Cigarette and alcohol use among teens is at the lowest level in decades, but marijuana use is on the rise, according to a survey released on Wednesday.
Just under 19 percent of high school seniors said they smoked cigarettes in the past month compared to a peak rate of 36.5 percent in the mid-1990s, results from the National Institutes of Health Monitoring the Future survey showed.
Rates of cigarette smoking among all teens surveyed decreased compared to last year's results.
Researchers said 100 percent smoke-free locations and higher cigarette prices helped drive down the number of teen smokers.
Although alcohol remains popular among teens, rates of underage and binge drinking showed significant declines, researchers said.
Overall, cigarette and alcohol usages by teens are at the lowest points since the first survey was taken in 1975.
Marijuana use among teens rose in 2011 for the fourth straight year -- a sharp contrast to a dramatic decline that occurred in the preceding decade.
Daily marijuana use is at a 30-year peak level among high school seniors, the survey found.
Monitoring the Future is an annual survey of eighth, 10th and 12th graders conducted by researchers at the University of Michigan with funding from the National Institute on Drug Abuse.
Nearly 47,000 students from 400 public and private schools were polled in classrooms earlier this year.
Among 12th graders, 36.4 percent said they smoked marijuana in the past year and 6.6 percent reported daily use, it found.
The 2011 survey for the first time included questions about use of synthetic marijuana, a blend of herbs and spices laced with chemicals and commonly branded Spice or K2.
More than 11 percent of high school seniors reported using the synthetic substance in the past year, it found.
Until recently, K2 and Spice were sold legally online, in gas stations and other shops. Earlier this year federal regulators banned some of the synthetic chemicals.
Next year researchers said they expect to ask questions about bath salts, an increasingly popular street drug that mimics the effects of drugs like LSD or cocaine.
Monitoring the Future is one of three major surveys used by federal health officials to monitor data on youth substance abuse.
(Reporting by Lauren Keiper; Editing by Ellen Wulfhorst and Greg McCune)