Acrolein Exposure in Hookah Smokers and Non-Smokers Exposed to Hookah Tobacco Secondhand Smoke: Implications for Regulating Hookah Tobacco Products

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.

A comprehensive bibliometric analysis of global research on the role of acrolein in Alzheimer's disease pathogenesis: involvement of amyloid-beta

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive and behavioral decline. Acrolein, an environmental pollutant and endogenous compound, is implicated in AD development. This research employs bibliometric analysis to assess current trends and key areas concerning acrolein-AD interaction.

Methods

The Web of Science was used to extensively review literature on acrolein and AD. Relevant data were systematically gathered and analyzed using VOSviewer, CiteSpace, and an online bibliometric tool.

Results

We identified 120 English publications in this specialized field across 19 journals. The Journal of Alzheimer's Disease was the most prominent. The primary contributors, both in terms of scientific output and influence, were the USA, the University of Kentucky, and Ramassamy C, representing countries/regions, institutions, and authors, respectively. In this field, the primary focus was on thoroughly studying acrolein, its roles, and its mechanisms in AD utilizing both in vivo and in vitro approaches. A significant portion of the research was based on proteomics, revealing complex molecular processes. The main focuses in the field were "oxidative stress," "lipid peroxidation," "amyloid-beta," and "cognitive impairment." Anticipated future research trajectories focus on the involvement of the internalization pathway, covering key areas such as synaptic dysfunction, metabolism, mechanisms, associations, neuroinflammation, inhibitors, tau phosphorylation, acrolein toxicity, brain infarction, antioxidants, chemistry, drug delivery, and dementia. Our analysis also supported our previous hypothesis that acrolein can interact with amyloid-beta to form a protein adduct leading to AD-like pathology and altering natural immune responses.

Conclusion

This study provides a broad and all-encompassing view of the topic, offering valuable insights and guidance to fellow researchers. These emerging directions underscore the continuous exploration of the complexities associated with AD. The analyses and findings aim to enhance our understanding of the intricate relationship between acrolein and AD for future research.

Acrolein suppresses anticancer drug-induced toxicity mediated by activating claudin-1 and Nrf2 axis in a spheroid model of human lung squamous cell carcinoma cells

Tobacco smoke contains various carcinogenic ingredients such as nicotine, acrolein, and benzopyrene; however, their effects on cancer treatment are not fully understood. Claudin-1 (CLDN1), a component of tight junctions, is involved in the increased resistance to anticancer drugs. In this study, we found that acrolein increases the mRNA and protein levels of CLDN1 in RERF-LC-AI cells derived from human lung squamous cell carcinoma (SCC). Acrolein increased the p-extracellular signal-regulated kinase (ERK) 1/2 levels without affecting the p-Akt level. The acrolein-induced elevation of CLDN1 expression was attenuated by U0126, a mitogen-activated protein kinase kinas (MEK) inhibitor. These results indicate that the activation of MEK/ERK pathway is involved in the acrolein-induced elevation of CLDN1 expression. In a spheroid model, acrolein suppressed the accumulation and toxicity of doxorubicin (DXR), which were rescued by CLDN1 silencing. The acrolein-induced effects were also observed in lung SCC-derived EBC-1 and LK-2 cells. Acrolein also increased the expression level of nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that regulates antioxidant and detoxifying genes, which were inhibited by CLDN1 silencing. In spheroid cells, the levels of reactive oxygen species were enhanced by acrolein, which was inhibited by CLDN1 silencing. Taken together, acrolein may reduce the anticancer drug-induced toxicity in human lung SCC cells mediated by high CLDN1 expression followed by the upregulation of Nrf2 signaling pathway.

