New method to measure 5G radiation from mobile phones and base stations

A team of researchers from Project GOLIAT has developed and applied a new protocol to measure exposure to mobile phone radiation, in particular from 5G. The researchers measured radiofrequency electromagnetic field (RF-EMF) levels during three different scenarios: when the mobile device is in flight mode (non-user), when the mobile phone is used intensively by either downloading or uploading data. The study demonstrates that e.

The research was conducted in Switzerland, one of the first countries in Europe to roll out 5G networks on a large scale. The results have now been published in Environmental Research and provide relevant data for epidemiological research, risk management and risk communication.

Methods

To measure the RF-EMF levels emitted by devices and base stations, the study team selected two cities (Zurich and Basel) and three rural villages (Hergiswil, Willisau, and Dagmersellen). In each, they defined different microenvironments or areas with different uses, such as residential or industrial areas, schools, public parks or public transport. The researchers measured exposure by wearing a backpack with a personal exposimeter and a mobile device equipped with a sensor and software to track the power emitted by the phone.

Results

In total, more than 30,000 data points were analysed. When using the mobile phone in flight mode scenario, RF-EMF exposure mainly comes from mobile phone base stations. The researchers found that exposure levels increased with increasing population density. The average for rural villages was 0.17 milliwatts per square metre (mW/m²), while the average for cities was 0.33 mW/m² for Basel and 0.48 mW/m² for Zurich. "The highest levels were found in urban business areas and public transport, which were still more than a hundred times below the international guideline values.", says Martin Röösli, researcher at the Swiss TPH and last author of the study.

In the scenario where maximum data download was triggered (the researcher's phone was set to download large files), the radiation increased significantly to an average of 6-7 mW/m². The authors attribute this increase partly to beamforming, a technique associated with 5G base stations that directs signals more efficiently to the user, leading to higher exposure levels when downloading data. The exposure was overall higher in the two cities likely due to the higher number of 5G base stations.

Finally, the scenario where highest RF-EMF levels were registered was the maximum data upload scenario, where the researcher's mobile phone was set to constantly upload large files. The average exposure was around 16 mW/m² in the cities and almost twice as high in the villages (29 mW/m²). In this scenario, the biggest source of radiation was the phone sending the data, and exposure was significantly higher in villages, due to the lower density of base stations, which reduces signal quality and forces devices to use more power to send data.

"We have to keep in mind that in our study the phone was about 30 cm away from the measuring device, which means that our results might underestimate the real exposure. A mobile phone user will held the phone closer to the body and thus the exposure to RF-EMF could be up to 10 times higher," says Adriana Fernandes Veludo, researcher at the Swiss TPH and first author of the study.

"In summary, this study shows that environmental exposure is lower when base station density is low. However, in such a situation, the emission from mobile phones is by orders of magnitude higher" says Adriana Fernandes Veludo. “This has the paradoxical consequence that a typical mobile phone user is more exposed to RF-EMF in areas with low base station density.”

This is the first study of its kind to provide significant data on 5G levels in the environment and from the own phone. The measurements will now be carried out twice within 3 years in nine more European countries, allowing potential changes in population exposure to be monitored as 5G is rolled out.

Reference

Veludo, A.F., Stroobandt, B., Van Bladel, H., Sandoval-Diez, N., Guxens M., Joseph, W., Röösli, M., Exploring RF-EMF levels in Swiss microenvironments: An evaluation of environmental and auto-induced downlink and uplink exposure in the era of 5G, Environmental Research, https://doi.org/10.1016/j.envres.2024.120550.