European citizens measure air pollution with their smartphones

A successful Dutch initiative that enlisted the general public to contribute to the understanding of air pollution is being scaled up thanks to the LIGHT2015 project and it is running during the International Year of Light and Light-based Technologies 2015 its first Europe-wide citizen campaign: iSPEX-EU. From 1 September to 15 October 2015, thousands of citizens in major European cities will take to their streets, squares and parks to measure air pollution with their smartphone. Participating cities include: Athens, Barcelona, Belgrade, Berlin, Copenhagen, London, Manchester, Milan, and Rome.


iSPEX-EU, which is organised by the iSPEX and LIGHT2015 projects, distributes small devices that can be attached to smartphones to measure air pollution. These add-ons are “spectropolarimeters” that, in combination with the phone’s camera, sensors, computing and communications capabilities, can be used to measure tiny particles in the air that contribute to air pollution and its impacts in an as-yet poorly understood way.

The application of iSPEX is two-fold: 1) It enables crowd-sourced measurements of tiny atmospheric particles, also known as aerosols, at locations and times that are not covered by current air pollution monitoring efforts. 2) It makes atmospheric science accessible to everyone, by active participation in scientific measurements.

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 polarization of the sunlight. The measurements taken using the phone camera can provide unique information about the properties of the particles in the air, including how concentrated these particles are. This type of measurement is crucial in assessing the impacts of atmospheric aerosols on health, environment and air traffic.

With the advent of smartphones and the development of iSPEX, citizens can now contribute to these crucial measurements and together form a flexible network that can deliver measurements from cities across Europe, even where no specialised equipment is available, and at any daylight hour. The active involvement of citizens in an important and real scientific experiment, pioneering a new form of citizen science where participants carry out complex, simultaneous mass-measurements, is the most important aspect of this project.

The citizen science approach was successfully trialed at national level in the Netherlands in 2013. Organised by Dutch national project iSPEX, the initiative involved thousands of volunteers and led to the assembling of atmospheric particle maps of the Netherlands that are significantly more detailed than those available from satellite monitoring.  This success of this project resulted in iSPEX-EU, the European expansion of this citizen science approach in contribution to an improved understanding of air pollution and its various impacts.

For more information visit and Follow also the twitter @ispex_eu and @LIGHT2015Europe accounts for the latest updates.

About Leiden Observatory

Leiden Observatory is part of Leiden University, one of Europe’s foremost research universities and lead institute of the iSPEX consortium. Its astronomical instrumentation researchers have developed the iSPEX smartphone add-on. Leiden Observatory is the world’s oldest university observatory and is one of the world’s leading astronomical institutes with over 25 faculty and over 70 PdD students.

Leiden Observatory plays an active role in astronomical outreach activities at local, national and international levels. It hosts the Universe Awareness (UNAWE) programme, which educates and inspires young children. With iSPEX add-on and app for the smartphone, Leiden Observatory introduces a new measurement technique for tiny atmospheric particles that make significant part of air pollution, but more important, also a modern measurement philosophy: citizen science. As such, iSPEX fosters scientific literacy and awareness of the environment in its participants, in young and old, in their families and friends, in bystanders, and in the general public through media exposure.


About LIGHT2015

LIGHT2015 is a European project funded through the European Union’s Horizon 2020 research and innovation programme of the European Commission. It aims to promote the importance of photonics to young people, entrepreneurs and the general public in all Member States of the EU during the International Year of Light and Light-based Technologies 2015 (IYL 2015).

LIGHT2015 activities will include LIGHTtalks, a series of inspirational events, which will take place throughout the European Union in different cities at different times for the whole duration of the project in order to bring photonics closer to students and entrepreneurs. A specific series of events targeted to local industry and entrepreneurs, will take place during the period 25-28 September 2015 to take advantage of the international “100 Hours / Weekend of Light” of the global IYL 2015 programme.

Another highlight of LIGHT2015 will be a community experiment on smartphone photonics where thousands of participants from throughout the EU will carry out optical measurements of the sky to yield information related to air pollution. To aid teachers and to inspire student, Photonics kits will be distributed to schools around Europe to support the scientific education at secondary schools.

LIGHT2015 Partners include the European Physical Society (EPS), the European Optical Society (EU), the Institute of Photonics Sciences (ICFO), Politecnico di Milano (POLIMI) the National University of Ireland Galway (NUI), Universiteit Leiden and EYESTvzw.


Elise Hendriks
iSPEX-EU Coordinator

Jorge Rivero González
LIGHT2015 Project Officer

David Lee
LIGHT2015 Coordinator