Effect of glycerol concentration on levels of toxicants emissions from water-pipe tobacco smoking (WTS)

Glycerol, flavorings and sweeteners constitute approximately 70% of water-pipe tobacco smoking (WTS) mixtures. Tobacco mixture combustion produces smoke toxins (e.g. carbonyl compounds), of which the type and amount are highly dependable on tobacco mixture formula. While glycerol in tobacco mixture contribute to enhanced smoking experience, its' combustion produces toxicants such as acrolein. According to WHO, there are no approved international upper limits regulations on WTS ingredients. This study aims to assess toxicant emission levels corresponding to increasing glycerol concentration in WTS mixtures, which may aid in developing tobacco regulations towards harm reduction.MethodsLaboratory experimental study. Using laboratory water-pipe smoking machine, levels of toxicant emissions in the smoke from WTS mixture samples containing varying glycerol concentrations were measured using High-performance Liquid Chromatography (HPLC). Smoke from 5 consecutive smoking cycles with 35 puffs each (ISO 22486 standard) was led through a trapping system as described in the Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) recommended method No. 74 (Determination of selected carbonyls in mainstream cigarette smoke by HPLC). Trapped carbonyls were then analysed by HPLC with a DAD detector.ResultsAcrolein emission is associated with glycerol addition in WTS mixture indicated by lab-made samples throughout all glycerol concentrations (10%, 20%, 40% and 60%), and brand samples with glycerol concentrations 10% to 20%. However, brand samples showed no increase in acrolein emission corresponding to the increase in glycerol concentrations from 20% to 60%.ConclusionThe effect of glycerol addition in waterpipe tobacco on acrolein emission varies between products. Tobacco fillers, additives and contents quality and other factors may affect toxicant emission levels. Therefore, regulatory recommendations towards defining upper limits of content concentrations require further investigations regarding potential confounders in acrolein emissions and health effects of market-available glycerol concentrations in waterpipe tobacco smoking.

The Tobacco Smoke Component, Acrolein, as a Major Culprit in Lung Diseases and Respiratory Cancers: Molecular Mechanisms of Acrolein Cytotoxic Activity

Acrolein, a highly reactive unsaturated aldehyde, is a ubiquitous environmental pollutant that seriously threatens human health and life. Due to its high reactivity, cytotoxicity and genotoxicity, acrolein is involved in the development of several diseases, including multiple sclerosis, neurodegenerative diseases such as Alzheimer’s disease, cardiovascular and respiratory diseases, diabetes mellitus and even the development of cancer. Traditional tobacco smokers and e-cigarette users are particularly exposed to the harmful effects of acrolein. High concentrations of acrolein have been found in both mainstream and side-stream tobacco smoke. Acrolein is considered one of cigarette smoke’s most toxic and harmful components. Chronic exposure to acrolein through cigarette smoke has been linked to the development of asthma, acute lung injury, chronic obstructive pulmonary disease (COPD) and even respiratory cancers. This review addresses the current state of knowledge on the pathological molecular mechanisms of acrolein in the induction, course and development of lung diseases and cancers in smokers.

Perception and assumptions of young waterpipe smokers in Mumbai, India

Background

Hookah smoking has been on raise all over the world, including India, especially among youngsters. There is growing evidence suggesting the high school children experimenting this form of tobacco.

Objective

The objective of this study was to investigate the characteristics, behavior, and perceptions related to hookah smoking among the hookah smokers in Mumbai.

Materials and Methods

A cross-sectional survey was conducted among 200 randomly selected young adults between the age group of 15-35 years in Mumbai who visited different dental clinics. The questionnaire was distributed as Google Forms online in the month of November and December 2019 and those who submitted completed responses were included in the study.

Results

Only 114 participants returned with the completed forms in the time period of 2 months. The results showed that the majority of participants were between 20 and 24 age, comprising 58% who were having the habit of hookah smoking. Among which 24% females, 76% males had history of hookah habit. Eight percent of males started smoking hookah from very young age. Males (29.89%) shared one hookah pot with four members. Forty percent of the participants stated that they are interested to smoke again because of hookah flavor.

Conclusion

Easy availability of newer forms of smoking at online markets could play a role in promoting the use of hookah among youngsters. Most products are being sold without any warnings, and there is no means to control the selling of the products to minors. Educational intervention is urgently needed to create awareness among youth about the harmful effects of hookah smoking.

