53 research outputs found
Monitoring Radioactivity in the Environment Under Routine and Emergency Conditions
The main purpose of environmental monitoring is to quantify the levels of radioactivity in the various compartments of the environment disregarding its origin: natural or anthropo-genic, under routine or accidental conditions, in view of the health effects on man and his environment. However, because of their historical background, which is connected to the development of nuclear industry, the monitoring programmes established in the European countries focus on artificial radioactivity.
Man-made radioactive matter can get into the biosphere by means of legally permitted dis-charges from nuclear installations or infrastructures where radioactive material is being used, e.g. hospitals and industry, or as the result of an accident. For each cause, specific sampling and monitoring programmes, as well as systems for internationally exchanging their results, have been implemented in the European Union and are still evolving.
Routine monitoring is done on a continuous basis throughout the country by sampling the main environmental compartments which lead to man; typically these are airborne particu-lates, surface water, drinking water and food (typically milk and the main constituents of the national diet). The aim of routine monitoring is then also to confirm that levels are within the maximum permitted levels for the whole population (Basic Safety Standards, (EC, 1996)) and to detect eventual trends in concentrations over time. A comprehensive overview of the sampling strategies and principal measurement methods in the countries of the EU will be given, as well as how this information is communicated to the general public.
In case of an accident, sampling and monitoring is tailored to the nature of the radioactive matter released and to the way in which it is dispersed. In particularly during the early phase of an accident with atmospheric release it is essential to be able to delineate the con-tamination as soon as possible to allow for immediate and appropriate countermeasures. Afterwards, once the radioactivity has deposited, it is important to have detailed informa-tion of the deposition pattern; a detailed deposition map at a fairly early stage will serve to steer medium and long term countermeasure strategies (e.g. agricultural, remediation). A summary of the most commonly used techniques, as well as a discussion of the various sampling network types (emergency preparedness, mobile) will be given.
The Chernobyl NPP accident on 26 April 1986 also triggered the European Commission to develop together with its Member States systems for the rapid exchange of information in case of a nuclear/radiological accident (European Community Urgent Radiological Informa-tion Exchange (ECURIE), European Radiological Data Exchange Platform (EURDEP)). These systems will also be further described.JRC.E.8-Nuclear security (Ispra
Evaluation of EC Measurement Comparison on Simulated Airborne Particulates - 137Cs in Air Filters
This report describes the full life cycle of the measurement comparison of 137Cs in air filters among 43 European laboratories monitoring radioactivity in the environment. Gravimetrically pipetting droplets of a gravimetrically diluted standardised 137Cs solution onto real air filters, SI-traceable reference values were established for intercomparison filters carrying a large range of activity close to the routine measurement conditions of the corresponding laboratory. The sample preparation and measurement processes applied in the participating laboratories are described and the results of the intercomparison are presented and discussed in detail. The results point at some problems of radioactivity measurement in air filters which need to be improved by several laboratories. Overall, with 41 out of 48 reported measurement results lying within +/- 33 % of the IRMM reference value, this comparison renders a rather fair result.JRC.D.4-Isotope measurement
The first version of the Pan-European Indoor Radon Map
A hypothetical Pan-European Indoor Radon Map has been developed using summary statistics estimated from 1.2 million indoor radon samples. In this study we have used the arithmetic mean (AM) over grid cells of 10 km10 km to predict a mean indoor radon concentration at ground-floor level of buildings in the grid cells where no or few data (N < 30) are available. Four interpolation techniques have been tested: inverse distance weighting (IDW), ordinary kriging (OK), collocated cokriging with uranium concentration as a secondary variable (CCK), and regression kriging with topsoil geochemistry and bedrock geology as secondary variables (RK). Cross-validation exercises have been carried out to assess the uncertainties associated with each method. Of the four methods tested, RK has proven to be the best one for predicting mean indoor radon concentrations; and by combining the RK predictions with theAMof the grids with 30 or more measurements, a Pan-European Indoor Radon Map has been produced. This map represents a first step towards a European radon exposure map and, in the future, a radon dose map
Similarities and differences between radon surveys across Europe: results from MetroRADON questionnaire
Background: As a major cause of lung cancer after smoking, indoor radon is a hazard for human health. Key steps of radon surveys are numerous and include metrology, survey design, development of maps, communication of results to stakeholders, etc. The Council Directive 2013/59/EURATOM introduced new challenges for European Union Member States, such as the identification of radon priority areas, which calls for efforts to improve all the key steps involved in radon surveys.
Objective: This study aims to compare existing radon measurement procedures between different European countries and to use the results to optimize the consistency of indoor radon data across Europe.
Design: A questionnaire was developed and sent to more than 70 European institutions working in this field to collect information on indoor radon surveys carried out in the respective countries, in order to identify the rationale and methodologies used.
Results: A total of 56 questionnaire forms on indoor radon surveys were completed and returned by universities, research institutions, and competent authorities on national and regional surveys from 24 European countries. The replies have been analyzed, and the main findings have been reported, although these replies did not allow to answer all the questions about comparability.
Conclusions: From the replies given by the respondents, there is evidence that European indoor radon surveys are comparable regarding measurement methods but not comparable regarding the survey design. Comparability regarding data management, statistical treatment, aggregation, and mapping is unclear on the basis of the replies putting in evidence the need of further information
European Atlas of Natural Radiation
Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose.
This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources.
It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations.
This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to:
• familiarize itself with natural radioactivity;
• be informed about the levels of natural radioactivity caused by different sources;
• have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor;
• and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.JRC.G.10-Knowledge for Nuclear Security and Safet
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
European Atlas of Natural Radiation
Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose.This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations.This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity;• be informed about the levels of natural radioactivity caused by different sources;• have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor;• and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.Additional information at: https://remon.jrc.ec.europa.eu/About/Atlas-of-Natural-Radiatio
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