Sleep is crucial for the health and development of children and adolescents, and yet many of them are not getting enough sleep. The increasing use of mobile phones and other devices is one of the main suspects, but very few studies have examined whether the low doses of radiofrequency electromagnetic fields (RF-EMF) emitted by these devices could contribute to the problem.

“In fact, no study has integrated exposures from different sources of RF-EMF or assessed whether the time of exposure (day or evening) has an impact on sleep,” explains Monica Guxens, whose research focuses on how different environmental exposures can affect cognitive development.

Guxens and her team studied over 1,500 preadolescents between 9 and 12 years old from two cohorts in Spain (Gipuzkoa and Sabadell) and one in the Netherlands. They estimated the overall RF-EMF doses received by each participant’s brain during the day, both from environmental sources (TV and radio antennas, WiFi, mobile phone stations) and proximal sources (personal-use devices connected to the internet). They also measured the participants’ sleep quantity and quality using a wrist accelerometer and sleep diaries.

Shorter sleep times

The results show that, on average, preadolescents spend around 50 minutes looking at screens, 2.5 minutes making phone calls and 7.5 hours sleeping per day. Those with high evening doses from phone calls slept 12 minutes less, on average, compared to those with no phone calls.

“We cannot exclude that this effect is due to other factors related to the phone call and not to RF-EMF exposure,” says Alba Cabré-Riera, lead author of the study. “But our findings do suggest that the amount of RF-EMF dose absorbed by the brain in the evening might be more relevant for adolescents’ sleep,” she adds.