Comparative Genotoxicity and Mutagenicity of Cigarette, Cigarillo, and Shisha Tobacco Products in Epithelial and Cardiac Cells

Epidemiology studies link cigarillos and shisha tobacco (delivered through a hookah waterpipe) to increased risk for cardiopulmonary diseases. Here we performed a comparative chemical constituent analysis between 3 cigarettes, 3 cigarillos, and 8 shisha tobacco products. The potency for genotoxicity and oxidative stress of each product's generated total particulate matter (TPM) was also assessed using immortalized oral, lung, and cardiac cell lines to represent target tissues. Levels of the carcinogenic carbonyl formaldehyde were 32- to 95-fold greater, while acrolein was similar across the shisha aerosols generated by charcoal heating compared to cigarettes and cigarillos. Electric-mediated aerosol generation dramatically increased acrolein to levels exceeding those in cigarettes and cigarillos by up to 43-fold. Equivalent cytotoxic-mediated cell death and dose response for genotoxicity through induction of mutagenicity and DNA strand breaks was seen between cigarettes and cigarillos, while minimal to no effect was observed with shisha tobacco products. In contrast, increased potency of TPM from cigarillos compared to cigarettes for inducing oxidative stress via reactive oxygen radicals and lipid peroxidation across cell lines was evident, while positivity was seen for shisha tobacco products albeit at much lower levels. Together, these studies provide new insight into the potential harmful effects of cigarillos for causing tobacco-associated diseases. The high level of carbonyls in shisha products, that in turn is impacted by the heating mechanism, reside largely in the gas phase which will distribute throughout the respiratory tract and systemic circulation to likely increase genotoxic stress.

Smoking habits and the influence of war on cigarette and shisha smoking in Syria

Tobacco smoking might be impacted by various influences, including psychological, socio-cultural, and economic factors. A community-based cross-sectional survey was conducted in Syrian Arab Republic from March to April 2019 using a web-based questionnaire. The survey aimed at assessing tobacco use (shisha and cigarettes) as well as examining the association between current tobacco use and various sociodemographic and war-related factors. The sample comprised 978 participants (251 males: 727 females) and had a mean age of 24.7 years (SD: 7.60). Most participants were single (n = 825, 84.4%), reside in Damascus and Rif-Dimashq (n = 579, 59.2%), and had a college/university education (n = 911, 93.1%). Concerning smoking, a total of 371 participants (37.9%) were identified to be current tobacco smokers, of whom 211, 84, 76 were exclusive shisha smokers, exclusive cigarette smokers, and dual smokers, respectively. The prevalence of cigarette smoking (exclusive and dual) among males and females was found to be 34.7%, and 10.0%, respectively. On the other hand, the prevalence of shisha smoking (exclusive and dual) among males and females was around 34.3% and 27.6%, respectively. Additionally, various factors have predicted a higher likelihood of cigarette smoking including male gender (AOR = 4.152; 95% CI: 2.842-6.064; p<0.001), and losing someone due to the war (AOR = 1.487; 95% CI: 1.028-2.151; p = 0.035), while unemployed individuals were found to have lower odds of being cigarette smokers (AOR = 0.634; 95% CI: 0.429-0.937; p = 0.022). Concerning shisha smoking, married (AOR = 0.622; 95% CI: 0.402-0.963; p = 0.033), and unemployed individuals (AOR = 0.679; 95% CI: 0.503-0.916; p = 0.011) were found to have lower odds of shisha smoking. Amid the tobacco epidemic in the region, rates of tobacco use in Syria are still worrying. The Syrian armed conflicts may possess a double-edged effect on smoking, and tobacco users who adopt smoking to cope with various stressors should be targeted with well-structured health education, along with appropriate psychological services.

Effects of hookah and cigarette smoking on the recovery after septoplasty

BACKGROUND

Hookah is a tobacco product of Middle Eastern origin; however, its popularity increases in Europe and the US. Despite its frequent use, hookah's potentially detrimental effects are underestimated as a result of the scarcity of the relevant research. Since septoplasty is one of the most commonly performed procedures of otolaryngology practice, we aimed to investigate the impact of hookah consumption on recovery after septoplasty.

METHODS

Patients who underwent septoplasty in Sanliurfa Training and Research Hospital Department of Otolaryngology between January 2017 and December 2019 were divided into four groups based on their history of hookah and cigarette smoking. The patients' prospectively collected data, including demographic features, healing time, and presence or absence of septal perforation during follow-up, were compared between these four groups.

