title: Temporal trends of radio-frequency electromagnetic field (RF-EMF) exposure in everyday environments across European cities.
abstract: BACKGROUND
  The rapid development and increased use of wireless telecommunication technologies led to a substantial change of radio-frequency electromagnetic field (RF-EMF) exposure in the general population but little is known about temporal trends of RF-EMF in our everyday environment.
  
  
  OBJECTIVE
  The objective of our study is to evaluate temporal trends of RF-EMF exposure levels in different microenvironments of three European cities using a common measurement protocol.
  
  
  METHODS
  We performed measurements in the cities of Basel (Switzerland), Ghent and Brussels (Belgium) during one year, between April 2011 and March 2012. RF-EMF exposure in 11 different frequency bands ranging from FM (Frequency Modulation, 88 MHz) to WLAN (Wireless Local Area Network, 2.5 GHz) was quantified with portable measurement devices (exposimeters) in various microenvironments: outdoor areas (residential areas, downtown and suburb), public transports (train, bus and tram or metro rides) and indoor places (airport, railway station and shopping centers). Measurements were collected every 4s during 10-50 min per environment and measurement day. Linear temporal trends were analyzed by mixed linear regression models.
  
  
  RESULTS
  Highest total RF-EMF exposure levels occurred in public transports (all public transports combined) with arithmetic mean values of 0.84 V/m in Brussels, 0.72 V/m in Ghent, and 0.59 V/m in Basel. In all outdoor areas combined, mean exposure levels were 0.41 V/m in Brussels, 0.31 V/m in Ghent and 0.26 V/m in Basel. Within one year, total RF-EMF exposure levels in all outdoor areas in combination increased by 57.1% (p<0.001) in Basel by 20.1% in Ghent (p=0.053) and by 38.2% (p=0.012) in Brussels. Exposure increase was most consistently observed in outdoor areas due to emissions from mobile phone base stations. In public transports RF-EMF levels tended also to increase but mostly without statistical significance.
  
  
  CONCLUSIONS
  An increase of RF-EMF exposure levels has been observed between April 2011 and March 2012 in various microenvironments of three European cities. Nevertheless, exposure levels were still far below regulatory limits of each country. A continuous monitoring is needed to identify high exposure areas and to anticipate critical development of RF-EMF exposure at public places.
authors.affiliation: Swiss Tropical and Public Health Institute, Department of Epidemiology and Public Health, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, Basel, Switzerland; Department of Information Technology, Ghent University/iMinds, Gaston Crommenlaan 8, B-9050 Ghent, Belgium.
authors.forename: Damiano
authors.initials: D
authors.lastname: Urbinello
authors.affiliation: Department of Information Technology, Ghent University/iMinds, Gaston Crommenlaan 8, B-9050 Ghent, Belgium.
authors.forename: Wout
authors.initials: W
authors.lastname: Joseph
authors.affiliation: Department of Information Technology, Ghent University/iMinds, Gaston Crommenlaan 8, B-9050 Ghent, Belgium.
authors.forename: Leen
authors.initials: L
authors.lastname: Verloock
authors.affiliation: Department of Information Technology, Ghent University/iMinds, Gaston Crommenlaan 8, B-9050 Ghent, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Martens
authors.affiliation: Swiss Tropical and Public Health Institute, Department of Epidemiology and Public Health, Socinstrasse 57, CH-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: D002947:Cities; D004574:Electromagnetic Fields; D004781:Environmental Exposure; D005060:Europe; D006801:Humans; D011846:Radio Waves
keywords: Exposimeter; Monitoring; Personal exposure; Radio-frequency electromagnetic field (RF-EMF); Temporal trends