The international consensus on cancer research conducted over the past decade has confirmed that second-hand smoke is a direct cause of lung cancer. The 1996 OMA position statement, Indoor Air Quality and Second Hand Smoke, notes that second-hand smoke is the third-ranking known cause of lung cancer after active smoking and indoor radon gas exposure, and that lung cancer kills more women then breast cancer, while being the leading cause of premature death for men. In 1992, the U.S. Environmental Protection Agency published a major assessment of the "Respiratory Health Effects of Passive Smoking" (US Environmental Protection Agency. 1992) which concluded that exposure is responsible for approximately 3,000 lung cancer deaths each year in non-smoking adults, and impairs the respiratory health of hundreds of thousands of children.
The 1997 California Environmental Protection Agency report concluded that second-hand smoke is a cause of lung cancer and is responsible for 3000 deaths annually in the United States. In 1998, the International Agency for Research on Cancer (IARC) conducted the largest European study ever examining the linkage between lung cancer and passive smoke (click here to view the study). The study found a 16% increase in the point estimate risk of lung cancer for non-smokers. An October 1998 editorial in the Journal of the National Cancer Institute (7 October 1998. 90(19): 1416-1417) concluded that the International Agency's new study data, plus previous evidence, presented "an inescapable scientific conclusion...that second-hand smoke is a low-level lung carcinogen."
In echoing the above and as a response to tobacco industry mischaracterization of earlier IARC research, the twenty-nine international experts of the scientific working group convened by the Monograph Program of the International Agency for Research on Cancer concluded in June 2002 that second-hand smoke is carcinogenic to humans and a cause of lung cancer: "Involuntary smoking involves exposure to the same numerous carcinogens and toxic substances that are present in tobacco smoke produced by active smoking, which is the principal cause of lung cancer...[thus] involuntary smoking is a cause of lung cancer in never smokers."
The monograph concluded that after conducting meta-analyses of more than fifty international studies of involuntary smoking and lung cancer risk in non-smokers over the past twenty-five years, there is a statistically significant and consistent association between lung cancer risk and those non-smokers exposed to second-hand smoke from active smokers, whether exposed to it by their spouses or in the workplace.
The following are links to other useful scientific articles on this topic:
- Secondhand smoke exposure in adulthood and risk of lung cancer among never smokers: A pooled analysis of two large studies. Brennan, Paul et al. International Journal of Cancer Volume 109, Issue 1 , Pages 125 - 131, March 2004.
- Environmental tobacco smoke exposure in women with cancer. de Andrade, M, Ebbert, JO, Wampfler, JA et al. Lung Cancer 2004; 43: 127-134.
- Secondhand smoke exposure in adulthood and risk of lung cancer among never smokers: A pooled analysis of two large studies.Brennan, P, Buffler, PA, Reynolds, P et al. Int J Cancer 2003 Dec 10.
- Tobacco smoking and chewing, alcohol drinking and lung cancer risk among men in southern India.Gajalakshmi, V, Hung, RJ, Mathew, A et al. Int J Cancer 2003 Nov 10; 107(3):441-7.
- Second hand smoke stimulates tumor angiogenesis and growth.. Zhu BQ, Heeschen C, Sievers RE, Karliner JS, Parmley WW, Glantz SA, Cooke JP. Cancer Cell, Vol 4, 191-196, September 2003.
- Secondhand smoke stimulates tumor angiogenesis and growth. Zhu, B-Q, Heeschen, C, Sievers, RE et al. Cancer Cell 2003 Sept; 4: 191-196.
- Exposure to secondhand smoke and excess lung cancer mortality risk among workers in the "5 Bís": bars, bowling alleys, billiard halls, betting establishments, and bingo parlours. Siegel, M and Skeer, M. Tobacco Control. 2003; 12:333-338.
- Risk Factors For Lung Cancer Among Nonsmoking Women. Kreuzer Michaela, et al. International Journal of Cancer. August 2002; 100: 706-713.
- Lifetime residential and workplace exposure to environmental tobacco smoke and lung cancer in never-smoking women, Canada 1994-1997. Johnson Kenneth C., et al. International Journal of Cancer. 28 June 2001; 93(6): 902-906.
- Declines in Lung Cancer Rates - California, 1988-1997. Centre for Disease Control. December 2000; 49(47): 1066-9.
- Environmental Tobacco Smoke, Genetic Susceptibility, and Risk of Lung Cancer in Never-Smoking Women. William P. Bennett, et al. Journal of the National Cancer Institute. December 1999; 91: 2009-2014.
- Multicenter Case-Control Study of Exposure to Environmental Tobacco Smoke and Lung Cancer in Europe. Paolo Boffetta, et al. Journal of the National Cancer Institute. 1998; 90(19): 1440-50.
- The Accumulated Evidence on Lung Cancer and Environmental Tobacco Smoke. Hackshaw AK, et al. British Medical Journal. 1997; 315:973-80.
- Environmental Tobacco Smoke and Lung Cancer in Nonsmoking Women - A Multicenter Study. Fontham, ET, et al. Journal of the American Medical Association. June 1994; 27 (22): 1752-1759.
- Passive Smoking and Lung Cancer in Nonsmoking Women. Brownson RC, et al. American Journal of Public Health. November 1992; 82(11): 1525-1530.