# Radio Frequency Electromagnetic Fields Exposure Assessment in Indoor Environments: A Review
## 3 Results
### Educational Buildings
Maximum peaks when considering only the Wi-Fi were equal to 4.5 \(\upmu\)W/m\({}^{2}\) (0.04 V/m, in terms of electric field, corresponding to 0.07% of the ICNIRP reference level) and 3.3 \(\upmu\)W/m\({}^{2}\) (0.035 V/m, in terms of electric field, corresponding to 0.06% of the ICNIRP reference level), for 2.4 GHz and 5 GHz, respectively. Total means values considering all teachers were equal to 2.8 \(\upmu\)W/m\({}^{2}\) (0.03 V/m, in terms of electric field, corresponding to 0.05% of the ICNIRP reference level) for Wi-Fi 2.4 GHz and to 3.1 \(\upmu\)W/m\({}^{2}\) (0.034 V/m, in terms of electric field, corresponding to 0.06% of the ICNIRP reference level) for 5 GHz. A study by [PERSON] [51] focused on the assessment of the RF levels from Wi-Fi and other sources in 23 schools in Australia. All measurements were performed via appointment mainly during school hours between 8.30 a.m. and 3.30 p.m.; one school was measured during school holidays and another during the school's sports day where all the students were off campus. Results showed that the mean and peak RF levels when considering just the Wi-Fi contribution in locations occupied by children in the classroom were of the order of 10\({}^{-4}\) and 10\({}^{-2}\)% of the ICNIRP exposure guidelines [43]. The authors concluded that the typical RF exposure of children from Wi-Fi at school was lower than the exposure due to other sources in the environment. In a study by [PERSON] et al. [52] the environmental and personal RF-EMF exposure was assessed in kindergarten considering the contribution of 16 frequency bands from 88 MHz to 5.8 GHz. The environmental exposure was assessed by spot measurements in five different points in each classroom, each one lasting 6 min. The personal measurements involved 10 children from five different kindergartens and were performed between 08.30 to 13.30 h (October-December 2015). The median value of the electric field obtained by environmental measures in the indoor facilities of the kindergartens was equal to 127 mV/m considering all the sources (i.e., all the contribution from the 16 considered frequency bands). As to the mobile phone base station exposure, the authors found levels equal to 66 mV/m for the downlink exposure (0.17% of the lowest ICNIRP reference level for the downlink band) and equal to 25 mV/m for the uplink exposure (0.06% of the lowest ICNIRP reference level for the uplink band). The Wi-Fi 2.4 GHz caused a level of exposure equal to 20 mV/m (0.03% of the of the ICNIRP reference level). Similarly, for personal exposure, median values were found equal to 81 mV/m (all bands, 0.29% of the lowest ICNIRP reference level for the whole frequency band), 62 mV/m (total mobile phone base station downlinks, 0.16% of the lowest ICNIRP reference level for downlink frequency band), 21 mV/m (total mobile phone base station uplinks, 0.05% of the lowest ICNIRP reference level for downlink frequency band), and 9 mV/m (Wi-Fi 2.4 GHz, 0.02% of the ICNIRP reference level). The measurements showed that environmental RF-EMF exposure levelsexceeded the personal RF-EMF exposure levels at kindergartens. Moreover, the authors found that the median exposure levels for those kindergartens <300 m from the nearest mobile phone base station were significantly higher compared with the medians for those >300 m away. In a recent study by [PERSON] et al. [53] extensive short-term/band-selective and long-term RF-EMF measurements were conducted at 92 primary and secondary schools in Turkey, in May, June, October and December, 2016. The short-term/band-selective measurements lasted 6 min in each point, while, after completing broadband and bandselective measurements, 24 h of E measurements were taken at the school with the highest average electric field strength (E\({}_{\mathrm{avg}}\)). Results showed that the maximum E\({}_{\mathrm{avg}}\) was recorded, 2.34 V/m (8% of the lowest ICNIRP reference level for the considered frequency band), in October, the month in which more students were at school.