Streetlight sensor can track localised air pollution
Image credit: chalmers uni
Air pollution could soon be measured on every street corner thanks to a small, optical nano-sensor, developed at Chalmers University of Technology, Sweden, which can be mounted onto an ordinary streetlight.
Exhaust gases from road traffic are responsible for the majority of nitrogen dioxide pollution in the air, a gas that is harmful to human health even at very low levels.
According to the World Health Organisation, air pollution is the single biggest environmental health risk worldwide.
The new optical nano-sensor can detect low concentrations of nitrogen dioxide very precisely – down to the parts-per-billion level (ppb).
The measuring technique is built upon an optical phenomenon, which is called a plasmon. It arises when metal nanoparticles are illuminated and absorb light of certain wavelengths.
The sensor is currently being trialled on a streetlight and on the roof of Nordstan in Gothenburg, one of Scandinavia’s biggest shopping malls. More will soon be placed along the route of Västlänken, a major railway tunnel construction project, also in Gothenburg.
“Air pollution is a global health problem. To be able to contribute to increased knowledge and a better environment feels great,” said Chalmers researcher Irem Tanyeli.
“With the help of these small, portable sensors, it can become both simpler and cheaper to measure dangerous emissions extremely accurately.”
The sensor will help to track where the most polluted areas in a city are and could complement burgeoning satellite technologies that are being used to take a bigger picture of air pollution hotspots.
“In the future, we hope that the technology also can be integrated into other urban infrastructure, like traffic lights or speed cameras, or for measuring air quality indoors,” Tanyeli said.
Urban Flows Observatory, an air quality centre at the University of Sheffield, is also set to conduct field testing, comparing the nanosensors’ results with data from a number of British reference stations.
“There is a lack of small functional nitrogen dioxide sensors on the market. We find this nano plasmonic solution interesting, and look forward to the test results,” said professor Martin Mayfield at Urban Flows Observatory.
Other interested parties include Stenhøj Sverige, a company which develops gas and smoke analysers for automotive repair shops and vehicle inspection companies.
The new sensor technology is not limited to measuring nitrogen dioxide as it can also be adapted to other types of gases.
“Nitrogen dioxide is just one of the many substances which can be detected with the help of optical nanosensors. There are great opportunities for this type of technology,” said Chalmers researcher Christoph Langhammer.
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