Tobacco-specific nitrosamines in new tobacco products

Cell signaling and epigenetic regulation of nicotine-induced carcinogenesis

Nicotine, a naturally occurring tobacco alkaloid responsible for tobacco addiction, has long been considered non-carcinogenic. However, emerging evidence suggests that nicotine may possess carcinogenic properties in mice and could be a potential carcinogen in humans. This review aims to summarize the potential molecular mechanisms underlying nicotine-induced carcinogenesis, with a specific focus on epigenetic regulation and the activation of nicotinic acetylcholine receptors (nAChRs) in addition to genotoxicity and excess reactive oxygen species (ROS). Additionally, we explore a novel hypothesis regarding nicotine's carcinogenicity involving the downregulation of stem-loop binding protein (SLBP), a critical regulator of canonical histone mRNA, and the polyadenylation of canonical histone mRNA. By shedding light on these mechanisms, this review underscores the need for further research to elucidate the carcinogenic potential of nicotine and its implications for human health.

Levels of nicotine and tobacco-specific nitrosamines in oral nicotine pouches

BACKGROUND

Nicotine pouches without tobacco are new products that deliver nicotine into the body via the oral mucosa. There is a lack of independent research on the chemical composition and product characteristics of these products, contributing to uncertainties regarding product regulation. This study sought to address knowledge gaps by assessing levels of nicotine and screening for tobacco-specific nitrosamines (TSNAs) in a sample of these products.

METHODS

Nicotine pouches (n=44) and nicotine-free pouches (n=2) from 20 different manufacturers were analysed regarding their contents of nicotine and TSNAs by gas chromatography with flame ionisation and liquid chromatography-tandem mass spectrometry, respectively. Product labelling and pH values of aqueous extracts were determined.

RESULTS

Nicotine contents of products ranged from 1.79 to 47.5 mg/pouch; median product weight, pH, and proportion of free-base nicotine were 0.643 g, 8.8, and 86%, respectively. A clear labelling of the nicotine content was missing on 29 products and nicotine strength descriptions were ambiguous. TSNAs were detected in 26 products, with a maximum of 13 ng N-nitrosonornicotine/pouch.

CONCLUSION

Although nicotine pouches may potentially be a reduced risk alternative for cigarette smokers or users of some other oral tobacco products, nicotine contents of some pouches were alarmingly high. Presence of carcinogenic TSNAs in the nicotine pouches is of serious concern. Better manufacturing processes and quality control standards should be implemented. Labels of nicotine strength on most products are misleading. A strict regulation regarding nicotine contents and its labelling would be advisable.

Quantitative measurement of harmful and potentially harmful constituents, pH, and moisture content in 16 commercial smokeless tobacco products

Smokeless tobacco products expose adult and youth tobacco users to various addictive and carcinogenic constituents that can cause long-term nicotine dependence and oral cancers. In this study, nicotine, benzo[a]pyrene (B[a]P), N'-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), acetaldehyde, crotonaldehyde, formaldehyde, moisture, and pH levels in 16 smokeless tobacco products were measured on a wet-weight basis (wwb). In addition, change in analytical variability with increasing replicate measurements was assessed. Total nicotine in the products varied from 6.2 to 35.5 mg/g. The percentage of total nicotine in the unprotonated form ranged from 0.1 to 62%; whereas, product moisture varied from 7.4 to 57%. The quantities of harmful and potentially harmful constituents (HPHCs) range from 0.46 to 179.9 ng/g for B [a]P, 270-12206 and 81-20716 ng/g for NNN and NNK, respectively, and 0.33-6.85 and 0.13-5.67 μg/g for acetaldehyde and formaldehyde, respectively. This study shows wide variation in smokeless tobacco product HPHC quantities. The results also show that analytical variability stabilizes after seven replicate measurements.

