Indoor exposure to environmental cigarette smoke, but not other inhaled particulates associates with respiratory symptoms and diminished lung function in adults

Abstract
Background and objective: Exposure to particulate matter (PM) can induce airway inflammation and exacerbation of asthma. However, there is limited knowledge about the effects of exposure to indoor sources of PM. We investigated the associations between self‐reported exposure to indoor sources of PM and lower airway symptoms and lung function. Methods: A population‐based cross‐sectional study of 3471 persons aged 18–69 years was conducted. Information about exposure to indoor sources of PM and airway symptoms was obtained from a self‐administered questionnaire. Results: Exposure to wood stoves, candles and gas cookers was not significantly associated with an increased prevalence of lower respiratory symptoms or decreased lung function. In contrast, persons exposed to environmental tobacco smoke for >5 h/day had a significantly increased risk of ‘wheeze’ (OR 1.69, 95% CI: 1.24–2.30) and ‘chronic cough’ (OR 1.57, 95% CI: 1.12–2.20), as well as decreased lung function (FEV1% predicted), compared with those who were not exposed. Similar trends were observed in never smokers. Conclusions: In this cross‐sectional study of an adult general population, self‐reported exposure to environmental tobacco smoke, but not self‐reported exposure to wood stoves, candles or gas cookers, appeared to be associated with an increased prevalence of lower airway symptoms and decreased lung function.