, but many of them do not get enough sleep. The use of mobile phones and other devices is one of the factors that affect sleep.
“There are very few studies examining the potential effect of RF-EMF on sleep”, says Mònica Guxens, ISGlobal researcher and senior author of the paper.
In particular, no study has integrated exposures from different RF-EMF sources during the day or assessed whether the time of exposure (day or evening) has an impact.
In this new study, researchers studied over 1,500 preadolescents between 9 and 12 years old, and assessed the overall RF-EMF dose received by each participants’ brain during the day, both from environmental sources (TV and radio antennas, WiFi, mobile phone stations near the home) and proximal sources (personal use of mobile and cordless phones, tablets, and laptops connected to the internet).
Information on the use of mobile devices and sleep disturbances was collected through a questionnaire. For a small group (around 300 participants), the researchers also collected information on the use of mobile devices after 7 pm, and measured sleep objectively during seven days, through the use of a wearable device (a wrist accelerometer) and sleep diaries.
The study results show that, on average, preadolescents spend almost 50 minutes a day looking at screens on mobile devices and 2.5 minutes per day making phone calls, which were the main contributor to brain RF-EMF doses.
There were differences between participants in the use of devices, but no association was found between all-day RF-EMF doses and sleep disturbances.
The average total sleep time was of 7.5 hours. Only 20% of pre-adolescents reported making or receiving phone calls in the evening, but those with high evening doses from phone calls showed reduced sleep time (12 minutes less on average, compared to those with no phone calls).
Researchers conclude that they cannot exclude that this effect is due to other factors related to the phone call and not to RF-EMF exposure. More studies are needed in the future to study these factors.