Exposure to Hookah Smoke Doubles Benzene Uptake, Potentially Increasing Risk for Leukemia
Findings from a new study show that hookah smokers and nonsmokers exposed to hookah (or waterpipe) secondhand tobacco smoke at social events in hookah lounges and in private homes had significant increases in uptake of benzene, a leukemogen that causes lymphohematopoietic cancers, especially acute myeloid leukemia. Because there is no safe level of exposure to benzene, the researchers are calling for regulatory actions to curb hookah-related exposure to toxicants. The study by Kassem et al is published in Cancer Epidemiology, Biomarkers & Prevention.
Study Methodology
The researchers analyzed data collected from 105 hookah smokers and 103 nonsmokers exposed exclusively to hookah tobacco at hookah lounges or in private homes in San Diego County, California. Participants were 18 years or older.
Data were collected between 2009 and 2011 and included information about tobacco use, demographics, and hookah smoking session observation. Two urine samples from each participant were also collected, one on the morning of and one on the morning after attending an indoor hookah-only social event at a hookah lounge or in a private home. The researchers then analyzed the levels of S-phenylmercapturic acid (SPMA), a metabolite of benzene, in the urine samples.
Study Findings
The researchers found that uptake of SPMA in hookah smokers’ increased 4.2-fold after hookah lounge events (P < .001) and increased 1.9-fold after home events (P = .055). In addition, nonsmokers’ uptake of SPMA increased 2.6-fold after attending a social event in a hookah lounge. In nonsmokers, SPMA levels were detected before and after home events, possibly indicating chronic exposure to benzene (P = 0.933).
“Hookah tobacco smoking involves the use of burning charcoal that is needed to heat the hookah tobacco to generate the smoke that the smoker inhales,” said Nada Kassem, DrPH, MS, RN, MCHES, Associate Director of the Center for Epidemiology and Community Health at San Diego State University, in a statement. “In addition to inhaling toxicants and carcinogens found in the hookah tobacco smoke, hookah smoker and nonsmokers who socialize with hookah smokers also inhale large quantities of charcoal combustion-generated toxic and carcinogenic emissions.”
Calls for Regulating Hookah Tobacco Use
The World Health Organization (WHO) and the U.S. National Toxicology Program have classified benzene as a Group 1 carcinogen. The WHO reported that benzene is carcinogenic to humans and that there is no safe level of exposure. Contrary to beliefs that hookah tobacco is a less harmful form of tobacco, the Centers for Disease Control and Prevention (CDC) reports that hookah smoking is not a safe alternative to smoking cigarettes.
Based on their findings, the study researchers are calling for regulatory actions to limit toxicants, including benzene, in hookah tobacco and charcoal products, an examination of hookah-related products labeling, inclusion of hookah smoking in clean indoor air legislation, and clinical trials to investigate and limit exposure to this form of charcoal-heated tobacco use.
Dr. Kassem is the corresponding author for the Cancer Epidemiology, Biomarkers & Prevention article.
Funding for this study was provided by the American Cancer Society and Flight Attendant Medical Research Institute. The study authors reported no conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
