People who smoke e-cigarettes face a significant risk of developing severe, chronic lung illnesses — such as asthma, bronchitis and emphysema — that have long been associated with smoking combustible cigarettes, according to a UCSF study released Monday.

The study found that people who use e-cigarettes in addition to smoking traditional tobacco triple their risk of chronic lung disease.

The study, from tobacco researcher Stanton Glantz, showed for the first time that e-cigarette smoking, or vaping, has long-term effects on respiratory health that are similar to those of traditional tobacco smoking. Earlier studies identified a link between e-cigarettes and lung disease at a single point in time, but researchers hadn’t demonstrated long-term impacts, Glantz said.

“They said there was no evidence of long-term effects. This study, looking at the general population over time, is starting to fill that hole,” said Glantz, director of the UCSF Center for Tobacco Control Research and Education and a critic of the e-cigarette industry for years.

The findings are important in the broader discussion about vaping versus smoking tobacco. Producers and promoters of e-cigarettes, including San Francisco’s Juul Labs, often argue that their product — a liquid concoction of nicotine, glycerin and other chemicals that add flavor — is safer than traditional smoking.

The UCSF study showed that smokers indeed reduce their risk of lung disease if they switch to e-cigarettes.

But Glantz noted that the study also found that many smokers end up using both e-cigarettes and traditional cigarettes, which is more dangerous than either option alone.

“In the e-cigarette debate, it’s all about, ‘Is this better than that, or what if you switch,’” Glantz said. “For people who switched, their risks declined. But in the real world, most are dual users. They’re actually worse off than tobacco smokers.”

The study, published in the American Journal of Preventive Medicine, analyzed data that tracked e-cigarette and tobacco use in 32,000 U.S. adults from 2013 to 2016. None of the participants had lung disease at the start of the study.

Researchers found that the odds of developing lung disease increased by about a third for people who used e-cigarettes, Glantz said.

The findings are not related to the outbreak of sudden-onset lung disease that has been alarming public health officials nationwide. More than 2,400 people have suffered lung injury and 52 have died since officials began tracking cases about six months ago, according to the Centers for Disease Control and Prevention.

One of those vaping deaths was a Marin County woman who died in November after she developed a sudden lung injury that quickly advanced from a bad cough to needing a breathing machine to dying within a day.

All of the lung injury patients reported vaping within three months of falling ill. Most of the people reported using THC products, not nicotine. But the cause of illness has not yet been identified.

The new study is bad news not only for those who vape, but also for e-cigarette sellers, including Juul, which have been under attack from health officials and politicians.

The San Francisco Board of Supervisors voted in June to ban the sales of e-cigarettes beginning Jan. 1, and cities around the Bay Area and the nation followed suit as health concerns about vaping increased. Juul placed an unsuccessful initiative on the San Francisco fall ballot seeking to reinstate some e-cigarette sales but dropped its backing — after spending $12 million — in the wake of a public backlash against not only the measure but vaping.

In September, the White House and the Food and Drug Administration warned that they could ban sales of popular flavored e-cigarette cartridges. Flavored pods represent an estimated 80% of Juul’s U.S. sales, and a federal prohibition could cost it hundreds of millions of dollars.

Michael Cabanatuan is a San Francisco Chronicle staff writer. Email: mcabanatuan@sfchronicle.com Twitter: @ctuan