Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
J Radiol Prot ; 43(4)2023 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-38035396

RESUMO

An anonymous web-based survey was developed to check different aspects (SHAMISEN SINGS project): stakeholder awareness and perceptions of available mobile applications (apps) for measuring ionising radiation doses and health/well-being indicators; whether they would be ready to use them in the post-accidental recovery; and what are their preferred methodologies to acquire information etc. The results show that participation of the citizens would be most beneficial during post-accident recovery, providing individual measurements of external ionizing dose and health/well-being parameters, with possible follow-up. Also, participants indicated different preferences for sources to gain knowledge on ionising radiation and for the functions that an ideal app should have. The level of awareness and readiness to use apps to measure ionising radiation dose depended on two main aspects: individual differences (age & gender) and whether people were from countries affected by the previous major accidents. We concluded that stakeholders could have benefits from the data management plan: (1) it potentiates resilience at individual and community level; (2) citizens' measurements contribute to environmental monitoring and public health screening; (3) linkages between different types of data (environmental exposure, individual behavioural diaries, and measurements of health indicators) allow to perform more rigorous epidemiological studies.


Assuntos
Telefone Celular , Aplicativos Móveis , Liberação Nociva de Radioativos , Resiliência Psicológica , Humanos , Exposição Ambiental
2.
Environ Health ; 22(1): 17, 2023 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-36803161

RESUMO

BACKGROUND: The SHAMISEN (Nuclear Emergency Situations - Improvement of Medical And Health Surveillance) European project was conducted in 2015-2017 to review the lessons learned from the experience of past nuclear accidents and develop recommendations for preparedness and health surveillance of populations affected by a nuclear accident. Using a toolkit approach, Tsuda et al. recently published a critical review of the article by Cléro et al. derived from the SHAMISEN project on thyroid cancer screening after nuclear accident. MAIN BODY: We address the main points of criticism of our publication on the SHAMISEN European project. CONCLUSION: We disagree with some of the arguments and criticisms mentioned by Tsuda et al. We continue to support the conclusions and recommendations of the SHAMISEN consortium, including the recommendation not to launch a mass thyroid cancer screening after a nuclear accident, but rather to make it available (with appropriate information counselling) to those who request it.


Assuntos
Acidente Nuclear de Fukushima , Neoplasias da Glândula Tireoide , Humanos , Neoplasias da Glândula Tireoide/epidemiologia , Política de Saúde , Métodos Epidemiológicos
3.
Int J Radiat Biol ; 98(12): 1816-1831, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35976054

RESUMO

BACKGROUND: Reproductive effects of ionizing radiation in organisms have been observed under laboratory and field conditions. Such assessments often rely on associations between exposure and effects, and thus lacking a detailed mechanistic understanding of causality between effects occurring at different levels of biological organization. The Adverse Outcome Pathway (AOP), a conceptual knowledge framework to capture, organize, evaluate and visualize the scientific knowledge of relevant toxicological effects, has the potential to evaluate the causal relationships between molecular, cellular, individual, and population effects. This paper presents the first development of a set of consensus AOPs for reproductive effects of ionizing radiation in wildlife. This work was performed by a group of experts formed during a workshop organized jointly by the Multidisciplinary European Low Dose Initiative (MELODI) and the European Radioecology Alliance (ALLIANCE) associations to present the AOP approach and tools. The work presents a series of taxon-specific case studies that were used to identify relevant empirical evidence, identify common AOP components and propose a set of consensus AOPs that could be organized into an AOP network with broader taxonomic applicability. CONCLUSION: Expert consultation led to the identification of key biological events and description of causal linkages between ionizing radiation, reproductive impairment and reduction in population fitness. The study characterized the knowledge domain of taxon-specific AOPs, identified knowledge gaps pertinent to reproductive-relevant AOP development and reflected on how AOPs could assist applications in radiation (radioecological) research, environmental health assessment, and radiological protection. Future advancement and consolidation of the AOPs is planned to include structured weight of evidence considerations, formalized review and critical assessment of the empirical evidence prior to formal submission and review by the OECD sponsored AOP development program.