Assessment of the Exposure to Tobacco-Specific Nitrosamines and Minor Tobacco Alkaloids in Users of Various Tobacco/Nicotine Products

Tobacco-specific nitrosamines (TSNAs), in particular, the human carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN), are important toxicants in tobacco and also (as contaminants) in nicotine products. In a clinical study comprising a period of 74 h under confinement, we investigated the exposure to NNK, NNN, N'-nitrosoanabasine (NAB), and N'-nitrosoanatabine (NAT) as well as to the minor tobacco alkaloids anabasine (AB) and anatabine (AT) by measuring suitable biomarkers in habitual users of combustible cigarettes (CCs), electronic cigarettes (ECs), heated tobacco products (HTPs), oral tobacco (OT), and nicotine replacement therapy products (NRTs). Non-users (NU) of any tobacco/nicotine products served as the (negative) control group. Smokers exhibited the highest levels for all biomarkers measured, except for AB in urine, which was found to be highest in OT users. Somewhat elevated levels compared to NU, EC, and NRT groups were also observed in the users of HTPs. In the users of tobacco-containing products (CC, HTP, and OT), most frequently the biomarkers significantly correlated with the dose markers such as daily consumption, urinary nicotine equivalents (Nequ), and plasma cotinine (CotP). In conclusion, except for smokers (CC) and OT users, exposure of users of ECs, HTPs, and NRTs to TSNAs as well as the minor tobacco alkaloids AB and AT is marginal and statistically not distinguishable from that of NU. Finally, our results for NNN in the saliva provide preliminary evidence for the formation of NNN from the precursor nornicotine in the presence of thiocyanate as a catalyst. The latter hypothesis requires experimental verification.

The Relationship Between Trauma Exposure and Adult Tobacco Use: Analysis of the National Epidemiologic Survey on Alcohol and Related Conditions (III)

INTRODUCTION

Previous research has examined cigarette smoking in trauma exposed populations. However, the relationships between trauma exposure and use of other tobacco products (eg, cigars, e-cigarettes) and specific trauma exposure characteristics that may be associated with tobacco use are understudied.

AIMS AND METHODS

Using the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions-III (N = 36 151 adults), we conducted weighted bivariate analyses of tobacco use among participants with no trauma exposure, trauma exposure, and trauma exposure with post-traumatic stress disorder (trauma + PTSD), stratified by tobacco product use. We also performed weighted logistic regressions testing relationships between trauma exposure and tobacco use, controlling for behavioral health (BH) conditions (mood, anxiety, substance use, personality disorders) and sociodemographics.

RESULTS

Approximately 44% of participants had experienced trauma; 6% experienced trauma + PTSD. Trauma exposed participants had a higher prevalence of tobacco use (30%--46% vs. 22%) and poly-tobacco use (34%--35% vs. 28%) than unexposed participants. Cigarettes were the most used tobacco product; trauma + PTSD (19%), and trauma (15%) participants had a higher prevalence of e-cigarette use than unexposed participants (11%). Trauma exposure was associated with current tobacco use (AOR = 1.36 trauma + PTSD; 1.23 trauma) (but not former use), particularly among participants exposed to violence/abuse (AOR = 1.23). Personality and substance use disorders were strongly associated with current and former tobacco use.

CONCLUSIONS

Trauma exposure, PTSD, and experiences of violence/abuse are associated with current tobacco use. BH conditions may also play a role in current and former tobacco use. Recognizing and addressing trauma exposure and BH conditions among tobacco users may improve cessation rates in these populations.

IMPLICATIONS

This study contributes to research on tobacco use disparities in behavioral health populations by providing a comprehensive examination of tobacco use in trauma exposed individuals. Prior research has examined cigarette smoking, but not other tobacco product use in these populations. This study presents findings on multiple tobacco use behaviors (tobacco product, poly-tobacco use, cessation attempts) in trauma exposed populations and characteristics of trauma exposure (severity, type of traumatic event) associated with tobacco use. These findings underscore the importance of further examining the implications of trauma exposure for tobacco use and of screening and addressing trauma in cessation treatment.

