title: The relation between past exposure to fine particulate air pollution and prevalent anxiety: observational cohort study.
abstract: OBJECTIVE
  To determine whether higher past exposure to particulate air pollution is associated with prevalent high symptoms of anxiety.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  Nurses' Health Study.
  
  
  METHODS
  71,271 women enrolled in the Nurses' Health Study residing throughout the contiguous United States who had valid estimates on exposure to particulate matter for at least one exposure period of interest and data on anxiety symptoms.
  
  
  METHODS
  Meaningfully high symptoms of anxiety, defined as a score of 6 points or greater on the phobic anxiety subscale of the Crown-Crisp index, administered in 2004.
  
  
  RESULTS
  The 71,271 eligible women were aged between 57 and 85 years (mean 70 years) at the time of assessment of anxiety symptoms, with a prevalence of high anxiety symptoms of 15%. Exposure to particulate matter was characterized using estimated average exposure to particulate matter <2.5 μm in diameter (PM2.5) and 2.5 to 10 μm in diameter (PM2.5-10) in the one month, three months, six months, one year, and 15 years prior to assessment of anxiety symptoms, and residential distance to the nearest major road two years prior to assessment. Significantly increased odds of high anxiety symptoms were observed with higher exposure to PM2.5 for multiple averaging periods (for example, odds ratio per 10 µg/m(3) increase in prior one month average PM2.5: 1.12, 95% confidence interval 1.06 to 1.19; in prior 12 month average PM2.5: 1.15, 1.06 to 1.26). Models including multiple exposure windows suggested short term averaging periods were more relevant than long term averaging periods. There was no association between anxiety and exposure to PM2.5-10. Residential proximity to major roads was not related to anxiety symptoms in a dose dependent manner.
  
  
  CONCLUSIONS
  Exposure to fine particulate matter (PM2.5) was associated with high symptoms of anxiety, with more recent exposures potentially more relevant than more distant exposures. Research evaluating whether reductions in exposure to ambient PM2.5 would reduce the population level burden of clinically relevant symptoms of anxiety is warranted.
authors: Department of Epidemiology, Harvard School of Public Health, Boston MA, USA Department of Environmental Health, Harvard School of Public Health, Boston MA, USA Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore MD, USA melindacpower@gmail.com.
authors: Melinda C
authors: MC
authors: Power
authors: Department of Environmental Health, Harvard School of Public Health, Boston MA, USA.
authors: Marianthi-Anna
authors: MA
authors: Kioumourtzoglou
authors: Department of Environmental Health, Harvard School of Public Health, Boston MA, USA Channing Division of Network Medicine, Department of Medicine at Brigham and Women's Hospital and Harvard Medical School, Boston MA, USA.
authors: Jaime E
authors: JE
authors: Hart
authors: Department of Epidemiology, Harvard School of Public Health, Boston MA, USA Channing Division of Network Medicine, Department of Medicine at Brigham and Women's Hospital and Harvard Medical School, Boston MA, USA Department of Psychiatry, Brigham and Women's Hospital and Harvard Medical School, Boston MA, USA.
authors: Olivia I
authors: OI
authors: Okereke
authors: Department of Epidemiology, Harvard School of Public Health, Boston MA, USA Department of Environmental Health, Harvard School of Public Health, Boston MA, USA Channing Division of Network Medicine, Department of Medicine at Brigham and Women's Hospital and Harvard Medical School, Boston MA, USA.
authors: Francine
authors: F
authors: Laden
authors: Department of Epidemiology, Harvard School of Public Health, Boston MA, USA Department of Environmental Health, Harvard School of Public Health, Boston MA, USA.
authors: Marc G
authors: MG
authors: Weisskopf
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution; D001007:Anxiety / Q000453:epidemiology*; D015331:Cohort Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008875:Middle Aged; D052638:Particulate Matter; D012959:Socioeconomic Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology
chemical_list: D052638:Particulate Matter