Mayors, Facebook and air pollution: A missed opportunity for citizen engagement?

According to the World Health Organisation, nearly the entire global population is still exposed to unsafe levels of air pollution. Road transportation is a significant contributor to this issue, prompting supranational and national authorities to implement policies aimed at reducing transport-related emissions. While evidence shows that such policies can significantly improve air quality, their success largely depends on effective citizen engagement. In this context, social media platforms have become one of the most widespread tools for citizen engagement in recent decades. Against this backdrop, this study explores whether the mayors of the Italian regional capitals use their Facebook pages to engage citizens in transport policies aimed at improving air quality and examines the levels of citizen engagement with posts on this topic. Using a dataset of 5009 Facebook posts published by mayors over one year, this study employed a zero-shot classification approach to identify and categorise posts about transport policies. An engagement matrix was then used to explore the levels of citizen engagement achieved by each Facebook page regarding these policies. Our findings lead to three main conclusions. First, despite the significant impact of transportation on human health, mayors devoted only a small number of their posts to transport policies. Second, while the levels of citizen engagement varied notably across pages, mayors primarily used their pages for public communication rather than fostering public participation. Finally, an intriguing pattern emerged between engagement levels and cities' air quality, suggesting a potential link between them and environmental conditions.