Hookah Smoke Linked to Benzene Exposure, Which May Increase Leukemia Risk: Study

A new study raises serious concerns about the safety of hookah smoking, which has become increasingly popular in recent years, with researchers indicating that users and bystanders may be exposed to potentially dangerous levels of the toxic chemical benzene, which may increase the risk of leukemia.

In a study published by the journal Cancer Epidemiology, Biomarkers & Prevention, researchers tested both hookah smokers and non-smokers, finding that smoking hookah was linked to an increased risk of leukemia, lung and oral cancers, coronary heart disease and pulmonary disease.

Researchers from the Center for Behavioral Epidemiology and Community Health at San Diego State University tested 105 hookah smokers and 103 non-smokers, examining the level of S-phenylmercapturic acid (SPMA) in the participants urine. SPMA is a metabolite of benzene, one of the key ingredients in hookah.

Participants provided spot urine samples on the morning of and morning after attending indoor hookah-only events, at a hookah lounge or a private home.

Hookah smokers had significantly increased levels of SPMA after attending an event. Hookah smokers had 4.2 times higher levels of SPMA after attending a hookah lounge event, and 1.9 times higher levels of SPMA after a home hookah event.

In contrast, non-smokers had levels of SPMA 2.6 times higher after a hookah lounge event. Yet, levels remained the same after home events as levels tested before attending any event.

Hookah is a form of tobacco that uses a partially filled water jar and heated charcoal to burn the tobacco. One of the key ingredients of hookah is benzene, which has been shown in other studies to cause leukemia.

Many users of hookah believe it to be safer than traditional cigarettes because the smoke passes through water before a user inhales it. It is also often flavored with sweet appealing flavors, like vanilla, mint and strawberry.

One hookah session can be the equivalent to smoking from 10 to 40 cigarettes. A study conducted by the National Institutes of Health revealed a single hookah session delivers 1.7 times the nicotine, 6.5 times the carbon monoxide and 46.4 times the tar of a single cigarette.

The World Health Organization (WHO) and the U.S. National Toxicology Program classified benzene as a group 1 carcinogen. Furthermore, the WHO says there are no safe levels of exposure to benzene.

Hookah smokers tend to be younger than non-smokers, have more close friends who are also current hookah smokers, are more likely to allow hookah smoking in their homes and are more likely to live with at least one hookah smoker.

In 2013, nearly 27% of U.S. college aged males used hookahs, along with 23% of college age females. More than 8% of male middle and high school students and 7% of female students used hookah. Most recent data found 1 in 5 high school seniors have used hookah.

Hookah is a social habit, often practiced in social settings, making it that much more dangerous to those who use it and those experiencing second-hand hookah smoke.

Nada Kassem, lead author of the study, and the team of researchers are calling for stronger interventions to reduce and prevent hookah use. In addition, they urge regulatory action to limit hookah-related exposure to toxic chemicals emitted during the smoking and stricter labeling of products.