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1.
ScientificWorldJournal ; 2021: 9978619, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34949965

RESUMO

The areas around Homa and Ruri hills in Homa Bay County in Kenya are associated with high background radiation levels. The activity concentration of the natural radionuclides (226Ra, 232Th, and 40K) in earthen building materials used in the areas of Homa and Ruri hills has been measured using a NaI (Tl) detector in this work. The measured values of radioactivity concentrations are used to estimate the associated radiological risk. The earthen building material samples from Ruri registered relatively high 232Th concentration values averaging 1094 ± 55 Bq/kg, nearly three times those of the samples from Homa. 226Ra level was not significantly different in both regions with Homa reporting 129 ± 10 Bq/kg and Ruri 111 ± 6 Bq/kg. 40K was however higher in the samples from Homa by an approximate factor of 2 relative to those from Ruri where the activity concentration was 489 ± 24 Bq/kg. The radium equivalents for 226Ra, 232Th, and 40K in the samples from Ruri were 111 ± 9, 1564 ± 125, and 38 ± 3 Bq/kg, while in Homa, the values were 129 ± 10, 570 ± 46, and 69 ± 5 Bq/kg, respectively. The calculated value of total radium equivalent in Ruri was 1713 ± 137 Bq/kg which was two times higher than that of Homa. 232Th contributed about 74% and 91% to the total radium equivalent in Homa and Ruri, respectively; thus, it was the one with the largest contribution to radiation exposure in both regions. The average indoor annual effective dose rates were 1.74 ± 0.14 and 3.78 ± 0.30 mSv/y in Homa and Ruri, respectively, both of which were above the recommended safety limit of 1 mSv/y.


Assuntos
Radiação de Fundo , Materiais de Construção , Poluentes Radioativos/análise , Humanos , Quênia , Poluentes Radioativos/toxicidade , Poluentes Radioativos do Solo/análise , Poluentes Radioativos do Solo/toxicidade , Espectrometria gama
2.
Appl Radiat Isot ; 176: 109881, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34343747

RESUMO

The investigation of radioactivity in samples is an application of gamma-ray spectrometry dealing with low and very low level gamma-ray activities of different isotopes. Gamma-ray spectrometry performed in the framework of radiological environmental monitoring may be done after selective sampling processes or after a chemical purification of a sample. Both cases imply that only some specific radionuclides should contribute to the obtained spectrum. Gamma-ray spectrometry performed with medium energy resolution detectors may allow the possible distinction of their photopeaks. Therefore, a cerium bromide (CeBr3) detector can be particularly attractive for routine tasks in radiological environmental monitoring as it has a high efficiency, medium energy resolution and it can work at room temperature. This study describes the conditions under which a CeBr3 detector can serve for some routine analysis in radiological analysis of samples collected in the environment or collected by air-samplers in environmental radiological monitoring programmes.


Assuntos
Radioisótopos de Césio/análise , Monitoramento Ambiental/métodos , Poluentes Radioativos/análise , Contagem de Cintilação/instrumentação , Calibragem , Limite de Detecção , Radioisótopos/análise , Reprodutibilidade dos Testes , Espectrometria gama/métodos
3.
Toxicol In Vitro ; 73: 105149, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33753177

RESUMO

In the situation of radiation triage, accidental exposure to uranium, or uranium contamination in food or water; haematopoietic decline or bone marrow sickness is observed in the aftermath followed by other systemic effects. Most studies done previously have been on cytogenetic analysis in blood lymphocytes of uranium miners wherein causal relationship was difficult to be established. This study provides new insights into the minimum risk level of uranium to human lymphocytes, DNA damage induced and alterations in the cell cycle progression through 96-h acute toxicity study. Cytotoxicity studies by MTT assay and flow cytometry showed that uranyl nitrate concentration of 1280 µM lead to 50% cell death, 640 µM caused 25% death, 250 µM caused 10% cell death and 5 µM was the NOAEL. Uranium caused DNA damages in a dose dependent manner as evident from comet and CBMN assays. A marked increase in G2/M phase cells was observed in the test culture groups. Halting of cell cycle at G2/M checkpoint also signified the extent of double strand breaks and genetic instability with increasing uranium dose in this study. Better cell cycle responses and lower genetic damage index observed in lower dosage of exposure, suggests adaptability and repair responses in human lymphocytes. Together these results advance our understanding of uranium effects on mammalian cells.