RESULTS

The entire cohort included 270 patients. The mean patient age was 29.2 ± 5.8 years. One hundred and thirty-two (48.9%) patients were non-smokers, 96 (35.5%) were cigarette smokers, 27 (10%) were hookah smokers and 15 (5.6%) consumed both tobacco products regularly. Mean healing time was 10 days, and septal perforation was encountered in 10 patients (3.7%). A comparison of the groups revealed that cigarette smoking did not impact septal perforation rates (P = .326) but prolonged the healing time. However, hookah smoking with or without cigarette smoking significantly influenced septal perforation rates and healing times.

CONCLUSION

Patients should be questioned about hookah smoking in addition to cigarette smoking before the septoplasty procedure. Patients with a positive history of hookah smoking should be followed closely in terms of delayed healing and increased septal perforation rates.

A Naturalistic Study of Carbon Monoxide, Heart Rate, Oxygen Saturation, and Perfusion Index in Hookah Lounge Patrons

BACKGROUND

Waterpipe (also known as hookah) smokers are exposed to several toxicants, heavy metals, and carcinogens. This study assessed physiologic data from hookah bar participants in an urban area in Florida. We hypothesized that hookah lounge patrons would have a decreased [Formula: see text] and perfusion index, as well as an increased heart rate and exhaled carbon monoxide (CO) levels upon exiting the bars.

METHODS

Exhaled CO levels, heart rate, pulse oximetry for carboxyhemoglobin, and perfusion index were obtained immediately before entering the hookah lounges and after exiting hookah lounges on a sample size of 200 patrons attending hookah lounges. Averages were then used for Wilcoxon signed-rank tests to assess differences across means.

RESULTS

Combining data from both hookah smokers and concurrent smokers, the mean CO measurements went from 5.7 ppm prior to lounge entry to 66.5 ppm after the lounge visit (P < .001). Conversion to carboxyhemoglobin for all hookah smokers represents an increase from 1.5% to 10.6% (P < .001). Carboxyhemoglobin mean values as measured with pulse oximetry increased from 1.4% prior to the lounge visit to 7.2% after the lounge visit (P < .001). The mean heart rate for the subjects also increased from 90.3 beats/min to 94.2 beats/min (P < .001). [Formula: see text] levels decreased from 98.4% to 97.8% (P < .001). Similarly, the mean perfusion index decreased from 3.1% to 2.7% (P = .002).

CONCLUSIONS

Hookah lounge smokers in the United States are exposed to high levels of CO that have the potential for detrimental health effects, as evidenced by rapid negative changes in physiological parameters. Respiratory therapists should be aware of potential cardiovascular changes in hookah lounge patrons who enter emergency rooms and health facilities due to recent exposures.

Factors Associated With the Differences Between Self-Report Smoking and Urinary Cotinine Criteria

During self-reporting, respondents underreport their smoking status for various reasons. We aimed to evaluate the difference between smoking status self-reporting and urinary cotinine tests in Korea respondents. Logistic regression analyses were performed to identify factors associated with the differences between self-reporting and urinary cotinine criteria. The dependent variable was the underreporting of smoking status; independent variables were sociodemographic, health status, and secondhand smoke (SHS) exposure. Total underreporting was 3.6% when Cot ≥164 and 4.0% when Cot-variable (classified) criteria underreported. Positive associations were found between smoking and age, education, drinking, and SHS. Underreporting in the nonsmoker group (odds ratio [OR] = 2.336; confidence interval [CI] = 1.717-3.179) was significantly associated with SHS, but this difference was nonsignificant in the ex-smoker group (OR = 1.184; CI = 0.879-1.638). Underreporting was 3.6% to 4.0%, and C-statistics was about 0.7, indicating that outcomes could be classified. SHS in nonsmokers was positively associated with underreporting; however, only the nonsmoker group had positive associations, demonstrating unintentional underreporting due to SHS.

Nicotine and Toxicant Exposure Among Concurrent Users (Co-Users) of Tobacco and Cannabis

BACKGROUND

Smoking cannabis may potentially increase exposure to numerous toxic chemicals that are commonly associated with tobacco use. There is a paucity of data related to toxicant exposures among concurrent users of tobacco and cannabis (co-users).

METHODS

Data are from the Population Assessment of Tobacco and Health Study Wave 1 Biomarker Restricted-Use Files. Analyses focused on adults who provided urine samples (N = 5859). Urine samples were analyzed for biomarkers of exposure to nicotine, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, and volatile organic compounds. Using weighted linear regression, we compared adjusted geometric mean concentrations of 15 biomarkers between user groups of various tobacco product types according to their self-reported past 30-day cannabis use.

