It's still too early to say whether e-cigarettes cause cancer the way regular cigarettes do, researchers say, but what they can tell at this stage is that at high voltage, the vapor they produce is a lot higher in at least one carcinogen than traditional smokes. A new study has found that at the high-voltage settings available in newer models of e-cigarettes, the level of formaldehyde produced is up to 15 times that found in cigarette smoke, reports the Wall Street Journal. An industry association spokesman counters that the researchers used a power level of 5 volts, causing overheating that doesn't occur at the usual 3.7-volt setting, and their machine took longer "puffs" than any 5-volt user would, reports CBS.
The study—which backs up earlier research—should make e-cigarette users consider the risks, researchers say, although most experts believe that e-cigarettes remain a lot safer than traditional ones. "A lot of people make the assumption that e-cigarettes are safe and they are perfectly fine after using for a year," the lead researcher tells NBC. "The hazards of e-cigarettes, if there are any, will be seen 10 to 15 years from now when they start to appear in chronic users." (Another recent study found that e-cigarette use has surpassed tobacco use among teenagers.)