Association of diabetes and exposure to fine particulate matter (PM_2.5) in the Southeastern United States

Fine particulate matter (PM_2.5) exposure can cause premature death and harmful chronic disease such as diabetes. The U.S. Environmental Protection Agency (EPA) sets annual PM_2.5 standards to reduce these negative health effects. Currently, annual average exposure over 12 µg/m³ is considered unhealthy. This study tests whether individuals living in locations exposed to elevated ambient levels of PM_2.5 concentrations were more likely to self-report diabetes. We examined the association of long-term exposure to PM_2.5 and diabetes at enrollment (2002–2009) in a cohort of 44,610 individuals residing in 12 states, recruited into the Southern Community Cohort Study (SCCS). Annual average PM_2.5 was estimated using remotely sensed satellite data integrated with ground monitoring data at participants’ residence in urban and rural locations. We used multilevel mixed-effects logistic regression models to estimate the associations between self-reported diabetes and historical exposure to elevated ambient levels of PM_2.5. We found a 10.1% increase in odds of reported diabetes with exposure to unhealthful levels of PM_2.5 exposure (>12 µg/m³ at enrollment) compared to respondents living in areas with lower annual PM_2.5 concentrations. Participants with medical histories of hypertension, hypercholesterolemia, and smoking had an overall 384% higher odds of reported diabetes than those without these clinical risk factors. Black participants were more likely to live in locations with higher ambient PM_2.5 concentrations, report high levels of clinical risk factors, and had a 29.1% increase in odds of reported diabetes than Whites. In SCCS participants, exposures to high ambient levels of PM_2.5 were associated with self-reported diabetes at enrollment. Reduction in PM_2.5 standards for the U.S. are recommended.