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[en] An analysis is presented of the ability of balanced mechanical ventilation systems to reduce the radon concentration in residential buildings efficiently. The analysis takes into account the following parameters: radon supply rate into the building, ventilation intensity, required indoor radon concentration and energy consumption. It is shown that the applicability of ventilation systems is limited mainly by energy consumption. Ventilation systems can be considered energetically acceptable if the ventilation intensity does not exceed 0.6 h-1, i.e. radon supply rate should not exceed 60 Bq/m3h for a required indoor radon concentration of 100 Bq/m3. Energy consumption can be significantly reduced by operating the ventilation system in a cyclic mode. Simulating the behavior of ventilation systems in time has been found as a useful tool for their design. In order to express by one parameter energy consumption and radon reduction, a completely new quantity - the 'radon-related energy need' has been proposed. (authors)
[en] 222Rn (radon) is an ever-present radioactive component of the surface layer of the atmosphere. The knowledge of the shape of radon activity concentration (RAC) time series has several important applications in atmospheric studies. This study presents the results of RAC analysis according to Garzon et al. approach during the years 1991-2009, as well as attempts to reconstruct the shape of composite diurnal RAC cycles using either Garzon et al. original approach or other methods. From this study, it follows that in order to accurately reconstruct the mean diurnal RAC cycles for individual months in our locality (Central European region), the parameters have to be calibrated by local RAC and measured global solar radiation data. The original Garzon et al. approach underestimates the amplitude of mean diurnal RAC cycles during April-August by up to 10%, and overestimates the amplitude during September-March by up to 25%. (authors)
[en] This case study provides a view of the behavior of radon in an uninhabited house, the likes of which were built in thousands in Slovakia between 1950 and 1990. In one room of the house that was in contact with the subsoil, an average annual radon activity concentration -RAC- as high as 1088 Bq m-3 was found. A high radon supply to this room from the subsoil was identified in the corner of the room, and this correlated very well with the temperature difference between indoor and outdoor air. In this room, an atypical annual variation of RAC was found, with a maximum in September (1600 Bq m-3). In the other rooms on the ground floor, RACs at the level of 400-500 Bq m-3 were detected. In the rooms on the first floor, RACs of up to ∼200 Bq m-3 were found. (authors)
[en] In this chapter, radioecological data are provided that can support the assessment of potential internal doses via the human food chain arising as the consequence of a large-scale pulsed inputs into marine systems. The objectives of this chapter are: • To analyse the data on temporal changes of concentration ratio (𝐶𝑅) in fish; • To quantity timescales required for contaminated marine biota to return to pre-accident levels; • To analyse the temporal changes of 137Cs activity concentrations in the seawater and bottom sediments; • To develop a simple model for the spatiotemporal changes in sediment-water distribution coefficient (𝐾d) values. The data help to understand the behaviour and bioavailability of radiocaesium distributed in the coastal areas during the pre-accident and post-accident periods.
[en] There is strong evidence both internationally and in Ireland that the correct installation of passive prevention systems in new buildings is the most cost-effective way of protecting the population against radon. Previous work considering membranes, granular fill material in the aggregate layer beneath the slab and sump system has been conducted in Ireland to improve the protection of buildings from radon. The implications of research on passive sumps potential to reduce radon concentrations are significant, as if it can be shown that the installation of passive sumps in Irish building is effective; this could constitute a low-cost, passive, sustainable method for minimizing radon levels in buildings. On-going experimental tests investigating the performance of different common cowls used for passive soil depressurization systems are presented, in addition to the impact of different vertical heights and horizontal lengths of pipe with a number of bends investigated. (authors)
[en] Estimation of the effective inhalation dose of short half-life radon progeny requires the quantification of radon equilibrium equivalent activity concentrations (EEC, Ceq). The aim of the present study is to develop new methodology that focuses on spot measurements to determine EEC from single gross alpha counts and determine an optimised protocol. The core of the approach is to measure alpha particles over time when the radon progeny attached to the sampling filter are significantly disintegrated. The calibration curve of single counts to EEC is theoretically deduced and validated by a comparison test. The advantage of the present method is its minimal requirements, including the use of common instruments and simple sampling, alpha counting and analysis procedures. This approach offers an option for radon practitioners working in a variety of fields, as well as the possibility for non-experts to easily measure Ceq. (authors)
[en] p-Anisidine being a component of wastewater generated through dye and pharmaceutical industries is highly toxic and carcinogenic in nature. Therefore, its presence in wastewater requires prior treatment before its disposal from the point of safety of human and aquatic life. Fenton’s oxidation is a type of advanced oxidation processes which is efficient, ecofriendly and reliable, and this was not studied for the removal of p-anisidine from wastewater. In this study, the effect of influent pH, hydrogen peroxide (H2O2) concentration and ferrous ion (Fe2+) concentration on the removal of p-anisidine by Fenton’s reagent was carried out on a laboratory scale. All samples were examined for initial and final concentrations of p-anisidine using UV–Vis spectrophotometry, and also initial and final COD was analyzed. p-Anisidine shows maximum absorbance at 296 nm. At pH 2.5 and [H2O2]/[Fe2+] of 70:1 for the initial p-anisidine concentration of 0.5 mM and for 24 h reaction time, the maximum removal of p-anisidine was found to be 88.95% and maximum COD removal was 76.43%.
[en] A national radon survey was conducted in Austria from 1992 to 2001 with the aim of identifying high radon areas for targeted actions to reduce radon exposure in these areas. Previous geological investigations had not accurately estimated radon exposure in Austria, so it was decided to perform systematic measurements of radon indoors. In 1992 the Austrian Radon Protection Commission recommended that the annual mean radon concentration in existing buildings should be no more than 400 Bq/m3, and that it should be no more than 200 Bq/m3 in new buildings.
[en] After local and sparse surveys that were carried out in the 1980s, a national survey of about 5400 dwellings was carried out in Italy from 1989 to 1996. This allowed for a representative estimate of the distribution of the annual average radon concentration at a national level and a regional level to be determined. This national survey was promoted and coordinated by the National Institute of Health and the former Italian National Agency for New Technologies, Energy and the Environment (currently the National Institute for Environmental Protection and Research), in collaboration with the 21 regional health authorities and the corresponding 21 regional reference laboratories for the control of environmental radioactivity (currently within the regional agencies for environmental protection). Following this national survey, and on the basis of its results, more detailed surveys were carried out in several regions — mainly in schools, but also in dwellings and workplaces. Most of them were focused on identifying radon prone areas. According to results from the Italian National Radon Archive, in total, more than 50 000 dwellings, schools and workplaces have been assessed (data updated to 2015) in radon surveys at the national, regional or subregional level carried out by national or regional public institutions involved in protection from radon exposure.
[en] Studies are being conducted for the past few decades in and around the uranium mining sites across the globe to identify environmental nuclear radiation risk to the common public. The area near Dasarlapally village was identified for uranium exploration by the AMDER, Hyderabad. The present study was carried out to measure the indoor radon and thoron activity concentrations in the dwellings of Dasarlapally village. For this purpose different types of dwellings were chosen randomly across the village. The measured annual average concentration of radon and thoron in dwellings were found to be 141 ± 42 and 139 ± 77 Bqm-3, respectively, and the calculated annual effective inhalation dose due to radon was determined to be 3.5 mSv. Seasonal variation and diurnal variation of radon and thoron activity concentration were investigated. The variation of radon and thoron activity concentration in different types of dwellings was also studied, and the variation was found to be statistically insignificant. The uncertainty propagated in the effective inhalation dose due to thoron was discussed. (authors)