Temporal and spatial variability of personal exposure to radio frequency electromagnetic fields

摘要

Background: Little is known about the population's exposure to radio frequency electromagnetic fieldsrn(RF-EMF) in industrialized countries.rnObjectives: To examine levels of exposure and the importance of different RF-EMF sources and settingsrnin a sample of volunteers living in a Swiss city.rnMethods: RF-EMF exposure of 166 volunteers from Basel, Switzerland, was measured with personalrnexposure meters (exposimeters). Participants carried an exposimeter for 1 week (two separate weeks inrn32 participants) and completed an activity diary. Mean values were calculated using the robustrnregression on order statistics (ROS) method.rnResults: Mean weekly exposure to all RF-EMF sources was 0.13 mW/m~2 (0.22 V/m) (range of individualrnmeans 0.014-0.881 mW/m~2). Exposure was mainly due to mobile phone base stations (32.0%), mobilernphone handsets (29.1%) and digital enhanced cordless telecommunications (DECT) phones (22.7%).rnPersons owning a DECT phone (total mean 0.15 mW/m~2) or mobile phone (0.14 mW/m~2) were exposedrnmore than those not owning a DECT or mobile phone (0.10 mW/m~2). Mean values were highest in trainsrn(1.16mW/m~2), airports (0.74 mW/m~2) and tramways or buses (0.36 mW/m~2), and higher during daytimern(0.16 mW/m~2) than nighttime (0.08 mW/m~2). The Spearman correlation coefficient between meanrnexposure in the first and second week was 0.61.rnConclusions: Exposure to RF-EMF varied considerably between persons and locations but was fairlyrnconsistent within persons. Mobile phone handsets, mobile phone base stations and cordless phonesrnwere important sources of exposure in urban Switzerland.