An evaluation of thoron (and radon) equilibrium factorclose towalls based on long-term measurements in dwellings

Thoron gas and its progeny behave quite differently in room environments, owing to the difference in their half-lives; therefore, it is important to measure simultaneously gas and progeny concentrations to estimate the time-integrated equilibrium factor. Furthermore, thoron concentration strongly depends on the distance from the source, i.e. generally walls in indoor environments. In the present work, therefore, the measurements of both thoron and radon gas and their progeny concentrations were consistently carried out close to the walls, in 43 dwellings located in the Sokobanja municipality, Serbia. Three different types of instruments have been used in the present survey to measure the time-integrated thoron and radon gas and their progeny concentrations simultaneously. The equilibrium factor for thoron measured ‘close to the wall’, FW Tn, ranged from 0.001 to 0.077 with a geometric mean (GM) [geometric standard deviation (GSD)] of 0.006 (2.2), whereas the equilibrium factor for radon, FRn, ranged from 0.06 to 0.95 with a GM (GSD) of 0.23 (2.0)

Radon regulation and research in Asian-Pacific region – is it possible to adopt European strategy?

Indoor radon is a major hazard to human health, being the second cause of lung cancer after smoking. Therefore, radon research in Asia has been intensified recently due to growing awareness of the harm that radon poses. Analysis of collected literature data showed that in Asia-Oceania some regions have – or believe to have - little indoor radon problem due to climate and low-Rn ground. It can be also concluded that every country has its own approach, techniques and protocols. Data are not harmonized within the region, however, measurement techniques were compared by regional intercomparisons exercises. In Europe, the EURATOM Basic Safety Standards published in 2013 include binding requirements (to be transposed in national legislations) on protection against indoor radon exposure, at work and at home, and on the manufacture and use of building materials. That is why many radon projects are underway in Europe. Among achievements of European radon research is the European radon map as part of the European Atlas of Natural Radiation, created by the Joint Research Centre of the European Commission. Another one is the EU funded Metro Radon project, devoted to QA in the chain from radon measurement to delineation of radon priority areas.The situation is different with studies about the usability of radon as tracer or possible predictor of tectonic phenomena, as some countries are located in seismically active zones, like India, Taiwan, China, Japan, etc. However, India and Taiwan are globally leaders in this research together with Italy, another seismically affected country. We give an overview of radon-related surveying and research activities in the South and East Asian region. We also discuss whether experiences made in radon studies and policy in Europe can be relevant to the Asia-Oceania region.＂European Radon Week 2020＂における発

Analysis of simultaneous time series of indoor, outdoor and soil air radon concentrations, meteorological and seismic data

It is well known that the temporal dynamic of indoor and outdoor radon concentrations show complex patterns, which are partly not easy to interpret. Clearly, for physical reasons, they must be related to possibly variable conditions of radon generation, migration and atmospheric dispersion and accumulation. The aim of this study was to analyse long-time series of simultaneously measured indoor and outdoor radon concentrations, together with environmental quantities, which may act as control variables of Rn. The study was performed in Chiba, Japan, using two ionization chambers for parallel indoor and outdoor radon concentrations measurements over 4 years. Meteorological and seismic data were obtained from the Japan Metrological Agency (JMA)

Progress of radon research in the South and East Asian countries

Indoor radon is a major hazard to human health, being the second cause of lung cancer after smoking. Therefore radon research in Asia has been intensified recently due to growing awareness of the harm that radon poses. We give an overview of radon-related surveying and research activities in the South and East Asian region.「第2回日本放射線安全管理学会・日本保健物理学会合同大会」における発

Assessment of the impact of climate parameters on the radon time series measured indoor, outdoor and in soil

Series of radon concentration and ambient parameters were monitored at hourly intervals in five measurement points on the campus of the QST in Chiba: 1) a rarely-visited partially-subterranean store-room in a public-service building, 2) two rarely-visited rooms on ground and first floor of a currently not used office building 3) outdoor and 4) in soil at 0.7 m depth. The distance between measurements points were not more than 150 m. Due to the different start date of sampling at each location, the simultaneous sampling period for all points totalled 1000 days.We derived mean daily, monthly and annual radon concentrations and the same statistics for the associated meteorological data. The statistical evaluation of these parameters shows the correlation between temporal variations of radon concentration and meteorological parameters. Since the rooms (1 and 2) are little visited, there is little influence of usage patterns, leaving geogenic, meteorological and building-specific factors and their interaction as sources of Rn variability. Although not typical for dwellings, the results of radon time-series analysis can be used to derive correction factors for radon concentration in Japanese indoor environments due to seasonal variation of climatic parameters as well as for determination of the influence of measurement time to the uncertainty of the estimated long-tern mean.3rd International Conference Radon in the Environmentにおける発

Analysis of simultaneous time series of indoor, outdoor and soil air radon concentrations, meteorological and seismic data

It is well known that the temporal dynamic of indoor and outdoor radon concentrations show complex patterns, which are partly not easy to interpret. Clearly, for physical reasons, they must be related to possibly variable conditions of radon generation, migration and atmospheric dispersion and accumulation. The aim of this study was to analyse long-time series of simultaneously measured indoor and outdoor radon concentrations, together with environmental quantities, which may act as control variables of Rn. The study was performed in Chiba, Japan, using two ionization chambers for parallel indoor and outdoor radon concentrations measurements over 4 years. Meteorological and seismic data were obtained from the Japan Metrological Agency (JMA)

Selected statistical problems in spatial evaluation of Rn related variables

Since indoor radon is considered a potential hazard to health, Rn prevention and mitigation are necessary in certain areas. In this article we address the issues of mapping support and resolution, and conceptually discuss two common ways of generating maps from given information. Further, a short overview is given on the sources of uncertainties which are inevitably associated to every estimate and how to treat them. Finally, some possibilities of generating classified risk indices are outlined, since it is most often necessary to classify regions by estimated hazard