As emotional debates rage over cigarettes--Should vending machine sales be curtailed? Should nicotine be regulated as a drug?--lost in the fray are the basics: Who smokes? Who gets hooked? What are the long-term and short-term health risks? How does smoking affect appearance? And how can you quit without putting on pounds?
Here's a sampling of facts gathered by statisticians and researchers.
* About 48 million U.S. adults, or 25.5% of the population, smoke.
* More men than women smoke: 25.3 million versus 22.7 million.
* Of adult smokers, 82% smoke every day; 18% don't.
* Most likely to smoke: Native Americans and Alaskan Natives (42.2%); least likely to smoke: Asians and Pacific Islanders (13.9%).
* An estimated 4.5 million teens, ages 12-17, are smokers.
* Smokers are more likely to be heavy drinkers and illicit-drug users.
* Tobacco use is blamed for nearly one in five deaths in the United States.
* Worldwide, about 3 million people a year die as a result of smoking. By 2020, the total is predicted to nearly triple, and smoking will be the single largest cause of death, according to a World Health Organization study released Monday.
* On average, a smoker loses 15 years of life.
* Men who smoke have a 22-times greater risk of dying of lung cancer than do men who have never smoked; women smokers' risk of dying of lung cancer is 12 times greater than that of women who have never smoked.
* This year, lung cancer is expected to be diagnosed in 177,000 people in the U.S.
* The incidence of lung cancer has declined in men but continues to increase in women; about 158,000 men and women will die of lung cancer in the United States this year.
* Since 1987, more women have died each year from lung cancer than from breast cancer.
* While the associations between smoking and lung cancer--as well as smoking and heart disease--are well-known, there are other cancers associated with smoking. Among them: cancers of the mouth, pharynx, larynx, esophagus, pancreas, cervix, kidney and bladder.
* Besides stained teeth, facial wrinkles are another effect of long-term smoking.
Once smokers reach their 40th birthday, they can expect to have more wrinkles than nonsmokers, according to a recent study at UC San Francisco. Researchers found facial wrinkling rare among subjects ages 30 to 39, whether they smoked or not. But the wrinkle effect of smoking seems to take hold at middle age. Female smokers were afflicted more than male smokers, the researchers found.
In a Danish study, researchers found an association between cigarette smoking and deep wrinkling in male smokers but not in female smokers. But researchers didn't take into account sun exposure and face cream use.
Researchers aren't sure why smoking leads to more wrinkles, but they speculate that smoke may dry or irritate the skin or that components of tobacco smoke that are absorbed could lead to blood vessel or connective tissue damage in the skin. Reduced blood flow to the skin due to smoking could contribute too.
* Nearly one-third of people who have ever tried a single cigarette develop dependence on tobacco.
* Then there are the "chippers"--researchers' term for very light, longtime cigarette smokers who seem not to be nicotine-dependent, despite decades of smoking cigarettes. They account for 5% of the smoking population.
In studies at the University of Pittsburgh, regular smokers deprived of nicotine showed changes in craving, mood, arousal and sleep disturbance, but chippers showed no changes in those areas when they were deprived of nicotine.
* Nearly 70% of adults who smoke want to quit.
* Overall, fewer than 3% of smokers quit successfully, but that percentage increases dramatically if there is a health risk or a formal cessation program.
* More smoking cessation options than ever are available.
The nicotine patch and nicotine gum are now available over-the-counter.
A nicotine nasal spray, available by prescription only, was approved in March.
And a noncombustible nicotine inhaler, under study in the U.S., is scheduled to go on the market this month in Denmark. The inhaler partially preserves the ritual of smoking. Nicotine release is controlled by inhaling air through a mouthpiece.
Length of treatment with these nicotine replacement therapies depends on an individual's smoking habits and other factors.
Other approaches are under study, including combining the patch with an antidepressant, combining the patch and the gum, or combining the gum and the inhaler. (Users are cautioned not to combine treatments on their own, and to stop smoking completely.)
Many smokers on the verge of quitting fear weight gain--and rightly so. Smokers typically gain about 8 pounds after they quit, several studies have found, probably because nicotine increases metabolic rate and ex-smokers often eat more, at least for a time. Increased physical activity can help.
Researchers followed 1,474 women who quit smoking. Those who increased their activity by walking about three hours a week (or engaging in exercise that burned about the same number of calories) gained an average of 4 pounds.
* Sources: Centers for Disease Control and Prevention's Office on Smoking and Health; Nina Schneider, chief, Nicotine Research Unit, West Los Angeles Veterans Administration Medical Center, and associate research psychologist, UCLA School of Medicine; Saul Shiffman, University of Pittsburgh Smoking Research Group; Virginia Ernster, professor of epidemiology, UC San Francisco School of Medicine; American Cancer Society; World Health Organization; American Journal of Public Health, January 1995, July 1996; Experimental and Clinical Psychopharmacology; U.S. Department of Health and Human Services; 1994 National Health Interview Survey; Scott Moldenhauer, Arizona Program for Nicotine and Tobacco Research at the University of Arizona, Tucson.