Introduction: Although epidemiological studies have reported an association between smoking and increases in tuberculosis, the relationship between indoor air pollution and risk of tuberculosis is not fully understood. A limited number of studies have suggested that smoking and indoor air pollution may play a role in the pathogenesis of tuberculosis. In this study, we investigated the effect of smoking and indoor air pollution on the risk of active tuberculosis.
Materials and methods: It is prospectively recorded age matched case-control study. Three hundred sixty two active tuberculosis cases and 409 healthy controls were included to the study. All participants were interviewed face to face by using a questionnaire including smoking habit, quantity and duration of smoking, number of room/person in the house, monthly income of the family, indoor heating system, and environmental tobacco smoke.
Results: Patients who smoke had a five fold (95% CI: 3.2-7.5, p< 0.0001) higher odds of having active tuberculosis compared with patients who do not smoke. Similarly, patients using coal or wood for indoor heating had a 1.6 fold (95% CI: 1.179-2.305, p< 0.003) higher odds having tuberculosis. People who have less income (< 200 Euro/month) had 3.2 fold (95% CI: 2.113-5.106, p< 0.0001) higher odds of having tuberculosis compared with people having high income. There was a significant correlation between heavy smoking (≥ 20 packet/year, p< 0.0001) and age onset of smoking (< 16 years of age, p< 0.041). There was no significant association between environmental tobacco smoke and tuberculosis.
Conclusion: Smoking and indoor air pollution may increase the risk of tuberculosis. There is a complex interaction between smoking, socioeconomic conditions, indoor air quality and tuberculosis. Our results suggest that effective indoor air quality control could help to prevent tuberculosis risk.