Marijuana use continues to increase among young people in the United States, according to an annual federally funded survey of drug, alcohol and cigarette use among U.S. youths. The proportion of eighth-graders who say they smoke marijuana daily increased from 1 percent to 1.2 percent between 2009 and 2010, while the rate among 10th- graders went from 2.8 percent to 3.3 percent, and among high school seniors from 5.1 percent to 6.1 percent, according to the Monitoring the Future Survey, which questioned 46,482 students from 396 public and private schools. Because cigarette smoking has been declining among high school seniors, marijuana is now more popular than cigarettes by some measures. In 2010, 21.4 percent of high school seniors had used marijuana in the past 30 days, while 19.2 percent had smoked cigarettes, according to the survey, which is conducted by the University of Michigan. 'These high rates of marijuana use during the teen and pre-teen years, when the brain continues to develop, places our young people at particular risk,' said Nora Volkow, director of the National Institute on Drug Abuse, in a statement. 'Not only does marijuana affect learning, judgment, and motor skills, but research tells us that about one in six people who start using it as adolescents become addicted.' The perception that regular marijuana smoking is harmful decreased among 10th- graders from 59.5 percent to 57.2 percent and among 12th-graders from 52.4 percent to 46.8 percent in 2010. 'We should examine the extent to which the debate over medical marijuana and marijuana legalization for adults is affecting teens' perceptions of risk,' Volkow said. 'We must also find better ways to communicate to teens that marijuana use can harm their short-term performance as well as their long-term potential.' The use of the drug Ecstasy also increased, according to the survey, with 2.4 percent of eighth-graders and 4.7 percent of 10th-graders saying they had used the drug in the past year. That's up from 1.3 percent and 3.7 percent, respectively. Although abuse of the prescription drug Vicodin during the past four years decreased among high school seniors from 9.7 percent to 8 percent, the use of OxyContin, another prescription opiate, stayed about the same for 12th-graders at 5.1 percent. In a bit of good news, binge drinking continued to drop. Among high school seniors, 23.2 percent reported having had five or more drinks in a row during the past two weeks, down from 25.2 percent in 2009 and a drop from the peak of 31.5 percent in 1998. 