title: Carotid Intima-Media Thickness and Long-Term Exposure to Traffic-Related Air Pollution in Middle-Aged Residents of Taiwan: A Cross-Sectional Study.
abstract: BACKGROUND
  Associations between long-term exposure to air pollution and carotid intima-media thickness (CIMT) have inconsistent findings.
  
  
  OBJECTIVE
  In this study we aimed to evaluate association between 1-year average exposure to traffic-related air pollution and CIMT in middle-aged adults in Asia.
  
  
  METHODS
  CIMT was measured in Taipei, Taiwan, between 2009 and 2011 in 689 volunteers 35-65 years of age who were recruited as the control subjects of an acute coronary heart disease cohort study. We applied land-use regression models developed by the European Study of Cohorts for Air Pollution Effects (ESCAPE) to estimate each subject's 1-year average exposure to traffic-related air pollutants with particulate matter diameters ≤ 10 μm (PM10) and ≤ 2.5 μm (PM2.5) and the absorbance levels of PM2.5 (PM2.5abs), nitrogen dioxide (NO2), and nitrogen oxides (NOx) in the urban environment.
  
  
  RESULTS
  One-year average air pollution exposures were 44.21 ± 4.19 μg/m3 for PM10, 27.34 ± 5.12 μg/m3 for PM2.5, and (1.97 ± 0.36) × 10-5/m for PM2.5abs. Multivariate regression analyses showed average percentage increases in maximum left CIMT of 4.23% (95% CI: 0.32, 8.13) per 1.0 × 10-5/m increase in PM2.5abs; 3.72% (95% CI: 0.32, 7.11) per 10-μg/m3 increase in PM10; 2.81% (95% CI: 0.32, 5.31) per 20-μg/m3 increase in NO2; and 0.74% (95% CI: 0.08, 1.41) per 10-μg/m3 increase in NOx. The associations were not evident for right CIMT, and PM2.5 mass concentration was not associated with the outcomes.
  
  
  CONCLUSIONS
  Long-term exposures to traffic-related air pollution of PM2.5abs, PM10, NO2, and NOx were positively associated with subclinical atherosclerosis in middle-aged adults.
authors: Department of Internal Medicine and Cardiovascular Center, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors: Ta-Chen
authors: TC
authors: Su
authors: Juey-Jen
authors: JJ
authors: Hwang
authors: Yu-Cheng
authors: YC
authors: Shen
authors: Chang-Chuan
authors: CC
authors: Chan
mesh_terms: D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects; D059168:Carotid Intima-Media Thickness / Q000706:statistics & numerical data; D003324:Coronary Artery Disease / Q000139:chemically induced / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009589:Nitrogen Oxides / Q000633:toxicity; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity; D012621:Seasons; D013624:Taiwan / Q000453:epidemiology; D001335:Vehicle Emissions / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions