Shisha smokers and nonsmokers exposed to shisha smoke at social events in shisha lounges had significant increases in uptake of benzene, a substance associated with an increased risk for leukaemia, according to a study published in Cancer Epidemiology, Biomarkers & Prevention.

“Shisha tobacco smoking involves the use of burning charcoal that is needed to heat the shisha tobacco to generate the smoke that the smoker inhales,” said Dr Nada Kassem, associate director at the Center for Behavioral Epidemiology and Community Health at San Diego State University.

“In addition to inhaling toxicants and carcinogens found in the shisha tobacco smoke, shisha smokers and nonsmokers who socialise with shisha smokers also inhale large quantities of charcoal combustion-generated toxic and carcinogenic emissions.”

Urine levels of S-phenylmercapturic acid (SPMA), a metabolite of benzene, were more than fourfold higher in shisha smokers and twofold higher in nonsmokers after attending a shisha-only smoking social event at a shisha lounge.

Levels of SPMA were also significantly increased in shisha smokers after attending a shisha-smoking event in a private home.

“Because there is no safe level of exposure to benzene, our results call for interventions to reduce or prevent shisha tobacco use, regulatory actions to limit shisha-related exposure to toxicants including benzene, and include shisha smoking in clean indoor air legislation,” Kassem added.

Kassem and colleagues analysed the levels of SPMA in the urine of 105 shisha smokers and 103 nonsmokers.

They obtained urine samples the morning of and the morning after participants attended a shisha-only smoking event at a shisha lounge or a private home.

Uptake of SPMA in shisha smokers increased 4.2-fold after smoking shisha tobacco at a social event at a shisha lounge and increased 1.9-fold after smoking shisha tobacco in a private home.

Additionally, nonsmokers’ uptake of SPMA increased 2.6-fold after attending a social event in a shisha lounge.

However, nonsmokers had similar levels of SPMA before and after attending shisha events in a private home.

According to Kassem, pre and post event levels were similar because nonsmokers’ uptake of benzene before the private shisha event was as high as the levels found in nonsmokers after attending the shisha event in shisha lounges, possibly indicating chronic exposure to benzene.

“In contrast to what is believed, shisha tobacco smoking is not a safe alternative to smoking other forms of tobacco,” Kassem said.

Source: AACR