Biomass fuel and risk of tuberculosis: a case–control study from Northern India
- 1School of Public Health, Post Graduate Institute of Medical Education and Research Chandigarh, India
- 2School of Public Health, Division of Environmental Health Sciences, University of California, Berkeley, USA
- Correspondence to Dr Rajesh Kumar, School of Public Health, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India;
- Accepted 22 September 2010
- Published Online First 30 November 2010
Background Although a known risk factor for several respiratory diseases, the relationship between cooking smoke and tuberculosis has not been conclusively established. Hence, a case–control study was conducted among adult women of Chandigarh Union Territory in India.
Methods Physician-diagnosed cases of sputum positive pulmonary tuberculosis (n=126) and age- and residence area-matched controls (n=252) were enrolled from clinics in urban, rural and slum areas. Interviews were conducted in the clinic using a pretested questionnaire to collect information on type of cooking fuel, education, occupation, socio-economic status, smoking, overcrowding and type of kitchen, etc. The conditional logistic regression model was used for control of confounding.
Results The study population was predominantly in the 20–29-year-old age group (58%) and lived in urban areas (67%). The majority were illiterate (52%) and housewives (93%), and nearly half (46%) had an income of no more than Rs 25 000. Among the cases, 20.6%, 27% and 52.4% used biomass fuel, kerosene and liquid petroleum gas (LPG), respectively, whereas among controls, the respective figures were: 12.3%, 26.2% and 61.5%. The unadjusted OR for biomass fuel compared with LPG was 2.33 (95% CI 1.18 to 4.59, p 0.01). Adjustment for confounding factors (education, type of kitchen, smoking tobacco and TB in a family member) and interaction between cooking fuel and smoker in family revealed an OR of 3.14 (95% CI 1.15 to 8.56, p=0.02) for biomass fuel in comparison with LPG.
Conclusions Cooking with biomass fuel increases the risk for pulmonary tuberculosis.
Funding This research was funded by the Fogarty International Training and Research in Environmental and Occupational Health Program (award 3D43-TW000815).
Competing interests None.
Patient consent Obtained.
Ethics approval Ethics approval was provided by the ethical committee of Post Graduate Institute of Medical Education and Research in Chandigarh as well as the University of California, Berkeley.
Provenance and peer review Not commissioned; externally peer reviewed.