A study on particles and some microbial markers in waterpipe tobacco smoke

Impact of waterpipe smoking on the salivary microbiome

Background

While oral mirobial dysbiosis due to tobacco smoking has been studied thoroughly, there is limited data on the effect of waterpipe smoking on the oral microbiome. This study aims to compare the salivary microbiome between waterpipe smokers and non-smokers.

Materials and methods

Unstimulated saliva samples were collected from 60 participants, 30 smokers and 30 non-smokers in Kuala Lumpur and Klang Valley, Malaysia. DNA extraction was performed using the Qiagen DNA mini kit, and the 16S rRNA bacterial gene was amplified and sequenced using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and the alpha and beta diversity of the bacterial community was assessed. Significantly differentiated taxa were identified using LEfSe analysis, while differentially expressed pathways were identified using MaAsLin2.

Results

A significant compositional change (beta diversity) was detected between the two groups (PERMANOVA P < 0.05). Specifically, the levels of phylum Firmicutes and genus Streptococcus were elevated in smokers, whereas phylum Proteobacteria and genus Haemophilus were depleted compared to non-smokers. At the species level, Streptococcus oralis, Streptococcus salivarius, and Streptococcus gingivalis were enriched in smokers. We observed significant differences in the abundance of thirty-seven microbial metabolic pathways between waterpipe smokers and non-smokers. The microbial pathways enriched in smokers were those implicated in polymer degradation and amino acid metabolism.

Conclusion

The taxonomic and metabolic profile of the salivary microbiome in waterpipe smokers compared to healthy controls exhibited a paradigm shift, thus, implying an alteration in the homeostatic balance of the oral cavity posing unique challenges for oral health.

Potential chemopreventive effects of Broccoli extract supplementation against 7, 12 dimethyl Benz(a)anthracene (DMBA) -induced toxicity in female rats

Dietary components have recently received rapidly expanding attention for their potential to halt or reverse the development of many oxidative stress-mediated diseases after exposure to environmental toxicants. 7, 12 dimethylbenz(a)anthracene (DMBA) is one of the most common environmental pollutants. The present study aimed to evaluate the chemo-preventive effects of broccoli as a nutritional component against DMBA intoxication in rats. A daily dose of aqueous (1 ml/rat) and methanolic (150 mg/kg) broccoli extracts, respectively, was given to 50-day-old female rats for 26 successive weeks after carcinogen intoxication with a single dose of 20 mg/ml of DMBA. DMBA intoxication resulted in a redox imbalance (a decreased GSH level and an increased MDA level) and increased DNA fragmentation in the liver, kidney, and brain. Besides, it affected the level of expression of the bcl2 gene in the liver, kidney, and brain tissue but didn't affect cfos gene expression accompanied by histopathological changes. The aqueous and methanolic broccoli extract supplements ameliorated the adverse effects by increasing the level of GSH, decreasing the MDA level, and reducing DNA fragmentation. Besides, broccoli extracts decreased the expression of bcl2 in the liver and brain and up-regulated bcl2 expression in the kidney, accompanied by lowering NF-κβ 65 expression in the liver and brain and γ-catenin expression in the liver and kidney. In conclusion, broccoli as a dietary component had a strong chemoprotective effect against oxidative stress, DNA damage, and genotoxicity induced by DMBA intoxication in rats.

The Role of Smoking in the Mechanisms of Development of Chronic Obstructive Pulmonary Disease and Atherosclerosis

Tobacco smoking is a major cause of chronic obstructive pulmonary disease (COPD) and atherosclerotic cardiovascular disease (ASCVD). These diseases share common pathogenesis and significantly influence each other's clinical presentation and prognosis. There is increasing evidence that the mechanisms underlying the comorbidity of COPD and ASCVD are complex and multifactorial. Smoking-induced systemic inflammation, impaired endothelial function and oxidative stress may contribute to the development and progression of both diseases. The components present in tobacco smoke can have adverse effects on various cellular functions, including macrophages and endothelial cells. Smoking may also affect the innate immune system, impair apoptosis, and promote oxidative stress in the respiratory and vascular systems. The purpose of this review is to discuss the importance of smoking in the mechanisms underlying the comorbid course of COPD and ASCVD.

