Spatiotemporal trends of ambient radiofrequency electromagnetic fields (RF-EMF) during the 5G rollout in Switzerland

The fifth generation of mobile phone technology (5G) is being extensively deployed worldwide, potentially reshaping the population's exposure to ambient radiofrequency electromagnetic fields (RF-EMF).

This study aims to characterise the changes in ambient exposure to RF-EMF during the rollout of 5G in Switzerland.

First, the ambient RF-EMF levels were characterised between July 2021 and May 2024 in 300 outdoor areas, 244 public spaces, and on 332 public transport rides. Two ExpoM-RF4 were used to measure the electric field strengths from 80 MHz to 6 GHz and recorded the root-mean-square (RMS) signals and the instantaneous highest signals (Peak). Second, we conducted a temporal comparison with the RF-EMF median levels measured at baseline (2021/22) and follow-up (2023/24) in the same microenvironments and at the same time (±one hour, ±one week). Thirdly, we compared the ambient RF-EMF exposure in a subset of 49 outdoor areas that were measured in 2014, 2021, and 2023.

Total RF-EMF median levels (RMS signals) remained constant or slightly increased between 2021/22 and 2023/24 in 150 outdoor areas (0.16 V/m to 0.17 V/m), 91 public spaces (0.24 V/m to 0.25 V/m), and in 101 public transport rides (0.20 V/m to 0.24 V/m). Minor but significant increases in median Time Division Duplexing (TDD) exposure levels, related to 5G, were observed in all areas from virtually 0 V/m to 0.04 V/m during that period. Peak signals followed a comparable trend.

Between 2014 and 2023, the overall ambient RF-EMF levels from mobile phone communication technology have not increased following the introduction of 5G in Switzerland. The extensive RF-EMF exposure measurements conducted by the same person during the rollout of 5G makes our study one of the most comprehensive time trend exposure analyses to date, which is highly valuable for future epidemiological research and public communication.

The presented RF-EMF measurements conducted in numerous environments during the rollout of 5G provide a baseline to which the population is unavoidably exposed to RF-EMF. Despite the substantial growth in mobile data traffic, the deployment of 5G has not drastically changed the exposure to ambient RF-EMF from mobile phone communication technology between 2021/22 and 2023/24.