An upcoming study in the journal Nicotine and Tobacco Research says that some tank-style e-cigarettes emit cancer-causing formaldehyde in their vapour at levels similar to traditional tobacco cigarettes. The New York Times, which revealed the findings ahead of publication, says a second study confirms the results.
The problem seems to be that some tank-style e-cigarettes (the larger, refillable style that vaporise liquid nicotine) get so hot, they cause formaldehyde to form in the vapour they put out.
The finding comes on the heels of the US FDA's proposal to regulate e-cigs under the same rules as traditional combustible tobacco. However, those proposed rules would focus on the ingredients that go into e-cig juice, not on the chemical makeup of the vapour that comes out. So far, e-cig emissions (the content of the vapour they produce) is an unregulated area.
It's a complicated area of study, in part because there are so many various manufacturers of e-cigs, and the products are largely non-standardised. One of the studies, performed at the Roswell Park Cancer Institute in Buffalo, found that levels of carcinogens increased markedly when the battery output of the tank-style e-cigs was boosted from 3.2 volts to 4.8 volts.
Then there's the way that consumers use e-cigs: the higher heat that scientists say creates carcinogens also produces more potent vapour. Many e-cig tinkerers boost the heat output of their devices, or dribble liquid nicotine directly on the heating element for a more intense vapour. The researchers say dripping puts out carcinogen levels that approach the concentration found in old-fashioned cigarettes.
Dr. Alan Shihadeh at the Virginia Commonwealth University's Center for the Study of Tobacco Products, who led one of the studies, acknowledged that while the e-cig study only examined a handful of carcinogens, traditional cigarettes put out dozens of cancer-causing compounds. As he told The New York Times:
If I was in a torture chamber and you said I had to puff on something, I'd choose an e-cigarette over a regular cigarette. But if you said I could choose an e-cigarette or clean air, I'd definitely choose clean air. And I definitely wouldn't drip.
The studies will be published beginning May 15th. Until then, maybe you should hold off on the heavy-duty vaping. E-cigs may not be exactly the same as the dead leaves Don Draper smoked, but this particular similarity isn't all that enticing. [NYT]