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