Indoor Exposure and Regional Inhaled Deposited Dose Rate during Smoking and Incense Stick Burning-The Jordanian Case as an Example for Eastern Mediterranean Conditions

Tobacco smoking and incense burning are commonly used in Jordanian microenvironments. While smoking in Jordan is prohibited inside closed spaces, incense burning remains uncontrolled. In this study, particle size distributions (diameter 0.01-25 µm) were measured and inhaled deposited dose rates were calculated during typical smoking and incense stick-burning scenarios inside a closed room, and the exposure was summarized in terms of number and mass concentrations of submicron (PN_Sub) and fine particles (PM_2.5). During cigarette smoking and incense stick-burning scenarios, the particle number concentrations exceeded 3 × 10⁵ cm^-3. They exceeded 5 × 10⁵ cm^-3 during shisha smoking. The emission rates were 1.9 × 10¹⁰, 6.8 × 10¹⁰, and 1.7 × 10¹⁰ particles/s, respectively, for incense, cigarettes, and shisha. That corresponded to about 7, 80, and 120 µg/s, respectively. Males received higher dose rates than females, with about 75% and 55% in the pulmonary/alveolar during walking and standing, respectively. The total dose rates were in the order of 10¹²-10¹³ #/h (10³-10⁴ µg/h), respectively, for PN_Sub and PM_2.5. The above reported concentrations, emissions rates, and dose rates are considered seriously high, recalling the fact that aerosols emitted during such scenarios consist of a vast range of toxicant compounds.

Inflammatory signaling on cytochrome P450-mediated drug metabolism in hepatocytes

Cytochrome P450 (CYP450) enzymes are membrane-bound blood proteins that are vital to drug detoxification, cell metabolism, and homeostasis. CYP450s belonging to CYP families 1-3 are responsible for nearly 80% of oxidative metabolism and complete elimination of approximately 50% of all common clinical drugs in humans liver hepatocytes. CYP450s can affect the body's response to drugs by altering the reaction, safety, bioavailability, and toxicity. They can also regulate metabolic organs and the body's local action sites to produce drug resistance through altered drug metabolism. Genetic polymorphisms in the CYP gene alone do not explain ethnic and individual differences in drug efficacy in the context of complex diseases. The purpose of this review is to summarize the impact of new inflammatory-response signaling pathways on the activity and expression of CYP drug-metabolizing enzymes. Included is a summary of recent studies that have identified drugs with the potential to regulate drug-metabolizing enzyme activity. Our goal is to inspire the development of clinical drug treatment processes that consider the impact of the inflammatory environment on drug treatment, as well as provide research targets for those studying drug metabolism.

Bacterial communities of hookah tobacco products are diverse and differ across brands and flavors

Abstract

Young adults are increasingly using non-cigarette products, such as hookahs, since they are perceived as healthier alternatives to cigarette smoking. However, hookah users are exposed to not only carcinogenic compounds but also microorganisms that may play an active role in the development of both infectious and chronic diseases among users. Nevertheless, existing hookah research in this area has focused only on microorganisms that may be transferred to users through the smoking apparatus and not on bacterial communities associated with hookah tobacco. To address this knowledge gap, we conducted time-series experiments on commercially available hookah brands (Al Fakher (flavors: two apple, mint, and watermelon) and Fumari (flavors: white gummy bear, ambrosia, and mint chocolate chill)) stored under three different temperature and relative humidity conditions over 14 days. To characterize bacterial communities, the total DNA was extracted on days 0, 5, 9, and 14, PCR-amplified for the V3V4 region of the bacterial 16S rRNA gene, sequenced on the Illumina HiSeq platform, and analyzed using R. Diversity (alpha and beta) analyses revealed that the microbiotas of Fumari and Al Fakher products differed significantly and that flavor had a significant effect on the hookah microbiota. Overall, Pseudomonas, Bacillus, Sphingomonas, and Methylobacterium were the predominant bacterial taxa across all products. Additionally, we observed compositional differences between hookah brands across the 14-day incubation. These data suggest that the bacterial communities of hookah tobacco are diverse and differ across brands and flavors, which may have critical implications regarding exposures to specific bacteria among hookah users.