Assuntos
Linfócitos/efeitos dos fármacos , Poluentes Radioativos/toxicidade , Nitrato de Uranil/toxicidade , Ciclo Celular/efeitos dos fármacos , Células Cultivadas , Ensaio Cometa , Dano ao DNA , Instabilidade Genômica/efeitos dos fármacos , Humanos , Testes para Micronúcleos , Testes de Toxicidade Aguda , Urânio
4.
Health Phys ; 120(1): 1-8, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32826521

RESUMO

Effluents containing tritium (H) dispersed into the fresh water or marine environment from nuclear facilities can be taken up by biota. Aquatic and marine organisms are among the important pathways through which tritium can enter into the human body, and hence, assessment of the extent of pollution of these ecosystems is very important for radiation dose assessments. Tritium present in environmental matrices can be classified as tissue-free water tritium (TFWT) and organically bound tritium (OBT). Optimization of a method for the determination of OBT in fish, based on thermal oxidation of the sample, is discussed. Samples were subjected to thermal oxidation in a pyrolyser system, and the water produced from the combustion was analyzed by liquid scintillation spectrometry. Results show that a maximum of ~2 g of processed fish sample can be combusted efficiently in the pyrolyser. Using this method, a recovery of 84% was achieved, and minimum detectable activity (MDA) for the method was determined to be 8.5 Bq kg (sample weight = 2 g, counting time = 30,000 s, and detection efficiency = 20%).


Assuntos
Peixes , Contaminação Radioativa de Alimentos/análise , Poluentes Radioativos/análise , Trítio/análise , Animais , Ecossistema , Peixes/metabolismo , Humanos , Índia , Centrais Nucleares , Compostos Orgânicos/química , Oxirredução , Pirólise , Monitoramento de Radiação/métodos , Radiometria/métodos , Contagem de Cintilação , Poluentes Radioativos da Água/análise
5.
Appl Radiat Isot ; 168: 109548, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33310505

RESUMO

Alpha spectrometry is one of the greatest nuclear techniques for identification and quantification of α-emitters in the environment due to nuclear fuel cycle operations, nuclear materials and geochemical studies or forensic medicine investigations. This study was conducted to re-evaluate and optimize the factors affecting the performance of a multi-chamber alpha spectrometer (EG&G Ortec) used in our laboratory using an aged α-source of 232U in equilibrium with its decay products. The results shown that the energy calibration within energy window 4-9 MeV has been done using alpha particle emissions of 232U (t1/2.70.6 y) and its decay products with good linear fitting (R2 > 0.999). At a source to detector spacing of 10 mm, the efficiency of the detectors varied between 15 and 20%; while the better resolution (FWHM) was ~36 keV. These values are lower than those warranted when supplied before 20 years. The minimum detectable activity (MDA) of the detectors varies between 0.8 and 3.1 mBq for the chamber in use. The alpha spectrometer was also verified by certified reference samples to measure activity concentration of alpha emitters (e.g., 238U, 232Th, 226Ra and 241Am) with acceptable coefficient of variance (<10%), ζ-score (<3) and P-test (<25%). As a result, the optimized alpha spectrometer is valid and can be utilized for monitoring and assessment of natural and artificial α-emitters in different environmental compartments.


Assuntos
Partículas alfa , Radiação de Fundo , Meio Ambiente , Poluentes Radioativos/análise , Radiometria/métodos , Calibragem , Limite de Detecção , Radiometria/normas
6.
Appl Radiat Isot ; 168: 109489, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33288398

RESUMO

Alpha-particle spectrometry, gamma spectrometry and neutron activation analysis techniques for determination of Th and U in environmental samples have been compared. The analytical parameters studied include detection limit, accuracy, repeatability, reproducibility and surrogate recovery. The results show that neutron activation analysis technique has the best accuracy among the studied techniques; the other two techniques were assessed relative to it. The percentage difference between the three techniques results is about [-20, 20]. In addition, U and Th concentrations are generally overestimated by gamma spectrometry and alpha-particle spectrometry in all cases except Th concentration in the former technique, which is underestimated.


