrounding rare earth element (REE) and uranium mines from northern Vietnam were measured using the RAD7. Results showed that222Rn concentrations were always higher than220Rn concentrations with large variation ranges from 25.7 to 573 Bq m-3and from 18.5 to 385 Bq m-3, respectively. The high correlation between220Rn and228Ra concentrations in surface soil of the studied sites were observed. The highest220Rn and222Rn concentrations are found at the sampling points of the REE NX-Lai Chau site. The220Rn and222Rn activities surrounding the REE mines were found to be higher than those surrounding the uranium mines. The average annual committed effective doses originated from the inhalation of220Rn and222Rn outdoor concentrations is about five times higher than the worldwide average value.


Assuntos
Monitoramento de Radiação , Radônio , Urânio , Radônio/análise , Urânio/análise , Vietnã , Mineração , Medição de Risco
15.
Environ Sci Pollut Res Int ; 30(24): 65379-65391, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37084045

RESUMO

Uranium mining causes several radiological impacts on the surrounding environment, notably in the water bodies, mainly due to the release of long half-life radionuclides from the 238U and 232Th series. The Ore Treatment Unit, an old uranium mine undergoing decommissioning, has three points of liquid effluent release (#014, #025, and #076). For current study, 78 samples of water were collected at #014, 33 samples at #025, and 63 samples at #076. The radionuclides were analyzed by gross alpha count, gross beta count, and by arsenazo spectrophotometry. Analyses were carried out using the radiological water quality criterion established by World Health Organization and other organizations, together with the Brazilian legislation, to assess if the released effluents may be used unrestrictedly by the individuals of the public. At #014, the mean values of activity concentration (AC), in Bq·L-1, were as follows: Unat = 0.107, 226Ra = 0.035, 210Pb = 0.031, 232Th = 0.007, and 228Ra = 0.049. At #025 the mean values of AC, in Bq·L-1, were as follows: Unat = 0.086, 226Ra = 0.015, 210Pb = 0.028, 232Th = 0.006, and 228Ra = 0.032. Finally, at point #076, the mean AC values, in Bq·L-1, were as follows: Unat = 3.624, 226Ra = 0.074, 210Pb = 0.054, 232Th = 0.013, and 228Ra = 0.069. The current study showed that natural radionuclides were not in secular equilibrium. Despite uranium presented its values outside the limits of guidance levels, it can be state that the unrestricted use of effluents released in the three water bodies is authorized from the radiological point of view. In terms of dose rate, the releases at three points were within the radiological limits of potability. On the other hand, in an additional analysis, #76 presented chemical toxicity above the authorized value, pointing the need of restricted use of water from the point of view of chemical toxicity.


Assuntos
Monitoramento de Radiação , Urânio , Humanos , Urânio/análise , Qualidade da Água , Brasil , Chumbo/análise , Radioisótopos/análise
16.
J Environ Radioact ; 261: 107117, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36773551

RESUMO

In this paper an original Monte Carlo code for calculating the mean critical angle of etching of the CR-39 and LR-115 type II solid state nuclear track detectors SSNTD have been developed in order to determine the levels of uranium and thorium contents in a variety of natural material samples. We have also measured these concentrations via others techniques. Results obtained by the current method are more precise than those obtained by detection efficiency and isotope dilution mass spectrometry methods. The dependence of the SSNTDs means critical angles on the initial alpha particle energy and the density of the material have been investigated. A series of equations were used to calculate the mean critical angle of SSNTDs detectors and to estimate the concentrations of uranium and thorium inside studied materials.


Assuntos
Monitoramento de Radiação , Urânio , Tório/análise , Urânio/análise , Marrocos , Monitoramento de Radiação/métodos
17.
Environ Monit Assess ; 195(3): 386, 2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36764975

RESUMO

Potential pollution of mining environmental liabilities' locations can be preliminarily and efficiently assessed by the potential generation of acid mine drainage and indices of contamination. This research evaluates the potential pollution by potentially toxic elements at locations with uranium mining liability evidence, using the net acid generation test and determining the background values to estimate acid mine drainage and indices of contamination. Sixty soil samples were collected, and the mineralogy and potentially toxic elements' total contents were determined by x-ray diffraction and optical spectrometry. The findings suggest that the soils related to a specific lithology might not present potential acid mine drainage generation but potential soil and sediment contamination. Future research is recommended on applying leaching tests to identify which potentially toxic elements are effectively being solubilized. Finally, it can be concluded that the study area's potential contamination is relatively low overall.