Key points

• Commercial hookah products harbor diverse bacterial communities.

• Brands and flavors impact the diversity of these communities.

• Research on their viability and transmission to users’ respiratory tracts is needed.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-12079-7.

Detoxification of phenanthrene in Arabidopsis thaliana involves a Dioxygenase For Auxin Oxidation 1 (AtDAO1)

Polycyclic aromatic hydrocarbon (PAH) contamination has a negative impact on ecosystems. PAHs are a large group of toxins with two or more benzene rings that are persistent in the environment. Some PAHs can be cytotoxic, teratogenic, and/or carcinogenic. In the bacterium Pseudomonas, PAHs can be modified by dioxygenases, which increase the reactivity of PAHs. We hypothesize that some plant dioxygenases are capable of PAH biodegradation. Herein, we investigate the involvement of Arabidopsis thaliana At1g14130 in the degradation of phenanthrene, our model PAH. The At1g14130 gene encodes Dioxygenase For Auxin Oxidation 1 (AtDAO1), an enzyme involved in the oxidative inactivation of the hormone auxin. Expression analysis using a β-glucuronidase (GUS) reporter revealed that At1g14130 is prominently expressed in new leaves of plants exposed to media with phenanthrene. Analysis of the oxidative state of gain-of-function mutants showed elevated levels of H₂O₂ after phenanthrene treatments, probably due to an increase in the oxidation of phenanthrene by AtDAO1. Biochemical assays with purified AtDAO1 and phenanthrene suggest an enzymatic activity towards the PAH. Thus, data presented in this study support the hypothesis that an auxin dioxygenase, AtDAO1, from Arabidopsis thaliana contributes to the degradation of phenanthrene and that there is possible toxic metabolite accumulation after PAH exposure.

Effect of hookah (water pipe) smoking on semen parameters

Hookah (water pipe) smoking, an old method of tobacco smoking, is regaining widespread popularity all over the world. Although the research in this field is still deficient, it has been proven for its harmful effect on human's health by increasing the risk of cardiovascular disease, infection and lung, oral and bladder cancer (Al-Numair et al., J Food Agric Environ, 5: 17, 2007; Bou Fakhreddine et al., Respir Med, 108: 1241-1253, 2014; Chaouachi, J Negat Results Biomed, 5: 17, 2006). However, no research was found to address its effect on human fertility or reproductive outcome. In this cross-sectional study, we aim to explore the effect of smoking hookah on human semen parameters among men attending In Vitro Fertilization LABs for seminal fluid analysis testing. 104 patients aged between 25 and 45, who are noncigarette smokers and have no chronic medical illness, were enrolled in the study: 50 hookah nonsmokers and 54 hookah smokers. Their semen parameters were compared. Semen volume, normal morphology and progressive motility were slightly lower in the hookah smoker (3.21 ml; 10.2%; 29.56%) versus (3.45 ml; 11.5%; 33.20%), respectively, in nonhookah smokers; however, the difference was not statistically significant. The effect of hookah smoking on semen observed in our study was not statistically significant. Further studies are needed to explore more and confirm any unfavourable effect.

Smoking Water-Pipe, Opium Use and Prevalence of Heart Disease: A Cross-sectional Analysis of Baseline Data from the Pars Cohort Study, Southern Iran

BACKGROUND

Associations between hookah and opium use and an increased risk of ischemic heart disease (IHD) have been suggested in a few studies, but more research is needed on the nature of these associations. We aimed to investigate the association between hookah and opium use and the prevalence of IHD in a population with relatively high prevalence of these exposures in Iran.

METHODS

Using baseline data from the Pars Cohort Study (PCS), a prospective study of individuals aged 40-75 years in Fars province, southern Iran, we calculated adjusted and crude odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the independent association of hookah and opium use with prevalence of IHD.

RESULTS

Of 9248 participants, 10.2% (95% CI: 9.5, 10.9) had self-reported IHD. Prevalence of ever use of hookah and opium was 48.9% (95% CI: 44.6, 53.6) and 10.2% (95% CI: 8.3, 12.5) among those with IHD, and 37.0% (95% CI: 35.7, 38.3) and 8.1% (95% CI: 7.5, 8.7) among those without IHD, respectively. Adjusted OR for the association with prevalence of IHD was 1.26 (95% CI: 1.08, 1.46) for hookah use and 1.71 (95% CI: 1.30, 2.24) for opium abuse. No dose-response association was found between hookah and prevalence of IHD.