Chemical characterization of tobacco-free "modern" oral nicotine pouches and their position on the toxicant and risk continuums

As compared with cigarette smoking, use of Swedish snus is associated with significantly fewer health risks. Nicotine pouches (NPs), a new form of oral nicotine product, are smokeless and tobacco-free, comprising a nicotine-containing cellulose matrix inside a fiber pouch. NPs are similar in appearance/use to snus, but without tobacco, have the potential to further reduce tobacco-related harm. This study aimed to evaluate toxicant levels of NPs to estimate their position on the tobacco/nicotine product continuums of toxicant delivery and risk. NPs, snus and nicotine replacement therapy products (NRTs) were analyzed for 24-26 compounds applicable to oral tobacco, and their levels were compared. Twenty of these compounds were further used to compare the toxicant profile of NPs, as well as estimated daily toxicant exposure from NP use, with that of tobacco/nicotine products spanning the risk continuum. Of the compounds measured, 22 (NPs), 22 (lozenge NRT), 20 (gum NRT), and 11 (snus) were not quantifiable. Compared with snus, NPs had lower levels of 10 HPHCs and comparable/undetectable levels of a further 13. Across the product categories, NPs and NRTs had the lowest toxicant profiles and estimations of relative toxicant exposure. Based on the present chemical analysis and estimated exposure, use of NPs appears likely to expose users to lower levels of toxic compounds than Swedish snus, which is recognized to offer reduced levels of harm than associated with tobacco smoking. We conclude that NPs should be placed close to NRTs on the tobacco/nicotine product toxicant delivery continuum, although further studies will be needed to confirm this.

Exposure to a Tobacco-Specific Carcinogen Among Adolescent Smokeless Tobacco Users in Rural California, United States

INTRODUCTION

Approximately the same percentage of male high school students in the United States currently uses conventional smokeless tobacco as smokes cigarettes, resulting in toxin exposure.

METHODS

This study assessed tobacco product use (smokeless, combustible, and electronic cigarettes) and nicotine and carcinogen exposures in a sample of 594 male rural high school baseball players-a population traditionally at risk for smokeless tobacco use. Salivary specimens were assayed for cotinine (a biomarker of nicotine exposure) and urine specimens for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL, a biomarker of the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) using liquid chromatography-tandem mass spectrometry.

RESULTS

The prevalence of past 30-day use of any tobacco product was 29%. Past 7-day smokeless tobacco use (prevalence: 13%) was associated with the highest levels of cotinine and NNAL observed in the sample, whether smokeless tobacco was used exclusively (geometric means: cotinine 11.1 ng/mL; NNAL 31.9 pg/mg-creatinine) or in combination with combustible products (geometric means: cotinine 31.6 ng/mL; NNAL 50.0 pg/mg creatinine). Cotinine and NNAL levels were incrementally higher in each increasing category of smokeless tobacco use frequency. However, observed levels were lower than previously reported for adults, likely reflecting less smokeless use per day among adolescents.

CONCLUSIONS

Based on these biomarker observations, adolescents who use conventional smokeless tobacco products are exposed to substantial levels of nicotine and NNK. Although exposed to lower levels than adult smokeless users, the findings are concerning given the young age of the sample and tendency for smokeless tobacco users to increase use intensity over time.

IMPLICATIONS

This study demonstrates that adolescents using smokeless tobacco are exposed to levels of nicotine and NNK that increase with use frequency and that exceed exposures among peers using other tobacco products. Youth smokeless tobacco use in the United States has not declined along with youth smoking prevalence, giving greater importance to this health concern. To reduce youth (and adult) exposures, needed actions include effective smokeless tobacco use prevention, potentially in combination with reducing the levels of harmful and potentially harmful chemicals in smokeless tobacco products currently popular among adolescents.

Smokeless tobacco induces toxicity and apoptosis in neuronal cells: a mechanistic evaluation

