In 1986, then Surgeon General C. Everett Koop declared secondhand smoke to be a health hazard. Case closed? Hardly. The past 20 years have seen pitched battles over banning smoking indoors, despite the fact that the accumulated scientific evidence clearly documents increased risk of lung cancer, heart disease, asthma, and other deadly ills.

Although smoking on airplanes is a thing of the distant past (Congress banned it in 1989) and most workers must huddle outside for a workday smoke, regulation of smoking in bars and restaurants remains patchwork. Indeed, two thirds of states lack comprehensive bans. Tobacco companies have argued that passive smoke isn't all that bad and that bans infringe on Americans' freedom of choice.

Enough already, Surgeon General Richard Carmona said Tuesday. In the office's first comprehensive report on passive smoke in 20 years, Carmona declared unequivocally that the science supports a total ban on smoking indoors. "Secondhand smoke is not a mere annoyance," he said. "It is a serious health hazard that can lead to disease and premature death in children and nonsmoking adults."

The report concludes bluntly that increasing ventilation doesn't help: There is no safe level for secondhand smoke, and the deadly effects of the toxic chemicals in cigarettes linger long after a butt is stubbed out. Even brief exposure can cause irreversible harm. Nonsmokers exposed to secondhand smoke increase their risk of heart disease by 25 to 30 percent and of lung cancer by 20 to 30 percent. California health officials estimate that secondhand smoke kills about 50,000 nonsmokers annually nationwide, mostly from heart disease.

"This report ought to serve as a catalyst for a dramatic increase in the enactment of laws banning smoking indoors," says Matt Myers, president of the Campaign for Tobacco-Free Kids.

Bars aren't the only risky venues. According to the EPA, 9 million to 12 million children ages 6 and younger are exposed to tobacco smoke in their homes. They are more at risk of sudden infant death syndrome, pneumonia, ear infections, and asthma. And the U.S. House of Representatives still lets members allow smoking in their offices and committee chambers.

"It underscores the seriousness of the issue," says Joseph Martyak, an executive vice president with the American Legacy Foundation, which runs ad campaigns aimed at getting teens to reject tobacco. The group is about to launch the second phase of its "Don't Pass Gas" campaign against secondhand smoke. The message: "Take it outside," Martyak says. "If you are going to smoke, don't do it around other people.

The surgeon general's report can be read at www.surgeongeneral.gov/library/secondhandsmoke