Assuntos
Rotas de Resultados Adversos , Proteção Radiológica , Consenso , Medição de Risco , Reprodução
4.
Int J Radiat Biol ; 98(6): 1185-1200, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-32659186

RESUMO

The objective of this paper is to present the results of discussions at a workshop held as part of the International Congress of Radiation Research (Environmental Health stream) in Manchester UK, 2019. The main objective of the workshop was to provide a platform for radioecologists to engage with radiobiologists to address major questions around developing an Ecosystem approach in radioecology and radiation protection of the environment. The aim was to establish a critical framework to guide research that would permit integration of a pan-ecosystem approach into radiation protection guidelines and regulation for the environment. The conclusions were that the interaction between radioecologists and radiobiologists is useful in particular in addressing field versus laboratory issues where there are issues and challenges in designing good field experiments and a need to cross validate field data against laboratory data and vice versa. Other main conclusions were that there is a need to appreciate wider issues in ecology to design good approaches for an ecosystems approach in radioecology and that with the capture of 'Big Data', novel tools such as machine learning can now be applied to help with the complex issues involved in developing an ecosystem approach.


Assuntos
Proteção Radiológica , Ecologia , Ecossistema
5.
PLoS One ; 16(8): e0256667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34428250

RESUMO

Adverse health outcomes of ionizing radiation given chronically at low dose rates are highly debated, a controversy also relevant for other stressors. Increased knowledge is needed for a more comprehensive understanding of the damaging potential of ionizing radiation from all dose rates and doses. There is a lack of relevant low dose rate data that is partly ascribed to the rarity of exposure facilities allowing chronic low dose rate exposures. Using the FIGARO facility, we assessed early (one day post-radiation) and late (recovery time of 100-200 days) hepatic genome-wide transcriptional profiles in male mice of two strains (CBA/CaOlaHsd and C57BL/6NHsd) exposed chronically to a low dose rate (2.5 mGy/h; 1200h, LDR), a mid-dose rate (10 mGy/h; 300h, MDR) and acutely to a high dose rate (100 mGy/h; 30h, HDR) of gamma irradiation, given to an equivalent total dose of 3 Gy. Dose-rate and strain-specific transcriptional responses were identified. Differently modulated transcriptional responses across all dose rate exposure groups were evident by the representation of functional biological pathways. Evidence of changed epigenetic regulation (global DNA methylation) was not detected. A period of recovery markedly reduced the number of differentially expressed genes. Using enrichment analysis to identify the functional significance of the modulated genes, perturbed signaling pathways associated with both cancer and non-cancer effects were observed, such as lipid metabolism and inflammation. These pathways were seen after chronic low dose rate and were not restricted to the acute high dose rate exposure. The transcriptional response induced by chronic low dose rate ionizing radiation suggests contribution to conditions such as cardiovascular diseases. We contribute with novel genome wide transcriptional data highlighting dose-rate-specific radiation responses and emphasize the importance of considering both dose rate, duration of exposure, and variability in susceptibility when assessing risks from ionizing radiation.


Assuntos
Raios gama , Radiação Ionizante , Transcrição Gênica/efeitos dos fármacos , Animais , Metilação de DNA/efeitos da radiação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Estresse Oxidativo/efeitos da radiação , Doses de Radiação
6.
Sci Rep ; 11(1): 4142, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602989

