Urban Fine Particulate Matter and Elements Associated with Subclinical Atherosclerosis in Adolescents and Young Adults

The relationships between the elemental constituents of PM2.5 and atherosclerosis remain limited, especially in young populations. This study included 755 subjects aged 12–30 years in the Taipei metropolis. A land use regression model was used to estimate residential annual mean concentrations of PM2.5 and eight elemental constituents. We evaluated the percent differences in carotid intima-media thickness (CIMT) with PM2.5 and elemental constituent exposures by linear regressions. Interquartile range increments for PM2.5 (4.5 μg/m3), sulfur (108.6 ng/m3), manganese (2.0 ng/m3), iron (34.5 ng/m3), copper (3.6 ng/m3), and zinc (20.7 ng/m3) were found to associate with 0.92% (95% confidence interval (CI): 0.17–1.66), 0.51% (0.02–1.00), 0.36% (0.05–0.67), 0.98% (0.15–1.82), 0.74% (0.01–1.48), and 1.20% (0.33–2.08) higher CIMTs, respectively. Factor analysis identified four air pollution source-related factors, and the factors interpreted as traffic and industry sources were associated with higher CIMTs. Stratified analyses showed the estimates were more evident in subjects who were ≥18 years old, females, or who had lower household income. Our study results provide new insight into the impacts of source-specific air pollution, and future research on source-specific air pollution effects in young populations, especially in vulnerable subpopulations, is warranted.