CONCLUSION

Hookah and opium abuse were associated with prevalent IHD in this study. Although more research is needed on these associations, particularly in prospective settings, reducing hookah and opium use could potentially reduce IHD risk.

Waterpipe Tobacco Chemical Content, Microbial Contamination, and Genotoxic Effects: A Systematic Review

The spread of tobacco smoking has increased over time at the global and national levels. One of the widely spread tobacco products is waterpipe. Recent studies showed that waterpipe tobacco smoke contains toxic substances, including carbon monoxide and nicotine. Some of them are genotoxic carcinogen, such as formaldehyde. This study aims to provide comprehensive insight into the types and depth of the scientific literature on waterpipe tobacco smoke chemical content, its genotoxic effects, and waterpipe device microbial contamination. We conducted a systematic comprehensive review of articles published between 1986 and December 2018. Primary research articles focusing on the content of waterpipe smoke, including chemical, genotoxic, and microbial contaminants, were eligible for inclusion. Of the 1,286 studies generated, 22 studies were included. Twenty-three chemical families were extracted from waterpipe smoke. Aldehydes were the most identified chemical family in 6 studies, and next is polycyclic hydrocarbons, found in 5 studies. About 206 chemical compounds were identified. Flavobacterium, Pseudomonas, coagulase-negative Staphylococci, and Streptococcus were the most abundant pathogen contaminants. Waterpipe smoke had elevated levels of many DNA damage markers (8-hydroxy-2′-deoxyguanosine and cytochrome P450 1A1) and inhibited levels of many DNA repair genes ( OGG1 and XRCC1) in waterpipe smokers. Waterpipe smoke is associated with the genotoxic effect, which elevates the levels of many DNA damage markers and inhibits the levels of many DNA repair genes. In addition, waterpipe smoking can expose smokers to a range of pathogenic bacteria.

Indoor Particle Concentrations, Size Distributions, and Exposures in Middle Eastern Microenvironments

There is limited research on indoor air quality in the Middle East. In this study, concentrations and size distributions of indoor particles were measured in eight Jordanian dwellings during the winter and summer. Supplemental measurements of selected gaseous pollutants were also conducted. Indoor cooking, heating via the combustion of natural gas and kerosene, and tobacco/shisha smoking were associated with significant increases in the concentrations of ultrafine, fine, and coarse particles. Particle number (PN) and particle mass (PM) size distributions varied with the different indoor emission sources and among the eight dwellings. Natural gas cooking and natural gas or kerosene heaters were associated with PN concentrations on the order of 100,000 to 400,000 cm−3 and PM2.5 concentrations often in the range of 10 to 150 µg/m3. Tobacco and shisha (waterpipe or hookah) smoking, the latter of which is common in Jordan, were found to be strong emitters of indoor ultrafine and fine particles in the dwellings. Non-combustion cooking activities emitted comparably less PN and PM2.5. Indoor cooking and combustion processes were also found to increase concentrations of carbon monoxide, nitrogen dioxide, and volatile organic compounds. In general, concentrations of indoor particles were lower during the summer compared to the winter. In the absence of indoor activities, indoor PN and PM2.5 concentrations were generally below 10,000 cm−3 and 30 µg/m3, respectively. Collectively, the results suggest that Jordanian indoor environments can be heavily polluted when compared to the surrounding outdoor atmosphere primarily due to the ubiquity of indoor combustion associated with cooking, heating, and smoking.