Assuntos
Partículas alfa , Análise de Ativação de Nêutrons/métodos , Poluentes Radioativos/análise , Espectrometria gama/métodos , Tório/análise , Urânio/análise , Limite de Detecção , Monitoramento de Radiação/métodos , Radiometria/métodos , Reprodutibilidade dos Testes , Síria
7.
J Environ Radioact ; 222: 106297, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32739734

RESUMO

An underground nuclear explosion (UNE) generates radioactive gases that can be transported through fractures to the ground surface over timescales of hours to months. If detected, the presence of particular short-lived radionuclides in the gas can provide strong evidence that a recent UNE has occurred. By drawing comparisons between sixteen similar historical U.S. UNEs where radioactive gas was or was not detected, we identified factors that control the occurrence and timing of breakthrough at the ground surface. The factors that we evaluated include the post-test atmospheric conditions, local geology, and surface geology at the UNE sites. The UNEs, all located on Pahute Mesa on the Nevada National Security Site (NNSS), had the same announced yield range (20-150 kt), similar burial depths in the unsaturated zone, and were designed and performed by the same organization during the mid-to-late 1980s. Results of the analysis indicate that breakthrough at the ground surface is largely controlled by a combination of the post-UNE barometric pressure changes in the months following the UNE, and the volume of air-filled pore space above the UNE. Conceptually simplified numerical models of each of the 16 historical UNEs that include these factors successfully predict the occurrence (5 of the UNEs) or lack of occurrence (remaining 11 UNEs) of post-UNE gas seepage to the ground surface. However, the data analysis and modeling indicates that estimates of the meteorological conditions and of the post-UNE, site-specific subsurface environment including air-filled porosity, in combination, may be necessary to successfully predict late-time detectable gas breakthrough for a suspected UNE site.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos , Monitoramento Ambiental , Gases , Geologia , Nevada , Radioisótopos
8.
Sci Data ; 7(1): 282, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32859938

RESUMO

The 2011 accident at Japan's Fukushima Daiichi Nuclear Power Plant released a considerable inventory of radioactive material into the local and global environments. While the vast majority of this contamination was in the form of gaseous and aerosol species, of which a large component was distributed out over the neighbouring Pacific Ocean (where it was subsequently deposited), a substantial portion of the radioactive release was in particulate form and was deposited across Fukushima Prefecture. To provide an underpinning understanding of the dynamics of this catastrophic accident, alongside assisting in the off-site remediation and eventual reactor decommissioning activities, the 'International Particle Analysis Database', or 'IPAD', was established to serve as an interactive repository for the continually expanding analysis dataset of the sub-mm ejecta particulate. In addition to a fully interrogatable database of analysis results for registered users (exploiting multiple search methods), the database also comprises an open-access front-end for members of the public to engage with the multi-national analysis activities by exploring a streamlined version of the data.


Assuntos
Acidente Nuclear de Fukushima , Poluentes Radioativos/análise , Japão , Oceano Pacífico
9.
Sci Rep ; 10(1): 10655, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32606447

RESUMO

In the beginning of April 2020, large fires that started in the Chernobyl Exclusion Zone (CEZ) established after the Chernobyl accident in 1986 caused media and public concerns about the health impact from the resuspended radioactivity. In this paper, the emissions of previously deposited radionuclides from these fires are assessed and their dispersion and impact on the population is examined relying on the most recent data on radioactive contamination and emission factors combined with satellite observations. About 341 GBq of 137Cs, 51 GBq of 90Sr, 2 GBq of 238Pu, 33 MBq of 239Pu, 66 MBq of 240Pu and 504 MBq of 241Am were released in 1st-22nd April 2020 or about 1,000,000,000 times lower than the original accident in 1986 and mostly distributed in Central and East Europe. The large size of biomass burning particles carrying radionuclides prevents long-range transport as confirmed by concentrations reported in Europe. The highest cumulative effective doses (> 15 µSv) were calculated for firefighters and the population living in the CEZ, while doses were much lower in Kiev (2-5 µSv) and negligible in Belarus, Russia and Europe. All doses are radiologically insignificant and no health impact on the European population is expected from the April 2020 fires.


