AUTHOR=Hedendahl Lena K. , Carlberg Michael , Koppel Tarmo , Hardell Lennart 

TITLE=Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi

JOURNAL=Frontiers in Public Health

VOLUME=Volume 5 - 2017

YEAR=2017

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2017.00279

DOI=10.3389/fpubh.2017.00279

ISSN=2296-2565

ABSTRACT=Introduction: Wireless access to the Internet is now commonly used in schools. Many schools give each student their own laptop and utilize the laptops and Wi-Fi connection for educational purposes. Most children also bring their own mobile phones to school. Since children are obliged by law to attend school, a safe environment is important. Lately it has been discussed if radiofrequency (RF) radiation can have long-term adverse effects on children's health. 
Method: This study conducted exposimetric measurements in schools to assess  RF emissions in the classroom by measuring the teachers' RF exposure in order to approximate the children's exposure.  Teachers in grades 7-12 carried a body borne exposimeter, EME Spy 200, in school during one to four days of work. The exposimeter can measure 20 different frequency bands from 87 to 5,850 MHz. 
Results: 18 teachers from seven schools participated. The mean exposure to RF radiation ranged from 1.1 to 66.1 µW/m2. The highest mean level, 396.6 µW/m2, occurred during five minutes of a lesson when the teacher let the students stream and watch YouTube videos. Maximum peaks went up to 82,857 µW/m2 from mobile phone uplink.
Discussion: Our measurements are in line with recent exposure studies in schools in other countries. The exposure levels varied between the different Wi-Fi systems,  and if the students were allowed to use their own smartphones on the school's Wi-Fi network or if they were connected to GSM/3G/4G base stations outside the school. An access point over the teacher's head gave higher exposure compared to a school with a wired Internet connection for the teacher in the classroom. All values were far below ICNIRP's reference values, but most mean levels measured were above the precautionary target level of 3-6 μW/m2 as proposed by the Bioinitiative Report. The length of time wireless devices are used is an essential determinant in overall exposure. Measures to minimize children’s exposure to RF radiation in school would include using wired connections, allowing laptops, tablets and mobile phones only in flight mode, and deactivating Wi-Fi access points, when not used for learning purposes,