A new study found that of the 19.5 percent of high school students who call themselves smokers, most don’t smoke daily or frequently. Between 1991 and 2009, heavy smoking declined among public and private high school students, but light smoking increased, according to a national survey.Among teen smokers, occasional smoking grew from 67.2 percent to 79.4 percent while heavy smoking dropped from 18 percent to 7.8 percent. Survey data showed no large smoking changes among African-American students, but heavy smoking by Hispanic students rose from 3.1 percent to 6.4 percent.Light smoking is defined as having one to five cigarettes a day, moderate smoking as six to 10 cigarettes daily and heavy smoking as 11 cigarettes or more a day.The downward trend of heavy smoking might sound encouraging but experts remain concerned. “It is important to note that light and intermittent smoking still has significant health risks,” said Terry Pechacek, Ph.D., a study co-author.Pechacek is the associate director for science at the Office on Smoking and Health of the Centers for Disease Control and Prevention.In the study, which appears online and in the September issue of the American Journal of Preventive Medicine, researchers analyzed responses from students in grades 9 to 12 who participated in national Youth Risk Behavior Surveys. Students completed the questionnaires voluntarily during classes at school. The size of the groups surveyed ranged from 10,904 to 16,410 students.“I have noticed more teenagers seem be smoking just a few cigarettes per day,” said John Frohna, M.D., a professor of pediatrics and internal medicine at University of Wisconsin-Madison. “I do think there are fewer kids in my practice who are smoking heavily, but I remain concerned that they are smoking at all.” He added, “We need to continue to reinforce the message that any smoking is unsafe. We also need to ensure strong enforcement of laws against selling cigarettes to children.”“Even though smoking prevalence among youth and adults has slowed, we’re closely watching to see whether light and intermittent smoking persists into adulthood despite tobacco control policies and changes in social norms that have previously led to sharper declines,” Pechacek said.This story was originally published by Health Behavior News Service.