Assuntos
Poluentes Radioativos/efeitos adversos , Acidente Nuclear de Chernobyl , Europa (Continente) , Humanos , Monitoramento de Radiação/métodos , Federação Russa , Incêndios Florestais
10.
Environ Geochem Health ; 42(12): 4385-4398, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32430800

RESUMO

The direct estimation of the value of the diffusion component of mass transfer of pollutants in arable soil horizons is an important task of scientific and applied importance. The values of effective diffusion coefficients of 60Co radionuclide (Deff) in water-saturated samples of different soils with disturbed structure and the same initial bulk density were obtained during the laboratory experiment. Of particular interest is the assessment of the contribution of individual specific characteristics of soils that have undergone the gleying process to the regulation of Deff60Co.There was noted a significant variability of Deff60Co for investigated soils due to different soil characteristics. To assess this, influence a statistical approach has been used, where edaphic factors representing the most important characteristics of the soils acted as independent variables (predictors), and the dependent (resulting) variable was Deff60Co. The contributions of each of the selected indicators of soils state (independent variables) in varying of Deff60Co were also identified. During the experiments, there was revealed a particularly strong increase in the Deff60Co for soils with a high Eh, ΣFr.<0.01 mm and decrease in the absolute value of the dependent variable with two predictors: pHH2O and P2O5mobile in conditions of excessive moisture. Based on the study of the dependence between the main physicochemical soil properties and the magnitude of effective diffusion coefficients (Deff60Co), the selected physicochemical characteristics of soils were ranked by the degree of influence on the value of the dependent variable: pHH2O > Eh > ΣFr.<0.01 mm > P2O5mobile > Corg.At the same time, the multiple linear regression analysis of the obtained data showed statistical significance for two independent predictors of the model (pHH2O and ΣFr.<0.01 mm). As a result, semi-partial determination coefficients responsible for the share of the total variation of the dependent variable due to the statistically significant corresponding independent variables (pHH2O and ΣFr.<0.01 mm) were calculated based on the data presented.


Assuntos
Radioisótopos de Cobalto/farmacocinética , Poluentes Radioativos/farmacocinética , Solo/química , Difusão
11.
Health Phys ; 119(2): 261-265, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32332420

RESUMO

INTRODUCTION: Following critiques of multiple personal contamination events from entries into the Oak Ridge National Laboratory's Spallation Neutron Source Transfer Bay, it was considered that the most likely causes for contamination were personal protective clothing doffing errors or moisture (sweat) allowing contamination to wick through the protective clothing. Radiological protection staff looked more closely, however, at the specific area of the clothing where contamination was highest; under enhanced lighting and photochromic manipulation, there appeared to have been some type of moisture in the area. Recognizing the possibility that moisture may have allowed for migration of contamination through the clothing, further experiments were undertaken to determine under which conditions this transport might have occurred. OBJECTIVE: The objective for this work was to identify the susceptibility of different types of personal protective clothing to various liquids encountered in the workplace. METHOD: Several tests were performed to determine if perspiration had enabled migration of contamination and to identify what other liquids might have affected contamination transport. Two layers of personal protective clothing were subjected to static conditions and dynamic conditions to include active rubbing of the materials while wet. Food dye added to each of the liquids tested enabled visual indications of liquid breakthrough. Additional tests were conducted to see if solid contamination could be transported through the materials along with the liquids. RESULTS: All but one type of non-rubberized personal protective clothing in use at Oak Ridge National Laboratory were permanently compromised to some extent by the solvents used for decontamination. CONCLUSION: It was determined that most common cleaning agents immediately and permanently destroyed the hydrophobic nature of several of the tested protective clothing materials, potentially allowing for radioactive contamination to penetrate through the material to the worker. Work around wet surfaces or performing wet decontamination will only be performed in protective clothing known to prevent transport of the wetting agent.


