Where there's smoke, there's fire...or a crowd of hookah users blowing out toxic vapor clouds.

Hookah's health halo has already taken a hit: Studies have suggested that a full hookah session packs 25 times the tar of a single cigarette. But now it seems that even the alternatives may not be as healthy as once thought.

Hookah pipes that heat liquid with electric heating disks kill an estimated 70% more lung cells than hookah pipes that burn traditional charcoal, according to new research from the University of Cincinnati.

In the study, graduate student Ryan Saadawi and his team set out to measure how different hookah-heating methods affect smokers' lungs. The researchers heated the same hookah tobacco with two types of charcoal briquettes, as well as the electric heaters. Unsurprisingly, researchers found that the lower-toxin charcoal had slightly lower concentrations of heavy metals and toxins (like arsenic and lead), but that both contained the chemicals.

The surprise came when the researchers exposed lung cells to an extract from the different charcoals' hookah smoke at various dilutions. They originally sought to compare these findings with electronically burned tobacco by a ceramic disk to serve as the control, but after 24 hours they found something far more alarming:

  • A lower-toxin charcoal briquette killed 10% of lung cells
  • Higher-toxin charcoal (laced with heavy metals) killed 25% of lung cells
  • E-charcoal killed an astonishing 80% of lung cells

"The results didn't make sense," lead study author Saadawi said in a press release. "My hypothesis was to find more dead lung cells in toxic charcoal."

Why hookahs heated by e-charcoal are so damaging to your lungs

The science: When tobacco burns, it releases harmful compounds like polycyclic aromatic hydrocarbons, which in turn kill lung cells (and, naturally, increase your risk of lung cancer). Both heat sources heated the tobacco to 572° Fahrenheit (yeah, really freakin' hot), but the electric disks were more consistent—they kept the tobacco hotter than the burning charcoal, which gets cooler each time a smoker inhales from the hookah pipe.

Saadawi theorizes the consistently hotter e-coal releases more hydrocarbons, which eliminate more lung cells—even though the contaiminated charcoal had a greater potential to be more toxic. 

So if you think hookah's a healther fix for cigs, think again. Any foreign substance you inhale into your lungs is going to do some damage. How serious that damage is depends on what you're smoking, how often you're smoking it, and, apparently, how you're smoking it.