Environmental Radiofrequency Electromagnetic Fields Exposure at Home, Mobile and Cordless Phone Use, and Sleep Problems in 7-Year-Old Children.
BACKGROUND
We evaluated if exposure to RF-EMF was associated with reported quality of sleep in 2,361 children, aged 7 years.


METHODS
This study was embedded in the Amsterdam Born Children and their Development (ABCD) birth cohort study. When children were about five years old, school and residential exposure to RF-EMF from base stations was assessed with a geospatial model (NISMap) and from indoor sources (cordless phone/WiFi) using parental self-reports. Parents also reported their children's use of mobile or cordless phones. When children were seven years old, we evaluated sleep quality as measured with the Child Sleep Habits Questionnaire (CSHQ) filled in by parents. Of eight CSHQ subscales, we evaluated sleep onset delay, sleep duration, night wakenings, parasomnias and daytime sleepiness with logistic or negative binomial regression models, adjusting for child's age and sex and indicators of socio-economic position of the parents. We evaluated the remaining three subscales (bedtime resistance, sleep anxiety, sleep disordered breathing) as unrelated outcomes (negative control) because these were a priori hypothesised not to be associated with RF-EMF.


RESULTS
Sleep onset delay, night wakenings, parasomnias and daytime sleepiness were not associated with residential exposure to RF-EMF from base stations. Sleep duration scores were associated with RF-EMF levels from base stations. Higher use mobile phones was associated with less favourable sleep duration, night wakenings and parasomnias, and also with bedtime resistance. Cordless phone use was not related to any of the sleeping scores.


CONCLUSIONS
Given the different results across the evaluated RF-EMF exposure sources and the observed association between mobile phone use and the negative control sleep scale, our study does not support the hypothesis that it is the exposure to RF-EMF that is detrimental to sleep quality in 7-year old children, but potentially other factors that are related to mobile phone usage.
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; Institute for Social and Preventive Medicine, Bern, Switzerland.
Anke
A
Huss
Department of Epidemiology, Documentation and Health Promotion, Public Health Service of Amsterdam (GGD), Amsterdam, The Netherlands.
Manon
M
van Eijsden
Center for Research in Environmental Epidemiology, Barcelona, Spain.
Monica
M
Guxens
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
Johan
J
Beekhuizen
Department of Environmental Health, Public Health Service of Amsterdam (GGD), Amsterdam, The Netherlands.
Rob
R
van Strien
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
Hans
H
Kromhout
Department of Public Health, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Tania
T
Vrijkotte
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; Julius Centre for Public Health Sciences and Primary Care, University Medical Centre, Utrecht, The Netherlands.
Roel
R
Vermeulen
D040421:Cell Phone / Q000706:statistics & numerical data; D002648:Child; D015331:Cohort Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D011846:Radio Waves / Q000009:adverse effects; D057566:Self Report; D012890:Sleep / Q000502:physiology*