Smokeless tobacco (SLT) or chewing tobacco has been a highly addictive practice in India across ages, posing major threat to the systemic health and possibly neurodegeneration. Earlier studies showed components of SLT could be harmful to neuronal health. However, mechanism of SLT in neurodegeneration remained unexplored. This study investigated the detrimental role of SLT on differentiated neuronal cell lines, PC12 and SH-SY5Y by using graded doses of water soluble lyophilised SLT. Reduced cell viability, compromised mitochondrial structure and functions were observed when neuronal cell lines were treated with SLT (6 mg/mL) for 24 h. There was reduction of oxidative phosphorylation and aerobic glycolysis as determined by diminution of ATP production (2.5X) and basal respiration (1.9X). Mitochondrial membrane potential was dropped by 3.5 times. Bid, a pro-apoptotic Bcl-2 family protein, has imperative role in regulating mitochondrial outer membrane permeabilization and subsequent cytochrome c release leading to apoptosis. This article for the first time indicated the involvement of Bid in SLT mediated neurotoxicity and possibly neurodegeneration. SLT treatment enhanced expression of cleaved-Bid in time dependent manner. The involvement of Bid was further confirmed by using Bid specific shRNA which reversed the effects of SLT and conferred significant protection from apoptosis up to 72 h. Thus, our results clearly indicated that SLT induced neuronal cell death occurred via production of ROS, alteration of mitochondrial morphology, membrane potential and oxidative phosphorylation, inactivation of survival pathway and activation of apoptotic markers mediated by Bid. Therefore, Bid could be a potential future therapeutic target for SLT induced neurodegeneration.

Effect of Tobacco-specific Nitrosamines on MUC5AC Expression in Human Airway Epithelial Cells

Background and Objectives: Nicotine is oxidized into tobacco-specific nitrosamines (TSNAs; NAB, NAT, NNN, NNAL, NNK) at high temperature and high pressure. TSNAs are associated with airway diseases characterized by mucus hypersecretion as a major pathophysiologic phenomenon. The aim of study is to investigate the effect of TSNAs on mucin overexpression and its molecular mechanism in human airway epithelial cells.Materials and Method: The cytotoxicity of TSNAs was evaluated using EX-Cytox and inverted microscopy. The mRNA and protein levels of MUC5AC and MUC5B were measured using real-time PCR and ELISA.Results: NAB, NNN, NNAL, and NNK did not affect cell viability. NAT did not affect cell viability up to a concentration of 100 μM in human airway epithelial cells. NAT, NNN, NNAL, and NNK significantly induced MUC5AC expression, but not MUC5B expression. NAB did not affect the expression of MUC5AC and MUC5B. Propranolol (a β-adrenergic receptor antagonist) inhibited NAT, NNN, NNAL, and NNK-induced MUC5AC expression, whereas α-bungarotoxin (an α7-nicotinic acetylcholine receptor antagonist) only inhibited NNN- and NNK-induced MUC5AC expression.Conclusion: These results suggested that NAT, NNN, NNAL, and NNK induce MUC5AC expression through β-adrenergic receptor and/or α7-nicotinic acetylcholine receptor in human airway epithelial cells, which may be involved in mucus hypersecretion in inflammatory airway diseases.

Comparison of tobacco-specific nitrosamine levels in smokeless tobacco products: High levels in products from Bangladesh

Bangladesh exhibits the second highest rate of smokeless tobacco (SLT) product usage in the world, and this has been associated with the high upper aerodigestive tract cancer incidence in this country. The goal of the present study was to examine the levels of the highly carcinogenic tobacco-specific nitrosamines (TSNAs) in Bangladeshi SLT products and compare these levels to that observed in SLT brands from southeast Asia and the USA. The levels of TSNAs and nicotine were determined by LC-MS/MS in twenty-eight SLT brands and several tobacco additives from Bangladesh, as well as several SLT brands from India, Pakistan and the USA. The levels of N-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB) in Bangladeshi SLT brands ranged from 1.1-59, 0.15-34, 0.79-45, and 0.037-13 μg/g SLT powder, respectively. The mean levels of the highly carcinogenic TSNAs (NNN+NNK) were 7.4-, 2.4-, and 63-fold higher in Bangladeshi SLT products as compared to SLT brands from the USA, India and Pakistan, respectively; these trends were also observed for NAT and NAB. Similar mean levels of nicotine were observed in the Bangladeshi brands (31 mg/g powder) versus brands from the USA (25 mg/g powder) and India (20 mg/g powder); they were 3-fold higher than brands from Pakistan (10 mg/g powder). Gul SLT brands exhibited the highest pH and the highest levels of unprotonated nicotine. The high levels of TSNAs in Bangladeshi SLT brands may be an important factor contributing to the high rates of upper aerodigestive tract cancer in Bangladesh.

