1 hookah session has 25 times more tar than a cigarette

There's a common misconception that hookahs aren't very dangerous. A recent Rutgers University study revealed that 24 percent of both smokers and nonsmokers under age 25 believe hookahs— shared pipes that allow users to inhale tobacco smoke that's been passed through a water basin—are safer than cigarettes. But according to a new study from the journal Public Health Reports, this is an even bigger myth than thought.

Researchers from the University of Pittsburgh School of Medicine found that one hookah session produces 2.5 times more nicotine, 10 times more carbon monoxide, 25 times more tar, and 125 times more smoke than a single cigarette.

To get their results, the team analyzed the results of 17 studies looking at the toxins inhaled through each type of tobacco product.

"It's not a perfect comparison because people smoke cigarettes and hookahs in very different ways," lead author Dr. Brian A. Primack, PhD, explained in a press release about the study. For example, cigarette smokers might smoke upwards of 20 cigarettes a day, whereas even frequent hookah smokers may engage in far fewer sessions throughout the same time period.

"We had to conduct the analysis this way—comparing a single hookah session to a single cigarette—because that's the way the underlying studies tend to report findings. So, the estimates we found cannot tell us exactly what is 'worse,'" he added. "But what they do suggest is that hookah smokers are exposed to a lot more toxicants than they probably realize."

What makes this even more troubling is that while smoking rates among U.S. adults recently dipped to a new low of just 14.9 percent, hookah and e-cigarette use is way up. According to the 2014 National Youth Tobacco Survey, hookah use actually doubled between 2011 and 2014—even as teen cigarette use dropped from 16 percent to 9 percent.