Spatially Resolved Monitoring of Radio-Frequency Electromagnetic Fields

Abstract

Radio-frequency electromagnetic fields are emitted by many applications, such as radio broadcasting and mobile communication. A part of the general public is increasingly concerned about the long-term effects of electromagnetic radiation on human health. However, the accurate exposure assessment in people's everyday life remains a formidable challenge. State-of-the-art personal exposure meters are expensive and tedious to use. Epidemiological large-scale studies are rare and governmental compliance measurements can only cover a small number of locations of high interest (e.g., schools). In this paper, we demonstrate that accurate, spatially resolved electromagnetic field measurements are feasible with commodity sensor nodes. We show the design, implementation, and evaluation on mobile air quality sensor nodes, which traverse a large urban area on top of public transport vehicles in Zurich, Switzerland. We collect a data set with over 4 million measurements and use it to develop the first exposure map of Zurich with a spatial resolution of 100 m. Further, we compare the found exposure levels to measurements from different urban cities across Europe.