Dr. Jon Hallberg is assistant professor in family medicine at the University of Minnesota, and medical director at Mill City Clinic. He is a regular medical analyst on MPR's All Things Considered. Photo courtesy of Dr. Jon Hallberg

France plans to ban electronic cigarette smoking in public places, according to Reuters.

What's in e-cigarettes, and are they harmful? Here's an edited transcript of Dr. Jon Hallberg's interview with Tom Crann of All Things Considered. Hallberg is a physician in family medicine at the University of Minnesota and medical director of the Mill City clinic.

TOM CRANN: We're going to talk about the news that in France, they are going to start treating electronic cigarettes like any other cigarette. They'll be subject to the same bans in public places. Municipalities closer to home have been wrestling with this issue as well. So tell us, how do e-cigarettes work?

JON HALLBERG: It's really interesting. I mean, there's a little battery inside. There's a little cartridge that contains some fluid. The battery heats it up, creates sort of an aerosol, and then you breathe it in, and some of the cigarettes even have a tip that sort of lights up when you're drawing or dragging on the cigarette. So it really mimics the cigarette smoking experience.

CRANN: What's in that fluid? Nicotine?

HALLBERG: The primary ingredient is nicotine, and it's important to note that nicotine is the addictive agent. It's not the cancer-causing agent. But unfortunately it sounds like some of these cigarettes that have other stuff in there, just like cigarettes, and that's one of the big concerns.

CRANN: You say nicotine is not a carcinogen. But what is nicotine? What does it do?

HALLBERG: Well, I think nicotine is akin to caffeine. It binds to receptors in the brain, and it does all of the things you sort of expect it to do. It gives you pleasure on one hand. It sort of focuses you a little bit. For some people it calms them down. But it's highly, highly addictive.

CRANN: Let's say they have just the nicotine and no other stuff, with no carcinogens; would that make them safer than traditional cigarettes?

HALLBERG: If that's exactly what it was, from a standpoint of trying to use this instead of actually smoking a cigarette, then yes, much safer. But I think what one of the big concerns is that it looks so much like a cigarette that young people might be inspired to start using them, and then the question is does that e-cigarette then become a gateway to the real thing.

CRANN: The nicotine in these would be no less addictive than nicotine in a regular cigarette.

HALLBERG: Yeah, I'm not sure we even know that. And these things, it's important to know, they're unregulated and we don't know exactly how much nicotine. I think that they purport that when you drag on it, it really mimics exactly the cigarette experience, but we really don't know that.

CRANN: Have there been any studies here in the U.S., or is there any regulation pending on any of this?

HALLBERG: Well, that's kind of where everything is at. I think that everybody is struggling with this - restaurants, local municipalities as you mentioned, state governments, countries. It's interesting. If you look online, all of the comments that are coming from different public health groups and the (Centers for Disease Control and Regulation), and they all come to the same conclusion: We need some more information about this. There are no randomized, controlled trials on this that are large-scale, that are helpful at this point.

CRANN: If a patient is trying to stop smoking and thinking about e-cigarettes, and they come to you, what's your advice?

HALLBERG: This is such an important question because this is happening. I would say every smoker in my practice that we've talked about smoking has brought this up on their own, and I can't recommend them yet because I don't know really know what's in them. Is it safer than what they're currently doing? I think it is. And so in that sense we can give sort of tacit approval, I think. But we have really good nicotine replacement things that are out there already.

CRANN: Such as gum and patches?

HALLBERG: Oh, and nasal spray. There's even an inhaler system. And the inhaler system that I often prescribe, it's intentionally designed not to look like a cigarette so it's not kind of a gateway experience. But yet they can mimic that tactile thing of putting it to their mouth, inhaling and getting the nicotine that they want.

CRANN: What is the most effective way right now for patients who really want to stop smoking?

HALLBERG: I wish there was "the way" -- that there was a single way to make this happen. I think that over and over again, the thing that comes up is the importance of setting a quit date; that looking out ahead, something significant on the calendar that becomes the date that that person kind of wraps their mind around that they will quit. And then starting to decrease the nicotine and getting up to that point, considering using a nicotine replacement substance when the time comes, such as a patch or a spray or an inhaler, possibly medication. But there is no single way, I'm afraid.