Suncor's refinery in Commerce City is Colorado's only oil refinery—processing about 98,000 barrels per day—and one of its biggest greenhouse gas emitters. Driving south on I-25, the enormous facility intrudes on the horizon adjacent to Denver's skyline. Communities surrounding the expansive industrial site contend with myriad impacts of living amid an oil refinery. Nearby residents experience disproportionate health impacts, including comparatively higher rates of respiratory problems like asthma, reproductive issues and birth complications, diabetes, and cardiovascular conditions. Studies have also found that they experience a 24 percent higher death rate than other Denver residents (Armijo and Hook, 2014; ENVIRONS, 2024). Yet, little research has captured the lived experiences of community members in the area and how they understand their health in relation to exposure to environmental pollution (Malin et al., 2024; 2025).

Here, we present evidence of people's adverse health experiences from living or working near Suncor and how their environmental health claims are contested by powerful institutions. We utilized community-based participatory research (CBPR) led by local community organization, Cultivando. CBPR is a methodological framework centering community needs and equitable participation in research, recognizing the impacted community as a unit of identity (Cohen et al., 2012; Israel et al., 2012; Wallerstein and Duran, 2006; Minkler and Wallerstein, 2011). We emphasized collaborative and equitable partnerships, co-designing, co-learning, and capacity-building throughout.

Bringing in data from 53 in-depth interviews, we document: (1) how people living or working around Suncor understand the refinery's impacts on their health; (2) experiences of community members compared to responses of medical practitioners; and (3) how their observations and understanding of environmentally related illness were contested by medical and state institutions. Drawing on people's narratives, we examine how living near Suncor shapes lived experiences of environmental health, environmental justice (EJ), and contested illness. Our findings illustrate how participants perceive medical practitioners and state institutions as overlooking or dismissing environmental health effects. This analysis contributes to research on contested illness and to literature on oil refineries' environmental health and EJ effects (Perera, 2017; Perera et al., 2019; Shriver et al., 2020).