Electronic cigarettes (e-cigarettes) are seen by some – including me – as a safer alternative to tobacco cigarettes. But e-cigarettes pose a special danger to teenagers, both as a gateway to traditional cigarettes and because they contain chemicals that may be linked to cancer.

The e-cigarettes are battery-powered devices that heat up a liquid – often containing nicotine – and create a vapor that gives users a comparable sensation to smoking.

A 2016 report from the U.S. surgeon general showed a whopping 900 percent increase in e-cigarette use by high school students from 2011 to 2015.

In fact, more adolescents now use e-cigarettes than smoke traditional cigarettes. And the total market for e-cigarettes expanded by 40 percent last year, to $1.16 billion.

There has not been a big drop-off from these disturbing numbers since then, as manufacturers and retailers across the country continue to target our youth.

A major health danger from e-cigarettes is as a gateway device to tobacco. A University of Pittsburgh study published in April followed late teens and young adults who had never smoked for a year and found that e-cigarettes quadrupled their chances of picking up a cigarette within 18 months.

And a study issued in March by the University of California at San Francisco found that adolescents who use e-cigarettes are exposed to significant levels of potentially cancer-causing chemicals found in tobacco cigarettes.

Dr. Mark L. Rubenstein, who conducted the study, said that “teenagers need to be warned that the vapor produced by e-cigarettes is not harmless water vapor, but actually contains some of the same toxic chemicals found in smoke from traditional cigarettes … kids should not be using them at all.”

While this is true, e-cigarettes can be useful in helping tobacco smokers quit.

When I give smokers a general physical exam, I screen for their bigtime risks of lung cancer, emphysema and heart disease. At the same time, I put on a full-court medical press to try to help them quit smoking – before it’s too late.

Multiple studies support my approach, indicating that whenever you quit, your chances of an acute medical problem drop almost immediately.

But unfortunately, there is no ready formula for quitting. Psychoactive drugs like Chantix (Varenicline) or Wellbutrin don’t work well and have side effects. Since nicotine is at the heart of the tobacco addiction, nicotine replacement products – including the patch, gum, lozenges, or a nasal spray – are a good place to start, but are often insufficient by themselves.

I have found that combining the nicotine patch with e-cigarettes to deal with the oral and psychological factors that keep people hooked on cigarettes is a good way to help my patients kick the smoking habit.

Food and Drug Administration Commissioner Dr. Scott Gottlieb, who I interviewed recently about this issue for Fox News, agrees with me. He sees the value of e-cigarettes as an aid to quitting smoking.

“We do think the e-cigarettes could offer a potential opportunity for adult smokers to transition off of combustible tobacco on to reduced risk products,” Gottlieb told me.

But at the same time, Gottlieb and others at the FDA are very worried about the dangers that e-cigarettes and other electronic nicotine delivery systems pose to young people. I share that worry.

“I’m very concerned about youth becoming addicted to nicotine through things like e-cigarettes … what we don’t want to see is a whole generation of children become addicted to nicotine from the use of e-cigarettes,” Gottlieb said.

Gottlieb said he and the FDA are in the middle of “very vigorous enforcement to crack down on the youth use.” The nationwide effort is targeting “manufacturers and outlets that are selling products to children.”

The FDA first set a regulation against selling or marketing e-cigarettes to children and teens under the age of 18 in 2016, when there were more than 2 million e-cigarette users in middle school and high school.

Gottlieb and the FDA are targeting manufacturers of the e-cigarette Juul, which looks like a USB drive and is a self-contained unit that comes in many flavors. A report by the Public Health Law Center found that Juul accounted for over half of e-cigarette sales in the U.S.

In late April the FDA issued warnings to 40 retailers who were found to be selling Jull to minors. If ignored, these warnings could lead to legal action against these retailers

And earlier this month, the FDA doubled down on this righteous action by sending 13 additional warning letters to “manufacturers, distributors, and retailers for selling e-liquids used in e-cigarettes with labeling and/or advertising that cause them to resemble kid-friendly food products, such as juice boxes, candy or cookies, some of them with cartoon-like imagery.”

One look at one of these so-called juice boxes is enough to convince any sane adult that these marketing practices are underhanded, which is likely one of the reasons that the Federal Trade Commission added its voice to these warnings.

Consider that the National Poison Data System found that there were a total of over 8,000 e-cigarette and liquid nicotine exposures among children younger than age 6 between January 2012 and April 2017. That means that nicotine liquid that was supposed to be plugged into an e-cigarette or other vaping device ended up in a child’s vulnerable mouth.

Dr. Gottlieb and the FDA are trying to protect our children from toxic addictive vapors. Unfortunately, all the health warnings and regulations and forceful letters to businesses may not be enough to stop this train, but it is certainly the right place to start. Parents, doctors and schools across the country need to add our muscle to the fight.