We present a method for the estimation of annual radon concentration based on
short-term (three months) measurements. The study involves results from two
independent sets of indoor radon ...concentration measurements performed in 16
cities of the Republic of Macedonia. The first data set contains winter and
annual radon concentration obtained during the National survey in 2010 and
the second, contains only the radon concentration measured during the winter
of 2013. Both data sets pertain to radon concentration from the same cities
and have been measured applying the same methodology in ground floor
dwellings. The results appeared to be consistent and the dispersion of radon
concentration was low. Linear regression analysis of the radon concentration
measured in winter of 2010 and of the 2010 annual radon concentration
revealed a high coefficient of determination R2 = 0.92, with a relative
uncertainty of 3%. Furthermore, this model was used to estimate the annual
radon concentration solely from winter-term measurements performed in
2013. The geometrical mean of the estimated annual radon concentration of
the 2013: radon concentration (A-2013) =98 Bqm-3 was almost equal to the
geometrical mean of the annual radon concentration from the 2010, radon
concentration (A-2010) = 99 Bqm-3. Analysis of the influence of building
characteristics, such as presence/absence of a basement in the building, or
the dominant building material on the estimated annual radon concentration
is also reported. Our results show that a low number of relatively
short-term radon measurements may produce a reasonable insight into a gross
average obtained in a larger survey.
nema
The study was conducted to assess the spatiality of the building factors’ effect on air quality through evaluation of indoor radon concentration in areas with different geology and geographical ...position. For that matter, a survey of indoor radon concentration was carried out in 174 kindergartens of three Bulgarian cities. The time-integrated measurements were performed in 777 ground floor rooms using alpha tract detectors, exposed for 3 months in cold period of 2014. The results of indoor radon concentrations vary from 20 to 1117 Bq/m
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. The differences in the mean radon concentrations measured in the different cities were related to geology. The effect of building-specific factors: elevator, basement, mechanical ventilation, type of windows, number of floors, building renovation, building materials, type of room, type of heating, construction period, and availability of foundation on radon concentration variations was examined applying univariate and multivariate analysis. Univariate analysis showed that the effects of building-specific factors on radon variation are different in different cities. The influence of building factors on radon concentration variations was more dominant in inland cities in comparison to the city situated on the sea coast. The multivariate analysis, which was applied to evaluate the impact of building factors simultaneously, confirmed this influence too.
As a part of the systematic survey of indoor radon in Bulgaria, the indoor radon concentration was measured in 296 kindergarten buildings of Sofia city during 3 months (February to April 2013) using ...the CR-39 nuclear tract detectors. In 256 buildings at least two frequently occupied rooms (mainly playrooms) were observed. Altogether, 922 measurements were performed. The frequency distribution was well described by the lognormal function. The measured radon concentrations range between 9 and 1415 Bq m(-3) with a geometric mean of 101 Bq m(-3) (2.08) and an arithmetic mean 132 Bq m(-3) with a standard deviation of 118 Bq m(-3). The radon concentrations obtained in this survey were compared with that in Sofia city dwellings obtained from a previous study. A detailed statistical analysis of the building factors was presented.
Subject of this study is an investigation of the variations of indoor radon concentration and ambient dose equivalent rate in outdoor and indoor environments of 40 dwellings, 31 elementary schools ...and five kindergartens. The buildings are located in three municipalities of two, geologically different, areas of the Republic of Macedonia. Indoor radon concentrations were measured by nuclear track detectors, deployed in the most occupied room of the building, between June 2013 and May 2014. During the deploying campaign, indoor and outdoor ambient dose equivalent rates were measured simultaneously at the same location. It appeared that the measured values varied from 22 to 990 Bq/m
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for indoor radon concentrations, from 50 to 195 nSv/h for outdoor ambient dose equivalent rates, and from 38 to 184 nSv/h for indoor ambient dose equivalent rates. The geometric mean value of indoor to outdoor ambient dose equivalent rates was found to be 0.88, i.e. the outdoor ambient dose equivalent rates were on average higher than the indoor ambient dose equivalent rates. All measured can reasonably well be described by log-normal distributions. A detailed statistical analysis of factors which influence the measured quantities is reported.
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