Air pollution is a significant global environmental threat exacerbated by anthropogenic processes, including urbanization, industrialization, and climate change. Active transportation (AT), defined as modes of travel that rely on physical human effort such as walking or cycling, has emerged as a strategy for improving population health and reducing environmental impacts. Active transportation contributes to sustainability goals by reducing dependence on motorized vehicles, lowering greenhouse gas emissions, decreasing traffic congestion, and increasing daily physical activity (PA), supporting both environmental and health outcomes. However, individuals engaging in PA near motorized traffic are exposed to traffic-related air pollutants. This creates a public health paradox in which environments that promote PA may simultaneously impair cardiopulmonary health. Although the physiological consequences of both air pollution and physical inactivity are well established, relatively few studies have investigated how active commuters, particularly those in suburban areas, perceive and respond to air-quality risks. Drawing on results from a survey of active transit users, this study addresses this gap by examining how active commuters in Markham, Ontario, perceive and respond to these risks. Results reveal that while commuters are aware of air quality risks and active commuters make some adjustments to their behaviour, air quality is not an important driver in active transportation decisions.
