title: Particulate matter components and subclinical atherosclerosis: common approaches to estimating exposure in a Multi-Ethnic Study of Atherosclerosis cross-sectional study.
abstract: BACKGROUND
  Concentrations of outdoor fine particulate matter (PM2.5) have been associated with cardiovascular disease. PM2.5 chemical composition may be responsible for effects of exposure to PM2.5.
  
  
  METHODS
  Using data from the Multi-Ethnic Study of Atherosclerosis (MESA) collected in 2000-2002 on 6,256 US adults without clinical cardiovascular disease in six U.S. metropolitan areas, we investigated cross-sectional associations of estimated long-term exposure to total PM2.5 mass and PM2.5 components (elemental carbon [EC], organic carbon [OC], silicon and sulfur) with measures of subclinical atherosclerosis (coronary artery calcium [CAC] and right common carotid intima-media thickness [CIMT]). Community monitors deployed for this study from 2007 to 2008 were used to estimate exposures at baseline addresses using three commonly-used approaches: (1) nearest monitor (the primary approach), (2) inverse-distance monitor weighting and (3) city-wide average.
  
  
  RESULTS
  Using the exposure estimate based on nearest monitor, in single-pollutant models, increased OC (effect estimate [95% CI] per IQR: 35.1 μm [26.8, 43.3]), EC (9.6 μm [3.6,15.7]), sulfur (22.7 μm [15.0,30.4]) and total PM2.5 (14.7 μm [9.0,20.5]) but not silicon (5.2 μm [-9.8,20.1]), were associated with increased CIMT; in two-pollutant models, only the association with OC was robust to control for the other pollutants. Findings were generally consistent across the three exposure estimation approaches. None of the PM measures were positively associated with either the presence or extent of CAC. In sensitivity analyses, effect estimates for OC and silicon were particularly sensitive to control for metropolitan area.
  
  
  CONCLUSIONS
  Employing commonly-used exposure estimation approaches, all of the PM2.5 components considered, except silicon, were associated with increased CIMT, with the evidence being strongest for OC; no component was associated with increased CAC. PM2.5 chemical components, or other features of the sources that produced them, may be important in determining the effect of PM exposure on atherosclerosis. These cross-sectional findings await confirmation in future work employing longitudinal outcome measures and using more sophisticated approaches to estimating exposure.
authors: Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, 4225 Roosevelt Way NE, #100, Seattle, WA, 98105, USA.
authors: Min
authors: M
authors: Sun
authors: Joel D
authors: JD
authors: Kaufman
authors: Sun-Young
authors: SY
authors: Kim
authors: Timothy V
authors: TV
authors: Larson
authors: Timothy R
authors: TR
authors: Gould
authors: Joseph F
authors: JF
authors: Polak
authors: Matthew J
authors: MJ
authors: Budoff
authors: Ana V
authors: AV
authors: Diez Roux
authors: Sverre
authors: S
authors: Vedal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D050197:Atherosclerosis / Q000139:chemically induced / Q000453:epidemiology*; D059168:Carotid Intima-Media Thickness; D015331:Cohort Studies; D003331:Coronary Vessels / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring; D005006:Ethnicity; D005260:Female; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D015995:Prevalence; D012044:Regression Analysis; D014481:United States / Q000453:epidemiology; D061205:Vascular Calcification / Q000139:chemically induced / Q000453:epidemiology*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
references: Am J Epidemiol. 1998 Mar 15;147(6):537-47
references: 9521180
references: Environ Health Perspect. 2000 May;108(5):419-26
references: 10811568
references: Occup Environ Med. 2005 Jul;62(7):453-60
references: 15961621
references: Atherosclerosis. 2011 Oct;218(2):344-9
references: 21726862
references: N Engl J Med. 1993 Dec 9;329(24):1753-9
references: 8179653
references: Environ Health Perspect. 2005 Feb;113(2):201-6
references: 15687058
references: Am J Epidemiol. 2002 Nov 1;156(9):871-81
references: 12397006
references: Environ Health Perspect. 2003 Apr;111(4):402-8
references: 12676590
references: Circulation. 2007 Jul 31;116(5):489-96
references: 17638927
references: Environ Sci Technol. 2009 Jul 1;43(13):4687-93
references: 19673252
references: Environ Health. 2009 Dec 21;8:58
references: 20025755
references: Radiology. 2005 Jan;234(1):35-43
references: 15618373
references: Epidemiology. 2004 Jan;15(1):46-56
references: 14712146
references: Am J Epidemiol. 2008 Mar 15;167(6):667-75
references: 18227099
references: Circulation. 2002 Dec 17;106(25):3143-421
references: 12485966
references: Am J Respir Crit Care Med. 1995 Mar;151(3 Pt 1):669-74
references: 7881654
references: Inhal Toxicol. 2000;12 Suppl 4:41-73
references: 12881886
references: JAMA. 2002 Mar 6;287(9):1132-41
references: 11879110
references: Epidemiology. 2009 Mar;20(2):280-8
references: 19194299
references: Lancet. 2002 Oct 19;360(9341):1203-9
references: 12401246
references: Am J Epidemiol. 2004 Jul 15;160(2):173-7
references: 15234939
references: Arch Intern Med. 2008 Jun 23;168(12):1333-9
references: 18574091
references: Environ Sci Technol. 2003 Nov 15;37(22):5135-42
references: 14655699
references: Epidemiology. 2006 Sep;17(5):545-51
references: 16755270
references: J Expo Anal Environ Epidemiol. 2002 Nov;12(6):427-32
references: 12415491
references: J Expo Anal Environ Epidemiol. 2003 Nov;13(6):443-53
references: 14603345
references: J Toxicol Environ Health A. 2003 Aug 22-Oct 10;66(16-19):1625-54
references: 12959833
references: Environ Health Perspect. 2010 Mar;118(3):363-9
references: 20064787
references: J Am Coll Cardiol. 1990 Mar 15;15(4):827-32
references: 2407762
references: Environ Health Perspect. 2002 Dec;110(12):1191-7
references: 12460797
references: Circulation. 2010 Jun 1;121(21):2331-78
references: 20458016
references: Environ Health Perspect. 2007 Jan;115(1):13-9
references: 17366813
references: J Air Waste Manag Assoc. 2004 Mar;54(3):360-6
references: 15061617
references: Environ Health. 2008 Jul 09;7:36
references: 18613971
references: Environ Health Perspect. 2006 Aug;114(8):1215-20
references: 16882528
references: J Air Waste Manag Assoc. 2003 Mar;53(3):325-38
references: 12661691
references: Epidemiology. 2008 Sep;19(5):680-9
references: 18714438
references: Environ Health Perspect. 2000 Apr;108(4):347-53
references: 10753094
references: Am J Epidemiol. 2012 Nov 1;176(9):825-37
references: 23043127
references: Environ Health Perspect. 2008 Apr;116(4):459-66
references: 18414627
references: N Engl J Med. 2007 Feb 1;356(5):447-58
references: 17267905
references: Environ Health Perspect. 2000 Oct;108(10):941-7
references: 11049813
references: Am J Respir Crit Care Med. 1999 Feb;159(2):373-82
references: 9927346