Associations Between Elemental Constituents of Fine Particulate Matter and Subclinical Atherosclerosis in Adolescents and Young Adults

Abstract BackgroundExisting studies have demonstrated the relationships between particulate matter (PM) exposure and subclinical atherosclerosis; however, whether PM and its elemental constituents predispose to atherosclerosis remains unclear in adolescents and young adults. This cross-sectional study included 789 subjects between the ages of 12 to 30 years who lived in Taipei metropolis since childhood. Health examination and carotid intima-media thickness (CIMT) measurements were performed between 2006 and 2008. Land use regression (LUR) model was used to estimate participants’ one-year exposure to fine particulate matter (PM2.5) and eight elemental constituents, i.e., silicon (Si), sulfur (S), titanium (Ti), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), and zinc (Zn). The associations between percent differences in CIMT at common carotid artery (CCA) segments and air pollutants were analyzed.ResultsAn interquartile range increment of PM2.5 (4.5 μg/m3), Fe (34.7 ng/m3), and Zn (20.7 ng/m3) are associated with 0.77% (95% confidence interval; 95%CI: 0.05 to 1.50), 0.83% (0.01 to 1.65), and 1.22% (0.35 to 2.10) higher for combined CIMT, respectively; while Mn (2.0 ng/m3) exposure is associated with 0.31% (0.01 to 0.60) higher for right CIMT. Stratified analyses show PM2.5 and elemental constituents, especially Zn, are associated with CIMT among subjects who are 18 years or older, females, lower household income, non-smokers, normal weight, non-hypertensive, non-hyperglycemic, or non-hypercholesterolemic. ConclusionsLong-term exposures to PM2.5 and elemental constituents mainly originating from traffic and industry operations are associated with subclinical atherosclerosis in young population. Individual characteristics, health behaviors, and biometric measures, may modify air pollution-related subclinical atherosclerosis.