Assuntos
Roupa de Proteção , Corantes/química , Dependência de Alimentos , Pessoal de Saúde , Humanos , Exposição Ocupacional , Equipamento de Proteção Individual , Exposição à Radiação , Poluentes Radioativos/química , Solventes/química
12.
Health Phys ; 119(1): 2-11, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32205714

RESUMO

Following large-scale nuclear power plant accidents such as those that occurred at Chernobyl (Ukraine) in 1986 and Fukushima Daiichi (Japan) in 2011, large populations are living in areas containing residual amounts of radioactivity. As a key session of the ConRad conference, experts were invited from different disciplines to provide state-of-the-art information on the topic of "living in contaminated areas." These experts provided their different perspectives on a range of topics including radiation protection principles and dose criteria, environmental measurements and dose estimation, maintaining decent living and working conditions, evidence of health risks, and social impact and risk communication. A short summary of these different perspectives is provided in this paper.


Assuntos
Poluentes Radioativos/química , Acidente Nuclear de Chernobyl , Acidente Nuclear de Fukushima , Humanos , Japão , Centrais Nucleares , Doses de Radiação , Exposição à Radiação , Monitoramento de Radiação , Proteção Radiológica , República de Belarus , Gestão de Riscos , Ucrânia
13.
Chemosphere ; 248: 126007, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32028159

RESUMO

Soluble and insoluble radioactive cesium in municipal solid waste incineration fly ash were analyzed by X-ray diffraction and gamma-ray spectrometry. A total of 60% of soluble radioactive cesium was determined using the Tessier extraction method, and it was almost same extraction rate with Japanese leaching test No.13. In addition, chloride compounds such as halite (NaCl) and sylvite (KCl) showed same behavior with soluble radioactive cesium, therefore, soluble radioactive cesium existed as a chloride (CsCl) with water solubility characteristics. Almost insoluble radioactive cesium trapped into silicate of crystalline phase or amorphous phase was eluted by hydrogen fluoride treatment. Radioactive 137Cs was released in three stages by heating treatment (untreated - 400 °C, 600 °C-800 °C, and 800 °C-1000 °C) according to decreasing amorphous content. The relationship between the concentrations of radioactive 137Cs and amorphous phase exhibited good linearity (R = 0.9278). Insoluble radioactive 137Cs was contained in inner part of the amorphous phase, and free radioactive cesium was determined from the concentration of the amorphous phase.


Assuntos
Radioisótopos de Césio/análise , Incineração , Monitoramento de Radiação , Poluentes Radioativos/análise , Carbono , Césio/química , Cloretos , Cinza de Carvão/química , Metais Pesados/análise , Radioatividade , Eliminação de Resíduos/métodos , Silicatos , Resíduos Sólidos/análise , Difração de Raios X
14.
J Radiol Prot ; 40(2): 444-464, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32018239

RESUMO

Internal dose assessment intercomparison exercises are useful tools: to verify the performance of an internal dosimetry service; to promote the harmonisation of dose assessments; and to identify weaknesses where further improvements are necessary. However, no such international intercomparisons have been performed for more than ten years. In the period May 2014-May 2016, the 'Technical Recommendations for Monitoring Individuals for Occupational Intakes of Radionuclides' were developed on the initiative of the European Commission, and later published within the EC Radiation Protection series, as RP188. In 2017 the Working Group 'Internal Dosimetry' of the European Radiation Dosimetry Group (EURADOS) organised a new intercomparison action, named ICIDOSE 2017, with the main aim of testing the practical applicability of these technical recommendations (RP188). Four case studies were proposed to participants: an artificially created case of inhalation of 60Co to simulate a simple special monitoring case; a real case of inhalation of 125I, with simple routine monitoring; a real and more complex case of incorporation of 234+235+238U, featuring both confirmatory and special monitoring; and a complex real case of an accidental incorporation of 241Am, including multiple administrations of diethylenetriamine pentaacetic acid (DTPA). Results were received from 66 participants from 26 countries; these were compared to reference or recommended solutions, developed for each case based on the application of RP188. In cases 1, 2 and 4 only a small number of results were identified as outliers, with the spread of all the results, expressed as the geometric standard deviation (GSD) of the values, assessed as 1.07, 1.04 and 1.43, respectively. This observed spread of the submitted results was improved from those obtained from similar cases in previous intercomparison exercises, showing that the availability of RP188 contributes to the harmonisation of the internal dose assessment process. There was a much wider spread of results for the uranium case: this case was characterised by an absence of any prior knowledge of the exposure scenario, and participants assumed a range of different exposure pathways and patterns.