RESUMO

Gamma radiation produces DNA instability and impaired phenotype. Previously, we observed negative effects on phenotype, DNA methylation, and gene expression profiles, in offspring of zebrafish exposed to gamma radiation during gametogenesis. We hypothesize that previously observed effects are accompanied with changes in the expression profile of non-coding RNAs, inherited by next generations. Non-coding RNA expression profile was analysed in F1 offspring (5.5 h post-fertilization) by high-throughput sequencing 1 year after parental irradiation (8.7 mGy/h, 5.2 Gy total dose). Using our previous F1-γ genome-wide gene expression data (GSE98539), hundreds of mRNAs were predicted as targets of differentially expressed (DE) miRNAs, involved in pathways such as insulin receptor, NFkB and PTEN signalling, linking to apoptosis and cancer. snRNAs belonging to the five major spliceosomal snRNAs were down-regulated in the F1-γ group, Indicating transcriptional and post-transcriptional alterations. In addition, DEpiRNA clusters were associated to 9 transposable elements (TEs) (LTR, LINE, and TIR) (p = 0.0024), probable as a response to the activation of these TEs. Moreover, the expression of the lincRNAs malat-1, and several others was altered in the offspring F1, in concordance with previously observed phenotypical alterations. In conclusion, our results demonstrate diverse gamma radiation-induced alterations in the ncRNA profiles of F1 offspring observable 1 year after parental irradiation.


Assuntos
Raios gama/efeitos adversos , RNA não Traduzido/genética , Peixe-Zebra/genética , Animais , Dano ao DNA/genética , Dano ao DNA/efeitos da radiação , Metilação de DNA/genética , Metilação de DNA/efeitos da radiação , Gametogênese/genética , Gametogênese/efeitos da radiação , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação , Transcriptoma/genética , Transcriptoma/efeitos da radiação
7.
Environ Int ; 146: 106278, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271440

RESUMO

This paper, the last in the Special Issue (SI) on the SHAMISEN project, presents an overview of the SHAMISEN Recommendations for Preparedness and Health Surveillance of Populations Affected by a Radiation Accident. The recommendations are based on the lessons learnt from previous nuclear accidents, and the engagement activities with different stakeholder groups, described in the other papers of this SI. The SHAMISEN project developed a total of 28 recommendations. They include general recommendations, applicable across all phases of an accident, and specific recommendations for each of the three main phases: preparedness, early and intermediate, and long-term recovery. The recommendations are subdivided by topic: health surveillance, epidemiological studies, dose reconstruction, evacuation, and training of and communication with health personnel and other actors involved in liaising with affected populations. Each recommendation is divided into 3 sections - why, how and who - thus providing background and concrete advice as to how each SHAMISEN recommendation should be implemented and by whom. It is notable that many recommendations are also applicable to other disaster types, including the current SARS-CoV-2 pandemic.


Assuntos
COVID-19 , Planejamento em Desastres , Desastres , Liberação Nociva de Radioativos , Pessoal de Saúde , Humanos , SARS-CoV-2
8.
Environ Int ; 146: 106230, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33171378

RESUMO

Exposure of the thyroid gland to ionizing radiation at a young age is the main recognized risk factor for differentiated thyroid cancer. After the Chernobyl and Fukushima nuclear accidents, thyroid cancer screening was implemented mainly for children, leading to case over-diagnosis as seen in South Korea after the implementation of opportunistic screening (where subjects are recruited at healthcare sites). The aim of cancer screening is to reduce morbidity and mortality, but screening can also cause negative effects on health (with unnecessary treatment if over-diagnosis) and on quality of life. This paper from the SHAMISEN special issue (Nuclear Emergency Situations - Improvement of Medical And Health Surveillance) presents the principles of cancer screening, the lessons learned from thyroid cancer screening, as well as the knowledge on thyroid cancer incidence after exposure to iodine-131. The SHAMISEN Consortium recommends to envisage systematic health screening after a nuclear accident, only when appropriately justified, i.e. ensuring that screening will do more good than harm. Based on the experience of the Fukushima screening, the consortium does not recommend mass or population-based thyroid cancer screening, as the negative psychological and physical effects are likely to outweigh any possible benefit in affected populations; thyroid health monitoring should however be made available to persons who request it (regardless of whether they are at increased risk or not), accompanied with appropriate information and support.


