As people flee cigarettes and turn to vaping, the surgeon general is warning that people may be trading one terrible vice for another, even going so far as to call it a “major public health concern.” Surgeon General Vivek H. Murthy sounded the alarm in a recent interview, according to a Washington Post report, which noted that Murthy called for way more research into their safety.

E-cigarettes have become the most common form of tobacco amount youth in the U.S., passing cigarettes back in 2014. Authorities are alarmed to see that the number of middle and high school students who are used e-cigarettes has tripled in the last five years, and it’s doubled among those who are between the ages of 18 an 24. That’s a big worry because people don’t really know just how harmful or not vaping is.

“We know enough right now to say that youth and young adults should not be using e-cigarettes or any other tobacco product, for that matter,” Murthy said according to the Post. “The key bottom line here is that the science tells us the use of nicotine-containing products by youth, including e-cigarettes, is unsafe.”

“No matter how it’s delivered, nicotine is harmful for youth and young adults,” the Surgeon General’s website states. “E-cigarettes typically contain nicotine as well as other chemicals that are known to damage health. For example, users risk exposing their respiratory systems to potentially harmful chemicals in e-cigarettes. Read about these and other risks young people face if they use e-cigarettes.

“You can influence your children’s decision about whether to use e-cigarettes. Even if you have used tobacco yourself, your children will listen if you discuss your struggles with nicotine addiction. Be clear that you don’t approve of them smoking or using e-cigarettes, and that you expect them to live tobacco-free.”