Utah has banned smoking in restaurants and other public places. Bars and private clubs will go smokeless in the next three years.

Now one Utah lawmaker wants cars to be smokeless, too, at least when small children are on board.

Sen. Scott McCoy, D-Salt Lake City, is looking into legislation that would ban smoking in cars when young children are on board. McCoy said he will spend time between now and January to build support for the idea.

Arkansas recently enacted a law like this, with a $25 fine for violators who have children age 6 or younger in the car. Other states are considering similar bans. The age coincides with the age at which children are required to be in car seats. McCoy said he would have to look at Utah's car seat law and see if that age would be suitable to use.

We don't see why that's relevant. Infants deserve protection as much as older children. It is proper to protect all kids from irresponsible adult behavior, and there are a great many laws already on the books that do this. Second-hand smoke is clearly a bad thing, and if it's OK to regulate it in public places, it is equally OK to regulate it in automobiles, which already fall under state jurisdiction.

One of the hurdles McCoy is going to have to clear is the outcry from smokers who argue their rights are being trampled. They will say that their cars are private spaces, similar to their homes, and they should be able to smoke freely, even with the windows rolled up. They will say that the next step is to ban them from smoking in their homes.

This is a legitimate worry. Society needs to guard against the encroachments of government on private life. But life in an automobile is not the same as life at one's home, and it is not equally protected. Motor vehicles are already heavily regulated. Driving is a privilege granted by the state, and it comes with many rules. You have to wear a seat belt, for example. You can't have a loaded gun in your car. You can't drive with a certain amount of alcohol in your blood. Children on a motorcycle must wear a helmet.

It would be improper in the future for the state to attempt to regulate smoking in a private home. Unfortunately, within the walls of one's castle it is easier to harm a child's health with impunity. But this doesn't mean the state should stand back and do nothing when it has clear jurisdiction.

This is not about regulating adults who have a right to make dumb choices. It is a plan to protect children who have no choice.

A car is different from a house in many ways. For starters, the space is much smaller. In even the most modest apartment there is likely to be fewer tobacco-related particulates per cubic foot than in a car with the windows up. Children are at the mercy of the adults they're riding with.

There is a considerable body of scientific evidence on the dangers of second-hand smoke. Children exposed to it for extended periods are more prone to asthma and ear infections. If the state can reduce some of this by enhancing rules in an area over which it already has jurisdiction, why shouldn't it act?

As with the Utah Indoor Clean Air Act, the law does not infringe on the rights of smokers so much as protect the rights of non-smokers to be free of the carcinogens and toxins found in cigarette smoke. The adult smoker may legally choose a product that, when used as directed, will kill a third of its users. But why should children be forced, even indirectly, to smoke? They shouldn't.

If this law is enacted, enforcement sould be delayed for a year or two to allow time for a public education campaign on the dangers of exposing children to second-hand to sink in.

That would give smokers time to think about how their actions affect others, especially their own beautiful kids.