# Radio Frequency Electromagnetic Fields Exposure Assessment in Indoor Environments: A Review
## 3 Results
### Educational Buildings
#### Exposure in Private Places
In a study by [PERSON] and colleagues [58] EMF exposure level measurements in Greece were performed in a variety of indoor dwellings, in three different parts of the country. A total number of 4540 measurements were taken in a wide frequency range (50 Hz-2100 MHz) in three regions, i.e., Attica, Lesvos and Zakynthos. The duration of each measurement was set between 5 and 15 min. All measurements are presented as time averaged values. Results showed that maximum levels of exposure were, in most cases, below 0.5 V/m, with peak values above 1 V/m and up to 5.6 V/m occasionally observed. A study by [PERSON] [59] assessed the exposure to RF-EMF in an apartment with a central location in Stockholm, located on the 6 th floor, with a tower including a bedroom on the first floor of the tower (7 th floor) and a conference room on the second and highest floor (8 th) of the tower, at the same level as the roof of the building. Results were obtained by repeated measures in different locations in the apartment, during day and night, for total of indoor 71 h of measurements. Mean and median values of the exposure were found to be equal 1.766 mW/m\({}^{2}\) and 1.051 mW/m\({}^{2}\) (0.81 V/m and 0.6 V/m). In a follow up study by [PERSON] et al. [19], the levels of exposure due RF-EMFs in different frequency bands (discarding the mobile phone uplink signals) were measured in 219 bedrooms in Lower Austria in 2006, 2009 and 2012. The authors analyzed both the differences among measurements obtained in different years, and the influence of different urbanization levels of the area in which the residential buildings were placed on the levels of exposure. The total exposure was due for a 15% to indoor sources and for the 85% to outdoor sources. Results showed that the arithmetic mean of the RF-EMF electric field decreased from 0.51 V/m in 2006, to 0.46 V/m in 2009, and to 0.37 V/m in 2012 (respectively, 1.76%, 1.59% and 1.28% of the lowest ICNIRP reference level for the considered frequency band). On the contrary, the median values were found to increase from 0.10 V/m in in 2006 to 0.14 V/m in 2012 (respectively, 0.34%, and 0.48% of the lowest ICNIRP reference level for the considered frequency band). This difference between the arithmetic mean and median was because the arithmetic mean also considers high outliers whereas the median represents the main part of the measurement spots. The highest increases from 2006 in the contribution to the RF-EMF exposure were found for UMTS (from 0 to 0.52 \(\mu\)W/m\({}^{2}\), equal to 0.01 V/m in terms of electric field strength, 0.02% of the ICNIRP reference level) and wireless local area networks (from 0 to 0.46 \(\mu\)W/m\({}^{2}\), equal to 0.01 V/m in terms of electric field strength, 0.02% of the ICNIRP reference level), while a decrease was observed in the exposure level in the frequency range of digital enhanced cordless telecommunications telephones (from 1.80 to 0.19 \(\mu\)W/m\({}^{2}\), respectively equal to 0.3 and 0.01 V/m in terms of electric field strength, 0.07% and 0.02% of the ICNIRP reference level). Comparing the levels of exposure in the household placed in rural areas, small towns, suburban and urban areas, the results showed higher total RF-EMFs in urban (117.73 \(\mu\)W/m\({}^{2}\), equal to 0.21 V/m in terms of electric field strength, 0.75% of the lowest ICNIRP reference level for the whole frequency band considered) than in rural (median 34.52 \(\mu\)W/m\({}^{2}\), equal to 0.11 V/m in terms of electric field strength, 0.4% of the lowest ICNIRP reference level for the whole frequency band considered) areas.