Contributions of charcoal, tobacco, and syrup to the toxicity and particle distribution of waterpipe tobacco smoke

The use of waterpipes in the United States is increasing in a largely unregulated market. The shisha smoked in a waterpipe is a complex matrix of tobacco, flavorings, and humectant with smoke generated by an external heat source. This study explored the relationship between shisha components and the particulate matter size distributions and toxicity of smoke generated with heating. Standard waterpipe puff topography of charcoal- or electronic- heated whole shisha and shisha components generated smoke particulate matter that was characterized using a TSI Engine Exhaust Particle Sizer. Relative toxicity of the whole smoke was determined via measurement of lysosomal integrity and measures of membrane integrity following acute exposure of type II alveolar cells at the air-liquid interface. All waterpipe aerosols exhibited a unimodal particle size distribution, the peak and concentration of which varied depending upon the shisha components present. Acute exposure to charcoal-heated whole shisha, flavoring syrup, or humectant smoke, or electronic-heated whole shisha smoke caused significant alveolar cell damage and death, indicating neither tobacco nor charcoal are needed for these cytotoxic effects to occur.

Bioaerosols in the waterpipe cafés: genera, levels, and factors influencing their concentrations

This study was conducted in order to assess the exposure to bacterial and fungal bioaerosols in the air of waterpipe cafés (AWPCs), in the hose of waterpipe (HWP), and in the water bowl of the waterpipe (WBWP) and to investigate the factors influence increasing the contamination levels in waterpipe cafés in Ardabil. From all the 50 cafés studied, the samples were taken from air and from water contained in water bowl and hose for bacterial and fungal analyses. The results demonstrated that the mean numbers of bacteria and fungi in the indoor air of café, hose, and water bowl were 33.90 ± 14.86 and 25.24 ± 1.99 CFU/m³, 72.16 ± 29.55 and 72.78 ± 42.45 CFU/plate, 53.7 ± 25.46 and 25.26 ± 13.94 CFU/ml, respectively. The predominant bacterial genera in waterpipe cafés were Pseudomonas and Bacillus in air, Staphylococcus and Pseudomonas in the hose, and Staphylococcus and Pseudomonas in the water bowl, respectively. The predominant fungal species in waterpipe cafés were Penicillium and Cladosporium in air, yeast and Fusarium in the hose, and Paecilomyces and yeast in the water bowl, respectively. The results of statistical analysis showed that there was a significant relationship between the mean concentrations of bacterial aerosol and qualitative variables such as type of heating system, materials of wall and ceiling, traditional restaurants, interior supermarkets, moisturized walls, the number of people, area of cafés, and temperature. But there was no significant relationship between these variables and the mean concentration of fungal aerosols. The results also showed that the levels of bioaerosols were high in the air, hose, and water bowl of the waterpipe. Therefore, cafés can be a potential source for the transmission of pathogenic agents and increase the risk of respiratory diseases among waterpipe smoking individuals.

Toxicant inhalation among singleton waterpipe tobacco users in natural settings

BACKGROUND

Studies that assess waterpipe tobacco smoking behaviour and toxicant exposure generally use controlled laboratory environments with small samples that may not fully capture real-world variability in human behaviour and waterpipe products. This study aimed to conduct real-time sampling of waterpipe tobacco use in natural environments using an in situ device.

METHODS

We used the REALTIME sampling instrument: a validated, portable, self-powered device designed to sample automatically a fixed percentage of the aerosol flowing through the waterpipe mouthpiece during every puff. We recruited participants at café and home settings in Jordan and measured puffing behaviour in addition to inhalation exposure of total particulate matter (TPM), carbon monoxide (CO), nicotine, polycyclic aromatic hydrocarbons and volatile aldehydes. We correlated total inhaled volume with five selected toxicants and calculated the regression line of this relationship.

RESULTS

Averaged across 79 singleton sessions (52% male, mean age 27.0, 95% home sessions), sessions lasted 46.9 min and participants drew 290 puffs and inhaled 214 L per session. Mean quantities of inhaled toxicants per session were 1910 mg TPM, 259 mg CO, 5.0 mg nicotine, 117 ng benzo[a]pyrene and 198 ng formaldehyde. We found positive correlations between total inhaled volume and TPM (r=0.472; p<0.001), CO (r=0.751; p<0.001), nicotine (r=0.301, p=0.035) and formaldehyde (r=0.526; p<0.001), but a non-significant correlation for benzo[a]pyrene (r=0.289; p=0.056).

CONCLUSIONS

In the natural environment, waterpipe tobacco users inhale large quantities of toxicants that induce tobacco-related disease, including cancer. Toxicant content per waterpipe session is at least equal, but for many toxicants several magnitudes of order higher, than that of a cigarette. Health warnings based on early controlled laboratory studies were well founded; if anything our findings suggest a greater exposure risk.

