What’s the Latest on E-Cigarettes and Cancer?

Claiming that use of electronic cigarettes among young people is reaching “epidemic proportions,” the U.S. Food and Drug Administration has undertaken a range of measures to ensure compliance with laws banning sales to minors and is considering toughening its stance toward manufacturers that fail to prevent widespread youth use of their products. And in June, 2022, the FDA banned JUUL products, among the most popular types of e-cigarette, from the U.S.

E-cigarettes, which deliver nicotine by vaporizing it, are considered less harmful than conventional cigarettes because they do not contain tar, the primary cancer-causing substance in tobacco products. Still, e-cigarette use has raised a variety of concerns among some health authorities. Although e-cigarettes are often touted as a way to help cigarette smokers kick the habit, the U.S. Preventive Services Task Force has found there is “insufficient evidence to recommend for or against [their] use for smoking cessation.” Some organizations have expressed concern that e-cigarette use may actually encourage young people to take up smoking.

The lack of tar doesn’t mean e-cigarettes are entirely free of cancer-causing substances. Studies have found a variety of such chemicals—including formaldehyde, toluene, acetaldehyde, and acrolein—as well as heavy metals such as cadmium, lead, nickel, and nitrosamines in e-cigarette aerosols or vapor. While the levels of these substances are far lower than in cigarette smoke, the long-term effect of exposure to them is unclear.

“E-cigarettes did not go into widespread use until 2012,” says Dana-Farber’s Andy Tan, PhD, MPH, MBA, who studies consumer communication techniques used by cigarette and e-cigarette manufacturers. “They haven’t been around for long enough to know if they pose a long-term cancer risk to humans. Follow-up studies to identify such risk can be undertaken only after an extended period of time—20 years or more.”

Still, the fact that they contain known cancer-causing substances is reason for caution, he says.