Indoor air pollution as a risk factor for lung cancer in women.

OBJECTIVES: Tobacco smoking is the most common risk factor for lung cancer. But a significant proportion of lung cancer occurs in non-smokers. Indoor pollution due to domestic fuels has been recently implicated as a causative agent in lung cancer especially in women. We conducted a case control study to find out the role of indoor air pollution due to domestic cooking fuels in Indian women.
METHODS: In a case control study 67 women with proven lung cancer were recruited. Forty-six females having a non-malignant respiratory disease constituted the control group. The patients and controls were asked about the exposure in various cooking fuels using a questionnaire. RESULT: There were 50 (74.6%) non-smokers and 17 (25.4%) smokers among the female cancer cases (p = 0.016). Adenocarcinoma was the commonest histological type of malignancy (n = 26, 38.8%) in the whole group and was the predominant form in the nonsmoking females. Tobacco smoking was the most important risk factor for lung cancer with OR of 4.87 (95% CI 1.34-17.76). Among non-smokers out of all the cooking fuels the risk of development of lung cancer was highest for biomass fuel exposure with an odds ratio of 5.33 (95% CI 1.7-16.7). Use of mixed fuels was associated with a lesser risk (OR = 3.04, 95% CI 1.1-8.38). ). In multivariate logistic regression analysis biomass fuel exposure was still significant with OR of 3.59 (95% CI 1.07-11.97) even after adjusting for smoking and passive smoking.
CONCLUSION: This study indicated that biomass fuel exposure is an important risk factor in the causation of lung cancer among women in addition of exposure to tobacco smoke.