The association between long-term exposure to PM2.5 constituents and diabetes incidence and blood glucose levels among World Trade Center Health Program general responders

Exposure to fine particulate matter (PM2.5) is associated with cardiometabolic risk among World Trade Center Health Program general responders, but current studies focus mainly on PM2.5 mass. We studied the associations between annual source-apportioned PM2.5 exposures, and self-reported diabetes or repeated blood glucose measurements among general responders enrolled between 2003 and 2019 (n = 34 764), residing in Tri-state area. We used non-negative matrix factorization to attribute PM2.5 component to sources (ie, biomass burning, oil combustion, metal industry, other industries, and motor vehicles). We used multivariable mixed-effect models to estimate the simultaneous associations of the source-apportioned PM2.5 exposures with the outcomes. We found (% change [95% CIs]) an interquartile range increase in PM2.5 attributed to metal industry sources (0.42 μg/m3) to be associated with an 8.35% (1.39%, 15.79%) higher risk of diabetes and a 1.31% (0.80%, 1.82%) increase in glucose levels. Source-specific associations with glucose were modified by sex, showing larger associations with biomass burning (1.08% [0.32%, 1.85%] per 0.44 μg/m3) and motor vehicle (1.34% [0.76%, 1.93%] per 0.92 μg/m3) pollution among women, and larger associations with oil-combustion (0.68% [0.03%, 1.34%] per 1.74 μg/m3) pollution among men. These findings can inform policies and interventions targeting emissions from these specific sources, particularly for general responders with a history of extreme air pollution exposures.