Inhabitants of several European cities have been invited to use their smartphones to measure air pollution.
Between 1 September and 15 October, citizens of Athens, Barcelona, Belgrade, Berlin, Copenhagen, London, Manchester, Milan and Rome can join the European iSPEX project to help monitor air quality in their cities.
iSPEX distributes small devices that can be attached to every regular smartphone, turning it into an optical sensor.
These so called spectropolarimeters, combined with the phone’s camera, sensors, computing and communications capabilities can be used to measure tiny particles in the air around.
The sensors can distinguish between particles of natural origin coming from sea salt, forest fires and volcanic eruptions, and human-made soot particles produced by combustion engines and industrial facilities.
The iSPEX app instructs participants to scan the cloud-free sky while the phone’s built-in camera takes pictures through the add-on. Each picture taken through the iSPEX add-on contains information on both the spectrum and the linear polarisation of the sunlight. The measurements taken using the phone camera can provide unique information about the properties of the particles in the air, including the amount of particles, their size distribution and type.
The project proponents hope the data gathered will improve understanding of the distribution of the particulate matter in the atmosphere compared to what has been possible with the conventional pollution measurement network.
The iSPEX project started in the Netherlands in 2013 with three national measurement days in which thousands of citizens took part.
The data was used to create an atmospheric particle maps of the Netherlands that achieved higher detail than those available from satellite monitoring and filled blind spots of established ground-based atmospheric measurement networks.