# Radio Frequency Electromagnetic Fields Exposure Assessment in Indoor Environments: A Review
## 3 Results
### Indoor Environments  
Many different indoor environments, summarized in Table 2, have been analyzed in order to assess the exposure to different types of RF-EMF sources. Most studies dealing with public environments, which often play the role of workplaces, focused on the exposure in offices, due to the high number of WiFi sources that are usually present [17]. The second most investigated public environment is represented by schools, due to the presence of children of different ages and to the attention paid to their precocity of exposure to RF-EMF [18]. Larger spaces like hospitals/health care facilities, universities and commercial locations (coffee shops, fast food outlets, general merchants), tourist visitor centers and hotel rooms have been investigated by only few studies, based mainly on spot and personal measurements. Also private places such as houses and flats were investigated, with a particular attention to the bedroom, as suggested by [PERSON] and [PERSON] [19]. Typical environmental factors influencing the level of exposure are linked to the degree of urbanization of the environment under exam, e.g., rural, suburban, urban [3; 20], the percentage of urban ground use of the area and the population density, e.g., the number of social meeting places such as pubs and railway stations, in which more people are present, potentially showing higher exposure [21; 22]. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Location**} & \multicolumn{6}{c}{**Population Density of the Area**} & \multicolumn{3}{c}{**Measurements**} & \multicolumn{1}{c}{**Simulation**} \\ \cline{3-10}  & \multirow{2}{*}{**Urban**} & \multirow{2}{*}{**Suburban**} & \multirow{2}{*}{**Rural**} & \multirow{2}{*}{**Industrial**} & \multirow{2}{*}{**Not**} & \multirow{2}{*}{**Spot/Long Term**} & \multirow{2}{*}{**Personal**} & \multirow{2}{*}{**Measurement**} & \\  & & & & & & & & & \\ \hline \multirow{8}{*}{\begin{tabular}{c} \end{tabular} } & Schools & X & X & X & & X & X & X & \\  & University & & & & & X & X & X & \\  & Kindergarten & X & & & & & X & X & \\  & Crehes & X & X & X & & & X & X & \\  & Offices & X & X & X & & & X & X & X \\  & Cinema & X & & & & & & X & \\  & Church & X & & & & & & X \\  & Small shop & & & & & & X & X & \\  & Shopping center & X & & & & X & X & \\  & Tourist visitor center & & & & & X & & \\  & Railway station & & & & & & X & \\  & Airport & & & X & & & & \\  & Hotels & X & X & & & X & & \\  & Health care facilities & & & & & X & & \\  & Other Workplaces & X & & X & X & & X & \\ \hline \multirow{8}{*}{\begin{tabular}{c} \end{tabular} } & houses & X & X & X & & X & X & X & \\  & bedroom & X & X & X & & & X & X & \\  & flat & X & X & & & X & \\ \hline \multirow{8}{*}{\
\begin{tabular}{c} \end{tabular} } & train & & & & & X & X & X \\  & bus & & & & & & X & \\  & meto & & & & & X & \\  & car & & & & & & \\  & airplane & & & & & & X \\  & public transport & & & & & & \\ \hline \multirow{8}{*}{
\begin{tabular}{c} \end{tabular} } & indoor unspecified & & & X & X & X & X \\  & room & & & X & & & X \\  & elevator & & & X & & & X \\  & corridor & & & X & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Investigated indoor environments. Special attention was given to public transportation, such as trains, as several studies on the exposure of the general public to radio-frequency (RF) electromagnetic fields (EMF) have established that public transport (bus, train, etc.) has become the dominant micro-environment in terms of RF-EMF exposure, with the largest RF-EMF strengths attributed to mobile-phone use [20]. This is due to several factors.