Assuntos
Acidente Nuclear de Chernobyl , Acidente Nuclear de Fukushima , Neoplasias da Glândula Tireoide , Criança , Detecção Precoce de Câncer , Humanos , Japão , Qualidade de Vida , República da Coreia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/epidemiologia
9.
Int J Radiat Biol ; 96(3): 340-343, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31550178

RESUMO

Purpose: The potential for individual radiosensitivity and radiosusceptibility testing, both in clinical practice and in systems of radiological protection, raises complex ethical considerations which must be addressed both in relation to the scientific research looking at the issues themselves, and in relation to any systems of safety and protection which are then proposed for introduction.Methods: This paper uses ethical principles for radiological protection derived by the ICRP together with other biomedical principles, to identify and evaluate some of the ethical issues associated with radiosensitivity testing.Results and conclusions: Although the evaluation is not exhaustive, it illustrates a range of different ethical aspects that would need to be considered, prior to making recommendations for how the field might better address these challenges in its future development.


Assuntos
Ética Médica , Radioterapia (Especialidade)/ética , Proteção Radiológica/métodos , Tolerância a Radiação , Humanos , Cooperação Internacional , Exposição Ocupacional , Saúde Ocupacional , Exposição à Radiação , Monitoramento de Radiação/ética , Radiação Ionizante , Medição de Risco
10.
Environ Pollut ; 255(Pt 1): 113238, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31655460

RESUMO

The effects of exposure to different levels of ionising radiation were assessed on the genetic, epigenetic and microbiome characteristics of the "hologenome" of earthworms collected at sites within the Chernobyl exclusion zone (CEZ). The earthworms Aporrectodea caliginosa (Savigny, 1826) and Octolasion lacteum (Örley, 1881) were the two species that were most frequently found at visited sites, however, only O. lacteum was present at sufficient number across different exposure levels to enable comparative hologenome analysis. The identification of morphotype O. lacteum as a probable single clade was established using a combination of mitochondrial (cytochrome oxidase I) and nuclear genome (Amplified Fragment Length Polymorphism (AFLP) using MspI loci). No clear site associated differences in population genetic structure was found between populations using the AFLP marker loci. Further, no relationship between ionising radiation exposure levels and the percentage of methylated loci or pattern of distribution of DNA methylation marks was found. Microbiome structure was clearly site dependent, with gut microbiome community structure and diversity being systematically associated with calculated site-specific earthworm dose rates. There was, however, also co-correlation between earthworm dose rates and other soil properties, notably soil pH; a property known to affect soil bacterial community structure. Such co-correlation means that it is not possible to attribute microbiome changes unequivocally to radionuclide exposure. A better understanding of the relationship between radionuclide exposure soil properties and their interactions on bacterial microbiome community response is, therefore, needed to establish whether these the observed microbiome changes are attributed directly to radiation exposure, other soil properties or to an interaction between multiple variables at sites within the CEZ.


Assuntos
Acidente Nuclear de Chernobyl , Microbiota/efeitos da radiação , Oligoquetos/fisiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Bactérias/efeitos dos fármacos , Epigênese Genética , Microbioma Gastrointestinal , Oligoquetos/efeitos dos fármacos , Oligoquetos/microbiologia , Oligoquetos/efeitos da radiação , Exposição à Radiação , Monitoramento de Radiação , Radioisótopos , Solo/química
11.
Sci Total Environ ; 695: 133835, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31425988

RESUMO

The current study investigated life stage, tissue and cell dependent sensitivity to ionizing radiation of the nematode Caenorhabditis elegans. Results showed that irradiation of post mitotic L4 stage larvae induced no significant effects with respect to mortality, morbidity or reproduction at either acute dose ≤6 Gy (1500 mGy·h-1) or chronic exposure ≤15 Gy (≤100 mGy·h-1). In contrast, chronic exposure from the embryo to the L4-young adult stage caused a dose and dose-rate dependent reprotoxicity with 43% reduction in total brood size at 6.7 Gy (108 mGy·h-1). Systematic irradiation of the different developmental stages showed that the most sensitive life stage was L1 to young L4. Exposure during these stages was associated with dose-rate dependent genotoxic effects, resulting in a 1.8 to 2 fold increase in germ cell apoptosis in larvae subjected to 40 or 100 mGy·h-1, respectively. This was accompanied by a dose-rate dependent reduction in the number of spermatids, which was positively correlated to the reprotoxic effect (0.99, PCC). RNAseq analysis of nematodes irradiated from L1 to L4 stage revealed a significant enrichment of differentially expressed genes related to both male and hermaphrodite reproductive processes. Gene network analysis revealed effects related to down-regulation of genes required for spindle formation and sperm meiosis/maturation, including smz-1, smz-2 and htas-1. Furthermore, the expression of a subset of 28 set-17 regulated Major Sperm Proteins (MSP) required for spermatid production was correlated (R2 0.80) to the reduction in reproduction and the number of spermatids. Collectively these observations corroborate the impairment of spermatogenesis as the major cause of gamma radiation induced life-stage dependent reprotoxic effect. Furthermore, the progeny of irradiated nematodes showed significant embryonal DNA damage that was associated with persistent effect on somatic growth. Unexpectedly, these nematodes maintained much of their reproductive capacity in spite of the reduced growth.