RESULTS

Past 30-day cannabis use was similar across various types of tobacco product use subgroups (range: 13%-23%) and significantly more common compared to non-tobacco users (1.0%; p < .001). Across all groups of tobacco users, those who co-used cannabis exhibited significantly higher concentrations of the biomarker of exposure to acrylonitrile (CYMA) compared to non-cannabis users (by 39%-464%). Tobacco-cannabis co-users also showed significantly elevated levels of the biomarker of exposure to acrylamide (AAMA) compared to exclusive tobacco users, and significantly higher exposure to many polycyclic aromatic hydrocarbons (including fluorene and pyrene).

CONCLUSIONS

Co-users exhibited higher concentrations for biomarkers of exposure to many combustion byproducts, compared to exclusive tobacco users. More robust measurements of cannabis use can address potential confounding in assessments of exposures to tobacco-related constituents, and potential health effects resulting from co-use.

IMPLICATIONS

With disproportionately greater rates of cannabis use occurring among tobacco users, it is critical to consider how concurrent cannabis use may influence health-related outcomes among smokers. Our findings suggest potential additive toxicant exposures among co-users of tobacco and cannabis. Lack of consideration and measurement of cannabis use in assessing tobacco-related exposures may confound estimates thought to be attributable to tobacco, particularly for non-specific biomarkers. Assessing tobacco and cannabis use in tandem will allow for more precise measurement of outcomes related to one or both substances, and can provide additional information on potential health effects related to co-use.

Urinary metabolites of furan in waterpipe tobacco smokers compared to non-smokers in home settings in the US

OBJECTIVES

Determine uptake of furan, a potential human carcinogen, in waterpipe tobacco (WPT) smokers in home settings.

METHODS

We analysed data from a US convenience sample of 50 exclusive WPT smokers, mean age 25.3 years, and 25 non-smokers, mean age 25.5 years. For WPT smokers, data were collected at a home visit by research assistants during which participants smoked one WPT head of one brand for a mean of 33.1 min in their homes. Research assistants provided and prepared a WP for participants by weighing and loading 10 g of WPT in the WP head. At the completion of the smoking session, research assistants measured the remaining WPT. Cotinine and six furan metabolites were quantified in first morning urine samples provided on 2 consecutive days for non-smokers, and on the morning of a WPT smoking session and on the following morning for smokers.

RESULTS

WPT smokers consumed a mean of 2.99 g WPT. In WPT smokers, urinary cotinine levels increased significantly 26.1 times the following morning; however, urinary metabolites of furan did not increase significantly. Compared to non-smokers, 2 furan metabolites, N-acetyl-S-[1-(5-acetylamino-5-carboxylpentyl)-1H-pyrrol-3-yl]-L-cysteine and N-acetyl-S-[1-(5-amino-5-carboxypentyl)-1H-pyrrol-3-yl]-L-cysteine sulfoxide, were significantly higher in WPT smokers in pre and in post WPT smoking levels.

CONCLUSIONS

To enable a more rigorous assessment of furan exposure from WPT smoking, future research should determine furan concentrations in WPT smoke, quantify furan metabolites from users of various WPT brands; and extend the investigation to social settings where WPT smoking is habitually practiced.

Biomarkers of Exposure among USA Adult Hookah Users: Results from Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study (2013-2014)

Hookah smoking has become common in the USA, especially among young adults. This study measured biomarkers of exposure to known tobacco product toxicants in a population-based sample of exclusive, established hookah users. Urinary biomarker data from 1753 adults in Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study were used to compare geometric mean concentrations of biomarkers of exposure in exclusive, established past 30-day hookah users to never users of tobacco. Geometric mean ratios were calculated comparing hookah user groups with never users adjusting for age, sex, race/ethnicity, education, past 30-day marijuana use, secondhand smoke exposure and creatinine. Past 30-day hookah users (n = 98) had 10.6 times the urinary cotinine level of never tobacco users. Compared to never tobacco users, past 30-day hookah users had 2.3 times the level of the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 1.3 times higher polycyclic aromatic hydrocarbons (PAHs) 3-hydroxyfluorene and 1-hydroxypyrene, 1.8 times higher levels of acrylonitrile, 1.3 times higher levels of acrylamide, and 1.2 times higher levels of acrolein exposure. These data indicate that hookah use is a significant source of exposure to nicotine, carcinogens, and respiratory toxicants.

