Smoking cigarettes is a terrible habit that will take a toll on one’s health. We know it. You know it. Assuredly, nearly everyone knows it.

So it’s probably with little compunction that most would favor the phasing out of smokers’ lounges at Denver International Airport.

Why should anyone enable that filthy practice?

But hang on a moment. Smoking is still legal in this country. Asking smokers to go for hours at a time — longer if there are delays and layovers involved — strikes us as punitive.

There are many actions and practices that are legal in this country but looked upon with disfavor in different quarters. A few that come to mind are gun possession, abortion, even eating fat-laden fast foods.

To be sure, some limits on these practices in some circumstances are within reason. We don’t think it’s too much to ask that those who legally carry guns are asked not to do so on airplanes, for instance.

There are compelling public safety reasons for that prohibition. Someone with a gun and bad intentions on an airplane could put a lot of innocent people in danger.

We also don’t think schools should be in the habit of routinely serving unhealthy lunches to their captive audiences of children.

But the imminent closure of three smoking lounges at DIA, with the retirement of the fourth and last lounge in 2018, feels more like an effort to punish people who smoke, not protect the public at large.

If the argument is that these indoor lounges are not completely safe for non-smokers — that some smoke still leaks out and exposes non-smokers and airport workers — then why is there not an effort to establish an outdoor smoking area beyond security checkpoints?

Airport officials tell us they don’t have space available for such a use.

Yes, we’ve heard arguments that airports are not designed for such things. But we also have seen airports redesigned and modified for all sorts of needs.

To be sure, smokers’ lounges are becoming an endangered feature at many airports across the country. The American Nonsmokers’ Rights Foundation counts at least 250 smoke-free airports.

And we understand that such bans are often an expression of the values that a community holds. No doubt, Colorado is all about living a healthy lifestyle and enjoying the state’s natural beauty.

We would hope, however, that Colorado is also about tolerance and the freedom of an individual to engage in legal activities so long as they don’t infringe on anyone else.