Assuntos
Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/efeitos da radiação , Raios gama , Animais , Apoptose , Dano ao DNA , Larva , Radiação Ionizante , Reprodução , Espermatogênese/efeitos da radiação
12.
Environ Pollut ; 251: 469-483, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31103007

RESUMO

The issue of potential long-term or hereditary effects for both humans and wildlife exposed to low doses (or dose rates) of ionising radiation is a major concern. Chronic exposure to ionising radiation, defined as an exposure over a large fraction of the organism's lifespan or even over several generations, can possibly have consequences in the progeny. Recent work has begun to show that epigenetics plays an important role in adaptation of organisms challenged to environmental stimulae. Changes to so-called epigenetic marks such as histone modifications, DNA methylation and non-coding RNAs result in altered transcriptomes and proteomes, without directly changing the DNA sequence. Moreover, some of these environmentally-induced epigenetic changes tend to persist over generations, and thus, epigenetic modifications are regarded as the conduits for environmental influence on the genome. Here, we review the current knowledge of possible involvement of epigenetics in the cascade of responses resulting from environmental exposure to ionising radiation. In addition, from a comparison of lab and field obtained data, we investigate evidence on radiation-induced changes in the epigenome and in particular the total or locus specific levels of DNA methylation. The challenges for future research and possible use of changes as an early warning (biomarker) of radiosensitivity and individual exposure is discussed. Such a biomarker could be used to detect and better understand the mechanisms of toxic action and inter/intra-species susceptibility to radiation within an environmental risk assessment and management context.


Assuntos
Metilação de DNA/efeitos da radiação , Epigênese Genética/efeitos da radiação , Exposição à Radiação/efeitos adversos , Radiação Ionizante , Animais , Animais Selvagens/genética , Ecotoxicologia , Humanos , Medição de Risco
13.
PLoS One ; 14(2): e0212123, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30759148

RESUMO

Ionizing radiation is a recognized genotoxic agent, however, little is known about the role of the functional form of DNA in these processes. Post translational modifications on histone proteins control the organization of chromatin and hence control transcriptional responses that ultimately affect the phenotype. The purpose of this study was to investigate effects on chromatin caused by ionizing radiation in fish. Direct exposure of zebrafish (Danio rerio) embryos to gamma radiation (10.9 mGy/h for 3h) induced hyper-enrichment of H3K4me3 at the genes hnf4a, gmnn and vegfab. A similar relative hyper-enrichment was seen at the hnf4a loci of irradiated Atlantic salmon (Salmo salar) embryos (30 mGy/h for 10 days). At the selected genes in ovaries of adult zebrafish irradiated during gametogenesis (8.7 and 53 mGy/h for 27 days), a reduced enrichment of H3K4me3 was observed, which was correlated with reduced levels of histone H3 was observed. F1 embryos of the exposed parents showed hyper-methylation of H3K4me3, H3K9me3 and H3K27me3 on the same three loci, while these differences were almost negligible in F2 embryos. Our results from three selected loci suggest that ionizing radiation can affect chromatin structure and organization, and that these changes can be detected in F1 offspring, but not in subsequent generations.


