Cigarette smoking may have earned a reputation as an unhealthy, cancer-causing pastime, but water pipes seem to have largely evaded the stigma. Now, new research shows that water pipes may simply be dangerous in slightly different ways, according to a study in Cancer Epidemiology, Biomarkers and Prevention.
Water pipes, also known as hookah, shisha and a host of other aliases, are a common social activity in the Middle East and have been growing in popularity: a 2011 study found more than 40% of college students had used a hookah, and many of them appeared to believe it was safer than cigarette smoking.
Doctors are trying to dissuade folks of that notion. "The tobacco is no less toxic in a hookah pipe," according to the Mayo Clinic, "and the water in the hookah does not filter out the toxic ingredients in the tobacco smoke. Hookah smokers may actually inhale more tobacco smoke than cigarette smokers do."
And yet the distinction appears to remain in many folks' minds. So to compare the two methods' effects, researchers at UC San Francisco conducted a randomized study of 13 volunteers (eight men and five women) who were well-versed in the arts of tobacco. Participants each smoked one way for four days, and a week later smoked the other way for four days. (Since individuals can excrete different amounts of toxins even if they smoke the same amount – a sort of secretion fingerprint – each test subject would have to smoke both ways to get an accurate comparison.)
The study participants smoked an average of 11 cigarettes per day or 3 water-pipe sessions per day.
When they measured the amount of nicotine in the blood, they found that water-pipe smoking led to about half the total nicotine levels of cigarette smokers – though the authors were quick to note that even a lower level can still sustain addiction.
And the scientists found that the levels of carbon monoxide in participants' breath were a full 2.5 times higher for water-pipers than for cigarette smokers. Carbon monoxide can increase the risk for heart attacks, stroke and sudden death in patients who have cardiovascular or lung illnesses.
The researchers also examined participants' urine and found that the hookah smokers had significantly higher levels of benzene, which has been linked to leukemia.
"A different pattern of carcinogen exposure might result in a different cancer risk profile between cigarette and water pipe smoking," the researchers write. "Of particular concern is the risk of leukemia related to high levels of benzene exposure with water pipe use."