Assuntos
Internacionalidade , Exposição Ocupacional/análise , Doses de Radiação , Poluentes Radioativos/análise , Radioisótopos/análise , Radiometria/métodos , Poluentes Radioativos do Ar/análise , Humanos
16.
Chemosphere ; 241: 125019, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31610456

RESUMO

The abundance and distribution of highly radioactive cesium-rich microparticles (CsMPs) that were released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) during the first stage of the nuclear disaster in March 2011 are described for 20 surface soils collected around the FDNPP. Based on the spatial distribution of the numbers (particles/g) and radioactive fraction (RF) of the CsMPs in surface soil, which is defined as the sum of the CsMP radioactivity (in Bq) divided by the total radioactivity (in Bq) of the soil sample, three regions of particular interest have been identified: i.) near-northwest (N-NW), ii.) far-northwest (F-NW), and iii.) southwest (SW). In these areas, the number and RF of CsMPs were determined to be 22.1-101 particles/g and 15.4-34.0%, 24.3-64.8 particles/g and 36.7-37.4%, and 0.869-8.00 particles/g and 27.6-80.2%, respectively. These distributions are consistent with the plume trajectories of material released from the FDNPP on March 14, 2011, in the late afternoon through to the late afternoon of March 15, 2011, indicating that the CsMPs formed only during this short period. Unit 3 is the most plausible source of the CsMPs at the beginning of the release based on an analysis of the sequence of release events. The lower RF values in the N-NW region indicate a larger influence from subsequent plumes that mainly consisted of soluble Cs species formed simultaneously with precipitation. The quantitative map of the distribution of CsMPs provides an important understanding of CsMP dispersion dynamics and can be used to assess risks in inhabited regions.


Assuntos
Radioisótopos de Césio/análise , Acidente Nuclear de Fukushima , Centrais Nucleares , Material Particulado/análise , Poluentes Radioativos/análise , Japão , Tamanho da Partícula , Monitoramento de Radiação , Radioatividade , Solo/química
17.
Environ Pollut ; 257: 113607, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31767232

RESUMO

The variability of nine microsatellite loci was studied for Plantago major L. populations from radioactive (East-Ural Radioactive Trace, EURT) and chemical (Karabash Copper Smelter, KCS) contaminated areas (Urals, Russia). The absorbed dose rates in the EURT area were 178-1455 times higher than background, and the indices of the total toxic load in the KCS area were 13-42 times higher than background values. In total, 65 alleles were identified in P. major populations, while the number of alleles per locus in the EURT and KCS samples was lower than in the background samples. The expected heterozygosity in all loci significantly exceeded the observed, indicating a high level of inbreeding. The largest number of rare alleles (11-21) was found in background samples, of which 3-7 alleles were private. In the technogenically disturbed zones, 8-11 rare alleles (1-2 private) were noted. The Bayesian analysis (K = 3) showed that no unique groups were found in any of the areas; descendants of all founders (pioneers) were represented in each population, but in different proportions. However, only 4.1% of the variability was distributed between local P. major populations (FST = 0.041) and 95.9% was concentrated within the samples. A pairwise comparison revealed genetic differentiation between all EURT samples. In the KCS area, there was no significant differentiation in pairs of samples that were at a distance of 3-4 km from each other. For samples from the KCS and background sites, the Mantel test showed a statistically significant relationship between geographical and genetic distances, therefore, the intensity of migration flows between these areas is high. For samples from the EURT and background areas, no such dependence was found. In both impact zones, P. major populations showed reduced genetic diversity. This article discusses the causes of this phenomenon.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais , Plantago/genética , Poluentes Radioativos , Teorema de Bayes , Variação Genética , Repetições de Microssatélites , Polimorfismo Genético , Federação Russa
18.
J Radiol Prot ; 40(2): 487-504, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31829987

