Mortality rate would plunge without passive smoking

By Martha Kerr

NEW YORK (Reuters Health) - Eliminating exposure to secondhand tobacco smoke could reduce the number of deaths related to heart disease in the United States by more than 500,000 over the next 25 years, according to researchers at the University of California, San Francisco.

The risk from passive smoking is currently estimated to be equivalent to actively smoking one cigarette per day, Dr. Kirsten Bibbins-Domingo told attendees of the American Heart Association's 7th Scientific Forum on Quality of Care and Outcomes Research, being held this week in Washington, DC.

Using the updated data from the latest National Health and Nutrition Examination Survey (NHANES III) and estimates of heart disease risk based on the Framingham Heart Study and other studies, Bibbins-Domingo and colleagues assessed the impact of ending passive smoking, using 2005 as the first year and projecting out to 2030.

Between 15 and 25 percent of individuals report that they are exposed to passive smoke in the home or workplace. Blood samples evaluated for cotinine levels, a chemical marker of exposure to tobacco smoke, indicated that exposure is actually closer to 29 to 43 percent of the population, Bibbins-Domingo told Reuters Health. "More people are exposed to passive smoke than they realize and likewise, the annual heart disease deaths per year (related to passive smoking) are underestimated."

Depending on the level of exposure, Bibbins-Domingo estimated that passive smoking is responsible for between 9,500 and 21,500 coronary heart disease-related deaths annually and between 14,600 and 32,400 heart attacks annually. The lower estimate is based on self-reports of exposure; the higher estimate is based on measurements of cotinine levels in the blood.

If passive smoking were eliminated now, by the year 2030 up to 953,200 new cases of coronary heart disease would be prevented, averting 842,900 heart attacks and 580,600 heart disease-related deaths, she predicted.

"The take-home message is that the burden of passive smoking is very real. This should drive public policy. Passive smoking in public places should be eliminated," Bibbins-Domingo asserted.

"The coasts have been pretty good in adopting these policies. Ten states have a complete ban on workplace smoking...But then there is the whole rest of the country" that is lagging behind.

"A nationwide passive smoking ban would have a dramatic effect," the California investigator concluded. "These public policies can eventually have an effect on personal habits."