title: Short-term impact of ambient air pollution and air temperature on blood pressure among pregnant women.
abstract: BACKGROUND
  Epidemiologic studies have reported inconsistent findings for the association between air pollution levels and blood pressure (BP), which has been studied mainly in elderly subjects. Short-term air pollution effects on BP have not been investigated in pregnant women, who may constitute a vulnerable population.
  
  
  METHODS
  Between 2002 and 2006, 1500 pregnant women from a mother-child cohort study conducted in Nancy and Poitiers, France, underwent 11,220 repeated BP measurements (average, 7.5 measurements/woman). Nitrogen dioxide (NO₂), particulate matter with an aerodynamic diameter below 10 μm (PM₁₀), and meteorologic variables were measured on an hourly basis at permanent monitoring sites. We studied changes of BP in relation to short-term variations of air pollution and temperature with mixed models adjusted for meteorologic and personal characteristics.
  
  
  RESULTS
  A 10°C decrease in temperature led to an increase in systolic BP of 0.5% (95% confidence interval = 0.1% to 1.0%). Elevated NO₂-levels 1 day, 5 days and averaged over 7 days before the BP measurement were associated with reduced systolic BP. The strongest decrease was observed for the 7-day NO₂ average (-0.4% [-0.7% to -0.2%] change for an 11 μg/m³ increase in NO₂). PM₁₀ effects on systolic BP differed according to pregnancy trimester: PM₁₀ concentration was associated with systolic BP increases during the first trimester and systolic BP decreases later in pregnancy.
  
  
  CONCLUSIONS
  We observed short-term associations of air pollution and of temperature with BP in pregnant women. Whether such changes in BP have clinical implications remains to be investigated.
authors: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology II, Neuherberg, Germany. regina.hampel@helmholtz-muenchen.de
authors: Regina
authors: R
authors: Hampel
authors: Johanna
authors: J
authors: Lepeule
authors: Alexandra
authors: A
authors: Schneider
authors: Sébastien
authors: S
authors: Bottagisi
authors: Marie-Aline
authors: MA
authors: Charles
authors: Pierre
authors: P
authors: Ducimetière
authors: Annette
authors: A
authors: Peters
authors: Rémy
authors: R
authors: Slama
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D005602:France; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis; D009585:Nitrogen Dioxide / Q000032:analysis / Q000494:pharmacology*; D011247:Pregnancy; D013696:Temperature
chemical_list: D000393:Air Pollutants; D009585:Nitrogen Dioxide