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Brussels Launches Europe’s Largest Citizen Science Project on Air Quality

Brussels, Belgium – Launched today, CurieuzenAir is the largest citizen science project on air quality ever carried out in Brussels. This pioneering project will mobilize thousands of citizens to map the air quality levels across the Brussels-Capital Region with professional guidance by scientists. The launch coincides with the lead-up to the EU Green Week 2021. The initiative is supported by Bloomberg Philanthropies’ Brussels Clean Air Partnership.


Brussels, the seat of the European Commission, will be the first European capital to undertake a citizen science project at this scale. Through simultaneous measurements at 3.000 different locations, CurieuzenAir aims to map the air quality across the Brussels-Capital Region with unprecedented spatial detail. To this end, families, companies, associations and schools will be given the opportunity to measure the air quality in their own street. Today through June 13, they can register for CurieuzenAir to receive one of the 3,000 measuring kits being made available. The measurements will take place during a four-week period beginning on September 25th. The pilot project intends to serve as a pioneering example for replication across other European cities.


Through CurieuzenAir, citizens can help science take a big step forward. Air quality differs strongly from one location to the next due to the so-called “street canyon” effect. In a narrow and busy street, pollutants linger for longer and the air quality worsens. At the same time, just around the corner in a nearby park or open space, the air quality can be remarkably better. Because air quality can vary so widely, mapping it across the Brussels-Capital Region requires many measurements in a great number of places. This is why CurieuzenAir calls upon the help of citizens and distributes 3.000 easy-to-deploy sensor kits. By jointly measuring the air quality at 3.000 locations across Brussels, citizens can help to solve a challenging scientific problem. CurieuzenAir will generate an internationally unique dataset that provides insight into the exposure and health impacts of air pollution. This data will help to better inform clean air policies and be used by Brussels Environment to improve air quality models. This way CurieuzenAir innovatively contributes to the EU’s new Zero Pollution Action Plan that places great emphasis on improving air quality with broad citizen engagement.


CurieuzenAir uses an inventive set-up that allows citizens to collect high-quality data. Participants attach a small “real estate panel” to a window at the front of their house. Inside the “nose” of the panel there are two test tubes, which determine the concentration of nitrogen dioxide (NO2), an indicator for traffic-related pollution, in the outside air. The real-estate panel remains in place for four weeks. The resulting data will undergo strict quality control and be calibrated against the 11 permanent air quality stations of Brussels Environment.


In a first for Brussels, CurieuzenAir brings together universities, NGOs, government agencies and media partners in a science-based, coordinated initiative on air quality. The air quality data will be collected under the professional guidance of scientists from the University of Antwerp, while the socio-economic analysis within the project will be directed by the Université Libre de Bruxelles. The city movement BRAL will assist with engaging citizens and local communities in the project. Media partners Le Soir, De Standaard and BRUZZ support CurieuzenAir with a professional communication campaign. The initiative is part of the Brussels Clean Air Partnership, a collaboration launched in October 2020 between Bloomberg Philanthropies, the Brussels-Capital Region Government, and Brussels Environment, to galvanize local and international partners to improve air quality through innovation, research and monitoring, citizen engagement, and education programs.

Brussels citizens can register their interest in participating in the CurieuzenAir project until June 13 at

Florence Lepoudre, BRAL: “We have already been working for years with the citizens of Brussels to improve the air quality. CurieuzenAir is the next important step for us. The expertise on large-scale citizen science provided by the University of Antwerp makes this a unique project for Brussels.”

Alain Maron, Brussels Minister for Climate Transition, Environment, Social Affairs and Health highlights the importance of the project and his support to put citizen science on the map: “I am delighted that so many inhabitants of Brussels have the opportunity to conduct air quality measurements themselves. The data from CurieuzenAir will provide a detailed insight in the air quality across Brussels, as well as the associated health effects. This will allow us to establish a science-based policy to reduce air pollution, in order to improve the quality of life of those living, working or visiting Brussels.”

Antha Williams, Global Head of Environment Programs at Bloomberg Philanthropies: “CurieuzenAir, the largest citizen science project in Europe, brings together citizens, researchers, government leaders, and low-cost technologies to monitor air quality throughout the city. Bloomberg Philanthropies is proud to collaborate with our partners in Brussels and hope this project sets an example that cities across the continent can draw on as they build a cleaner, healthier future.”


Note to editors:

  • 3.000 citizen scientists will help provide a detailed map of Brussels’ air quality in Brussels
  • Nitrogen dioxide (NO2) is an indicator of traffic-based air pollution, and will be measured using diffusion tubes that will be installed outside windows
  • The measurement campaign will last four weeks from 25 September to 23 October 2021
  • Citizen-science project is an initiative by the University of Antwerp, BRAL, Universite Libre de Bruxelles, Bloomberg Philanthropies, Environment Brussels and media partners Le Soir, De Standaard, and BRUZZ.

Media Contacts:
Florence Lepoudre – BRAL (FR, NL, EN)
+32 472 780 772

Daphne Wang – Bloomberg Philanthropies (EN)
+1 646 771 1473