EMN for radiation protection - an evolving European metrology network

The European Council DIRECTIVE 2013/59/EURATOM laying down the basic safety standards for protection against the dangers arising from exposure to ionizing radiation is currently the main European regulation on ionizing radiation. The practical implementation of the European basic safety standards has become more complex due to the lack of consideration of the metrological implications and the adaptation to new technological developments, which lead to new standards, technological innovations, and improved capabilities. It was considered by EURAMET to be of a vital importance to have a metrology network that acts as a focal point between the metrology communities and the relevant radiation protection stakeholders, including regulators, standardization bodies, manufacturers, users of radiation sources and international organizations and radiation protection platforms. One of the most important tasks of this European Metrology Network (EMN) for Radiation Protection is to give a strong voice to the field of radiation protection metrology in Europe, so that it can provide responsible guidance and support to future technological developments. Additionally, metrological competence and capacity are essential to determine ambient or occupational exposures and urgent metrological needs exist in case of emergency situations. The EMN for Radiation Protection is in operation since 2021. The first Chair, Annette Röttger (PTB, Germany), Vice-Chair, Teemu Siiskonen (STUK, Finland) and Secretary Behnam Khanbabaee (PTB, Germany) have been elected. At the second meeting in 2022, first actions have been identified. In this contribution, the planned actions and next steps will be presented.ERPW 2022 - European Radiation Protection Week, 9-14th October 2022, Estoril, Portuga

Low Clinical Burden of 2009 Pandemic Influenza A (H1N1) Infection during Pregnancy on the Island of La Réunion

BACKGROUND: Pregnant women have been identified as a group at risk, both for respiratory complications than for the admissions to the Intensive Care Unit (ICU) during the 2009 H1N1 influenza pandemic (pdm). The purpose of this prospective register-based cohort-study was to characterize the clinical virulence of the pdm (H1N1/09)v during pregnancy in La Réunion. METHODS/PRINCIPAL FINDINGS: Over a twelve-week pdm wave (13 July to 3 October 2009), 294 pregnant women presented with an influenza-like illness (ILI) to one of the three maternity departments of the South Reunion area, Indian Ocean. Out of these, 278 were checked by RT-PCR for influenza viruses (157 positive and 121 negative, of whom, 141 with pdm flu and 132 with ILIs of non pdm origin, 5 untyped). The median body temperature was higher in women experiencing pdm flu than in those with non pdm ILI (38.9 degrees C versus 38.3 degrees C, P<0.0001), without evidence linked to circulating viremia. Oseltamivir was given for 86% of pdm flu cases in a median time inferior than 48 hrs (range 0-7 days). The hospitalization rate for pdm flu was of 60% and not associated with underlying conditions. Six viral pneumonia and fourteen asthma attacks were observed among 84 hospitalized pdm flu cases, of whom, only one led to the ICU for an acute lung injury. No maternal death occurred during the pdm wave. None adverse pregnancy outcome was associated with pdm flu. No congenital birth defect, nor early-onset neonatal influenza infection was attributable to pdm flu exposure. CONCLUSIONS/SIGNIFICANCE: This report mitigates substantially the presumed severity of pandemic H1N1/09 influenza infection during pregnancy. The reasons for which the clinical burden of H1N1/09 influenza virus may differ worldwide raise questions about a differential local viral-strain effect and public health preparedness, notably in timely access to special care and antiviral treatments

Establishing relationships between environmental exposures to radionuclides and the consequences for wildlife inferences and weight of evidence

International audienceEcological risk assessments for radioactive substances are based on a number of inference rules to compensate for knowledge gaps, and generally require the implementation of a weight-of-evidence approach. Until recently, dose (rate)–response relationships used to derive radioprotection criteria for wildlife have mainly relied on laboratory studies from a limited number of species as representatives of biodiversity. There is no doubt that additional knowledge, combined with advanced conceptual and mathematical approaches, is needed to develop general rules and increase confidence when extrapolating from test species to complex biological/ecological systems. Moreover, field data sets based on robust sampling strategies are still needed to validate benchmark values derived from controlled laboratory tests, and to indicate potential indirect ecological effects, if any. This paper illustrates, through several examples, the need for implementing a combined laboratory–field-model approach to obtain science-based benchmark doses (or dose rates) (e.g. screening benchmarks for ecological risk assessments or derived consideration reference levels), based on robust meta-analysis of dose–effect relationships covering ecologically relevant exposure time scales, species, and endpoints. © The International Society for Prosthetics and Orthotics Reprints and permissions sagepub.co.uk/journalsPermissions.na

From molecules to phenotype: mechanisms involved in stress, sociability and hypolocomotion after chronic gamma radiation in adult zebrafish

