Research chemist Peyton Jacob III of the University of California, San Francisco, and Dr. Neal Benowitz, both at San Francisco General Hospital and Trauma Center, said hookah -- water pipe -- 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," Jacob said in a statement. "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."
Compared to non-smokers, Benowitz said, "If you are smoking from a hookah daily, you are likely to be at increased risk for cancer."
A 2009 survey found 3-in-10 U.S. university students had smoked tobacco from a water pipe on at least one occasion, with hookah use being disproportionately popular among white students, males, fraternity and sorority members.
The study included eight men and five women, all of whom had previous experience smoking cigarettes and using water pipes. The volunteers smoked an average of three water pipe sessions or 11 cigarettes per day.
Some of the toxins inhaled when hookah smoking included: volative organic chemicals of acrylamide, acrolein and benzene; olyaromatic hydrocarbons of naphthalene.
Levels of a benzene byproduct doubled in the urine of volunteers after using a hookah in comparison to smoking cigarettes, the study found.