Abstract
Air pollution is a serious problem that is causing increasing concern among European citizens. It is responsible for more than 400,000 premature deaths in Europe each year and considerably damages human health, agriculture, and the natural environment. Despite these facts, the readiness and power of citizens to take actions is limited. To address this challenge, the citizen science project CAPTOR was launched in 2016. Using low-cost measurement devices, citizens in three European testbeds supported the monitoring of tropospheric ozone. This paper presents the results from 53 interviews with involved residents and shows that the active involvement of individuals in a complex process such as measuring tropospheric ozone can have important impacts on their knowledge and attitudes. In an attempt to expand the benefits of low-cost air quality sensors from an individual to a regional level, certain preconditions are key. Strong support in assuring data quality, visibility of the collected data in online and offline media, broad dissemination of results, and intensified communication with political decision-makers are needed.