The city of Brussels is asking local businesses and citizens to measure nitrogen dioxide (NO2) levels from their homes in order to determine the quality of the air in one of the most polluted cities in Europe.
Known as CurieuzenAir, it is the largest and most detailed citizen research study ever carried out on air quality in the Belgian capital, with measuring devices to be used at 3,000 different locations from 25 September to 23 October. Locals can still register until mid June.
Participants will receive an instrument to fix to their window, which they will then return once the four weeks are up.
Euronews spoke to one couple Amandine and Geoffrey, who said they were concerned for their family and the air they breathe.
"We were interested because we have four children here in the city... and we spend a lot of time outside and we really want a better air quality for our children and for ourselves in the city," Geoffrey explained.
At the end of the campaign, the data collected will be analysed by experts and will enable a better assessment of the effects of NO2 on health in order to inform Brussels residents and policy-makers how they can improve the situation.
Elke Van de Brandt, Brussels' mobility minister, told Euronews: "The people in Brussels are really longing for better air quality... so we know that in the end, people want to follow this direction... people do want to change the city.
"And of course, getting there will create some friction. But we need to explain to people why it's better for everybody."