Biomarkers of Exposure among Adult Smokeless Tobacco Users in the Population Assessment of Tobacco and Health Study (Wave 1, 2013-2014)

BACKGROUND

Monitoring population-level toxicant exposures from smokeless tobacco (SLT) use is important for assessing population health risks due to product use. In this study, we assessed tobacco biomarkers of exposure (BOE) among SLT users from the Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health (PATH) Study.

METHODS

Urinary biospecimens were collected from adults ages 18 and older. Biomarkers of nicotine, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), volatile organic compounds (VOC), metals, and inorganic arsenic were analyzed and reported among exclusive current established SLT users in comparison with exclusive current established cigarette smokers, dual SLT and cigarette users, and never tobacco users.

RESULTS

In general, SLT users (n = 448) have significantly higher concentrations of BOE to nicotine, TSNAs, and PAHs compared with never tobacco users; significant dose-response relationships between frequency of SLT use and biomarker concentrations were also reported among exclusive SLT daily users. Exclusive SLT daily users have higher geometric mean concentrations of total nicotine equivalent-2 (TNE2) and TSNAs than exclusive cigarette daily smokers. In contrast, geometric mean concentrations of PAHs and VOCs were substantially lower among exclusive SLT daily users than exclusive cigarette daily smokers.

CONCLUSIONS

Our study produced a comprehensive assessment of SLT product use and 52 biomarkers of tobacco exposure. Compared with cigarette smokers, SLT users experience greater concentrations of some tobacco toxicants, including nicotine and TSNAs.

IMPACT

Our data add information on the risk assessment of exposure to SLT-related toxicants. High levels of harmful constituents in SLT remain a health concern.

New versatile zincic sorbent for tobacco specific nitrosamines and lead ion capture

New carbon-doped ferric zinc oxide sorbents were fabricated to capture the environment carcinogen tobacco specific nitrosamines (TSNA) efficiently in solution, following new adsorption model of electrostatic attraction instead of traditional geometric constraints. The influence of ferric content on the structure-property of the sorbents was systemically studied with XRD, N2 adsorption-desorption and SEM methods combined with the adsorption of TSNA in different solutions. New sorbent captured 99% of 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK) in simulated surface water and 40% of TSNA in the tobacco extract solution, more than activated carbon or zeolites. Ferric ZnO sorbent took about 15 min to reach the adsorption equilibrium in the NNK or Pb(Ⅱ) solution, faster than NaZSM-5 zeolite. Moreover, the adsorbed NNK on ferric ZnO sorbent decomposed at mild conditions for the first time, providing a new way to control environment pollution.

The Role of Marketing Practices and Tobacco Control Initiatives on Smokeless Tobacco Sales, 2005-2010

BACKGROUND

Little is known about how policies and industry activities impact smokeless tobacco demand. We examined how tobacco control policies and retail promotion may affect smokeless tobacco sales.

METHODS

We used Nielsen market-level retail scanner data for smokeless tobacco sales in convenience stores in 30 US regions from 2005 to 2010. Tobacco policy variables, including excise taxes, state tobacco control program expenditures, and clean indoor air laws, were merged to Nielsen markets. We estimated regression models for per capita unit sales.

RESULTS

Higher cigarette tax was significantly associated with lower sales volume of smokeless tobacco. Sales of smokeless tobacco in markets with a weight-based SLT excise tax were higher than in markets with an ad valorem tax. A higher average product price was associated with decreased sales overall but results varied by package quantity and brand.

CONCLUSIONS

This study observed that smokeless tobacco products were both complements and substitutes to cigarettes. Thus, smokeless tobacco may act as complements for some population segments and substitutes for others. A weight-based tax generally favors premium smokeless tobacco products.

Efficiently capturing tobacco specific nitrosamines with Hβ zeolite in solution

The high-efficiency capture of Tobacco Specific Nitrosamines by Hβ zeolite in solution is reported for the first time, along with the adsorption of 4-methylnitrosamino-1-3-pyridyl-1-butanone in aqueous solution. Different from other zeolites such as NaZSM-5, the specific pore size of Hβ exerted a crucial function endowing the zeolite a higher removal of TSNA and selectivity of NNK. The adsorption thermodynamics of NNK by Hβ in aqueous adsorption was fitted to Temkin adsorption model with a linearly decreasing isosteric heat of adsorption. In addition, the adsorptive capacity of Hβ zeolite for NNK reached over 70 mg g-1, offering a powerful sorbent of TSNA to protect environment.

