title: Memory performance, wireless communication and exposure to radiofrequency electromagnetic fields: A prospective cohort study in adolescents.
abstract: BACKGROUND
  The aim of this study is to investigate whether memory performance in adolescents is affected by radiofrequency electromagnetic fields (RF-EMF) from wireless device use or by the wireless device use itself due to non-radiation related factors in that context.
  
  
  METHODS
  We conducted a prospective cohort study with 439 adolescents. Verbal and figural memory tasks at baseline and after one year were completed using a standardized, computerized cognitive test battery. Use of wireless devices was inquired by questionnaire and operator recorded mobile phone use data was obtained for a subgroup of 234 adolescents. RF-EMF dose measures considering various factors affecting RF-EMF exposure were computed for the brain and the whole body. Data were analysed using a longitudinal approach, to investigate whether cumulative exposure over one year was related to changes in memory performance. All analyses were adjusted for relevant confounders.
  
  
  RESULTS
  The kappa coefficients between cumulative mobile phone call duration and RF-EMF brain and whole body dose were 0.62 and 0.67, respectively for the whole sample and 0.48 and 0.28, respectively for the sample with operator data. In linear exposure-response models an interquartile increase in cumulative operator recorded mobile phone call duration was associated with a decrease in figural memory performance score by -0.15 (95% CI: -0.33, 0.03) units. For cumulative RF-EMF brain and whole body dose corresponding decreases in figural memory scores were -0.26 (95% CI: -0.42, -0.10) and -0.40 (95% CI: -0.79, -0.01), respectively. No exposure-response associations were observed for sending text messages and duration of gaming, which produces tiny RF-EMF emissions.
  
  
  CONCLUSIONS
  A change in memory performance over one year was negatively associated with cumulative duration of wireless phone use and more strongly with RF-EMF dose. This may indicate that RF-EMF exposure affects memory performance.
authors.affiliation: Swiss Tropical and Public Health Institute, Department of Epidemiology and Public Health, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Schoeni
authors.affiliation: Swiss Tropical and Public Health Institute, Department of Epidemiology and Public Health, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Katharina
authors.initials: K
authors.lastname: Roser
authors.affiliation: Swiss Tropical and Public Health Institute, Department of Epidemiology and Public Health, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Basel, Switzerland. Electronic address: martin.roosli@unibas.ch.
authors.forename: Martin
authors.initials: M
authors.lastname: Röösli
mesh_terms: D000293:Adolescent; D040421:Cell Phone; D015331:Cohort Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000528:radiation effects*; D008962:Models, Theoretical; D011446:Prospective Studies; D011846:Radio Waves / Q000009:adverse effects*; D012423:Rural Health; D011795:Surveys and Questionnaires; D013557:Switzerland; D014504:Urban Health
keywords: Adolescents; Memory performance; Mobile phone use; RF-EMF dose