Back in the Vapor Den where consumers lounge on couches enjoying e-cigs, Hall pulls out drawer after drawer of clear liquid droppers filled with exotic flavors.
"We’ve got strawberry parfaits, banana custards, blueberry parfaits, apple juice," says Hall. "And milk and honey for a more savory option."
Flavoring Compounds May Be Toxic
But Flori Sassano, a pharmacologist at the University of North Carolina, worries about all those fruity ingredients.
“Even though they all sound great," says Sassano. "That doesn’t mean they're actually made from that. They’re made from chemicals.”
Scientists do not know how the body reacts to inhaling artificial flavors. The Food and Drug Administration has only tested the flavor agents for consumption, that's why Sassano just completed a study on e-liquids. The research was published today in the Journal PLOS Biology. Sassano's team exposed human cells in test tubes to about 150 of the more than 7,700 commercially available flavored nicotine liquids.
“We found that some of them were very highly toxic to the cells," says Sassano. “Not only stopping the growth but also killing them.”
The researchers found that results varied widely across the e-liquid products tested, and overall, more ingredients led to increased toxicity. The worst culprits were cinnamaldehyde and vanillin. And it wasn’t just the flavors that were dangerous. Sassano also found that the base ingredients used in e-liquids, propylene glycol and vegetable glycerin, were harmful to the cells.
Potentially Hard on the Heart
This worries Stanton Glantz, the director of the Center for Tobacco Control Research and Education at UCSF.
“When e-cigarettes first became available there was a lot of hope that they would be better than cigarettes but the more we learn the worse they look," Glantz says.
He recently presented research at the annual meeting of the Society for Research on Nicotine and Tobacco indicating e-cigarettes might increase your risk of heart attacks.
“If you use e-cigarettes only on a daily basis you have nearly a doubling of your risk of having a heart attack," says Glantz. "When people use an e-cigarette it shuts off normal functioning of their arteries just like a cigarette does.”
But other researchers said Glantz's conclusions were premature. The data Glantz used was sourced from surveys conducted by the Centers for Disease Control and Prevention. The agency asked participants whether they vaped and whether they had a heart attack. It did not follow people over time to determine if vaping was the likely cause of the cardiac arrest.
"We don't even know that these people used e-cigarettes before they had the heart attack," Michael Siegel says, a professor at Boston University's School of Public Health, who spoke to ABC News.
In other words, the participants could have been life long smokers who had just starting vaping.
Glantz agrees that more long term studies are needed to know whether e-cigs cause cardiac arrest.
Vaping May Make it Hard to Breathe
There’s also a growing body of research showing that vaping may lead to asthma and lung inflammation.
“The evidence for adverse affects on lungs is that they're actually looking worse than cigarettes,” Glantz says.
Because scientists have only studied vaping for the last five to ten years, conclusive data on it’s health effects isn’t available yet. A recent report from the National Academies of Science, Engineering and Medicine concluded that e-cigarettes are 'likely far less harmful than conventional cigarettes.' Even so, Glantz and other doctors worry that users are under a false impression that vaping is safe.
The issue goes before San Francisco voters soon. In June, residents will vote on whether to ban all flavored vaping and tobacco products. You can check an online database of e-liquid ingredients to determine if your favorite flavor is toxic.