About 60 percent of Americans — 175 million people — now live in communities that restrict smoking in public places.

On Nov. 3, voters in St. Louis County can add the county's nearly 1 million residents to the list by voting for Proposition N. That would protect the right of nonsmokers to breathe clean air in enclosed public spaces, including restaurants and bars.

Approval would trigger a similar ban in the city of St. Louis. The city's Board of Aldermen approved the ordinance Friday, contingent on passage of the county ban.

The smoking restrictions could cause some economic hardship and dislocation. But regardless of what opponents may argue, there is indisputable scientific evidence that secondhand tobacco smoke is a serious public health threat.

Most recently, the Institute of Medicine, part of the National Academies of Science, reported Oct. 15 that exposure to secondhand smoke increases the risk of heart attack. Clean indoor air laws significantly reduce that risk, the Institute found.

The report confirms what the U.S. surgeon general and scores of peer-reviewed studies have concluded: Clean indoor air laws reduce the incidence of heart disease and heart attacks.

That's the overwhelming reason to Vote Yes on Proposition N.

People who own smoke shops, some bowling alleys and restaurants are opposing Proposition N. It's only natural that small-business owners would be concerned about the potential economic impact. The tobacco industry has spent years — and millions of dollars — fanning those fears.

An association of bowling center owners worries, in particular, about the "double standard" inherent in the ordinance. Bowling alleys would have to restrict smoking in their establishments, but large casinos that are their competitors are exempted.

We agree. Just because big casinos have more political clout than bowling centers, they shouldn't get a pass.

The good news for worried restaurant and bar owners is that scores of peer-reviewed economic analyses show clean indoor air laws have minimal adverse economic impact. That certainly has been the case in Ballwin and Arnold.

Some opponents say Proposition N would infringe on the rights of business owners, who should be able to decide whether smoking is allowed. Should we also allow them to serve tainted food from unsanitary kitchens or block fire exits or disable fire sprinklers?

Secondhand smoke is a public health threat, just like unsanitary restaurant kitchens or unsafe stores.

For workers who spend their days and nights in smoke-filled bars and restaurants, the danger is magnified. They include many young people working at their first jobs. Often, those workers aren't offered health insurance and aren't in an economic position to quit. People shouldn't be forced to risk their health just to earn a living.

Proposition N is less comprehensive than clean air laws in Illinois or Kansas City, which means it's not as strong as it should be. But it's much better than the current state of affairs.

More than 75 percent of St. Louis County residents are nonsmokers. Their health shouldn't be held hostage to the minority's tobacco addiction.