“…Results of descriptive statistic were presented in 55 papers, describing the analysis of measurement results from 39 countries In 27 papers, covering the results of surveys in Albania, Azerbaijan, Belarus, Belgium, Bulgaria, Denmark, Finland, France, Germany, Greece, Italy, Malta, Montenegro, Netherlands, Norway, Romania, Serbia, Slovakia, Spain, Sweden, Switzerland and Ukraine, authors used the obtained average values to assess the percentile, or number of houses where the indoor radon concentration exceeded some predetermined levels (Andersen et al, 2001; Baluci et al, 2013; Bochicchio et al, 2005; Bode Tushe et al, 2016; Cinelli et al, 2011; Cucoş (Dinu) et al, 2017; Hoffmann et al, 2017; Ivanova et al, 2013; Jensen et al, 2004; Kemski et al, 2004; Nikolopoulos et al, 2002; Pavlenko et al, 2014; Poffijn et al, 1994; Sainz Fernández et al, 2017; Stoop et al, 1998; Swedjemark, 2002; Swedjemark et al, 1993; Tondeur et al, 1997; Valmari et al, 2010; Vicanova et al, 1998; Vukotic et al, 2018; Weltner et al, 2002; Yaroshevich et al, 2012; Z.S. Žunić et al, 2010a, Žunić et al, 2010b; Žunić et al, 2009). In surveys conducted in Azerbaijan, Belgium and Spain, the correlation of the results of indoor radon measurement with the geological characteristics of the region was investigated, while in Albania, the comparison with known uranium concentration in soil was performed.…”