A University of Cincinnati researcher, studying the safety of hookah steam stones, has found residues of toxic metals in simulated smoking scenarios.
Hookah steam stones are billed by the companies who make them as "hookah without the tobacco risk," and commonly considered a safer alternative to cigarette smoking.
But Amberlie Clutterbuck, a UC doctoral student, found residues of toxic metals that included chromium, arsenic and cadmium.
She and other UC researchers write in May's Microchemical Journal. "These pebble-like rocks are soaked in the same type of fluid used in various hookah tobaccos, such as mo'assel which is popular in the USA, and heated in the heads of the hookah device in place of tobacco to create a smoke-like vapor cloud, plus small aerosol droplets."
The study suggests most of the toxic metals come from the charcoal used to heat the hookah apparatus, since the toxic metals from the steam stones don't consistently travel through the hookah to the mouthpiece.
In 2014, the Food and Drug Administration mandated that companies manufacturing newer tobacco products, including hookah, must register and market only products following and FDA review.