Generally speaking, the federal government is in the business of protecting public health. It works hard to ensure that medicines are safe before they can be sold to the public. It issues recalls when toys pose choking dangers to small children. Last year, it got expanded power to regulate the tobacco industry so it could do more to discourage smoking, especially among kids.

Cigarette So why not protect the 7 million people who live in public housing by banning smoking in those complexes?

That's the question posed by a pediatrician and two lawyers who focus on the public health consequences of smoking. Writing in Thursday's edition of the New England Journal of Medicine, they urge the Department of Housing and Urban Development to make use of a new federal policy that gives public housing authorities the power to make smoking verboten in the apartments they rent to low-income people.

This proposal is sure to be unpopular with many people, not the least being smokers who live in publicly owned or publicly subsidized housing. Many people take it on faith that the rights to liberty and privacy protect people who want to smoke in their homes.

But that's not necessarily true, the authors write. Courts have ruled that smoking restrictions do not violate the U.S. Constitution and that the government can implement a ban if it has a "reasonable basis" for doing so (such as protecting the health of children). They note that the federal Fair Housing Act does not include a right to smoke.

That doesn't mean that smoking privileges should be removed lightly. The only ethical way to deal with public housing residents who are already addicted to tobacco is to offer them places in smoking cessation programs and give them time to adjust, the authors write.

In any event, their burden would be more than outweighed by the benefits to nonsmoking residents, the authors argue. Forty-one percent of public housing units are occupied by families with children and 32% include an elderly person – two groups that are particularly vulnerable to tobacco smoke. As we all know, exposure to secondhand smoke increases the risk of lung cancer, heart disease, asthma and other health problems. A 2006 report from the surgeon general says that "there is no risk-free level of exposure to secondhand smoke."

Without an outright ban, it would be difficult or impossible for low-income people to live in a smoke-free environment. They can't simply "vote with their feet" and move to another building if they can't afford to pay higher rent, the authors write.

There's reason to think a smoking ban would actually be popular. Thousands of landlords from Chicago to Oregon have made their apartment buildings smoke-free, and have so far kept from going out of business.