RESUMO

Legacy sites are a global issue. Experience has shown that every legacy site is different and case-specific management and remediation options have to be considered. Each site presents a unique mix of physical, chemical and radiological hazards and the significance of those hazards is likely to change over time. A life-cycle approach to remediation is therefore appropriate, with priority consideration allocated according to the major hazards, as technically determined by reference to policy on protection objectives and the corresponding regulatory requirements. Additionally, consideration will typically need to be given to wider issues as may be raised by stakeholders. The remediation approach also needs to take account of the waste management options on-site or involving off-site management and disposal. Radiological and wider environmental impact assessments are a crucial part of the holistic evaluation of hazards and risks (along with economic and societal impacts), which in turn underpin project planning, regulatory and wider decision making. This paper examines the role of radioecology in the assessment process, its contribution to reduction of scientific uncertainties in modelling ecosystem processes of release, transport and fate of radionuclides and evaluation of potential ensuing impacts on humans and the environment. Relevant examples are presented to illustrate the complexities of the processes in regulatory decision making, the various conditions that significantly affect the final solutions and how radioecology can be used in these situations. Whilst a case-specific approach will usually need to be taken to legacy sites, future remediation and clean-up work can be helpfully informed through sharing of experience from other sites. Continued international collaboration between all parties involved in legacy site management is therefore needed to inform on the development of practical regulatory guidance and to ensure that radioecological research is focussed on addressing the key issues that give rise to uncertainties that challenge regulatory and wider decision making.


Assuntos
Recuperação e Remediação Ambiental , Poluentes Radioativos , Gerenciamento de Resíduos/métodos , Ecossistema , Exposição Ambiental , Humanos , Internacionalidade , Monitoramento de Radiação , Medição de Risco
20.
Chemosphere ; 241: 124964, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31604195

RESUMO

Around former glass factories in south eastern Sweden, there are dozens of dumps whose radioactivity and physico-chemical properties were not investigated previously. Thus, radiometric and physico-chemical characteristics of waste at Madesjö glass dump were studied to evaluate pre-recycling storage requirements and potential radiological and environmental risks. The material was sieved, hand-sorted, leached and scanned with X-Ray Fluorescence (XRF). External dose rates and activity concentrations of Naturally Occurring Radioactive Materials from 238U, 232Th series and 40K were also measured coupled with a radiological risk assessment. Results showed that the waste was 95% glass and dominated by fine fractions (<11.3 mm) at 43.6%. The fine fraction had pH 7.8, 2.6% moisture content, 123 mg kg-1 Total Dissolved Solids, 37.2 mg kg-1 Dissolved Organic Carbon and 10.5 mg kg-1 fluorides. Compared with Swedish EPA guidelines, the elements As, Cd, Pb and Zn were in hazardous concentrations while Pb leached more than the limits for inert and non-hazardous wastes. With 40K activity concentration up to 3000 Bq kg-1, enhanced external dose rates of 40K were established (0.20 µSv h-1) although no radiological risk was found since both External Hazard Index (Hex) and Gamma Index (Iγ) were <1. The glass dump needs remediation and storage of the waste materials under a safe hazardous waste class 'Bank Account' storage cell as a secondary resource for potential future recycling.


Assuntos
Fenômenos Químicos , Vidro/análise , Poluentes Radioativos/análise , Resíduos Radioativos/análise , Resíduos/análise , Resíduos Perigosos , Radioisótopos de Potássio/análise , Reciclagem , Espectrometria por Raios X , Suécia , Tório/análise , Urânio/análise
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