More young Americans profess to be nonsmokers, and overall cigarette consumption is down. But many of these purported "nonsmokers" are in fact casual smokers -- lighting up in social settings even if they are not technically addicted to nicotine -- the Wall Street Journal reported June 6.

"You're going to have many more of these types of folks who smoke on an intermittent basis," said Matthew McKenna, director of the Center for Disease Control and Prevention's office on smoking and health. "The phenomenon has increased between 20 and 25 percent over the past 10 years.

"In the past, people were much more likely to say they smoked every day, and that has decreased," said McKenna. Even so, some social smokers may go through an entire pack of cigarettes in a weekend.

Changing social norms, indoor-smoking bans and the rising cost of cigarettes have contributed to the casual-smoking trend. Most young smokers recognize the danger of daily smoking, but don't realize that health risks are tied to the total number of cigarettes smoked, not the frequency. "Even intermittent smoking is harmful…and whether you call that addiction or not doesn't matter," said McKenna.

Some social smokers said they were regular smokers in high school, but then cut back. "When I go out to the bar that's when I really crave it because you can smoke in the bars," said Steve Killingworth, 27, of Ann Arbor, Mich. "Maybe the same thing that makes you crave alcohol makes you crave cigarettes."