Diurnal and spatial variations of radon and its influence on ionization of the nearground atmospheric layer

The most abundant and efficient source of air ionization in the lower layer of the atmosphere is radon. As an alpha emitter, radon plays cruciant role in the earth atmospheric electricity. Besides physical, radon and ions have a significant biological role concerning human health: radon is health hazard while the ions are beneficial ingredient of the air we breathe. Measurements were made using continual radon monitor Rad-7 and air ion counter CDI-06. Diurnal and spa¬tial variations of both atmospheric constitutens are mutually related and dependant mo¬stly on radon exhalation potential, meterological parameters, aerosol con¬cen-tra¬ti¬on and formation of temperature inversion layer. Indoor concentrations are re¬la¬ted to radon accumulation and partiallz influenced by external radon concentratio

Annual and seasonal variations of indoor radon concentration in Skopje (Republic of Macedonia)

This paper presents the results of a survey of indoor radon concentrations in the dwellings of 10 Municipalities in the Skopje: the capital and the largest city of the Republic of Macedonia (600 000 habitants). The indoor radon concentrations were measured during the four successive seasons from December 2008 to December 2009 using integrating passive alpha track-etch detectors with an exposure period of three months. The annual mean indoor radon concentration in each measuring site was estimated as an arithmetic mean from the four individual measurements. The measurements were completed for 124 dwellings, of which 112 dwellings revealed indoor radon concentrations lower than 200 Bq m−3, and 3 showed radon concentrations in excess of 400 Bq m−3. The annual mean indoor radon concentrations were found to be log-normally distributed, ranging from 18 to 502 Bq m−3. The geometric mean value of the indoor radon concentration in Skopje region was estimated to be 83*/1.94 Bq m−3. The results of analysis of variance showed statistically significant differences among annual mean values of the indoor radon concentrations of among the different municipalities (p=0.021). The influence of the factors linked to building characteristics in relation to the annual mean of indoor radon concentration was also a subject to examination. The factors which allow differentiation into subgroups (significance level p<0.05) were: the floor level (p<0.0001), presence of basement (p<0.0001), and type of heating (p=0.004). Seasonal dependence of indoor radon concentration was observed. The minimum indoor radon concentrations were found in the summer season whereas maximum levels were observed in the winter season (p< 0.0001)

Active and passive radon concentration measurements and first-step mapping in schools of Banja Luka, Republic of Srpska

Radon concentration measurements were performed in all 25 primary schools in Banja Luka city, the capital of Republika 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 (>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 screening one. Thus, the conclusion concerns only long time measurements as valid indicator of annual radon activity.JRC.E.8-Nuclear securit

First Evolution of Radon Concentrations Spatial Distribution based on the geological parameters and multiple linear regression method in schools of Sjenica community, Western Serbia (Balkan area)

Purpose: The paper deals with the analysis of radon survey in 34 schools over Sjenica community, in West Serbia, aiming at systematically continuation of previously performed surveys (2008-2010) in the 340 schools in South Serbia, as the project activities (Serbian Ministry of Education Since and Technical Development) considering optimization of the design of a national survey and improving the knowledge of radon distribution in Serbia. In addition , the results of this survey triggered, based on Sjenica (Pestar) region complex geology and measured annual Rn concentrations, an attempt of the explanation of radon spatial variation in Sjenica community by multivariable linear regression (MLR) method in total of 36 public buildings investigated (beside schools, the kindergarten and meterological station). Argumatation: Schools are workplaces which are subject to Rn regulations (EC 2014,BSS).Among other, the BSS require establishing reference levels for long-term indoor Rn concentration, not exceeding 300 Bq/m3 for both dwellings and workplaces. The 36 public buildings were surveyed the whole year in the Sjenica community in West Serbia by long term measurements with CR-39 detectors (commercially named Gamma 1, Landaurer, Sweden). Sjenica community is the largest community of 1059 km2 surface in Serbia and it was found that indoor radon (Rn) lower than 100 Bq/m3 are most probable and although with lower probability,that Rn higher than action level of 300 Bq/m3could occur in 14% of the buildings , indicating potential of the investigated area as high natural background area. The highest measured indoor Rn concentration was 1130 Bq/m3. Conclusion: The predictive model was developed, in order to determine how geological parameters best merge to explain the indoor radon concentrations. The results of this investigation highlight that it is possible to predict indoor radon concentrations using the geological data to an acceptable level of accuracy with a limited number of measurements. There is potential of the investigated area as high natural background area

