Secondhand smoke, also known as passive smoking causes 603,000 deaths per year worldwide, of which 165,000 are children, Dr Annette Prüss-Ustün and team of the World Health Organization wrote in the medical journal The Lancet. The authors state that this is the first study to determine secondhand smoking's impact worldwide.
The last time comprehensive data on 192 countries was gathered was 2004, the year used for this analysis, the author explained. The death toll as well as life-years lost were calculated.
Below are some highlighted data from the study - globally in 2004:
- 40% of the world's children are exposed to secondhand smoke
- 33% of males who don't smoke are exposed to secondhand smoke
- 35% of females who don't smoke are exposed to secondhand smoke
- Secondhand smoke is thought to have caused 165,000 lower respiratory infection deaths, 379,000 ischemic stroke deaths, 36,900 asthma deaths, and 21,400 lung cancer deaths.
- 603,000 premature deaths were caused by passive smoking, approximately 1% of all premature deaths
10.9 million years of good health were lost, about 0.7% of DALYs* burden for that year. 61% of DALYs were in children
* DALYs = Disability Adjusted Life Years. It is the sum total of years of potential life lost because of premature death, plus the years of productive life lost due to disability.
The largest disease burdens - Worldwide in 2004 due to secondhand smoke were:
- Children under 5 years - 5,939,000 had lower respiratory tract infections
- Adults - 2,836,000 had ischemic heart disease
- Children - 1,246,000 had asthma
The authors wrote:
- "Two-thirds of these deaths occur in Africa and south Asia. Children's exposure to second-hand smoke most likely happens at home. The combination of infectious diseases and tobacco seems to be a deadly combination for children in these regions and might hamper the efforts to reduce the mortality rate for those aged younger than 5 years as sought by Millennium Development Goal 4."
Smoke exposure at home is slightly higher in the Middle East and Asia.
The most compelling evidence of the damage caused by secondhand smoke is among children.
The number of coronary events dropped rapidly after certain countries banned smoking in indoor workplaces, the authors reported.
- "Policy makers should bear in mind that enforcing complete smoke-free laws will probably substantially reduce the number of deaths attributable to exposure to second-hand smoke within the first year of its implementation, with accompanying reduction in costs of illness in social and health systems."
- Globally, there are 60% more adult female non-smokers than adult male non-smokers
- Women are 50% more likely to be exposed to environmental tobacco smoke in the eastern Mediterranean, southeast Asia and some regions of the Americas.
Comprehensive smoke-free legislation is only present where just 7.4% of the world's population lives. In such countries, it has been found that people's exposure to environmental tobacco smoke is 90% lower in bars and restaurants and 60% lower in general.
Such comprehensive legislation also benefits smokers, who smoke less and are more likely to consider and attempt giving it up.
The authors concluded:
- "Policy makers should also take action in two other areas to protect children and adults. First, although the benefits of smoke-free laws clearly extend to homes, protection of children and women from second-hand smoke in many regions needs to include complementary educational strategies to reduce exposure to second-hand smoke at home.
Voluntary smoke-free home policies reduce exposure of children and adult non-smokers to second-hand smoke, reduce smoking in adults, and seem to reduce smoking in youths. Second, exposure to secondhand smoke contributes to the death of thousands of children younger than 5 years in low-income countries.
Prompt attention is needed to dispel the myth that developing countries can wait to deal with tobacco-related diseases until they have dealt with infectious diseases. Together, tobacco smoke and infections lead to substantial, avoidable mortality and loss of active life-years of children."
"Although the social-norm change that comes with smokefree laws can spill over to homes, broad initiatives are needed to motivate families to put their own policies into place to reduce exposure to second-hand smoke at home. In some countries, smokefree homes are becoming the norm, but far from universally.
(Conclusion) There can be no question that the 1•2 billion smokers in the world are exposing billions of non-smokers to second-hand smoke, a disease-causing indoor-air pollutant. Few sources of indoor-air pollution can be completely eliminated. However, smoking indoors can be eliminated - with substantial benefits, as shown by this new set of estimates."
Mattias Oberg PhD, Prof Maritta S Jaakkola PhD, Prof Alistair Woodward PhD, Armando Peruga DrPH, Dr Annette Prüss-Ustün PhD
The Lancet, Early Online Publication, 26 November 2010. doi:10.1016/S0140-6736(10)61388-8
Written by Christian Nordqvist