Waterpipe smoking and risk of coronary artery disease

PURPOSE OF REVIEW

Smoking tobacco using a water pipe is becoming more prevalent globally, particularly amongst younger populations. In addition to its growing popularity, more evidence is emerging regarding associated harm, and several misconceptions exist concerning the likely adverse health effects of waterpipe smoking (WPS). It is timely, therefore, to examine the body of evidence linking WPS to coronary artery disease (CAD). Here, we review the direct evidence linking WPS to CAD and examine additional, indirect evidence of associated harm. We discuss the clinical and public health implications of the current evidence and provide suggestions for further research.

RECENT FINDINGS

A multicentre case-control study in Lebanon has recently demonstrated an association between WPS and CAD. There are few prior studies making this direct link. However, a large body of evidence has emerged showing close similarities between WPS and cigarette smoking with regard to the toxicity of smoke and acute inflammatory and haemodynamic effects following exposure to it.

SUMMARY

There are consistent similarities between WPS and cigarette smoking in regard to association with CAD, the nature of the smoke produced, and the acute haemodynamic effects and inflammatory responses that follow exposure. These findings justify both public health and clinical interventions to reduce WPS. Further studies are warranted to confirm a causal association between WPS and CAD.

BTEX in indoor air of waterpipe cafés: Levels and factors influencing their concentrations

BTEX (benzene, toluene, ethylbenzene and xylene) concentrations, factors affecting their levels, and the exposure risks related to these compounds were studied in waterpipe (Ghalyun/Hookah) cafés of Ardabil city in Islamic Republic of Iran. 81 waterpipe cafés from different districts of Ardabil city were selected and their ambient air was monitored for BTEX compounds. Air samples were taken from standing breathing zone of employees, ~150 cm above the ground level, and were analyzed using GC-FID. In each case, the types of smoked tobacco (regular, fruit flavored), types of ventilation systems (natural/artificial), and the floor level at which the café was located were investigated. A high mean concentration of 4.96±2.63 mg/m(3) corresponding to long term exposure to benzene-related cancer risk of 4314×10(-6) was estimated. The levels of the remaining compounds were lower than the national guideline limits, but their hazard quotients (HQ) for long term exposure to ethylbenzene (1.15) and xylene (17.32) exceeded the HQ unit value. Total hazard indices (HI) of 63.23 were obtained for non-cancer risks. Type of the smoked tobacco was the most important factor influencing BTEX concentrations in the cafés. BTEX concentrations in indoor ambient air of Ardabil waterpipe cafés were noticeably high, and therefore may pose important risks for human health on both short and long term exposures.

Identification, characterization and antibiotic resistance of bacterial isolates obtained from waterpipe device hoses

The general lack of knowledge about the health effects of waterpipe smoking is among the reasons for its global spread. In this study, bacterial contamination of waterpipe hoses was investigated. Twenty hoses were collected from waterpipe cafés and screened for bacterial pathogens using standard culture and isolation techniques. Additionally, resistance of isolated bacteria to common antibiotics was determined by identifying the minimum inhibitory concentration (MIC) of each isolate. Forty eight bacterial isolates were detected. Isolates included both Gram-positive and Gram-negative pathogens from species that included Micrococcus (12), Corynebacterium (13) and Bacillus (9). In addition, some of the detected pathogens were found to be resistant to aztreonam (79%), cefixime (79%), norfloxacin, amoxicillin (47%), clarithromycin (46%) and enrofloxacin (38%). In conclusion, the hose of the waterpipe device is a good environment for the growth of bacterial pathogens, which can then be transmitted to users.

Waterpipe tobacco smoking: what is the evidence that it supports nicotine/tobacco dependence?

OBJECTIVE

Waterpipe tobacco smoking (WTS) involves passing tobacco smoke through water prior to inhalation, and has spread worldwide. This spread becomes a public health concern if it is associated with tobacco-caused disease and if WTS supports tobacco/nicotine dependence. A growing literature demonstrates that WTS is associated with disability, disease and death. This narrative review examines if WTS supports nicotine/tobacco dependence, and is intended to help guide tobacco control efforts worldwide.

