title: Exposure to radiofrequency electromagnetic fields and sleep quality: a prospective cohort study.
abstract: BACKGROUND
  There is persistent public concern about sleep disturbances due to radiofrequency electromagnetic field (RF-EMF) exposure. The aim of this prospective cohort study was to investigate whether sleep quality is affected by mobile phone use or by other RF-EMF sources in the everyday environment.
  
  
  METHODS
  We conducted a prospective cohort study with 955 study participants aged between 30 and 60 years. Sleep quality and daytime sleepiness was assessed by means of standardized questionnaires in May 2008 (baseline) and May 2009 (follow-up). We also asked about mobile and cordless phone use and asked study participants for consent to obtain their mobile phone connection data from the mobile phone operators. Exposure to environmental RF-EMF was computed for each study participant using a previously developed and validated prediction model. In a nested sample of 119 study participants, RF-EMF exposure was measured in the bedroom and data on sleep behavior was collected by means of actigraphy during two weeks. Data were analyzed using multivariable regression models adjusted for relevant confounders.
  
  
  RESULTS
  In the longitudinal analyses neither operator-recorded nor self-reported mobile phone use was associated with sleep disturbances or daytime sleepiness. Also, exposure to environmental RF-EMF did not affect self-reported sleep quality. The results from the longitudinal analyses were confirmed in the nested sleep study with objectively recorded exposure and measured sleep behavior data.
  
  
  CONCLUSIONS
  We did not find evidence for adverse effects on sleep quality from RF-EMF exposure in our everyday environment.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Mohler
authors.forename: Patrizia
authors.initials: P
authors.lastname: Frei
authors.forename: Jürg
authors.initials: J
authors.lastname: Fröhlich
authors.forename: Charlotte
authors.initials: C
authors.lastname: Braun-Fahrländer
authors.forename: Martin
authors.initials: M
authors.lastname: Röösli
mesh_terms: D000328:Adult; D040421:Cell Phone; D015331:Cohort Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D011446:Prospective Studies; D011846:Radio Waves / Q000009:adverse effects*; D012044:Regression Analysis; D012890:Sleep / Q000528:radiation effects*; D011795:Surveys and Questionnaires; D013557:Switzerland