Urinary NNAL in hookah smokers and non-smokers after attending a hookah social event in a hookah lounge or a private home

Biomarkers of Waterpipe Tobacco Smoke Exposure: A Systematic Review and Meta-Analysis

INTRODUCTION

The prevalence of waterpipe tobacco smoking is increasing globally. Biomarkers of waterpipe tobacco smoke (WTS) exposure are less studied.

AIMS AND METHODS

To identify the types of biomarkers of WTS exposure and estimate changes in biomarker concentrations pre- to post-WTS exposure. PubMed, Embase, Web of Science, CINAHL Plus, PsycINFO, and Cochrane Library were searched for studies up to April 24, 2023. The types of biomarkers were identified. Random-effects models were used to estimate changes in biomarker concentrations pre- to post-WTS exposure.

RESULTS

Seventy-three studies involving 3755 participants exposed to WTS (49% male, mean age: 24.8 years) and 11 types of biomarkers of WTS exposure were identified. The biomarkers included tobacco alkaloids, expired carbon monoxide (eCO), carboxyhemoglobin (COHb), tobacco-specific nitrosamines, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, unmetabolized VOCs, unmetabolized PAHs, furan metabolites, and heterocyclic aromatic amines. Compared with pre-WTS exposure, eCO (breath; mean difference [MD] 27.00 ppm; 95% confidence interval [CI]: 20.91 to 33.08), COHb (blood; MD 4.30%; 95%CI: 2.57 to 6.03), COHb (breath; MD 7.14%; 95%CI: 4.96 to 9.31), nicotine (blood; MD 8.23 ng/mL; 95%CI: 6.27 to 10.19), and cotinine (urine; MD 110.40 ng/mL; 95%CI: 46.26 to 174.54) significantly increased post-WTS exposure.

CONCLUSIONS

Biomarkers of WTS exposure were systematically identified. The similarity between the biomarkers of WTS exposure and those of cigarette smoke and higher concentrations of some biomarkers post-WTS exposure underscore the need for further research on applying biomarkers in surveillance, interventions, and regulations to mitigate the harms of waterpipe tobacco smoking.

IMPLICATIONS

This study provides the first comprehensive overview of biomarkers investigated and available for assessing WTS exposure and their concentration changes in the human body. Researchers can use biomarkers such as eCO, COHb, nicotine, and cotinine to measure the health risks associated with WTS exposure and objectively evaluate the effectiveness of public health interventions aimed at reducing waterpipe tobacco smoking. Public health policymaking can also be informed through increased biomarker concentrations following WTS exposure, to implement regulations and public health education campaigns on limiting or preventing waterpipe tobacco smoking.

Perceived Harms of Waterpipe Tobacco Heating Sources Among Young Adult Waterpipe Tobacco Smokers

Background. Waterpipe tobacco smoking is associated with many negative health outcomes due to toxicants produced by heating the tobacco using charcoal or electrical heaters. Little is known about how young adult waterpipe tobacco smokers perceive harms of these heating sources. Aims. To examine young adult waterpipe tobacco smokers' perceived harms of electrical heaters and charcoal to heat waterpipe tobacco. Method. This online cross-sectional study enrolled 18- to 32-year-olds who smoked waterpipe tobacco within the past 30 days. Participants completed measures assessing, for each heating source, amount and knowledge of toxicants released (e.g., carbon monoxide, cancer-causing chemicals), perceived safety, worry about inhaling toxicants, perceived health risk, desire to quit, and intention to smoke in the next month. Question order for knowledge of and perceived harms was counterbalanced for each heating source. Results. Analyses were based on responses from 199 participants. Perceived harms for both heating sources were average to low. Despite some question order effects, participants viewed charcoal as more harmful than electrical heaters. Participants knew more about chemicals released from charcoal than electrical heaters. Greater knowledge of chemicals released by both heating sources correlated positively with perceived harms. Perceived harms were associated with a stronger desire to quit, yet unrelated with likelihood of smoking waterpipe during the next month. Discussion. Many young adult waterpipe tobacco smokers view charcoal as more harmful than electrical heaters, although knowledge about harms for each heating source is poor. Conclusion. Interventions are needed to inform the public about harms of waterpipe heating sources in order to curb use.