Twice as many high school students used nicotine-based electronic cigarettes in 2018 compared with last year, according to a new survey exploring teen smoking, drinking and drug use.

In the survey’s 44-year history, this was the largest single-year increase, surpassing even the surge in marijuana smoking during the mid-1970s, according to the Associated Press.

The federally funded survey, conducted earlier this year by researchers at the University of Michigan, has prompted regulators to press for measures making it harder for kids to purchase the vaping devices.

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Experts credit the increase to modern versions of the e-cigarettes, like the Juul, which looks like a USB thumb drive and can be easily disguised.

"They can put it in their sleeve or their pocket. They can do it wherever, whenever. They can do it in class if they're sneaky about it," Trina Hale, a junior at South Charleston High School in West Virginia said of the increased popularity of vaping.

Of the 45,000 students in grades 8, 10 and 12 who were surveyed across the country, one in five reported having vaped in the previous month.

Behind vaping and alcohol, teens also use marijuana, with one in 17 high schoolers smoking it every day. While marijuana smoking, in general, is about the same level as previous years, vaping marijuana did increase.

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Use of other drugs, like cigarettes, cocaine, LSD, ecstasy, heroin and opioid pills, all declined.

The nicotine present in e-cigarettes is harmful to developing brains and can make kids more likely to take up cigarette smoking later in life or even try other drugs, researchers believe.

The Associated Press contributed to this report.