Researchers equated the health risk of secondhand smoke exposure to smoking one cigarette per day, and said that eliminating such exposure could save a half-million lives over the next quarter century, Reuters reported May 10.

Researcher Kirsten Bibbins-Domingo and colleagues from the University of California at San Francisco reached their conclusions based on existing coronary-health studies and research showing that up to 43 percent of the population is exposed to secondhand smoke. "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," she said.

The study authors estimated that secondhand smoke causes between 9,500 and 21,500 heart-related deaths and 14,600 to 32,400 heart attacks annually. Bibbins-Domingo and colleagues said that if secondhand smoke was eliminated today, there would be 842,900 fewer heart attacks and 580,600 fewer heart disease-related deaths by 2030.

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