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.

Deriving high-resolution urban air pollution maps using mobile sensor nodes

“…To monitor air pollution, the sensor nodes are equipped with a semiconductor-based ozone (O 3 ) sensor [15], electrochemical-based carbon monoxide (CO) and nitrogen dioxide (NO 2 ) sensors [16,17], and a novel compact device to measure UFP concentrations [9]. Additionally, the nodes monitor radiofrequency electromagnetic fields [18] and environmental parameters, such as temperature and humidity [19]. Over the past two years, we collected huge data sets of spatially resolved pollution measurements, as summarized in Table 1.…”

“…Low-cost gas sensors are often embedded in custom-built, personal sensor nodes that are part of participatory sensing networks [40,41]. Participants can directly monitor the exposure level at locations where they spent their time [42].…”

Empowering smartphone users with sensor node for air quality measurement

“…Concentrations of most of the mentioned gasses are measured either using passive electrochemical sensors, featuring lower power consumption, but higher prices and shorter life-time [7], or using longer-lasting and lower priced semiconductor metal-oxide (MOX) sensors [8,9]. Requiring heating, minimization of their high power consumption remains an open research topic [10,11].…”

“…Particularly interesting are concepts of participatory sensing, featuring citizens participating in context-aware collection of information. In such designs, sensors typically use smartphones for geo-tagging and relaying information into the web-service accessed by public [5][6][7][8].Typically, concentrations of atmospheric gasses and pollutants, such as CO, CO 2 , NO 2 , O 3 , SO 2 , and volatile-organic compounds (VOC), are measured, along with temperature, humidity, barometric pressure and particulate matter. Concentrations of most of the mentioned gasses are measured either using passive electrochemical sensors, featuring lower power consumption, but higher prices and shorter life-time [7], or using longer-lasting and lower priced semiconductor metal-oxide (MOX) sensors [8,9].…”

“…In such designs, sensors typically use smartphones for geo-tagging and relaying information into the web-service accessed by public [5][6][7][8].…”