CurieuzeNeuzen Vlaanderen — Belgium's 20,000-Point Citizen Science Air Quality Map

CurieuzeNeuzen Vlaanderen was a month-long citizen science campaign led by Prof. Filip Meysman at the University of Antwerp, in partnership with the Flemish Environment Agency (VMM), the Flemish Institute for Technological Research (VITO), KU Leuven's HIVA institute, and the newspaper De Standaard. From 53,000 applicants, 20,000 households, schools, and businesses across Flanders were selected to hang two NO2 passive-sampler tubes at their address for the month of April–May 2018.
Return and data quality were unusually high for a mass citizen-science exercise: over 99% of tubes were returned, 96% (19,161 samples) produced valid readings, and 89% passed stricter quality screening for the final statistical analysis. The resulting street-level map, published in September 2018, showed sharp block-by-block variation — for example a hotspot of 45–50 µg/m³ on a single street in historic Bruges, above the EU's 40 µg/m³ annual limit — and was used to sharpen the ATMOSYS air-quality model's estimates of population exposure.
The campaign did not itself mandate policy change, and organisers were explicit that its primary output was a public information and research dataset rather than a regulatory instrument. Its scale and rigour nonetheless made it replicable: follow-up editions ran in Antwerp (CurieuzeLucht, 2020) and Brussels (CurieuzenAir), each adapting the same passive-sampler protocol to a different city administration and citizen base.

Read the full analysis: https://www.irceline.be/en/documentation/projects/curieuzeneuzen-flanders