title: Response of biomarkers of inflammation and coagulation to short-term changes in central site, local, and predicted particle number concentrations.
abstract: OBJECTIVE
  Previous studies have reported acute (hours-28 days) associations between ambient ultrafine particles (UFP; diameter <0.1) and biomarkers of cardiovascular health using central site data. We evaluated particle number concentration (a proxy measure for UFP) measured at a central site, a local near-highway site and predicted residential concentrations with response of biomarkers of inflammation and coagulation in a near-highway population.
  
  
  METHODS
  Participants provided two blood samples for analysis of interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α receptor II, and fibrinogen. Mixed effect models were used to evaluate the association between PNC levels on the same day, prior 2 days, and moving averages of 3 to 28 days.
  
  
  RESULTS
  Estimated effects on biomarkers of a 5000 unit increase in central site PNC generally increased with longer averaging times for IL-6, hs-CRP, and fibrinogen. Effect estimates were highest for a 28-day moving average, with 91% (95% confidence interval [CI]: 9, 230) higher IL-6 levels, 74% (95% CI: -7, 220) higher hs-CRP levels, and 59% (95% CI: -13, 130) higher fibrinogen levels. We observed no clear trend between near-highway or predicted residential PNC and any of the biomarkers.
  
  
  CONCLUSIONS
  Only central site PNC increased blood markers of inflammation while near-highway and predicted residential values did not. We cannot fully explain this result, although differing PNC composition is a possibility. Future studies would assist in understanding these findings.
authors: Division of Environmental Health, School of Public Health, Georgia State University, Atlanta. Electronic address: cfuller@gsu.edu.
authors: Christina H
authors: CH
authors: Fuller
authors: Department of Biostatistics, Harvard School of Public Health, Boston, MA; Department of Epidemiology, Harvard School of Public Health, Boston, MA.
authors: Paige L
authors: PL
authors: Williams
authors: Department of Epidemiology, Harvard School of Public Health, Boston, MA; Cardiovascular Epidemiology Research Unit, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA.
authors: Murray A
authors: MA
authors: Mittleman
authors: Exposure Science Division, Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ.
authors: Allison P
authors: AP
authors: Patton
authors: Department of Environmental Health, Harvard School of Public Health, Boston, MA.
authors: John D
authors: JD
authors: Spengler
authors: Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA.
authors: Doug
authors: D
authors: Brugge
mesh_terms: D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D015415:Biomarkers; D002097:C-Reactive Protein / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014504:Urban Health; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D052638:Particulate Matter; D014409:Tumor Necrosis Factor-alpha; D001335:Vehicle Emissions; D005340:Fibrinogen; D002097:C-Reactive Protein
keywords: Cardiovascular; Coagulation; Highway; Inflammation; Particles