Assuntos
Metais Pesados , Poluentes do Solo , Urânio , Urânio/análise , México , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Solo/química , Mineração , Ácidos/análise , Metais Pesados/análise
18.
Environ Technol ; 44(2): 170-184, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34384343

RESUMO

A novel, low-cost adsorbent material was prepared by the immobilization of humic acid on a silica gel surface coated with cross-linked chitosan (SiChiHA). The adsorbent was developed to remove selectively of Th(IV) and U(VI) from aqueous solution, including their pre-concentration and separation from lanthanides and high salinity conditions. A simple waste-less humic acid immobilization method was shown to be successful based on FT-IR, SEM-EDS, and zeta potential characterization results. The adsorbent was found to be stable over a wide pH range, with the highest capacities obtained at pH 3.5 (Th(IV)) and pH 5 (U(VI)). Langmuir model calculations yielded a maximum capacity of 30.6 mg g-1 and 75.4 mg g-1 for Th(IV) and U(VI). The adsorption process was found to be rapid (half concentration was removed within 10 min) and best described by a pseudo-second order rate equation. Increasing NaCl concentration up to 2 mol L-1 or lanthanide concentration up to 100 times did not significantly affect the removal efficiency for either Th(IV) of U(VI). Both elements could be sequentially separated by elution with ammonium citrate and nitric acid, respectively. The adsorption-desorption experiment showed that the adsorbent could be used for at least five cycles without significant capacity loss. This study provides insight into the development of low-cost adsorbent with practical functionality, including separation and regeneration ability, the advantageous properties scarcely reported in low-cost adsorbent literature.


Assuntos
Quitosana , Urânio , Substâncias Húmicas , Urânio/análise , Tório/química , Sílica Gel , Espectroscopia de Infravermelho com Transformada de Fourier , Cinética , Adsorção , Concentração de Íons de Hidrogênio
19.
Environ Geochem Health ; 45(5): 1183-1200, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35711076

RESUMO

Uranium is chemo- and radiotoxic element which can cause multifactorial health hazards. Natural and anthropogenic uranium contamination raises concerns about potential public health problems. Natural contamination plays a significant role with regard to uranium exposure in the general population, whereas anthropogenic contamination leads to occupational uranium exposure, particularly in nuclear industry workers. In this review, we present a state-of-the-art status concerning uranium-induced health risks with a focus on epidemiological findings of uranium processing and enrichment plant workers. We provide a general overview of physicochemical properties of uranium and analytical methods for measuring or monitoring uranium, describe environmental and occupational exposure scenarios, and discuss the challenges for objectively investigating risks from uranium exposure.


Assuntos
Exposição Ocupacional , Urânio , Humanos , Urânio/toxicidade , Urânio/análise
20.
Radiat Prot Dosimetry ; 199(2): 134-145, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36484650

RESUMO

In this study, the results of environmental radioactivity studies conducted in Köprübasi, Manisa district, where Türkiye's uranium mineral exploration and processing studies were carried out, are shared. Because this is a populated area, there is a need for radio ecological dosimetry assessment to investigate the possible risk to the population. The region where radiological monitoring is carried out is discussed in two parts as the areas where uranium mineral exploration is performed and the settlements close to these areas. It was observed that 714-4714 nGy/h values were obtained in the outdoor absorbed dose rate in air measurements taken in the areas where mineral exploration was performed and this value reached up to 22 857 nGy/h in open field mining areas. In the residential areas, it was recorded that the outdoor absorbed dose rate in air values ranged between 142 and 242 nGy/h and the indoor values ranged between 171 and 400 nGy/h. The world absorbed dose rate in air average values is 57 nGy/h (outdoor) and 75 nGy/h (indoor). The high 226Ra values in the radioactivity analyses of the soil samples draw attention. The mean values of the activity concentrations of the radionuclides 226Ra, 232Th and 40K in the soil samples are 3169, 55 and 802 Bq/kg and the world averages of these values are 35, 30 and 400 Bq/kg, respectively. It was determined that high 226Ra value in the soil in the areas close to the open field uranium mining area was passed on to the agricultural products. Radioactivity measurement results of drinking water samples did not exceed World Health Organization guidelines. According to the radon gas measurement results of 44 houses in Köprübasi villages, the average radon concentrations in winter, spring, summer and autumn seasons were 72, 61, 50 and 55 Bq/m3, and the annual average value was 60 Bq/m3, respectively. Although these values are greater than the world average of 46 Bq/m3, they are below the recommended limit value (100 Bq/m3). By evaluating the data obtained, the total annual effective equivalent dose values (originating from outdoor-indoor absorbed dose in air, drinking water and indoor radon gas concentration) to which the people in the region are exposed were calculated as a 3.12 mSv.


Assuntos
Água Potável , Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Radônio , Poluentes Radioativos do Solo , Urânio , Humanos , Tório/análise , Urânio/análise , Rádio (Elemento)/análise , Água Potável/análise , Radônio/análise , Solo , Poluentes Radioativos do Solo/análise , Radioisótopos de Potássio/análise
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