International audienc

Selenate bioaccumulation and toxicity in Chlamydomonas reinhardtii: Influence of ambient sulphate ion concentration

International audienceThe aim of the present study was to investigate selenate toxicity in the unicellular green algae Chlamydomonas reinhardtii as a function of sulphate ion concentration and the relationship with intracellular bioaccumulation. The toxicity of selenate was evaluated by measuring the effect of different selenate concentrations on algal growth during a 96 h exposure period. A non-linear regression according to the Hill model was used to describe the dose-effect relationship and estimate the effect concentrations (EC) of selenate. EC50 values of 0.40 [0.24-0.52] μmol L-1 and of 3.10 [1.65-4.86] μmol L-1 of ambient selenate were obtained, at 8 and 80 μmol L-1 of sulphate ions in the medium, respectively. For non-toxic and low-level ambient selenate concentrations, bioaccumulation in presence of 80 μmol L-1 was one tenth that of 8 μmol L-1 of sulphate ions. When expressed as intracellular selenium burden, EC50 values determined at 8 and 80 μmol L-1 of sulphate ions were not significantly different (126 and 67 nmol Se·109 cells-1, respectively). In conclusion, toxicity appeared to be correlated to selenate bioaccumulation which suggests that toxicity must be linked to intracellular selenium accumulation that is directly dependent on ambient sulphate ions that may compete with selenate for transport sites. © 2009 Elsevier B.V. All rights reserved

Comparative genotoxicity of aluminium and cadmium in embryonic zebrafish cells

International audienceAluminium is a toxic metal whose genotoxicity has been scarcely studied in aquatic species and more generally in mammals. Recently, human and ecological disaster caused by the discharge of red mud in Hungary has revived questions about the toxicity of this metal particularly for the environment. On the contrary, cadmium is a highly toxic metal whose genotoxicity has been well characterized in various mammalian cells. However on non-human cells, little is known about its impact on DNA damage and repair.In this study, the genotoxic potential of both metals on embryonic zebrafish cells ZF4 was analyzed and particularly the impairment of the major DNA double strand breaks (DSB)-repair pathway, i.e. non-homologous end-joining (NHEJ).To this aim, DNA single strand breaks (SSB) and DSB were evaluated using the comet assay and the immunodetection of γ-H2AX proteins, respectively, in AlCl3 or CdCl2 exposed ZF4 cells. These exposures result in the production of DSBs a few hours after incubation. The DNA-PK kinase activity, essential for NHEJ, is more affected by the presence of aluminium than cadmium. Altogether our data provide evidence of the high toxicity induced by aluminium in zebrafish and indicates the pertinence of genotoxicity evaluation in organisms living in contaminated water. © 2012 Elsevier B.V

More than thirty years after the Chernobyl accident: what do we know about the effects of radiation on the environment?

Editorial

DNA alterations and effects on growth and reproduction in Daphnia magna during chronic exposure to gamma radiation over three successive generations

International audienceThis study examined chronic effects of external Cs-137 gamma radiation on Daphnia magna exposed over three successive generations (F0, F1 and F2) to environmentally relevant dose rates (ranging from 0.007 to 35.4mGyh-1). Investigated endpoints included survival, growth, reproduction and DNA alterations quantified using random-amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Results demonstrated that radiation effects on survival, growth and reproduction increased in severity from generation F0 to generation F2. Mortality after 21 days at 35.4mGyh-1 increased from 20% in F0 to 30% in F2. Growth was affected by a slight reduction in maximum length at 35.4mGyh-1 in F0 and by reductions of 5 and 13% in growth rate, respectively, at 4.70 and 35.4mGyh-1 in F2. Reproduction was affected by a reduction of 19% in 21 day-fecundity at 35.4mGyh-1 in F0 and by a delay of 1.9 days in brood release as low as 0.070mGyh-1 in F2. In parallel, DNA alterations became significant at decreasing dose rates over the course of F0 (from 4.70mGyh-1 at hatching to 0.007mGyh-1 after ~21 days) and from F0 to F2 (0.070mGyh-1 at hatching to 0.007mGyh-1 after ~21 days), demonstrating their rapid accumulation in F0 daphnids and their transmission to offspring generations. Transiently more efficient DNA repair leading to some recovery at the organism level was suggested in F1, with no effect on survival, a slight reduction of 12% in 21 day-fecundity at 35.4mGyh-1 and DNA alterations significant at highest dose rates only. The study improved our understanding of long term responses to low doses of radiation at the molecular and organismic levels in a non-human species for a better radioprotection of aquatic ecosystems. © 2015 Elsevier B.V