title: Particulate air pollution exposure and C-reactive protein during early pregnancy.
abstract: BACKGROUND
  It is not well understood how air pollution leads to adverse pregnancy outcomes. One pathway may be through C-reactive protein, a biomarker of systemic inflammation that has been reported to increase the risk of preterm delivery. We examined whether air pollution influences serum concentrations of C-reactive protein in early pregnancy.
  
  
  METHODS
  We studied 1696 pregnant women in Allegheny County, PA, from 1997 through 2001. C-reactive protein concentrations were assayed in blood collected before the 22nd week of gestation. We estimated levels of particles of less than 10 μm (PM10) and less than 2.5 μm diameter (PM2.5), carbon monoxide, nitrogen dioxide, sulfur dioxide, and ozone at the maternal zip code using Kriging interpolation for measurements obtained from ambient stations. Associations between air pollution and high C-reactive protein concentrations (≥ 8 ng/mL) were evaluated using logistic regression.
  
  
  RESULTS
  Among nonsmokers, an observed 9.2 μg/m increase in PM10 (averaged over 28 days prior to the blood sample) was associated with an odds ratios of 1.41 for high C-reactive protein concentrations (95% confidence interval = 0.99-2.00). Similarly, a 4.6 μg/m increase in PM2.5 was associated with an odds ratio of 1.47 (1.05-2.06). The odds ratio was 1.49 (0.75-2.96) per 7.9 ppb increase in ozone during summer. There were no associations in smokers or for other air pollutants, and there was no evidence for effect-measure modification by obesity.
  
  
  CONCLUSIONS
  PM10, PM2.5, and ozone exposures were associated with increased C-reactive protein concentrations in early pregnancy, suggesting that these air pollutants contribute to inflammation and thereby possibly to adverse pregnancy outcomes.
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA. pel27@pitt.edu
authors.forename: Pei-Chen
authors.initials: PC
authors.lastname: Lee
authors.forename: Evelyn O
authors.initials: EO
authors.lastname: Talbott
authors.forename: James M
authors.initials: JM
authors.lastname: Roberts
authors.forename: Janet M
authors.initials: JM
authors.lastname: Catov
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Sharma
authors.forename: Beate
authors.initials: B
authors.lastname: Ritz
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D002097:C-Reactive Protein / Q000378:metabolism*; D002248:Carbon Monoxide / Q000009:adverse effects / Q000032:analysis; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D018811:Maternal Exposure; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D010126:Ozone / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter; D010414:Pennsylvania; D011247:Pregnancy; D011256:Pregnancy Outcome; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D002248:Carbon Monoxide; D002097:C-Reactive Protein; D009585:Nitrogen Dioxide