Many people believe that smoking tobacco through a hookah is less harmful than smoking cigarettes.

But in a new study at UC San Francisco, researchers measuring chemicals in the blood and urine have concluded that hookah smoke contains a different - but still harmful - mix of toxins.
UCSF research chemist Peyton Jacob III, PhD, and UCSF tobacco researcher Neal Benowitz, MD, both based at San Francisco General Hospital and Trauma Center, said hookah use exposes smokers to higher levels of carbon monoxide, especially hazardous to those with heart or respiratory conditions, and to higher levels of benzene, long associated with leukemia risk.

"People want to know if it is a lesser health risk if they switch from cigarettes to smoking a water pipe on a daily basis. We found that water-pipe smoking is not a safe alternative to cigarette smoking, nor is it likely to be an effective harm-reduction strategy," Jacob said.

And compared to non-smokers, Benowitz said, "If you are smoking from a hookah daily, you are likely to be at increased risk for cancer."

Jacob said, "In addition to delivering toxic substances from the charcoal and tobacco, the heat causes chemical reactions in the mixture which produce toxic volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Some PAHs are highly carcinogenic and can cause lung cancer."

Intake of nicotine, the addictive component of tobacco, was less with water pipe use.

The findings are published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.