Solid fuel smoke exposure and risk of obstructive airways disease

This study was designed to investigate whether there is an association between Obstructive Airways Disease (OAD) and indoor exposure to baking home-made bread smoke (BHBS) in ground oven at home. In this hospital-based case-control study, 83 patients with OAD (cases) were compared with 72 patients without any known pulmonary diseases from the surgical ward (controls) who were frequently matched with cases on age. The interview was performed using the modified questionnaire recommended by the "American Thoracic Society". The questionnaire comprised of demographic information, occupational history, cigarette smoking and indoor exposure to BHBS in ground oven at home. The exposure to BHBS was considered both as a dichotomous and quantitative variable (number of years being exposed to smoke) and the population attributable fraction (PAF) was estimated due to BHBS exposure. The percentage of indoor exposure to BHBS was measured as 51.8% and 30.6% in the cases and the controls, respectively. The average years of exposure to BHBS was 20.46 years (SD: 11.60) for the cases and 15.38 years (SD: 13.20) for the controls. The univariate analysis comparing the cases and the controls showed that exposure to BHBS (as a binary variable) and occupational exposure to dust was significantly associated with OAD. In the multivariate model, only exposure to BHBS was associated with OAD (OR=2.22, 95%CI = 1.14-4.35). Duration of exposure to BHBS (as a quantitative variable) was significantly associated with OAD in the univariate model. In the multivariate model, only the duration of exposure to BHBS (years) showed a significant association with OAD (OR=1.04, 95% CI=1.01-1.08). Population attributable risk due to BHBS exposure was equal to 28.5%.