## 3 Results  
### Statistical Analysis  
In this section, we present the spot measurement results from the four regions. Figure 3 depicts the boxplot of the total E-field values, alongside a separate boxplot for the E-field values registered from all cellular frequency bands. Table 2 summarizes the results, showing the minimum (Min), maximum (Max), and root mean square (RMS) calculated electric field values for both the entire measurement frequency range (27 MHz-6 GHz) and the 5G FR1 band (3.4 GHz-3.8 GHz), for each region. As observed, there was a high dispersion in the measurements. This is because the spots were selected randomly, irrespective of the distance from the BS, LOS, and the built area around the spot, which are the factors that play a significant role in the propagation of electromagnetic waves and, consequently, the levels of EMFs. It is worth noting that none of the 400 values exceeded the ICNIRP limits [21] or the stricter Greek national limits, which are 60% of the ICNIRP values [22], even when considering the expanded uncertainty of the measurements. The expanded uncertainty of the measurement equipment used in Central Macedonia was 36.2% for the total electric field, while in Attica, it was 37.2%. The highest total electric field value recorded across all four regions, even when accounting for the respective uncertainty levels, remained at least 1.5 times below the strictest Greek national limit. Observing the values, it is clear that  
Figure 2: Number of installed and operating 5G BS in Greece per month. higher values are associated with higher population and BS density, which are detailed in Table 1.  
Conducting the Kruskal-Wallis test on the data from different environments revealed significant differences in the E-field values (\(p\)-value \(<0.05\)) between urban and suburban regions of Central Macedonia and Attica for both total and cellular band E-field levels. A potential statistical correlation was observed only in the urban regions of Central Macedonia and Attica, specifically for the E-field derived from cellular bands (\(p\)-value = 0.12). These two regions have similar built-up area patterns, although the population and BS density in the urban area of Attica are higher. The suburban regions of Attica and Central Macedonia differ significantly not only in population and BS density, but also in built-up area patterns; in Therni, the built-up area is sparser, with lower-height buildings. These results suggest that geographic and urban/suburban categorizations significantly impact electric field measurements in these regions of Greece. Examining the contribution of cellular bands to the total electric field (Figure 4) revealed that they are the dominant contributors to EMFs in the two urban areas. On the contrary, in the suburban area of Attica, they account for 49% of the total electric field, whereas in the C. Macedonia suburban environment, they account for only 28%. It is worth noting that the higher contribution of FM and \"Other\" frequency bands in suburban areas is not due to these bands being higher than in urban areas, but rather because the lower field values from cellular frequencies make the contribution of the other bands relatively higher. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Region**} & \multicolumn{3}{c}{**Total (V/m)**} & \multicolumn{3}{c}{**FR1 (V/m)**} \\ \cline{2-7}  & **min** & **max** & **rms** & **min** & **max** & **rms** \\ \hline Attica, urban & 0.19 & 7.02 & 1.68 & 0.02 & 0.72 & 0.17 \\ Central Macedonia, urban & 0.14 & 13.00 & 1.65 & 0.02 & 0.61 & 0.13 \\ Attica, suburban & 0.16 & 4.06 & 0.92 & 0.02 & 0.46 & 0.06 \\ Central Macedonia, suburban & 0.10 & 4.81 & 0.57 & 0.01 & 0.24 & 0.03 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Electric field strength statistics (min, max, RMS) by region: total and FR1 band values. Figure 3: Boxplot of the total electric field and the electric field values from all cellular networks across the four regions.