Almost three-quarters of a million more young adults in the US used e-cigarettes between 2019 and 2021 during the period that spanned the EVALI outbreak (E-cigarette or vaping product use–associated lung injury) and COVID-19 pandemic, according to a new study by researchers at the American Cancer Society.  

In the study, published in the American Journal of Preventive Medicine, scientists report the year-on-year increase was primarily among adults who never smoked cigarettes.

“Unfortunately, these numbers show we’re moving in the wrong direction concerning e-cigarette use in this vulnerable population,” says Priti Bandi, PhD, scientific director of cancer risk factors and screening surveillance research at the American Cancer Society and lead author of the study, in a release. “Our research finding is concerning as it may point to an increase in nicotine addiction risk for young adults, potentially contributing to progression to combustible tobacco products and may also increase exposure to unknown toxicants, carcinogens, and the risk of respiratory diseases.”

Researchers pooled data from the National Health Interview Survey from 2019, 2020, and 2021 to estimate current e-cigarette use prevalence, adjusted prevalence difference between survey years, population counts, age group, and cigarette smoking status (persons who currently, formerly, or never smoked).

The study results showed between 2019 and 2021, e-cigarette use prevalence increased from 8.8% in 2019 to 10.2% in 2021 among younger US adults ages 18 to 29 years. Of note, among those young adults who never smoked cigarettes, e-cigarette use jumped from 4.9% in 2019 to 5.2% in 2020 to 6.4% in 2021. This group of young adults constituted 53% (2.68 million) of younger adults who used e-cigarettes in 2021, increasing by 0.71 million persons from 2019. 

The study also showed among middle-aged and older US adults, e-cigarette prevalence was similar in 2019 and 2021 irrespective of combustible cigarette smoking status. People who formerly smoked cigarettes constituted the largest population proportion of people who use e-cigarettes among adults older than 30 years in 2021 (51.1% or 3.1 million).

“E-cigarette use is not harmless at any age. It may have serious health risks, including negative short-term effects on airways and blood vessels, and we do not know the long-term effects of their use,” says Bandi in the release. “We must address the rise in e-cigarette use among younger adults who never smoked cigarettes and, at the same time, help those who may have switched from cigarettes to e-cigarettes to stop using these devices completely.”