Assuntos
Raios gama/efeitos adversos , Loci Gênicos/efeitos da radiação , Código das Histonas/efeitos da radiação , Salmo salar/genética , Peixe-Zebra/genética , Animais , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/efeitos da radiação , Gametogênese/efeitos da radiação , Loci Gênicos/genética , Histonas/química , Histonas/metabolismo , Lisina/metabolismo , Metilação/efeitos da radiação , Salmo salar/embriologia , Salmo salar/fisiologia , Peixe-Zebra/embriologia , Peixe-Zebra/fisiologia
14.
Environ Res ; 168: 211-221, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30317106

RESUMO

The effect of gamma radiation delivered over 24 h on the induction of bystander signals of three earthworm species exposed in vivo was investigated: A. chlorotica, A. caliginosa, and E. tetraedra. Worms were exposed to external gamma irradiation (Co-60 source) for 24 h and samples of head, body, and clitellum were dissected from exposed and control worms and placed in culture medium for 24 h at 19 C. The harvested medium was filtered and assayed for expression of bystander signals using both clonogenic and mitochondrial reporter assays. Different responses were observed in the different species and in the different tissues. A. chlorotica worm-treated reporters show insignificant mitochondrial response for all sections, yet a significant clonogenic reduction in survival for body sections. A. caliginosa worm-treated reporters show a significant mitochondrial response for some sections and insignificant mitochondrial response and insignificant reduction in clonogenic survival for the rest. E. tetraedra worms from a control site show significant evidence of bystander signalling, measured by mitochondrial response in reporter cells, for all sections while those harvested from a contaminated site show insignificant changes in baseline signalling when exposed to the challenge dose. In vivo exposure of earthworm species shows evidence of bystander signalling using two different reporter assays. This effect varied between the different species and tissues. There is also evidence of attenuated bystander signalling in worms harvested from a site contaminated with radiation.


Assuntos
Raios gama , Oligoquetos/efeitos da radiação , Animais , Efeito Espectador , Relação Dose-Resposta à Radiação , Transdução de Sinais
15.
Sci Rep ; 8(1): 15373, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30337673

RESUMO

Ionizing radiation is known to cause DNA damage, yet the mechanisms underlying potential transgenerational effects of exposure have been scarcely studied. Previously, we observed effects in offspring of zebrafish exposed to gamma radiation during gametogenesis. Here, we hypothesize that these effects are accompanied by changes of DNA methylation possibly inherited by subsequent generations. We assessed DNA methylation in F1 embryos (5.5 hours post fertilization) with whole genome bisulfite sequencing following parental exposure to 8.7 mGy/h for 27 days and found 5658 differentially methylated regions (DMRs). DMRs were predominantly located at known regulatory regions, such as gene promoters and enhancers. Pathway analysis indicated the involvement of DMRs related to similar pathways found with gene expression analysis, such as development, apoptosis and cancers, which could be linked to previous observed developmental defects and genomic instability in the offspring. Follow up of 19 F1 DMRs in F2 and F3 embryos revealed persistent effects up to the F3 generation at 5 regions. These results indicate that ionizing radiation related effects in offspring can be linked to DNA methylation changes that partly can persist over generations. Monitoring DNA methylation could serve as a biomarker to provide an indication of ancestral exposures to ionizing radiation.


Assuntos
Metilação de DNA , Embrião não Mamífero/metabolismo , Epigênese Genética/efeitos da radiação , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Radiação Ionizante , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Dano ao DNA , Embrião não Mamífero/citologia , Embrião não Mamífero/efeitos da radiação , Gametogênese , Instabilidade Genômica , Reprodução , Peixe-Zebra/fisiologia
16.
Environ Res ; 162: 318-324, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29407763

RESUMO

This consensus paper presents the results of a workshop held in Essen, Germany in September 2017, called to examine critically the current approach to radiological environmental protection. The meeting brought together participants from the field of low dose radiobiology and those working in radioecology. Both groups have a common aim of identifying radiation exposures and protecting populations and individuals from harmful effects of ionising radiation exposure, but rarely work closely together. A key question in radiobiology is to understand mechanisms triggered by low doses or dose rates, leading to adverse outcomes of individuals while in radioecology a key objective is to recognise when harm is occurring at the level of the ecosystem. The discussion provided a total of six strategic recommendations which would help to address these questions.


