Table 4. School and home questionnaires content.

Domain	Content
School
Personal information	These questions cover personal characteristics of participants
Public transport	To assess the amount of time each participant spends in a given public mode of transport
RF-EMF exposure-mobile phone	To assess usage/handling habits (for example 5G compatibility of phone, voice calls, internet activities, social media, etc.). as well as phone accessory usage (for example headphones)
RF-EMF exposure-Laptop/Tablet	To assess personal usage time (i.e. how long, when, where) and activities. Additionally, wireless headphone usage asked
RF-EMF exposure-cordless phone	To indicate cordless phone pattern usage
RF-EMF-other sources close to body	To indicate usage pattern of electronic accessories such as smartwatch, VR, portable gaming consoles, etc.
Electronic media use	These questions cover excessive use of electronic media
School time	To indicate the student’s feelings; e.g.; happiness, sadness, etc. at school
Health and wellbeing	These questions cover health questions regarding their physical and psychological health
Sleep Disturbance Scale for Children (SDSC)	To identify sleeping patterns and problematic sleeping behavior
Sports and free time	To indicate participants’ hobbies during leisure time.
Family and friend	To indicate the relationship level of participant with family and friends
Alcohol, tobacco usage	To assess drinking and smoking patterns
Noise annoyance and sensitivity	To indicate noise (from different sources) annoyance at school and home. Also the role of noise in daily life activities disruption
Home
Electronic media use	These questions cover engagement in online harassment of others or receiving such messages themselves
Patient Health Questionnaire-9 (PHQ-9)	To assess the severity of depressive symptoms
Generalized Anxiety Disorder (GAD-7)	To assess anxiety
Eating Disorder Examination Questionnaire-7 (EDE-Q7)	to assess body dissatisfaction
Non-Suicidal Self Injury (NSSI)	To assess non-suicidal self injury
Puberty	To assess the pubertal development
Health-Related Quality of Life Questionnaire (KIDSCREEN-10 Index)	To assess the general health-related quality of life (HRQoL)
Selected Zerssen Items	To assess non-specific somatic symptoms
The Strengths and Difficulties Questionnaire (SDQ)	To assess behavioral problems
Rosenberg Self Esteem	To assess the self esteem
Headache Impact Test-6 (HIT-6)	To assess headache
School support questions	To assess the students feeling towards school and if they receive support from students and teachers.
Interim
Electronic media use	To assess which devices the adolescents use, mobile phone usage and which platforms adolescents use and how much time they spent
Reading behaviour	To assess if adolescents read in their free time
SDSC	To assess sleep disturbance and if they use devices before going to bed
KIDSCREEN-10 Index	To assess the general health-related quality of life (HRQoL)
GAD-7	To assess anxiety