“Mind if I smoke?” is an old refrain from the days when smoking was a ubiquitous habit and people frequently puffed on cigarettes in offices, on airplanes and at restaurants. Big Tobacco pushed the idea that "common courtesy" was enough to protect nonsmokers from toxic secondhand smoke, and that smoke-free laws were unnecessary.

It wasn't true then, and it's not true today. Even as cigarette use is shrinking across the country, another type of smoking — marijuana — is becoming increasingly widespread in public places, bringing with it a resurgence of secondhand smoke and airborne carcinogens. And now, nobody’s even asking if nonsmokers mind.