Assuntos
Proteção Radiológica , Radiobiologia , Conservação dos Recursos Naturais , Alemanha , Humanos , Doses de Radiação
17.
Environ Mol Mutagen ; 58(8): 560-569, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28856770

RESUMO

Risk estimates for radiation-induced cancer in humans are based on epidemiological data largely drawn from the Japanese atomic bomb survivor studies, which received an acute high dose rate (HDR) ionising radiation. Limited knowledge exists about the effects of chronic low dose rate (LDR) exposure, particularly with respect to the application of the dose and dose rate effectiveness factor. As part of a study to investigate the development of colon cancer following chronic LDR vs. acute HDR radiation, this study presents the results of genotoxic effects in blood of exposed mice. CBAB6 F1 Apc+/+ (wild type) and ApcMin/+ mice were chronically exposed to estimated whole body absorbed doses of 1.7 or 3.2 Gy 60 Co-γ-rays at a LDR (2.2 mGy h-1 ) or acutely exposed to 2.6 Gy HDR X-rays (1.3 Gy min-1 ). Genotoxic endpoints assessed in blood included chromosomal damage (flow cytometry based micronuclei (MN) assay), mutation analyses (Pig-a gene mutation assay), and levels of DNA lesions (Comet assay, single-strand breaks (ssb), alkali labile sites (als), oxidized DNA bases). Ionising radiation (ca. 3 Gy) induced genotoxic effects dependent on the dose rate. Chromosomal aberrations (MN assay) increased 3- and 10-fold after chronic LDR and acute HDR, respectively. Phenotypic mutation frequencies as well as DNA lesions (ssb/als) were modulated after acute HDR but not after chronic LDR. The ApcMin/+ genotype did not influence the outcome in any of the investigated endpoints. The results herein will add to the scant data available on genotoxic effects following chronic LDR of ionising radiation. Environ. Mol. Mutagen. 58:560-569, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.


Assuntos
Sobrevivência Celular/efeitos da radiação , Aberrações Cromossômicas/efeitos da radiação , Dano ao DNA/efeitos da radiação , Neoplasias Induzidas por Radiação/genética , Proteína da Polipose Adenomatosa do Colo/genética , Animais , Relação Dose-Resposta à Radiação , Raios gama , Humanos , Camundongos , Testes para Micronúcleos , Mutação , Neoplasias Induzidas por Radiação/patologia , Raios X
18.
PLoS One ; 12(6): e0179259, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28628668

RESUMO

Ionizing radiation from natural sources or anthropogenic activity has the potential to cause oxidative stress or genetic damage in living organisms, through the ionization and excitation of molecules and the subsequent production of free radicals and reactive oxygen species (ROS). The present work focuses on radiation-induced biological effects using the zebrafish (Danio rerio) vertebrate model. Changes in developmental traits and gene expression in zebrafish were assessed after continuous external gamma irradiation (0.4, 3.9, 15 and 38 mGy/h) with corresponding controls, starting at 2.5 hours post fertilization (hpf) and lasting through embryogenesis and the early larval stage. The lowest dose rate corresponded to recommended benchmarks at which adverse effects are not expected to occur in aquatic ecosystems (2-10 mGy/day). The survival observed at 96 hours post fertilization (hpf) in the 38 mGy/h group was significantly lower, while other groups showed no significant difference compared to controls. The total hatching was significantly lower from controls in the 15 mGy/h group and a delay in hatching onset in the 0.4 mGy/h group was observed. The deformity frequency was significantly increased by prolonged exposure duration at dose rates ≥ 0.4 mGy/h. Molecular responses analyzed by RNA-seq at gastrulation (5.5 hpf transcriptome) indicate that the radiation induced adverse effects occurred during the earliest stages of development. A dose-response relationship was found in the numbers of differentially regulated genes in exposure groups compared to controls at a total dose as low as 1.62 mGy. Ingenuity Pathway Analysis identified retinoic acid receptor activation, apoptosis, and glutathione mediated detoxification signaling as the most affected pathways in the lower dose rate (0.54 mGy/h), while eif2 and mTOR, i.e., involved in the modulation of angiogenesis, were most affected in higher dose rates (5.4 and 10.9 mGy/h). By comparing gene expression data, myc was found to be the most significant upstream regulator, followed by tp53, TNF, hnf4a, TGFb1 and cebpa, while crabp2b and vegfab were identified as most frequent downstream target genes. These genes are associated with various developmental processes. The present findings show that continuous gamma irradiation (≥ 0.54 mGy/h) during early gastrula causes gene expression changes that are linked to developmental defects in zebrafish embryos.


