title: Indoor heating sources and respiratory symptoms in nonsmoking women.
abstract: BACKGROUND
  Secondary heating appliances are important indoor sources of air pollution, including particulate matter, nitrogen dioxide (NO2), and sulfur dioxide (SO2). We hypothesized that the use of secondary heating sources increases respiratory symptoms in women living in nonsmoking households and specifically that concentrations of SO2 and NO2 emitted from heating sources are associated with respiratory symptoms.
  
  
  METHODS
  Mothers who delivered babies at 12 hospitals in Connecticut and Virginia (1993-1996) were enrolled. There were 888 women who contributed symptom and exposure information during the winter heating season (15 October to 15 April), for a total of 9783 reporting periods (median = 12 reporting periods per woman, interquartile range 11-12). Adjusted rate ratios (RRs) of effects of source use and measured concentrations on rate of days with symptoms were obtained using generalized estimating equations for a log-linear Poisson model, controlling age, education, race, history of allergies, number of children, dwelling type, and residence state.
  
  
  RESULTS
  In adjusted models, each hour-per-day increase in kerosene heater use is associated with an increase in wheezing (RR = 1.06; 95% confidence interval (CI) = 1.01-1.11). Each hour of fireplace use is associated with increased cough (1.05; 1.01-1.09), sore throat (1.04; 1.00-1.08), and marginally with chest tightness (1.05; 0.99-1.12). Each 10 ppb increase in SO2 (a proxy for sulfate aerosol) is associated with increased wheezing (1.57; 1.10-2.26) and chest tightness (1.32; 1.01-1.71).
  
  
  CONCLUSIONS
  Emissions from fireplaces, gas space heaters, and kerosene heaters may contribute to respiratory symptoms in a population of nonsmoking women.
authors.affiliation: Department of Epidemiology and Public Health, Yale Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University School of Medicine, 60 College Street, New Haven, CT 06520-8034, USA. elizabeth.triche@yale.edu
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Triche
authors.forename: Kathleen
authors.initials: K
authors.lastname: Belanger
authors.forename: Michael B
authors.initials: MB
authors.lastname: Bracken
authors.forename: William S
authors.initials: WS
authors.lastname: Beckett
authors.forename: Theodore R
authors.initials: TR
authors.lastname: Holford
authors.forename: Janneane F
authors.initials: JF
authors.lastname: Gent
authors.forename: Jean-Ellen
authors.initials: JE
authors.lastname: McSharry
authors.forename: Brian P
authors.initials: BP
authors.lastname: Leaderer
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects* / Q000032:analysis; D003237:Connecticut / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D006361:Heating / Q000009:adverse effects* / Q000379:methods; D006798:Housing; D006801:Humans; D016012:Poisson Distribution; D012140:Respiratory Tract Diseases / Q000209:etiology* / Q000503:physiopathology; D014768:Virginia / Q000453:epidemiology