title: Validity of at home model predictions as a proxy for personal exposure to radiofrequency electromagnetic fields from mobile phone base stations.
abstract: BACKGROUND
  Epidemiological studies on the potential health effects of RF-EMF from mobile phone base stations require efficient and accurate exposure assessment methods. Previous studies have demonstrated that the 3D geospatial model NISMap is able to rank locations by indoor and outdoor RF-EMF exposure levels. This study extends on previous work by evaluating the suitability of using NISMap to estimate indoor RF-EMF exposure levels at home as a proxy for personal exposure to RF-EMF from mobile phone base stations.
  
  
  METHODS
  For 93 individuals in the Netherlands we measured personal exposure to RF-EMF from mobile phone base stations during a 24h period using an EME-SPY 121 exposimeter. Each individual kept a diary from which we extracted the time spent at home and in the bedroom. We used NISMap to model exposure at the home address of the participant (at bedroom height). We then compared model predictions with measurements for the 24h period, when at home, and in the bedroom by the Spearman correlation coefficient (rsp) and by calculating specificity and sensitivity using the 90th percentile of the exposure distribution as a cutpoint for high exposure.
  
  
  RESULTS
  We found a low to moderate rsp of 0.36 for the 24h period, 0.51 for measurements at home, and 0.41 for measurements in the bedroom. The specificity was high (0.9) but with a low sensitivity (0.3).
  
  
  CONCLUSIONS
  These results indicate that a meaningful ranking of personal RF-EMF can be achieved, even though the correlation between model predictions and 24h personal RF-EMF measurements is lower than with at home measurements. However, the use of at home RF-EMF field predictions from mobile phone base stations in epidemiological studies leads to significant exposure misclassification that will result in a loss of statistical power to detect health effects.
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Division Environmental Epidemiology, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands; Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: a.l.martens@uu.nl.
authors.forename: Astrid L
authors.initials: AL
authors.lastname: Martens
authors.affiliation: National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands. Electronic address: john.bolte@rivm.nl.
authors.forename: John F B
authors.initials: JF
authors.lastname: Bolte
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Division Environmental Epidemiology, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands. Electronic address: beekhuizenjohan@gmail.com.
authors.forename: Johan
authors.initials: J
authors.lastname: Beekhuizen
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Division Environmental Epidemiology, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands. Electronic address: h.kromhout@uu.nl.
authors.forename: Hans
authors.initials: H
authors.lastname: Kromhout
authors.affiliation: Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; KLM Health Services, Schiphol, The Netherlands. Electronic address: Tjabe.Smid@klm.com.
authors.forename: Tjabe
authors.initials: T
authors.lastname: Smid
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Division Environmental Epidemiology, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands; Julius Centre for Health Sciences and Primary Care, University Medical Center, Utrecht, The Netherlands; Imperial College, Department of Epidemiology and Public Health, London, United Kingdom. Electronic address: R.C.H.Vermeulen@uu.nl.
authors.forename: Roel C H
authors.initials: RC
authors.lastname: Vermeulen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D040421:Cell Phone; D004574:Electromagnetic Fields; D005260:Female; D006798:Housing; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009426:Netherlands; D000069079:Radiation Exposure / Q000032:analysis*; D011846:Radio Waves; D055815:Young Adult
keywords: Electromagnetic fields; Exposure assessment; Mobile phone base station; Model; RF-EMF