Fire without smoke.

It was just six years ago that Sean Marsee died. Sean gained national attention when his tragic story was reported in the October 1985 Reader's Digest. In top physical shape, 18-year-old Sean was a high school senior and star of the Talihina High School track team in Ada, Oklahoma. Twenty-eight medals decorated his room. But Sean was also a snuff dipper, and had been since the age of 12.

As he sat in Dr. Carl Hook's office, fear gripped his heart. "It doesn't look good. We'll have to do a biopsy," reported the throat specialist as he examined the angry red spot on Sean's tongue. The biopsy confirmed Dr. Hook's and Sean's greatest fear: cancer of the mouth.

You can guess the end of the story. Part of his tongue was removed, and heavy resection was performed on affected glands in his neck. A second operation followed, and then X-ray irradiation.

But nothing seemed to work for long. In only a few months fresh metastases appeared. If only he could retrace his steps. But for Sean it was too late.

Little had he known that with every chew and with every dip of tobacco he was slowly being destroyed by fire without smoke.

Yet Sean Marsee did not die in vain. To a large degree it was his story, along with others like it, that led to the passage of federal laws in 1986 requiring that warning labels be placed on cans of snuff and packages of smokeless tobacco. At the same time, a ban was placed on electronic advertising of the products.

Such measures may help to stem the rise in the use of these dangerous products. In the 15 years from 1970 to 1985, the production of snuff in the United States increased by 56 percent. During the same period the production of chewing tobacco rose 36 percent.

Current statistics show that more than 12 million Americans from all walks of life are using the stuff. The highest rates are among teenagers and young adult males, but surprisingly, even women and young girls are beginning to use it.

What is especially shocking is that some parents allow their children in kindergarten to dip and chew. They even pack the products in lunch boxes when they go to school.

The likelihood of using smokeless tobacco increases year by year from grade school through high school. And the overall situation is getting worse. A study of schoolchildren in Louisiana showed that in every age category more smokeless tobacco was being used in the early 1980s than in the mid-1970s.

In more than 50 percent of the cases, peer pressure is the most important initiating factor. There is also a strong desire to model one's lifestyle after the top athletes. Instead of having a cigarette dangling from their lips, many athletes now carry a bulge in their cheeks. If smokeless tobacco makes them champions, it can do the same for you - or so goes the thinking.

The tobacco companies want you to believe that smokeless tobacco is a safe alternative to cigarettes. It offers you all of the pleasures of cigarettes with none of the risks, they suggest. But what is the truth?

Like cigarettes, smokeless tobacco contains nicotine, a powerful addictive drug. The chewer or dipper obtains the same blood and brain levels of nicotine as does the smoker. The addiction is every bit as real.

The surgeon general's office reports that "the role of nicotine in the compulsive use of tobacco is the same as the role of morphine in the compulsive use of opium, or cocaine in the compulsive use of coca derivatives."

Nicotine increases and reinforces brief feelings of well-being. But nicotine also increases the heart rate, raises blood pressure and damages the junction points between the cells that make up the inner lining of the arteries.

Nor is nicotine the only problem. There are more than 2,550 chemical compounds in smokeless tobacco. True, most of them are inert or harmless, but many are real villains. For example, acids and proteins in the tobacco leaf encourage the formation of bacterial plaques that stain the teeth and erode the enamel! Tooth decay is the result.

Other complaints of users of smokeless tobacco include an inflammation of the gums called gingivitis, erosion or recession of the gums, and inflammation of the salivary glands.

The worst villains in smokeless tobacco are the N-nitrosamines, a large group of cancer-producing compounds.

The accompanying table shows the nitrosamine exposure that the average person in the United States gets through using such products as beer, cosmetics, and bacon-a total of about one microgram per day. This amount is small because the government does not allow nitrosamines in these products to exceed 5 parts per billion.

But when it comes to tobacco, much higher levels are permitted. On the average, a smoker gets 16 times as much as a nonsmoker. Even that amount is small compared to the snuff user. He gets 165 times the combined amount of nitrosamines found in beer, cosmetics, and bacon.

Along with nitrosamines, other carcinogens, including polynuclear aromatic hydrocarbons and radiation-emitting polonium-210, are found in smokeless tobacco. Each adds its influence to the initiation and promotion of various cancers.

Users of smokeless tobacco have much higher risks of cancer of the mouth, tongue, lips, and cheeks than do nonusers. The highest rates are found in Southeast Asia, especially India. There a large portion of the population chews pan. This is a quid made up of pepper leaf and either betel or areca nut, mixed with a dab of lime. Whenever tobacco is added to the quid, a dramatic increase in the incidence of oral cancer is seen.

But the mouth is not the only danger spot. Some of the juice from a mouthful of tobacco is swallowed. It bathes the pharynx, the upper region of the larynx, the esophagus, and finally the stomach. All of these sites are placed at a greater risk for cancer.

In most people the results of chewing tobacco and snuff are slow, silent, and insidious. But make no mistake. Like Delilah of old, these products promise pleasure and satisfaction, but at a price. And once they have you in their power, they will blind you by their fleeting pleasures. Like Samson, you'll end up grinding in the prison house. What it will cost you in ill health only time will tell.

What can you do to protect yourself.?

First, if you currently do not use the stuff, don't yield to a temptation to "try it just once." It simply isn't worth the risk.

If you currently are a user, either occasional or regular, decide today to give it up. Your breath will be sweeter, your teeth will be whiter, your environment will be cleaner, and your risk of cancer of the mouth will be much lower.

If you need help in quitting, join a stop-smoking program. Since nicotine is the addictive agent, the same techniques that help smokers to quit will work for you.

If you are a parent, educate your children about the dangers. Health Productions at the School of Public Health at Loma Linda University (Loma Linda, California 92350) has just produced an excellent 16-minute slide/tape and video program on this subject. Get a copy, view it with your family, and then discuss it together.

Also, encourage your children to choose wisely the athletes they want to emulate. In the past two years more than 12 major league baseball teams have stopped distributing smokeless tobacco to their players. Some teams have shown a 50 percent decline in the number of athletes using it.

One of those players no longer using it is Ryne Sandberg, second baseman for the Chicago Cubs. "If you think smokeless tobacco won't hurt you, your logic's out in left field," says the four-time all-star in an anti-smokeless tobacco campaign for the Dental Health Adviser.

Don't be fooled by macho images in the tobacco ads. They show rugged cowboys, successful athletes, hardworking men - but as Sean Marsee found out too late, you can expect a white, thickened, wrinkled plaque on the gums or cheeks, or a cancer in the mouth, or a coronary heart attack, or paralyzing stroke.

When you play with fire you're bound to get burned, even if that fire comes without smoke.