Thanks to endless PSAs (and those posters in health class), we know cigarettes are addictive and full of cancer-causing toxins. Using hookahs, however, tends to get a pass in these conversations. But those Instagrammable smoke rings are chock-full of bad stuff.

New research from the University of Pittsburgh found that a typical one-hour smoking session involves more than double the nicotine, 10 times the carbon monoxide, and 25 times the tar as smoking a single cigarette. It’s not a perfect comparison—you can definitely smoke more than one cigarette in a hour. But the findings are still alarming, especially with news that for the first time ever, hookah smoking is more popular than cigarettes among teens.

(h/t ScienceDaily)

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