Critical review of major sources of human exposure to N-nitrosamines

More than 24 N-nitrosamine compounds contribute to the total N-nitrosamine (TNA) burden monitored routinely to assess human exposure to this important group of known and suspected human carcinogens. A literature review (n = 122) identified multiple sources of human exposure to TNAs, including waters (40 ± 10.5 ng/L; average ± standard deviation), food and beverages (6.7 ± 0.8 ng/g), tobacco (16,100 ± 3650 ng/g) and personal care products (1500 ± 750 ng/g). Due to source control interventions, levels of TNAs in beer have dropped by about 96% between 1980 and 1990, whereas N-nitrosamine levels in other known sources have shown little to no change. Maximum daily TNA exposure in the U.S. in units of ng/d is estimated at 25,000 ± 4,950, driven by consumption of tobacco products (22,000 ± 4350), food (1900 ± 380), alcohol (1000 ± 200), and drinking water (120 ± 24). Behavioral choices of individuals in non-occupational settings were calculated to result in a spectrum of exposure values ranging from a lower bound of 1900 ± 380 ng/d to a higher bound of 25,000 ± 4950 ng/d, indicating opportunities for a possible 12-fold reduction in TNA exposure to 8% of the above maximum through deliberate choices in diet and lifestyle.

Tobacco-specific nitrosamines: A literature review

Cigarette smoke is a complex mixture of chemicals, including several tobacco-specific nitrosamines (TSNA). Most TSNA are formed in tobacco during the post-harvest period, while a number are produced when a cigarette is burned. Considerable evidence supports the role of TSNA important causative factors for cancers of the lung, pancreas, esophagus, and oral cavity in people who use tobacco products. Of the known TSNA, nicotine-derived nitrosamine ketone (NNK) and N-nitrosonornicotine (NNN) are the most carcinogenic. Other TSNA include N'-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB). New tobacco products (e.g., e-cigarettes) designed to attract consumers who are concerned about the health effects of tobacco have been appearing on the market. Several studies have reported that certain TSNA have been detected in the replacement liquids and vapour of e-cigarettes, but the levels are generally considerably lower than in tobacco cigarettes. Additionally, the FDA recently announced its intention to regulate TSNA in e-cigarettes, cigar tobacco and pipe tobacco. With the rise of new technologies for reducing the use of tobacco products-such as e-cigarettes- to evaluate exposure levels to these harmful chemicals over time, researchers will be monitoring levels of TSNA in the body as a result of the use of these devices.

Regulation of toxic contents of smokeless tobacco products

Effective regulation of contents of tobacco products is one of the primary milestones to reduce negative health effects associated with the use of smokeless tobacco (SLT) products. As per the available sources, testing of some SLT products has been done on ad hoc basis, but there is a lack of comprehensive and periodic analysis of these products. In addition, the available results indicate huge variations among the levels of pH, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, N-nitrosonornicotine, benzo[a]pyrene, heavy metals and nicotine within different products as well as within different brands of the same product. This review was aimed to throw light on the variations and gaps in testing of SLT products and emphasize the need for strong policy regulation for monitoring the chemical constituents of these products.

Electronic cigarettes: a systematic review of available studies on health risk assessment

OBJECTIVE

This paper primarily aimed to review articles which specifically quantified the risk of electronic cigarette's (e-cigarette) usage via the health risk assessment (HRA) approach.

METHODS

Systematic literature searches were conducted using PubMed search engine databases. Search terms such as "electronic cigarette", "e-cigarette", "electronic nicotine delivery systems", "electronic cigarette liquid", "electronic cigarette vapors", and "health risk assessment" were used to identify the relevant articles to be included in this review. To enable comparison, hazard quotient (HQ) and lifetime cancer risk (LCR) for the chemicals measured in the selected articles were calculated for three of the articles using the formula: [1] HQ=average daily dose (ADD)/reference dose (RfD) or exposure air concentration (EC)/reference concentration (RfC); [2] LCR=lifetime average daily dose (LADD) × cancer slope factor (CSF) or exposure air concentration (EC) × inhalation unit risk (IUR).

