Some are posers who simply want an accessory with their designer gin. Others are weekend bingers who can't resist mooching a few whenever there's talk and drink around. And some are true heavyweights, cutting down, trying to get clean.
Together they form the fastest-growing category of tobacco users of the modern smoke-free era: social, or occasional, smokers, who light up regularly but not daily.
In 1990, about 18 percent of California smokers said they fit this description. By 1998, the most recent year for which data are available, the rate among California smokers had climbed to almost 30 percent. And although numbers on so-called occasionals are still sketchy, national trends appear headed in the same direction, even as overall consumption decreases.
"When we first reported on the size of this group a few years ago," says John Pierce, a cancer prevention specialist at the University of California, San Diego, "no one believed us. We were all accustomed to thinking of smokers as people who smoked a pack a day or more. Now researchers everywhere are finding rates of 18 percent and higher. We are witnessing an enormous change in smoking behavior."
Public health researchers attribute the change in part to stricter anti-smoking laws, particularly workplace bans. But at least as important, they say, are the restraints that many smokers are placing on themselves, such as married people who have volunteered to take their smoking outside in consideration of their spouse or children.
"The result," Pierce says, "is that there's no place left to smoke, except maybe the car or the garden." In effect, public and private restrictions are stripping the habit of its most traditional connections: the coffee break, the pre- and post-lunch treat, the emergency stress-reducer.
This smoke-free environment shapes the habits of younger smokers most of all, public health researchers say. Many younger than 25 who are experimenting with cigarettes haven't really had the chance to string together a pack's worth of smokes through a day, to establish a daily routine.
The downside, addiction specialists say, is that rates of smoking are on the rise among younger people, and many who start in their late teens and early 20s seem to consider cigarettes a strictly social, and therefore mostly harmless, pleasure.
"The only time I smoke is when I'm out, drinking beer," says Gerardo Guzman, 26, a California State University, Northridge, student who works for a public advocacy organization.
"That's about it. I can't smoke at work, I can't smoke at home. My environment doesn't really allow me to be a regular smoker." Guzman has been smoking in this way, off and on, for nine years.
Part-timer smokers are challenging the conventional understanding of smoking itself. These are cigarettes, after all: as habit-forming as it gets. Most rehabilitation specialists and drug users rate nicotine as the most addictive drug of all, ahead of alcohol, cocaine and even heroin.
As hooked as many smokers are, they still exercise control over their habits. When the price of cigarettes goes up, they tend to smoke less. When anti-tobacco advertising is in full force, say public policy researchers, many smokers cut down.
The danger of more modest smoking, doctors hasten to say, is that smokers don't think of it as a bad habit.
"When I ask females between the ages of 21 and 30 whether they smoke, I'd say about 75 percent of them say, 'No, not really,' " says Dr. Vanessa Tatum, a spokeswoman for the American Lung Association.
Still, most occasionals run nowhere near the health risks that heavy smokers do. The relationship between smoking and disease is what doctors call dose-response: the more you smoke, the higher your risk of getting sick. A pack a month is much easier on the body than a pack a day, for example, which roughly quadruples your risk of developing heart disease or cancer, compared with a nonsmoker.
"For the guy who smokes a single cigarette every New Year's Eve, there's probably no increased disease risk at all," says David Burns, an authority on tobacco health risk at UC San Diego. "But the risk levels go up very quickly as soon as you start smoking weekly or even monthly."