Heavy use of e-cigarettes may deliver big doses of formaldehyde, which can be a cause of lung cancer, study suggests

Vapor produced by electronic cigarettes can contain a surprisingly high concentration of formaldehyde—a known carcinogen that can cause lung cancer through prolonged exposure—researchers reported Wednesday in a study published in the New England Journal of Medicine, Rob Stein reports for NPR. (Getty Images by Dan Kilwood)

Use of e-cigarettes among rural teens has risen in recent years, prompting the U.S. Food and Drug Administration to propose rules to give it authority over e-cigarettes, an industry that accounts for about $2.5 billion in annual sales.

"E-cigarettes work by heating a liquid that contains nicotine to create a vapor that users inhale," Stein writes. David Peyton, a chemistry professor at Portland State University who helped conduct the research, told Stein, "We simulated vaping by drawing the vapor—the aerosol—into a syringe, sort of simulating the lungs. That enabled the researchers to conduct a detailed chemical analysis of the vapor. They found something unexpected when the devices were dialed up to their highest settings."

The e-cigarette industry dismissed the report, saying they found formaldehyde only when e-cigarettes were cranked up to their highest voltage levels, Stein writes. Gregory Conley of the American Vaping Association told him, "They clearly did not talk to [people who use e-cigarettes] to understand this. They think, 'Oh, well. If we hit the button for so many seconds and that produces formaldehyde, then we have a new public health crisis to report."

"If you hold the button on an e-cigarette for 100 seconds, you could potentially produce 100 times more formaldehyde than you would ever get from a cigarette," Conley said. "But no human vaper would ever vape at that condition because within one second their lungs would be incredibly uncomfortable." (Read more)