RESULTS

Four articles pertaining to HRA of e-cigarettes were critically reviewed, three of the papers focused on specific chemicals namely nicotine, propylene glycol (PG), glycerol and 1,2-propanediol, while one article evaluated the health risks posed by heavy metals contained in e-cigarettes. The calculated HQs for the chemicals in this review had large variations. HQs of the six chemicals, i.e. nicotine, PG, glycerol, cadmium, ethylene glycol, nickel, aluminum and titanium, were found to have the potential to contribute to non-carcinogenic health risks. None of the LCR calculated had risks exceeding the acceptable limit.

CONCLUSION

There are limited HRA studies and the ones that were available provided inconsistent scientific evidences on the health risk characterization arising from the usage of e-cigarettes. As such, there is a need to perform more studies on HRA of e-cigarettes by using uniformed and comprehensive steps and similar reference threshold levels of exposures.

Key issues surrounding the health impacts of electronic nicotine delivery systems (ENDS) and other sources of nicotine

Answer questions and earn CME/CNE Over the last decade, the use of electronic nicotine delivery systems (ENDS), including the electronic cigarette or e-cigarette, has grown rapidly. More youth now use ENDS than any tobacco product. This extensive research review shows that there are scientifically sound, sometimes competing arguments about ENDS that are not immediately and/or completely resolvable. However, the preponderance of the scientific evidence to date suggests that current-generation ENDS products are demonstrably less harmful than combustible tobacco products such as conventional cigarettes in several key ways, including by generating far lower levels of carcinogens and other toxic compounds than combustible products or those that contain tobacco. To place ENDS in context, the authors begin by reviewing the trends in use of major nicotine-containing products. Because nicotine is the common core-and highly addictive-constituent across all tobacco products, its toxicology is examined. With its long history as the only nicotine product widely accepted as being relatively safe, nicotine-replacement therapy (NRT) is also examined. A section is also included that examines snus, the most debated potential harm-reduction product before ENDS. Between discussions of NRT and snus, ENDS are extensively examined: what they are, knowledge about their level of "harm," their relationship to smoking cessation, the so-called gateway effect, and dual use/poly-use. CA Cancer J Clin 2017;67:449-471. © 2017 American Cancer Society.

Biomarkers of exposure to new and emerging tobacco delivery products

Accurate and reliable measurements of exposure to tobacco products are essential for identifying and confirming patterns of tobacco product use and for assessing their potential biological effects in both human populations and experimental systems. Due to the introduction of new tobacco-derived products and the development of novel ways to modify and use conventional tobacco products, precise and specific assessments of exposure to tobacco are now more important than ever. Biomarkers that were developed and validated to measure exposure to cigarettes are being evaluated to assess their use for measuring exposure to these new products. Here, we review current methods for measuring exposure to new and emerging tobacco products, such as electronic cigarettes, little cigars, water pipes, and cigarillos. Rigorously validated biomarkers specific to these new products have not yet been identified. Here, we discuss the strengths and limitations of current approaches, including whether they provide reliable exposure estimates for new and emerging products. We provide specific guidance for choosing practical and economical biomarkers for different study designs and experimental conditions. Our goal is to help both new and experienced investigators measure exposure to tobacco products accurately and avoid common experimental errors. With the identification of the capacity gaps in biomarker research on new and emerging tobacco products, we hope to provide researchers, policymakers, and funding agencies with a clear action plan for conducting and promoting research on the patterns of use and health effects of these products.

Indicators of dependence for different types of tobacco product users: Descriptive findings from Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health (PATH) study

BACKGROUND AND AIMS

With no established standard for assessing tobacco dependence (TD) across tobacco products in surveys, the Population Assessment of Tobacco and Health (PATH) Study provides a unique platform for examining the psychometric properties and validity of multiple indicators of tobacco dependence across a range of tobacco products.

