Clean air action: applications of citizen science to identify and address air pollution emission sources

To help understand how citizen science initiatives reflect or focus on sources of air pollution, this paper presents reflections from a purposive literature review of 33 case studies. Specifically it provides insights and a typology of citizen science initiatives that characterize how citizen science initiatives impact air pollution sources and provides recommendations for future approaches that could strengthen participatory science focused on pollution sources. Some of the key findings of the study are despite the growing number of citizen science projects designed to investigate air pollution and related health concerns, the public still lacks a clear shared understanding of where air pollution comes from—the relevant sources of emissions. This lack of source awareness can impede clear air action in various ways. To help strengthen outcomes focused on source awareness, this paper catalogs how citizen science initiatives investigate sources of air pollution. The paper summarizes insights drawn from a literature review and outlines a new typology for citizen science initiatives focused on pollution sources. It articulates six pathways for achieving outcomes. The review revealed that these initiatives not only help increase public knowledge, but identify new hyperlocal sources, strengthen source-specific enforcement action, tie exposure and health impacts to specific emissions sources, and spur stronger compliance by polluting companies. Common features in achieving clear outcomes included taking time to build trust, a commitment to joint scientist-civil society leadership, and defining clear ways to use data. Challenges addressing source awareness arose from the complexity and diversity of air pollution sources and community frustration over the difficulties of definitively connecting pollution emissions data to specific sources.