Two new studies add even more weight to the existing evidence that secondhand smoke is a serious health threat. Writing in BMJ (Vol. 330; No. 7486:277-281 and 287-288), researchers from Europe report that kids exposed to secondhand smoke have a higher risk of lung cancer, while researchers in Hong Kong link secondhand smoke to a greater risk of death from any cause — including lung cancer.
The European team, led by epidemiologist Paolo Vineis of Imperial College, London, studied more than 123,000 people who were either nonsmokers or had given up smoking at least 10 years earlier. All the participants provided information on their exposure to secondhand smoke, including where they were exposed and whether they had been exposed as children.
People who had been exposed to secondhand smoke for many hours every day in childhood had more than triple the risk of developing lung cancer compared to people who were not exposed to secondhand smoke as children. Former smokers were more at risk of developing lung cancer than people who never smoked.
The Hong Kong team, led by Sarah McGhee of the University of Hong Kong, analyzed the causes of death for more than 5,600 nonsmokers. Those who were exposed to secondhand smoke in the home were 24% more likely to die from any cause, including lung cancer, other lung diseases, other cancers, heart disease, and stroke if there was one smoker at home. If there were two smokers in the household, their chance of dying increased by 74%.