Water Pipe (Hookah) Smoking and Cardiovascular Disease Risk: A Scientific Statement From the American Heart Association

Tobacco smoking with a water pipe or hookah is increasing globally. There are millions of water pipe tobacco smokers worldwide, and in the United States, water pipe use is more common among youth and young adults than among adults. The spread of water pipe tobacco smoking has been abetted by the marketing of flavored tobacco, a social media environment that promotes water pipe smoking, and misperceptions about the addictive potential and potential adverse health effects of this form of tobacco use. There is growing evidence that water pipe tobacco smoking affects heart rate, blood pressure regulation, baroreflex sensitivity, tissue oxygenation, and vascular function over the short term. Long-term water pipe use is associated with increased risk of coronary artery disease. Several harmful or potentially harmful substances present in cigarette smoke are also present in water pipe smoke, often at levels exceeding those found in cigarette smoke. Water pipe tobacco smokers have a higher risk of initiation of cigarette smoking than never smokers. Future studies that focus on the long-term adverse health effects of intermittent water pipe tobacco use are critical to strengthen the evidence base and to inform the regulation of water pipe products and use. The objectives of this statement are to describe the design and operation of water pipes and their use patterns, to identify harmful and potentially harmful constituents in water pipe smoke, to document the cardiovascular risks of water pipe use, to review current approaches to water pipe smoking cessation, and to offer guidance to healthcare providers for the identification and treatment of individuals who smoke tobacco using water pipes.

The effects of hookah/waterpipe smoking on general health and the cardiovascular system

Hookah or waterpipe smoking or use is an emerging trend in the US population, especially among the youth. The misperception of hookah being less harmful than cigarettes and the availability of different but "appealing" flavors are considered among the main reasons for this trend. Hookah users however are exposed to many of the same toxic compounds/by-products as cigarette users, but at dramatically higher levels, which might lead to more severe negative health effects. In fact, hookah users are at risks of infections, cancers, lung disease, and other medical conditions. Moreover, because of the overlapping toxicant/chemical profile to conventional cigarettes, hookah smoke effects on the cardiovascular system are thought to be comparable to those of conventional cigarettes. A major source of tobacco addiction is nicotine, whose levels in hookah are extremely variable as they depend on the type of tobacco used. Taken together, in this review of literature, we will provide insights on the negative health effects of hookah in general, with a focus on what is known regarding its impact on the cardiovascular system.

Waterpipe device cleaning practices and disposal of waste associated with waterpipe tobacco smoking in homes in the USA

OBJECTIVES

To quantify postsmoking waterpipe tobacco (WPT) waste and describe postsmoking waterpipe (WP) device cleaning practices and disposal of associated waste in home settings.

METHODS

We analysed data from a US convenience sample of 50 exclusive WPT smokers, mean age 25.3 years. Data were collected at a home visit during which participants smoked one WPT head and completed a self-administered questionnaire on WP cleaning practices and disposal of waste associated with WPT use. Research assistants provided and prepared a WP for participants by weighing and loading 10 g of WPT in the WP head and placing 470 mL of water in the WP bowl. At the completion of the smoking session, research assistants measured the remaining WPT and water. Descriptive analyses were performed.

RESULTS

Of the 10 g of fresh WPT used for each smoking session, 70.1% (mean=7.01 g) was discarded postsmoking as waste; for each 470 mL of water used in the WP bowl, 94.3% (mean=443 mL) was discarded. WP device cleaning practices ranged from never cleaning the device to cleaning it after each smoking session. Respondents reported discarding smoked WPT residue in the trash (81.6%) or the kitchen sink (14.3%) and discarding postsmoking charcoal in the trash (57.6%), the kitchen sink (27.3%) or backyard soil (9.1%). Respondents reported discarding smoked WP water in the kitchen sink (76.5%), bathroom sink (14.7%), toilet (2.9%) and backyard soil (5.9%).

CONCLUSIONS

Interventions and regulations are needed to inform proper WP device cleaning practices and disposal of waste associated with WPT use.

TRIAL REGISTRATION NUMBER

NCT03253653.

