Hookahs, attractive to young people who think the hip method of smoking is also a safer one, may not be so harmless, say researchers who've found the water pipe fumes contain benzene, a toxin linked to increased risk of leukemia.
In a hookah, charcoal is burned to heat the hookah tobacco, creating the smoke that the user inhales, but also creating charcoal combustion-generated toxic and carcinogenic emissions, the researchers say.
"In contrast to what is believed, hookah tobacco smoking is not a safe alternative to smoking other forms of tobacco," says study author Nada Kassem of the Center for Behavioral Epidemiology and Community Health at San Diego State University.
Hookahs, or water pipes, use special tobacco that comes in flavors such as cherry, chocolate, apple, cappuccino and many others that makes them attractive to younger smokers and has led to the growing popularity of hookah cafes or lounges.
Despite a belief that hookahs are safer than smoking cigarettes, they present many of the same health risks, according to the Centers for Disease Control and Prevention.
In the study led by Kassem, researchers measured levels of S-phenylmercapturic acid (SPMA) -- produced when the body metabolizes benzene -- in 105 smokers and in103 nonsmokers who were exposed to the smoke created by the water pipes.
In people who had attended an event in a hookah cafe, hookah smokers had SPMA levels four times above normal, and in those people who were at the event but did not smoke the hookah, their levels were 2.6 times higher, the researchers report in the journal Cancer Epidemiology, Biomarkers & Prevention.
Prior research has indicated links between benzene and a greater risk of leukemia, which suggests hookah use should be looked at more closely and with a critical eye, Kassem suggests.
"Because there is no safe level of exposure to benzene, our results call for interventions to reduce or prevent hookah tobacco use, regulatory actions to limit hookah-related exposure to toxicants including benzene, and include hookah smoking in clean indoor air legislation," she says.
Aside from the benzene issue, there are other risks to hookah smoking, especially given the length of a typical hookah session, says Dr. Richard Hurt of the Mayo Clinic.
"When you smoke a cigarette, a person smokes it maybe for just a few minutes and then you're through with it," he says.
"'But hookah sessions are social and people sit there for an hour or so kind of puffing on these things, thinking that the water is filtering out all the bad stuff, when the reality is it does not do that."
A single hookah smoking session can deliver 1.7 times as much nicotine, 46.4 times the tar and 6.5 times the amount of carbon monoxide of a single smoked cigarette, a study funded by the National Institutes of Health found.