A study led by University of Barcelona researchers and carried out together with more than 1,650 students and their family members from 18 educational centers in Barcelona shows that citizen science is a valid approach able for doing high quality science, and in this case, able to provide nitrogen dioxide values with an unprecedented resolution and to assess the impact of the pollution in the health of their inhabitants.
source https://phys.org/news/2021-07-schools-barcelona-city-air-pollution.html