Voters and legislators kicked cigarettes out of most bars and restaurants years ago. But now they’re back in a different form: Electronic cigarettes—smokeless cartridges that release nicotine vapors—are popping up in public places. Several cities and states—including North Dakota, New Jersey, and Utah—have explicitly banned their use indoors, but many haven’t. And while the dangers of secondhand smoke are well documented—and you know to keep your distance from smoke—how hazardous is the vapor from e-cigs? Read the full article in Men’s Health.