Assuntos
Raios gama , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/genética , Animais , Ecossistema , Embrião não Mamífero/metabolismo , Embrião não Mamífero/efeitos da radiação , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/efeitos da radiação , Perfilação da Expressão Gênica , Larva/genética , Larva/metabolismo , Larva/efeitos da radiação , Reação em Cadeia da Polimerase em Tempo Real , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética
19.
Sci Rep ; 6: 32977, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27596356

RESUMO

Even today, 70 years after Hiroshima and accidents like in Chernobyl and Fukushima, we still have limited knowledge about the health effects of low dose rate (LDR) radiation. Despite their human relevance after occupational and accidental exposure, only few animal studies on the genotoxic effects of chronic LDR radiation have been performed. Selenium (Se) is involved in oxidative stress defence, protecting DNA and other biomolecules from reactive oxygen species (ROS). It is hypothesised that Se deficiency, as it occurs in several parts of the world, may aggravate harmful effects of ROS-inducing stressors such as ionising radiation. We performed a study in the newly established LDR-facility Figaro on the combined effects of Se deprivation and LDR γ exposure in DNA repair knockout mice (Ogg1(-/-)) and control animals (Ogg1(+/-)). Genotoxic effects were seen after continuous radiation (1.4 mGy/h) for 45 days. Chromosomal damage (micronucleus), phenotypic mutations (Pig-a gene mutation of RBC(CD24-)) and DNA lesions (single strand breaks/alkali labile sites) were significantly increased in blood cells of irradiated animals, covering three types of genotoxic activity. This study demonstrates that chronic LDR γ radiation is genotoxic in an exposure scenario realistic for humans, supporting the hypothesis that even LDR γ radiation may induce cancer.


Assuntos
Células Sanguíneas/efeitos da radiação , Dano ao DNA/efeitos da radiação , DNA Glicosilases/fisiologia , Reparo do DNA/efeitos da radiação , Raios gama/efeitos adversos , Animais , DNA Glicosilases/efeitos da radiação , Relação Dose-Resposta à Radiação , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Selênio/deficiência
20.
J Radiol Prot ; 36(2): S64-S81, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27270668

RESUMO

Any activity that might result in exposure of a population to contaminants requires communication of the associated risks. This communication is complicated by several factors including public perceptions, distrust, uncertainties in risk assessment and news media. These factors are especially prominent in communication of risks from ionizing radiation. A number of guidelines about the communication of risks related to radiation exposures have been made by national and international authorities and other stakeholders. The present paper investigates whether those guidelines were followed and evaluates how the radiation risk related information was presented in European newspapers and Russia in the aftermath of the Fukushima accident. It examines the use of measurement units and risk comparisons, the quality of the statements on radiation risk related issues and the use of visual materials in 1340 newspaper articles from Belgium, Italy, Norway, Russia, Slovenia and Spain. Our results indicated several misinterpretations and misrepresentations of radiological risks in the newspaper articles. We also show an inconsistency in the information that was reported with advice provided to risk communicators (e.g. authorities and experts) in the guidelines. The results suggest that risk communicators should improve their communication practices regarding radiological risks, in order to improve emergency management response.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA