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

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.

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.

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.

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.