DATA SOURCES

PUBMED search using: (("waterpipe" or "narghile" or "arghile" or "shisha" or "goza" or "narkeela" or "hookah" or "hubble bubble")) AND ("dependence" or "addiction").

STUDY SELECTION

Excluded were articles not in English, without original data, and that were not topic-related. Thirty-two articles were included with others identified by inspecting reference lists and other sources.

DATA SYNTHESIS

WTS and the delivery of the dependence-producing drug nicotine were examined, and then the extent to which the articles addressed WTS-induced nicotine/dependence explicitly, as well as implicitly with reference to criteria for dependence outlined by the WHO.

CONCLUSIONS

WTS supports nicotine/tobacco dependence because it is associated with nicotine delivery, and because some smokers experience withdrawal when they abstain from waterpipe, alter their behaviour in order to access a waterpipe and have difficulty quitting, even when motivated to do so. There is a strong need to support research investigating measurement of WTS-induced tobacco dependence, to inform the public of the risks of WTS, which include dependence, disability, disease and death, and to include WTS in the same public health policies that address tobacco cigarettes.

Toxicant content, physical properties and biological activity of waterpipe tobacco smoke and its tobacco-free alternatives

OBJECTIVES

Waterpipe smoking using sweetened, flavoured tobacco products has become a widespread global phenomenon. In this paper, we review chemical, physical and biological properties of waterpipe smoke.

DATA SOURCES

Peer-reviewed publications indexed in major databases between 1991 and 2014. Search keywords included a combination of: waterpipe, narghile, hookah, shisha along with names of chemical compounds and classes of compounds, in addition to terms commonly used in cellular biology and aerosol sizing.

STUDY SELECTION

The search was limited to articles published in English which reported novel data on waterpipe tobacco smoke (WTS) toxicant content, biological activity or particle size and which met various criteria for analytical rigour including: method specificity and selectivity, precision, accuracy and recovery, linearity, range, and stability.

DATA EXTRACTION

Multiple researchers reviewed the reports and collectively agreed on which data were pertinent for inclusion.

DATA SYNTHESIS

Waterpipe smoke contains significant concentrations of toxicants thought to cause dependence, heart disease, lung disease and cancer in cigarette smokers, and includes 27 known or suspected carcinogens. Waterpipe smoke is a respirable aerosol that induces cellular responses associated with pulmonary and arterial diseases. Except nicotine, smoke generated using tobacco-free preparations marketed for 'health conscious' users contains the same or greater doses of toxicants, with the same cellular effects as conventional products. Toxicant yield data from the analytical laboratory are consistent with studies of exposure biomarkers in waterpipe users.

CONCLUSIONS

A sufficient evidence base exists to support public health interventions that highlight the fact that WTS presents a serious inhalation hazard.

A review of air quality, biological indicators and health effects of second-hand waterpipe smoke exposure

Objective

There has been a rapid increase in the use of waterpipe tobacco and non-tobacco based shisha in many countries. Understanding the impact and effects of second-hand smoke (SHS) from cigarette was a crucial factor in reducing cigarette use, leading to clean indoor air laws and smoking bans. This article reviews what is known about the effects of SHS exposure from waterpipes.

Data sources

We used PubMed and EMBASE to review the literature. Articles were grouped into quantitative measures of air quality and biological markers, health effects, exposure across different settings, different types of shisha and use in different countries.

Study selection

Criteria for study selection were based on the key words related to SHS: waterpipe, hookah, shisha and third-hand smoke.

Data extraction

Independent extraction with two reviewers was performed with inclusion criteria applied to articles on SHS and waterpipe/hookah/shisha. We excluded articles related to pregnancy or prenatal exposure to SHS, animal studies, and non-specific source of exposure as well as articles not written in English.

Data synthesis

A primary literature search yielded 54 articles, of which only 11 were included based on relevance to SHS from a waterpipe/hookah/shisha.

Conclusions

The negative health consequences of second-hand waterpipe exposure have major implications for clean indoor air laws and for occupational safety. There exists an urgent need for public health campaigns about the effects on children and household members from smoking waterpipe at home, and for further development and implementation of regulations to protect the health of the public from this rapidly emerging threat.