title: Annual average ambient particulate matter exposure estimates, measured home particulate matter, and hair nicotine are associated with respiratory outcomes in adults with asthma.
abstract: BACKGROUND
  While exposure to outdoor particulate matter (PM) has been associated with poor asthma outcomes, few studies have investigated the combined effects of outdoor and indoor PM (including secondhand tobacco smoke).
  
  
  OBJECTIVE
  To examine the associations between PM and asthma outcomes.
  
  
  METHODS
  We analyzed data from a cohort of adults with asthma and rhinitis (n=302; 82% both conditions; 13% asthma only; 5% rhinitis alone) including measures of home PM, tobacco smoke exposure (hair nicotine and self-report), ambient PM from regional monitoring, distance to roadway, and season (wet or dry). The outcomes of interest were frequent respiratory symptoms and forced expiratory volume in 1 second (FEV1) below the lower limit of normal (NHANES reference values). Multivariable regression analyses examined the associations (Odds Ratio [OR] and 95% Confidence Interval [95%CI]) between exposures and these outcomes, adjusted by sociodemographic characteristics.
  
  
  RESULTS
  In adjusted analyses of each exposure, the highest tertile of home PM and season of interview were associated with increased odds for more frequent respiratory symptoms (OR=1.64 95%CI: [1.00, 2.69] and OR=1.66 95%CI: [1.09, 2.51]). The highest tertile of hair nicotine was significantly associated with FEV1 below the lower limit of normal (OR=1.80 95%CI: [1.00, 3.25]). In a model including home PM, ambient PM, hair nicotine, and season, only two associations remained strong: hair nicotine with FEV1 below the lower limit of normal and season of measurement (dry, April-October) with increased respiratory symptoms (OR=1.85 95%CI: [1.00, 3.41] and OR=1.54 95%CI: [1.0, 2.37]). When that model was stratified by sex, the highest tertiles of ambient PM and hair nicotine were associated with FEV1 below the lower limit of normal among women (OR=2.23 95%CI: [1.08, 4.61] and OR=2.90 95%CI: [1.32, 6.38]), but not men. The highest tertile of hair nicotine was also associated with increased respiratory symptoms in women but not men (OR=2.38 95%CI: [1.26, 4.49]). When stratified by age, the middle quartile of ambient PM and the highest hair nicotine tertile were associated with increased respiratory symptoms (OR=2.07 95%CI: [1.01, 4.24] and OR=2.55 95%CI: [1.21, 5.36]) in those under 55 but not in the older stratum.
  
  
  CONCLUSIONS
  Exposure to PM from both home and ambient sources is associated with increased symptoms and lower lung function in adults with asthma, although these associations vary by type of PM, the respiratory outcome studied, sex and age.
authors: Department of Medicine, University of California, San Francisco, CA, USA; School of Public Health, University of California, Berkeley, USA. Electronic address: jbalmes@medsfgh.ucsf.edu.
authors: John R
authors: JR
authors: Balmes
authors: MGC Data Services, San Diego, CA, USA.
authors: Miriam
authors: M
authors: Cisternas
authors: Department of Medicine, University of California, San Francisco, CA, USA.
authors: Patricia J
authors: PJ
authors: Quinlan
authors: Department of Medicine, University of California, San Francisco, CA, USA.
authors: Laura
authors: L
authors: Trupin
authors: Sonoma Technology, Inc., Petaluma, CA, USA.
authors: Fred W
authors: FW
authors: Lurmann
authors: Department of Medicine, University of California, San Francisco, CA, USA.
authors: Patricia P
authors: PP
authors: Katz
authors: Department of Medicine, University of California, San Francisco, CA, USA.
authors: Paul D
authors: PD
authors: Blanc
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000032:analysis*; D001249:Asthma / Q000139:chemically induced / Q000453:epidemiology* / Q000503:physiopathology; D002140:California; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006197:Hair / Q000737:chemistry; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000032:analysis*; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis*; D012220:Rhinitis / Q000139:chemically induced / Q000453:epidemiology / Q000503:physiopathology; D012621:Seasons; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects / Q000032:analysis*; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D014028:Tobacco Smoke Pollution; D009538:Nicotine
keywords: Asthma; Hair nicotine; Indoor particulate matter; Lung function; Outdoor particulate matter; Respiratory symptoms