Background: Biomass smoke has been associated with many diseases. The aim of this study was to evaluate the relationship between biomass smoke and chronic bronchitis in women in the rural setting of Peshawar, Pakistan.
Methods: Three villages in rural Peshawar were randomly selected as "test villages" where biomass fuel was used. The women responsible for cooking in these villages were interviewed for the prevalence of bronchitis, and data were compared to those obtained from three matching "control villages" where liquid petroleum gas was used as fuel. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a statistical software package (EPI Info, version 6.0 [public domain software]; Centers for Disease Control and Prevention; Atlanta, GA).
Results: This study was carried out in 1,426 female test patients and 1,131 female control subjects. Chronic bronchitis was found in 100 women (7.01%) in the test group and 33 women (2.92%) in the control group. The OR was 2.51 (95% CI, 1.65 to 3.83). A strong association was found between bronchitis and the use of wood (OR, 2.38; 95% CI, 2.12 to 3.01), dung cake (OR, 2.01; 95% CI, 1.72 to 2.42), rice straws (OR, 3.32; 95% CI, 1.11 to 9.88), and kai grass (OR, 1.96; 95% CI, 1.75 to 2.45). Cooking in the living room and bronchitis were highly associated (OR, 2.5; 95% CI, 1.94 to 3.66). An association between the presence of a kitchen and bronchitis was established with an OR of 2.65 (95% CI, 2.10 to 3.42). In the test group, 75% of kitchens were ventilated; in the control group, 82% were ventilated. The difference between the two groups was nonsignificant (p>0.6; chi2=0.39; OR, 0.83; 95% CI, 0.5 to 1.4).
Conclusions: Biomass fuel exposure is strongly associated with chronic bronchitis in women who are involved in cooking in rural Peshawar.