Secondhand smoke may trigger heart attacks
Secondhand tobacco smoke contains at least 250 chemicals that are known to be toxic or carcinogenic, and is responsible for more than 35,000 heart disease deaths in the U.S. each year, as well as 3,000 lung cancer deaths.
A new study published in May in the British Medical Journal reports that the implementation of a comprehensive local clean indoor air ordinance in Helena, Mont., may have resulted in a rapid reduction in heart attacks. The study found hospital admissions for acute myocardial infarction declined by about 40 percent during the six months the ordinance was in effect and rebounded after the ordinance was suspended.
Dr. Terry Pechacek, associate director of science in CDCâ€™s Office on Smoking and Health, who was invited to write a commentary on the study, said, "This study is important because it focuses attention on the large body of evidence that suggests that secondhand smoke exposure causes surprisingly large increases in acute cardiovascular risk."
According to Pechacek, research indicates that nonsmokers who are exposed to secondhand smoke at typical levels may incur more than one-third of the heart disease risk of someone who smokes 20 cigarettes a day. Also, even short-term exposures - lasting as little as 30 minutes - may pose significant risks, especially in persons who already have or are at special risk of heart disease.
These effects are quite different from those of secondhand smoke exposure on lung cancer, where the very significant risk increases over years of exposure. The commentary reviews recent evidence on specific mechanisms in the body that may account for these findings.
Dr. Pechacek and co-author, Stephen Babb, a CDC health education specialist, note in the commentary that the public health implications of these findings are dramatic. They suggest that persons with pre-existing heart disease or high-risk profiles for heart disease should avoid all indoor environments that allow smoking.
Family members should avoid exposing these persons to secondhand smoke at home or in vehicles. On a broader level, these findings suggest that comprehensive clean indoor air policies similar to Helenaâ€™s could result in an almost immediate drop in heart attacks. If such policies were implemented nationwide, they could potentially save thousands of lives each year by sharply reducing the toll of heart disease - the nationâ€™s leading killer.
"The public health implications of these findings are dramatic," said State Health Officer, Donald E. Williamson. "The impact of secondhand smoke exposure on heart disease risk appears to be substantial and rapid, but rapidly reversible through the establishment of smoke-free environments. This study further reinforces the importance of implementing smoke-free policies as an effective way to decrease exposure to a common and completely preventable public health hazard in our state," he said.
Both the U.S. Surgeon General and the U.S. Task Force on Community Preventive Services have concluded that the most effective method for reducing secondhand smoke exposure is the establishment of smoke-free environments.
The Tobacco Prevention and Control Division of the Alabama Department of Public Health educates communities regarding the hazardous effects of exposure to secondhand smoke and monitors progress toward a smoke-free Alabama.
The division is currently assessing work sitesâ€™ tobacco-related policies. The program compiled a database that analyzes the relative strength of city ordinances regarding tobacco.
Ninety-seven Alabama cities with a population of 2,000 or more have ordinances addressing secondhand smoke, but most provide only limited protection. The program also assessed the strength of public schoolsâ€™ policies regarding tobacco use and exposure. All public schools are required by the Alabama Administrative Code to be tobacco free. The Clean Indoor Air Act of 2003 also requires school events to be smoke free.
To obtain a copy of the research article or the Acute Cardiovascular Risks of Secondhand Smoke Exposure commentary, visit the British Medical Journal web site at www.bmj.com. For more information about secondhand smoke visit the CDC web site at www.cdc.gov.