Effects of exposure to direct and secondhand hookah and e-cigarette aerosols on ambient air quality and cardiopulmonary health in adults and children: protocol for a panel study

INTRODUCTION

Use of alternative nicotine delivery systems, such as electronic cigarettes and hookahs, has increased dramatically in the USA, but limited research has been conducted on the secondhand effects of these products, especially in children. The objective of this study is to assess the cardiopulmonary effects of e-cigarette and hookah use in vaping and smoking adults, and in non-smoking/non-vaping adults and children exposed to secondhand particles and gases.

METHODS AND ANALYSIS

This study uses a pre/post design, with four groups: two control groups (non-smoking/non-vaping and cigarette smoking) and two test groups (hookah smoking and e-cigarette vaping). Participants will be recruited by household, so that each home includes one smoking or vaping adult and one non-smoking/non-vaping adult and/or child (5-18 years). Non-smoking/non-vaping homes include an adult and child who do not smoke or vape and do not live with individuals who do. Air quality measures will be completed during a household smoking or vaping session (ambient air for non-smoking/non-vaping group), while cardiopulmonary measures and biological samples will be taken directly before and after the smoking/vaping session, and again 24 hours later, for all participants. Air quality measures include carbon monoxide, black carbon, particulate matter, trace elements, nicotine and carbonyls; cardiopulmonary measures include heart rate variability, blood pressure, pulmonary function and exhaled carbon monoxide; biological samples will assess cotinine, inflammatory cytokines and biomarkers in urine, saliva and nasal mucosa.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Board at New York University School of Medicine (s16-02226 and s17-01143). Special attention was given to the inclusion of children, who are likely significantly impacted by the use of these products at home, and thus should be included in research. Results of the study will be distributed at conferences, in peer-reviewed journals and to relevant public health authorities for use in developing policy.

Identification of acrolein metabolites in human buccal cells, blood, and urine after consumption of commercial fried food

SCOPE

Acrolein is a highly electrophilic α,β-unsaturated aldehyde and is associated with human diseases. It is formed by Maillard reaction during food processing and could be detected in the emissions of overheated cooking oils. Consequently, humans are at risk of acrolein exposure through consumption of such prepared food.

METHODS AND RESULTS

We conducted three human studies that healthy subjects (21-30 years) were served fried foods including fried chicken and French fries from three commercial fast food restaurants. Acrolein-related metabolites including urinary 3-hydroxypropyl mercapturic acid (3-HPMA), serum acrolein-protein conjugates (Acr-FDP), and buccal acrolein-induced DNA damages (Acr-dG adducts) along with GSH levels in serum or buccal cells were investigated for different times after consumption.

CONCLUSION

Urinary 3-HPMA levels were increased after 2-hr consumption of fried food with an elimination half-life of 10 hr. In addition, increased Acr-dG adducts in oral cavity were inversely correlated to buccal glutathione (GSH) levels after consumption. However, there was no significant change in systemic GSH levels or Acr-FDP adducts in serum. These results indicate that exposure of acrolein from consuming fried food affects local oral cavity homeostasis. This may provide a possible link between intake of fried food and increased risk of upper aerodigestive tract cancers.

Longitudinal stability in cigarette smokers of urinary biomarkers of exposure to the toxicants acrylonitrile and acrolein

The urinary metabolites cyanoethyl mercapturic acid (CEMA) and 3-hydroxypropyl mercapturic acid (3-HPMA) have been widely used as biomarkers of exposure to acrylonitrile and acrolein, respectively, but there are no published data on their consistency over time in the urine of cigarette smokers. We provided, free of charge over a 20 week period, Spectrum NRC600/601 research cigarettes to cigarette smokers in the control arm of a randomized clinical trial of the reduced nicotine cigarette. Urine samples were collected at weeks 4, 8, 12, 16, and 20 and analyzed for CEMA and 3-HPMA, and total nicotine equivalents (TNE) using validated methods. Creatinine-corrected intra-class correlation coefficients for CEMA, 3-HPMA, and TNE were 0.67, 0.46, and 0.68, respectively, indicating good longitudinal consistency for CEMA, while that of 3-HPMA was fair. A strong correlation between CEMA and TNE values was observed. These data support the use of CEMA as a reliable biomarker of tobacco smoke exposure. This is the first report of the longitudinal stability of the biomarkers of acrylonitrile and acrolein exposure in smokers. The data indicate that CEMA, the biomarker of acrylonitrile exposure, is consistent over time in cigarette smokers, supporting its use. While 3-HPMA levels were less stable over time, this biomarker is nevertheless a useful monitor of human acrolein exposure because of its specificity to this toxicant.

