November 2017 is een onderzoek gepubliceerd naar de stralingsblootstelling van leerkrachten in schoolgebouwen met een Wi-Fi netwerk.

Het hoogste gemiddeld niveau is gemeten in de periode waarbij de leerlingen data en YouTube filmpjes mochten streamen.

Op 20 november 2017 is het onderzoek: Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi gepubliceerd.
In dit onderzoek hebben 18 leerkrachten van 7 verschillende scholen meegedaan waarbij zij gedurende 1-4 dagen een exposimeter hebben gedragen.

Enkele resultaten uit dit onderzoek waren:

- Het gemiddelde blootstellingsniveau lag tussen 1,1 en 66,1 µW/m2
- Het hoogste gemiddele blootstellingsniveau was 396,6 µW/m2  gedurende 5 minuten waar de studenten mochten streamen/Youtuben.
- Het maximale piekniveau was 82.857 µW/m2 afkomstig van een mobiele telefoon uplink

 

De verschillen in blootstellingsniveaus worden duidelijker in de volgende grafieken:

In onderstaande grafiek worden tussen 15:20 en 15:25 door de leerlingen actief videos gestreamed

In onderstaande grafiek wordt de blootstelling weergegeven van een leraar in een klas zonder Wifi en laptops.
Alleen de mobiele telefoon van de leraar zelf geeft hier een af en toe hoge piekblootstellingen.



















*  Duidelijk is te zien is dat het gemiddelde blootstelingsniveau in de 2e grafiek in de buurt komt van het aanbevolen voorzorgsniveau van 3-6 µW/m2.

*  In het klaslokaal met vele laptops en Wifi-verbindingen wordt dit voorzorgsniveau ruim en veelal zeer ruim overschreden.



Verder wordt in dit onderzoek ingegaan op de gezondheidseffecten die in verband worden gebracht met het gebruik van laptops, tablets en de bijbehorende lesmethodes in het onderwijs.

Hier worden tientallen effecten besproken die mogelijk een uitwerking hebben op de gezondheid van leerlingen.

Zie voor dit onderzoeksrapport: https://www.frontiersin.org/articles/10.3389/fpubh.2017.00279/full


Enkele quotes uit dit onderzoek:

In the WHO study, Health Behavior in School-aged Children (HBSC) conducted during 2013/2014 results from Sweden showed that girls' mental health has deteriorated compared with the same study made during 2009/2010. The study has since 1985/1986 taken place around the world every fourth year among 11-, 13-, and 15-year-old girls and boys in over 40 different countries.

In Sweden, sleep problems in particular have increased among 13- and 15-year-old girls.
Of the girls, 39% have sleep problems more than once a week.
Also, boys at the same age have sleeping problems, though to a lesser extent (around 27%).

To feel depressed, nervous, or irritated has increased among Swedish, 13- and 15-year-old girls and were about twice as common compared with boys at the same age.

The conclusion of the HBSC report brings up that "the fast technical development has changed children's and adolescents' everyday life in many ways, which may have influenced their mental well-being" (25).

In the latest yearly inquiry in Norrbotten, Sweden, there is a statistically significant correlation between school districts with high amount of screen time and how many students in the community that feel depressed (10).

Screen time can affect us in many different ways. Long hours of sitting in front of a screen can lead to aches in the neck, back, and shoulders. In the yearly inquiry in Norrbotten, almost one-fourth of the 16-year-old girls often had aches in their neck, back, or shoulder (10).

Screen time has been shown to have a higher correlation to overweight and obesity than lack of physical activity (12), since prolonged sedentary activities can be a metabolic risk factor (13) and less physical activity may reduce cardiorespiratory fitness (14).

There are also concerns about the emotional development for especially young children with a high amount of screen time. Time is taken from play, physical activities, and being with friends, parents, and siblings, which are important parts when growing up. The development of mirror neurons in the brain, which give us the possibility to imitate the behavior of other people, can be affected (15). Empathetic concern among American college students has dropped sharply since 1979 and especially since the year of 2000 according to a meta-analysis on studies performed between 1979 and 2009 (16).

High ICT usage among young adults in Gothenburg led to an increased risk for depression, sleep problems, and stress (17). Among adolescents in Japan using a mobile phone after lights out at night gave sleep disturbances, increased tiredness during day time, and several had suicide thoughts and worse mental health (18, 19).

In a review, bedtime access and use of portable screen-based media devices showed a statistically significant association with inadequate sleep quality, poor sleep quality, and excessive daytime sleepiness (20). Increased duration of mobile phone use has been linked to higher risks for depressed mood and mobile phone addiction (11, 21, 22).

Adolescents at risk for mental health problems showed an association between both the amount of time spent using digital technologies and the numbers of text messages sent and increased same-day symptoms from attention deficit hyperactivity (ADHD) and conduct disorders (23). One study in Switzerland raised the question "whether problematic mobile phone use is the consequence of unfavorable conditions or whether and to what extent problematic mobile phone use reinforces behavioral problems as well as decreased mood and psychological well-being" (24).