E-cigarettes are more popular among US teens than combustible cigarettes or any other tobacco product, according to a national study conducted by the University of Michigan.

About nine per cent of surveyed eighth graders said they had used an e-cigarette in the past 30 days compared with traditional cigarettes at 4 per cent. Among 10th graders the e-cig percentage was 16 per cent vs 7 per cent. Grade 12 respondents were closer together at 17 per cent vs 14 per cent, the university said.
"This could be a result of e-cigarettes being relatively new," said Lloyd Johnston, principal investigator of the project. "So today's 12th-graders may not have had the opportunity to begin using them when they were younger. Future surveys should be able to tell us if that is the case."
Monitoring the Future is an annual survey funded by the National Institutes of Health that this year contacted nearly 42,000 students in grades 8, 10 and 12 at 389 schools. Summarising the results, the NIH’s National Institute of Drug Abuse said, “while many of these student e-cigarette users have a history of cigarette and/or smokeless tobacco exposure, approximately 2.9 per cent of 8th graders, 4.5 per cent of 10th graders and 3.8 per cent of 12th graders report past month use of e-cigarettes while denying ever using tobacco cigarettes or smokeless tobacco."