We've long known that hookah is about as unhealthy as smoking cigarettes. In fact, the amount of smoke inhaled over an hour of hookah can be equivalent to smoking 100 cigarettes, according to the World Health Organization.
If that doesn't convince you to drop the shisha habit, researchers from the University of Pittsburgh Schools of the Health Sciences have just announced an even scarier metric: One hookah smoking session delivers 25 times the tar of a single cigarette.
The researchers analyzed 17 studies that were relevant to hookah smoking and contained sufficient data to extract reliable estimates on toxicants inhaled. They found that one hookah session -- based on an average of 45 to 60 minutes -- delivers approximately 125 times the smoke, 25 times the tar, 2.5 times the nicotine and 10 times the carbon monoxide of smoking one cigarette.
"Our results show that hookah tobacco smoking poses real health concerns and that it should be monitored more closely than it is currently," lead author Dr. Brian A. Primack said in a statement released Monday. "For example, hookah smoking was not included in the 2015 Youth Risk Behavior Surveillance Survey System questionnaire, which assesses cigarette smoking, chewing tobacco, electronic cigarettes and many other forms of substance abuse."
Tar is a poisonous byproduct of burning tobacco. Exposure can raise a person's risk for lung cancer, emphysema and other lung diseases. Tar is also responsible for smokers' stained hands and teeth.
The researchers acknowledged that comparing hookah and cigarette smoking is difficult because people smoke the two in very different ways.
"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," Primack said.
The estimates they found can't definitively point out which smoking habit is "worse," but Primack said the findings do show that "hookah smokers are exposed to a lot more toxicants than they probably realize."
Many young adults believe smoking hookah and cigarette alternatives is a less risky behavior than smoking cigarettes, but again, this isn't true. In a previous study, researchers found that roughly 25 percent of young adults believe hookah is safer than cigarettes.