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The subject of this study is the radon concentrations variations, measured with a nuclear track detectors in a total of 58 premises in all 29 primary schools of 4 municipalities in the Eastern part of the Republic of Macedonia. Despite a relatively small territory, the variability of radon concentrations proved to be significant. The geometric means (geometric standard deviations) of radon concentrations in the examined municipalities were in the range from GM = 71 Bq/m 3 (GSD = 2.08) to GM = 162 Bq/m 3 (GSD = 2.69), while for the entire region it was: GM = 96 Bq/m 3 (GSD = 2.47). The influence of the geographical and geological features of the school site as well as the building characteristics on the radon variations were investigated. The analysis showed that type of municipality, building materials, basement and geology have significant effects and respectively describe 6%, 16%, 22%, 39% of the radon total variability.

The subject of this study is the radon concentrations variations, measured with a nuclear track detectors in a total of 58 premises in all 29 primary schools of 4 municipalities in the Eastern part of the Republic of Macedonia. Despite a relatively small territory, the variability of radon concentrations proved to be significant. The geometric means (geometric standard deviations) of radon concentrations in the examined municipalities were in the range from GM = 71 Bq/m 3 (GSD = 2.08) to GM = 162 Bq/m 3 (GSD = 2.69), while for the entire region it was: GM = 96 Bq/m 3 (GSD = 2.47). The influence of the geographical and geological features of the school site as well as the building characteristics on the radon variations were investigated. The analysis showed that type of municipality, building materials, basement and geology have significant effects and respectively describe 6%, 16%, 22%, 39% of the radon total variability.

A first step in mapping indoor radon concentration in Kosovo and Metohija was taken by carrying out 153 measurements in residential houses. About 21% of the territory of these areas was covered by mapping. Dosimeters with CR-39 detectors were used to measure indoor Rn-222 concentration, all deployed on the ground floor of typical houses. The arithmetic mean (AM) over AMs within 10 km x 10 km grid cells is 202 Bqm(-3) and geometric mean (GM) is 148 Bqm(-3). The data for mapping are arranged according to recommendations made by the Joint Research Centre (JRC) of the European Commission (EC) in 2006. This paper presents the status of the survey of natural radioactivity in Kosovo and Metohija.

Geo-referenced datasets of indoor radon concentrations and radium concentrations in soil are available for the Republic of Macedonia. However, the indoor Rn-222 data are spatially strongly clustered as the measurements were essentially confined to major towns and cities. Hence, the estimation of the geographical distribution of Rn-222 concentration based only on the Rn-222 data is difficult to be made. On the other hand, geochemical measurements Ra-226 are quite well distributed over the country. Since Ra-226 is the source of Rn-222, one may think of using Ra-226 as a predictor for Rn-222. In this paper we present a method for modelling the stochastic dependency of indoor Rn-222 of soil Ra-226. The method is new in the area on Rn-222 assessment and still needs to be validated by more case studies. It must be born in mind that the indoor Rn-222 depends, in some cases more strongly, on controlling factors other than the Ra-226 in soil, so that its estimation from Ra-226 alone is inevitably imperfect. The results must therefore be understood as estimates in absence of other information, and as a motivation to carry out measurements in regions where the model predicts higher Rn-222 levels, but for which no measurements are available so far.

This paper deals with calculated effective doses that members of real population received from radon gas and its short lived progeny during air inhalation in their dwellings at field site Kalna in Eastern Serbia. There are two crucial parameters in effective dose calculation: Dose Conversion Factor (DCF) for particular subjects (including real gender, age and physical activity level) and indoor concentration of radon and its short lived progeny in field area. According to the results of indoor radon measurements in the area of former uranium mine, Kalna, the effective dose for this real population was estimated by using the dosimetric lung model, developed by authors according ICRP Publication 66. Authentic software was developed for determination of effective dose per unit inhaled activity of radon progeny, DCF expressed in unit [mSv/WLM]. The results, obtained according to ICRP 66 dosimeter lung model, were compared with results calculated according to ICRP Publication 65. The dosimetric results were, also, compared and discussed with epidemiological approach data, according to UNSCEAR.

In this paper the results of radon concentration measurements performed in 207 schools in 7 communities of Southern Serbia are presented. The annual radon concentration varied from 17 Bqm(-3) to 428 Bqm(-3) with a median value of 96 Bqm(-3). The arithmetic mean (AM) of the 207 annual averages was 118 Bqm(-3) with a standard deviation (SD) of 78 Bqm(-3). The best distribution fitting of radon concentration by log-normal function was obtained. The log-normal parameters are the following: geometric mean (GM) = 97 Bqm(-3), geometric standard deviation (GSD) = 1.9. In addition, a spatial distribution of the indoor radon concentration over the investigated areas is observed.