College Student Beliefs and Behavior Regarding Sharing When Smoking Hookahs

Objectives: We examined college students' beliefs and behavior regarding sharing when smoking a hookah, a practice that may involve substantial risk of disease transmission. Methods: We carried out a cross-sectional Web-based survey of undergraduate ever users of hookah (N = 970) at a US university in 2007. Results: Hookah sharing started at initiation of hookah use. The first-time participants smoked hookah, 96.9% shared it, and 97.5% were with friends either in a hookah lounge (59.5%) or at a friend's home (30%). Participants shared a hookah when they first smoked it because sharing was acceptable with friends, family, or trusted others, normative etiquette, not problematic/harmful, cheaper, or the only smoking option. Participants did not use a mouth tip when they first smoked a hookah because it is not necessary with friends/family, there was no tip available, they were unaware of tips, or did not want to use one. Conclusions: Overwhelmingly, hookah sharing started at smoking initiation. Efforts are needed to create an environment in which sharing hookah practices are less acceptable such as increasing awareness of potential health risks of sharing, particularly among youth, and providing disposable hoses, disposable mouth tips, and proper hookah device cleaning practices in private and public hookah venues settings.

Biomarkers of Exposure to Secondhand and Thirdhand Tobacco Smoke: Recent Advances and Future Perspectives

Smoking is the leading preventable disease worldwide and passive smoking is estimated to be the cause of about 1.0% of worldwide mortality. The determination of tobacco smoke biomarkers in human biological matrices is key to assess the health effects related to the exposure to environmental tobacco smoke. The biomonitoring of cotinine, the main nicotine metabolite, in human biofluids-including urine, serum or saliva-has been extensively used to assess this exposure. However, the simultaneous determination of cotinine together with other tobacco biomarkers and the selection of alternative biological matrices, such as hair, skin or exhaled breath, would enable a better characterization of the kind and extent of tobacco exposure. This review aims to perform a critical analysis of the up-to-date literature focused on the simultaneous determination of multiple tobacco smoke biomarkers studied in different biological matrices, due to the exposure to secondhand smoke (SHS) and thirdhand smoke (THS). Target biomarkers included both tobacco-specific biomarkers-nicotine and tobacco specific nitrosamine biomarkers-and tobacco-related biomarkers, such as those from polycyclic aromatic hydrocarbons, volatile organic compounds, metals and carbon monoxide. To conclude, we discuss the suitability of determining multiple biomarkers through several relevant examples of SHS and THS exposure.

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

Tobacco smoking and exposure to tobacco secondhand smoke (SHS) can cause lung cancer. We determined uptake of NNK (4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone), a tobacco specific potent pulmonary carcinogen, in hookah smokers and non-smokers exposed to hookah tobacco SHS. We analyzed data from a community-based convenience sample of 201 of adult (aged ≥18 years) exclusive hookah smokers (n = 99) and non-smokers (n = 102) residing in San Diego County, California. Participants spent an average of three consecutive hours indoors, in hookah lounges or private homes, where hookah tobacco was smoked exclusively. Total NNAL [the sum of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides], the major metabolites of NNK, were quantified in spot urine samples provided the morning of and the morning after attending a hookah event. Among hookah smokers urinary NNAL increased significantly (p<0.001) following a hookah social event; the geometric mean doubled, from 1.97 to 4.16 pg/mg. Among non-smokers the increase was not significant (p = 0.059). Post hookah event urinary NNAL levels were highest in daily hookah smokers, and significantly higher than in non-daily smokers or non-smokers (GM: 14.96 pg/mg vs. 3.13 pg/mg and 0.67 pg/mg, respectively). For both hookah smokers and non-smokers, pre-to-post event change in urinary NNAL was not significantly different between hookah lounges and homes. We suggest posting health warning signs inside hookah lounges, and encouraging voluntary bans of smoking hookah tobacco in private homes.