Magnolia Carlson decided to give up cigarettes when her lungs hurt after she tried going for a run.

"I'm 20; I was smoking half a pack a day," Carlson said. "I feel better about myself now."

Working at a Minneapolis tobacco store made it tricky to stop smoking entirely, but she found an alternative: vaping. "Right now I need nicotine, and I don't want to smoke cigarettes anymore, so it seems like a better option," she said.

But not a totally carefree one, she admits. "I mean, putting anything into your body like that is obviously going to be harmful."

Researchers increasingly are agreeing with that. Recent studies have concluded that vaping may pose several unexpected health threats.

Vaping involves inhaling an aerosol — referred to as vapor — through e-cigarettes (which look like regular cigarettes) or vapor pens (which resemble old-fashioned fountain pens). The device is loaded with a liquid that a battery-powered heating element converts to a mist that can be drawn into the lungs and then exhaled. The liquid typically contains nicotine, although it doesn't have to.

It's a trend that is sweeping the nation, despite the uncertainty surrounding its effects on health.

According to a study by Johns Hopkins Bloomberg School of Public Health that was published in February, heating coils in some e-cigarettes may leak metals that are potentially harmful to users. The researchers found lead, chromium and nickel in the aerosol of e-cigarettes.

Exposure to lead can increase the risk of neurotoxicity and cardiovascular disease, while chromium and nickel exposure can lead to respiratory disease and lung cancer, according to the study.

However, e-cigarettes don't always contain a metal coil. Carlson, an employee of Hideaway tobacco shop in Dinkytown, said that there are e-cigarettes available with different types of heating elements.

Mackenzie Renswick, an assistant manager at a vape shop in northeast Minneapolis called Smokeless Smoking, agreed that these other options are good.

"Ceramic coils are fantastic," she said. But research hasn't yet revealed too much about whether ceramic coils or other options make a difference.

Renswick also mentioned the importance of keeping up with changing the coil to avoid the combustion of the e-cigarette heating devices. But the study found that the concentrations of metal seemed to be higher in e-cigarettes with coils that were changed more frequently.

Studies change focus

The first commercially successful e-cigarette was introduced in China in 2003. Its popularity spread quickly through Europe, and imports to the United States began in 2006.

In 2008, the company that created the device, Ruyan — which translates roughly to "like smoke" — funded an international study that declared that the vapor was largely free of the carcinogens created by burning tobacco leaves, making them 100 times safer than regular cigarettes.

Nonetheless, some countries banned e-cigarettes. In the United States, the Food and Drug Administration temporarily stopped their import by arguing that they were drug delivery devices and, therefore, needed FDA approval, but that argument was overturned in court.

By then, trade associations, led by the Electronic Cigarette Association, and user groups such as the Alliance of Electronic Smokers had funded more studies seconding Ruyan's original report.

Many of these studies focused on how cigarette smokers could use vaping to wean themselves off tobacco. In this context, the e-cigarettes were presented as being a health benefit. Another asset of the devices that the studies ballyhooed was that they cut the dangers posed by secondhand smoke.

As vaping has grown in popularity in the past couple of years, so has the number of independent studies of it. While the consensus among researchers is that more investigation is required before coming to any concrete conclusions about the health effects of e-cigarette coils and vaping in general, the amount of literature indicating possible risks is growing.

A study released in January by the National Academy of Sciences found that e-cigarette smoke may cause damage to DNA and hinder DNA repair. The researchers said they need more data to confirm their findings, but if authenticated, they could indicate an increase in the risk of lung cancer, bladder cancer and heart disease.

A University of California, San Francisco, study found an association between the daily use of e-cigarettes and the odds of having a heart attack.

On top of that, according to highlights of a report by the National Academies of Sciences, Engineering and Medicine, evidence "suggests that e-cigarettes are not without biological effects in humans" and the "use of e-cigarettes results in dependence on the devices, though with apparently less risk and severity than that of combustible tobacco cigarettes."

Less danger

Both Carlson and Renswick acknowledge that vaping likely affects health in some way. But, they argue, it's not as bad as inhaling the smoke from burning tobacco.

Like Carlson, Renswick said that she felt significantly healthier within weeks of switching to vaping from smoking.

"In cigarettes, there are thousands of carcinogens," Renswick said. She said the only ingredients in vape liquid are propylene glycol, vegetable glycerin, nicotine and artificial flavoring. "But that's all there is to it."

Carlson agreed.

"It might be bad for you in a different way, but at least you're not inhaling all those carcinogens," she said. She predicted that e-cigarette users will weigh the odds between the known dangers of tobacco and the unconfirmed potential ones of vaping, and unless research comes out saying vaping is absolutely terrible for health, its popularity will continue.

"I don't think people are going to stop, because they're already willing to risk it," she said.

In Renswick's opinion, vaping is still worth it even in the midst of all of this new research. "I do believe the pros outweigh the cons," she said. "I've been doing this for about three years now, and I haven't really noticed any negative side effect from it. Like in my lungs, my breathing … nothing, at least compared to cigarettes."

Phoebe Deutsch said that vaping changed her life. Deutsch, 22, started smoking when she was 14, and for years she smoked cigarettes every 20 to 30 minutes. Shortly after her 21st birthday, she met Renswick, who told her more about vaping and helped her purchase vaping equipment.

"Within three months, I had no desire to smoke cigarettes anymore," Deutsch said, describing how her anxiety, chest pains, heart palpitations and other health problems have subsided greatly since she started vaping instead of smoking. "I definitely felt addicted to cigarettes, and I don't feel addicted to vaping."

As with Carlson and Renswick, the possibility of health risks associated with vaping doesn't concern Deutsch.

"I'm not worried about it, because regardless if it's harmful, it's better than smoking. That's been proven," Deutsch said. "I'm helping myself. I'm better and healthier, and that's what really matters."

She said more research and education surrounding vaping are necessary for reaching more concrete findings rather than adhering to diluted truths or inconclusive evidence.

"The more research, the better, for sure," Renswick agreed.

Lauren Otto is a University of Minnesota student on assignment for the Star Tribune.