I have in my office a sign from the Coastal Medical Oxygen Service of St. Petersburg, Fla. that says in big red letters, "NO SMOKING, OXYGEN IN USE." It belonged to my Uncle Mike, a former smoker and emphysema victim who needed the oxygen for his crumbling lungs. I took the sign when he died.

I did more than that. I went outside the bungalow where Mike had lived and threw my cigarettes into a trash can. I vowed never to smoke again -- and I didn't for maybe a day or two. I have since quit and loathe cigarettes with the passion of a convert. That's the background to what follows.

The Wall Street Journal the other day called on Sen. Jesse Helms (R-N.C.) to "confound his critics and show statesmanship" by supporting, instead of denouncing, the Reagan administration's proposal to end tobacco subsidies. The Journal noted that cigarettes are unhealthy, but its bottom line was, well, the bottom line. It asked Helms to look upon the tobacco program as he would, say, milk subsidies: in the name of fiscal consistency, it had to go.

But I, in the name of a one-time plumber named Mike Rosenberg, call on Helms to truly confound his critics, to scramble their brains and leave them dumbstruck. In the name of moral consistency, Helms and his cohorts in the right- to-life movement ought to denounce smoking just as they do abortion. After all, cigarettes kill, too.

Now I would be the first to concede that this comparison is a bit overdrawn. Helms and the other guardians of our morality might argue that since abortion takes the life of what they call "the unborn innocent," it's different from smoking. Not quite. Smoking by pregnant women hurts the unborn but, even so, your average victim is the born and the not-so-innocent. Many smokers, though, are kids, especially young girls, and only in some theoretical sense do they "choose" to smoke. For them, the health consequences are so distant they seem to have little bearing on reality. But they do. This year, for the first time, lung cancer is expected to replace breast cancer as the leading cause of death among women. No one knows how to prevent breast cancer. Everyone knows how to prevent most lung cancer.

The issue here is not fiscal consistency, but moral consistency. It hardly matters that at $60 million a year the government's tobacco program is small. It would be immoral at $1 a year. What's the government doing in a business whose product is addictive, unhealthy and, in many cases, fatal? Where's the logic in placing a health warning on cigarette packs and checks in the pockets of tobacco farmers? If Helms were not from a tobacco state, he might be among the first to note, with his usual understatement, that the government is denouncing smoking out of one side of its mouth -- and inhaling with the other.

It's tough for a politician to tell a local industry it ought to roll over and die. It may, in fact, be too much to ask of any politician. Tobacco already takes a high human toll, and the collapse of the industry would certainly, although temporarily, add to it. Growing tobacco may not be morally uplifting, but neither, for that matter, is poverty.

It's easy for people such as me to call for an end to tobacco supports and quite another thing to say what should be done for growers and others dependent on the foul and filthy leaf.

So don't count on Helms or any other member of Congress from a tobacco state to lead this particular moral crusade. But that doesn't let the rest of the Congress off the hook. Here it has an issue in which morality and austerity meet in happy conjunction -- in which cheap is also right. The Wall Street Journal, its eye on the bottom line, thinks the government ought to get out of the tobacco business. So do I, but I have my eye on something else. It's a "No Smoking" sign in my office.