E-cigarette emissions tend to be less carcinogenic than traditional cigarette emissions, reports MedPage Today, with some notable exceptions.

Researchers modeled the cancer potencies of a range of e-cigarettes and other nicotine-delivering aerosols using published chemical analyses of emissions and their associated inhalation unit risks.

Potencies were compared using a conversion procedure for expressing smoke and e-cigarette vapors in common units, and lifetime cancer risks were calculated associated with various potencies using daily cancer consumption estimates.

“Many electronic e-cigarette emissions have cancer potencies within an order of magnitude of a nicotine inhaler, a product generally regarded as safe,” Stephens wrote. “Notwithstanding, some e-cigarette emissions tended towards much higher cancer potencies and risks, a few possibly approaching those of tobacco smoke.”