Radon concentration measurements were performed in all 25 primary schools in Banja Luka city, the capital of Republic of Srpska, during 2011 and 2012, using both active RAD7 continual radon measuring instruments and CR-39 passive (commercially known as Gamma) detectors. The two complimentary methods were employed not only to obtain annual averages, but also to study the dynamics of radon concentration changes during the week. For each school, average and temporal variations of radon concentrations were analysed, taking into consideration local geology, building materials and meteorological conditions. The influence of forced ventilation, caused by frequent opening of doors and windows during working hours, with typical dawn and weekend peaks is evident in most but not all schools. Elevated levels of radon concentration ( GT 400 Bq m(-3)) were found in a few schools using both methods. Although high correlation factor of 0.8 between passive and active methods was found, still short-time (one-week) measurements cannot be used for annual estimation of radon activity but only as a screening one. Thus, the conclusion concerns only long time measurements as valid indicator of annual radon activity.

Radon concentration measurements were performed in all 25 primary schools in Banja Luka city, the capital of Republic of Srpska, during 2011 and 2012, using both active RAD7 continual radon measuring instruments and CR-39 passive (commercially known as Gamma) detectors. The two complimentary methods were employed not only to obtain annual averages, but also to study the dynamics of radon concentration changes during the week. For each school, average and temporal variations of radon concentrations were analysed, taking into consideration local geology, building materials and meteorological conditions. The influence of forced ventilation, caused by frequent opening of doors and windows during working hours, with typical dawn and weekend peaks is evident in most but not all schools. Elevated levels of radon concentration ( GT 400 Bq m(-3)) were found in a few schools using both methods. Although high correlation factor of 0.8 between passive and active methods was found, still short-time (one-week) measurements cannot be used for annual estimation of radon activity but only as a screening one. Thus, the conclusion concerns only long time measurements as valid indicator of annual radon activity.

In this paper the results of radon concentration measurements performed in 207 schools in 7 communities of Southern Serbia are presented. The annual radon concentration varied from 17 Bqm(-3) to 428 Bqm(-3) with a median value of 96 Bqm(-3). The arithmetic mean (AM) of the 207 annual averages was 118 Bqm(-3) with a standard deviation (SD) of 78 Bqm(-3). The best distribution fitting of radon concentration by log-normal function was obtained. The log-normal parameters are the following: geometric mean (GM) = 97 Bqm(-3), geometric standard deviation (GSD) = 1.9. In addition, a spatial distribution of the indoor radon concentration over the investigated areas is observed.

A first step in mapping indoor radon concentration in Kosovo and Metohija was taken by carrying out 153 measurements in residential houses. About 21% of the territory of these areas was covered by mapping. Dosimeters with CR-39 detectors were used to measure indoor Rn-222 concentration, all deployed on the ground floor of typical houses. The arithmetic mean (AM) over AMs within 10 km x 10 km grid cells is 202 Bqm(-3) and geometric mean (GM) is 148 Bqm(-3). The data for mapping are arranged according to recommendations made by the Joint Research Centre (JRC) of the European Commission (EC) in 2006. This paper presents the status of the survey of natural radioactivity in Kosovo and Metohija.

Geo-referenced datasets of indoor radon concentrations and radium concentrations in soil are available for the Republic of Macedonia. However, the indoor Rn-222 data are spatially strongly clustered as the measurements were essentially confined to major towns and cities. Hence, the estimation of the geographical distribution of Rn-222 concentration based only on the Rn-222 data is difficult to be made. On the other hand, geochemical measurements Ra-226 are quite well distributed over the country. Since Ra-226 is the source of Rn-222, one may think of using Ra-226 as a predictor for Rn-222. In this paper we present a method for modelling the stochastic dependency of indoor Rn-222 of soil Ra-226. The method is new in the area on Rn-222 assessment and still needs to be validated by more case studies. It must be born in mind that the indoor Rn-222 depends, in some cases more strongly, on controlling factors other than the Ra-226 in soil, so that its estimation from Ra-226 alone is inevitably imperfect. The results must therefore be understood as estimates in absence of other information, and as a motivation to carry out measurements in regions where the model predicts higher Rn-222 levels, but for which no measurements are available so far.

This paper deals with calculated effective doses that members of real population received from radon gas and its short lived progeny during air inhalation in their dwellings at field site Kalna in Eastern Serbia. There are two crucial parameters in effective dose calculation: Dose Conversion Factor (DCF) for particular subjects (including real gender, age and physical activity level) and indoor concentration of radon and its short lived progeny in field area. According to the results of indoor radon measurements in the area of former uranium mine, Kalna, the effective dose for this real population was estimated by using the dosimetric lung model, developed by authors according ICRP Publication 66. Authentic software was developed for determination of effective dose per unit inhaled activity of radon progeny, DCF expressed in unit [mSv/WLM]. The results, obtained according to ICRP 66 dosimeter lung model, were compared with results calculated according to ICRP Publication 65. The dosimetric results were, also, compared and discussed with epidemiological approach data, according to UNSCEAR.