Behavioural and social determinants of ambient air pollution exposure: an umbrella review

Abstract

Air quality indices play a critical role in assessing and communicating the health risks associated with ambient air pollution. In Canada, the Air Quality Health Index is designed for real-time public communication, while the Air Health Trend Indicator monitors temporal trends in population-level health risks and supports policy evaluation. However, as air quality indices are primarily grounded in population-level biostatistics, there is a growing need to incorporate behavioural and social determinants, for which evidence remains fragmented across disciplines and geographical contexts. This umbrella review systematically examined how behavioural and social factors influence exposure to ambient air pollution, with the aim of informing the refinement of air quality indices in diverse local contexts, including Canada. Five databases (PubMed, CINAHL, Scopus, GreenFILE, Environment Complete) were systematically searched in November 2024 to identify studies reporting human behaviours and social structures as either exogenous or endogenous variables associated with exposure to ambient air pollution. Quality assessment using the JBI tools, quantitative descriptive analysis, and qualitative thematic analysis were conducted. Findings from 18 reviews included participants varying in age, region, race, behaviour type, and health conditions. Evidence synthesis identified two overarching categories—human behaviour, society—comprising three behavioural themes (physical activity, travel, protection), four societal themes (public health, urban planning, neighbourhood/housing, social identity), and 17 subthemes. Findings indicate that time spent outdoors is associated with increased individual exposure to air pollution, while social factors such as greenspace and public health advisories, as well as race and socio-economic status, influence community-level exposure. The findings highlight the need to integrate behavioural and social factors into air quality assessment frameworks. A more nuanced understanding of behaviour-society-environment interactions is essential to underpin the development of equitable, evidence-based public health interventions that both mitigate health risks among vulnerable populations and promote overall public health in increasingly polluted urban environments.