Some results of a radon survey in 207 Serbian schools

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 Bq m-3 with a median value of 96 Bq m-3. The arithmetic mean (AM) of the 207 annual averages was 118 Bq m-3 with a standard deviation (SD) of 78 Bq m-3. The best distribution fitting of radon concentration by log-normal function was obtained. The log-normal parameters are the following: geometric mean (GM) = Bq m-3, geometric standard deviation (GSD) = 1.9. In addition, a spatial distribution of the indoor radon concentration over the investigated areas is observed.JRC.E.8-Nuclear securit

Case study in schools of Eastern Macedonia: factors affecting radon concentrations

Purpose: This paper presents indoor radon concentrations, impact factors and potential sources in 29 schools in the Eastern part of Republic of Macedonia. Argument: The radon concentrations were measured with nuclear track detectors exposed in two ground floor rooms of each school in period of one school year semester starting from January and to June in 2016. The radon concentrations in 3 of 56 rooms exceed the National action level. The geometric mean value of measured radon concentrations for all rooms was 96 Bq/m3; GSD=2.47. There was no correlation between radon and location altitude. Also, no effect of type of room and type of windows on radon concentration was found. Ground floor buildings and buildings with one floor had higher radon concentrations, than buildings with two floors. The radon concentration in building without basement was higher than that in buildings with basement, as well as higher in stone buildings than brick buildings. Relation between radon concentration and lithostratigrafic units was confirmed. The highest radon concentration was obtained on locations with andesite and breccia bed rock. Conclusion: The impact level of each of the examined factors on radon variations were quantified by a determination factor (R2) The highest R2 value was related with factor: basement. Тhe individual factor effect on radon variation as well as explanations of the obtained results are discussed in this pape

Prediction of indoor radon risk from radium concentration in soil: Republic of Macedonia case study

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

The indoor radon and thoron concentrations in schools of Skopje (Republic of North Macedonia) and Banja Luka (Republic of Srpska) cities measured by raduet detectors

Radon (222Rn) and thoron (220Rn) are natural radioactive gases, generated in the terrestrial materials. They are the main sources of public exposure to ionising radiation in indoor environment worldwide. Differences in half-lives of 222Rn (T1/2=3.8 d) and 220Rn (T1/2=55.6 s) lead to its different indoor behavior. Se¬ve¬ral studies of indoor 222Rn and 220Rn in Northern Macedonia have been per¬for¬med, starting with measurements in dwellings in 2008 and continuing with mea¬su¬re-ments in schools during 2012. The surveys in the Republic of Srpska began later (in 2011) with the simultaneous 222Rn and 220Rn measurements in the dwellings and schools of Banja Luka cities. This paper, as a result of our coop¬eration, su¬m-ma¬rizes the results and general conclusions obtained from 222Rn and 220Rn mea¬su-re¬ments in schools of capitals. In both cities, the measurements were made using Raduet - nuclear tracer detectors; deployed at distances: >0.5m (Skopje) and 0.2m (Banja Luka); and exposed in a period: March 2012 - May 2012 (Skopje) and April 2011 -May, 2012 (Banja Luka). Results for 222Rn and 220Rn concentrations in both cities have a log-normal distribution. The 222Rn geometric mean value of 71 Bq/m3 in Skopje are higher than in Banja Luka city (GM = 50 Bq/m3). Among other factors that affect 222Rn variations, this difference could be related to the different exposure time of detectors. Furthermore, the dispersion of the 222Rn results in each city expressed through geometric standard deviation is relatively low: GSD = 2.13 (Skopje) and GSD = 2.11 (Banja Luka) indicating re¬la¬ti-vely homogeneous data sets. The 220Rn concentrations in Banja Luka (GM = 51 Bq/m3) were higher than in Skopje (GM = 11 Bq/m3). It is obvious that in the case of 220Rn, the exposure pe¬ri¬od did not play a significant role. One of the reasons for this difference could be the position of the detectors as well as the different buil-ding materials in the sch¬o¬ols. On contrary, the dispersion of the 220Rn results in Skop¬je (GSD = 3.38) was greater than in Banja Luka (GSD = 2.07)