title: Smoking-related respiratory symptoms in tehran: a cross-sectional study.
abstract: BACKGROUND
  Active smoking and passive exposure to environmental tobacco smoke cause respiratory symptoms as well as long-term complications. We know little about the sources of exposure to tobacco smoke in our population and the symptoms that can be related to smoking in adults and children.
  
  
  METHODS
  A survey on the range of symptoms relevant to smoke exposure was conducted. Residents of Tehran were interviewed by telephone through random digit dialing. Exposure to tobacco smoke and other environmental pollutants were sought at individual level. A geographical information system was used to determine the levels of the pollutants corresponding to addresses of the participants.
  
  
  RESULTS
  We interviewed 34,121 individuals. Of the male and female adults, 21.3% and 3.4% were current smokers, respectively. About one third of the children and teenagers were exposed to smoking in one way or the other. In regression analysis, respiratory symptoms such as cough, phlegm, breathlessness, chest tightness, and throat discomfort were consistently associated with smoking in adults. In teenage group, cough and phlegm were related to habitual smoking. We failed to find a significant relation between passive smoking and symptoms in children.
  
  
  CONCLUSIONS
  The range of respiratory symptoms associated with smoking is different in various age groups. The high percentage of children exposed to passive smoking expedites rigorous educational measures.
authors.affiliation: School of Public Health and Center for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Masud
authors.initials: M
authors.lastname: Yunesian
authors.forename: Javad
authors.initials: J
authors.lastname: Homayoun-Vash
authors.forename: Fariba
authors.initials: F
authors.lastname: Asghari
authors.forename: Mohammad-Hosein
authors.initials: MH
authors.lastname: Foruzanfar
authors.forename: Ahmad-Reza
authors.initials: AR
authors.lastname: Hosein-Poor
authors.forename: Dariush
authors.initials: D
authors.lastname: Farhud