Passive smoking and lung cancer in Chandigarh, India

The aim of this study is to assess the relationship between exposure to env ironmental tobacco smoke (ETS) and lung cancer in non-smokers, a case-contr ol study among lifetime non-smokers was conducted in Chandigarh, India. Cas es consisted of 58 non-smoking histologically confirmed lung cancer patient s; two controls for each case were selected, one among other patients admit ted to the wards and one among the visitors to hospital patients. Subjects were asked about ETS exposure from different tobacco products in childhood and in adulthood at home, at the work place and in vehicles. Multivariate l ogistic regression analysis was used to assess the effects of the ETS expos ure variables on lung cancer. Exposure to ETS during childhood was strongly associated with lung cancer (odds ratio (OR) = 3.9; 95% confidence interva l (CI)= 1.9-8.2)! the effect mostly arising from exposure to cigarettes smo ke. The excess risk was observed with either a smoking father or mother. An increasing risk was found with increasing number of smokers and duration o f exposure. Restricting the analysis to women produced higher estimates of the risk. No increased risk was found with exposure to a smoking spouse, ex cept for those exposed only to cigarette smoke (OR = 5.1; 95% CI = 1.5-17). A weak association was seen between lung cancer and ETS exposure at the wo rkplace, which increased with the number of years of exposure. Exposure in vehicles also was detected as a risk factor for lung cancer in non-smokers. This study suggests that ETS exposure may be a strong risk factor for lung cancer also in India, a country with low prevalence of smoking and, theref ore, low rates of lung cancer. Other studies need to be conducted in simila r settings to confirm the role played by ETS exposure early in life in the causation of lung cancer. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.