PARTICIPANTS

A U.S. nationally representative sample from the 32,320 adult Wave 1 interviews with analyses focused on 14,287 respondents who were current established users of tobacco products.

FINDINGS

This analysis confirms a single primary latent construct underlying responses to TD indicators for cigarettes, e-cigarettes, cigars, hookah, and smokeless tobacco products. Mutually exclusive past year tobacco-user groups included: cigarette only (n=8689), e-cigarette only (n=437), cigar only (traditional, cigarillo, or filtered) (n=706), hookah only (n=461), smokeless tobacco only (n=971), cigarette plus e-cigarette (n=709), and multiple tobacco product users (n=2314). Differential Item Functioning (DIF) analyses supported use of 16 of the 24 examined TD indicators for comparisons across tobacco users. With cigarette users as a reference (mean=0.0, SD=1.0), we observed a range of TD with hookah (mean=-1.71) and cigar (mean=-1.92) only users being the lowest, and cigarette plus e-cigarette product users being the highest (mean=0.35). Regression models including sociodemographic factors supported concurrent validity with increased product use frequency and TD among cigarette-only (p<0.001), e-cigarette only (p<0.002), cigar (p<0.001), hookah only (p<0.001), and smokeless tobacco users (p<0.001).

CONCLUSION

The PATH Study Adult Wave 1 Questionnaire provided psychometrically valid measures of TD that enables future regulatory investigations of nicotine dependence across tobacco products.

Creating an Optimal Microenvironment within Mesoporous Silica MCM-41 for Capture of Tobacco-Specific Nitrosamines in Solution

To meet the requirement of capturing tobacco-specific nitrosamines (TSNA) for environment protection, a unique microenvironment was carefully created inside the channels of mesoporous silica MCM-41. In situ carbonization of template micelles at 923 K, combined with the excess aluminum used in one-pot synthesis of MCM-41, is adopted to tailor the tortuosity of mecsoporous channels, while loaded metal oxides (5 wt %) and the Al component in the framework are employed to exert the necessary electrostatic interaction toward the target carcinogens TSNA in solution. The elaborated microenvironment created in mesoporous sorbents was characterized with XRD, N₂ adsorption-desorption, TEM, XPS, and TG-DSC methods. Various solutions of Burley- and Virginia-type tobaccos were used to assess the adsorption performance of new mesoporous sorbents, and the influence of the solid-to-liquid ratio, adsorption time, and loading amount of CuO on the adsorption was carefully examined. The representative sample 5%Cu/AM-10c could capture 27.2% of TSNA in Burley tobacco solution, and its capacity reached 0.3 mg g^-1 in Snus tobacco extract solution, offering a promising candidate for the protection of the environment and public health.

Snus use, smoking and survival among prostate cancer patients

Smoking is associated with prostate cancer mortality. The Scandinavian smokeless tobacco product snus is a source of nicotine but not the combustion products of smoke and has not been studied with respect to prostate cancer survival. The study is nested among 9,582 men with incident prostate cancer within a prospective cohort of 336,381 Swedish construction workers. Information on tobacco use was collected at study entry between 1971 and 1992, and categorized into (i) never users of any tobacco, (ii) exclusive snus: ever users of snus only, (iii) exclusive smokers: ever smokers (cigarette, cigar and/or pipe) only and (iv) ever users of both snus and smoking. Hazard ratios for prostate cancer-specific and total mortality for smoking and snus use based on Cox proportional hazards models adjusted for age, calendar period at diagnosis and body mass index at baseline. During 36 years of follow-up, 4,758 patients died-2,489 due to prostate cancer. Compared to never users of tobacco, exclusive smokers were at increased risk of prostate cancer mortality (HR 1.15, 95% CI: 1.05-1.27) and total mortality (HR 1.17, 95% CI: 1.09-1.26). Exclusive snus users also had increased risks for prostate cancer mortality (HR 1.24, 95% CI: 1.03-1.49) and total mortality (HR 1.19, 95% CI: 1.04-1.37). Among men diagnosed with nonmetastatic disease, the HR for prostate cancer death among exclusive snus users was 3.17 (95% CI: 1.66-6.06). The study is limited by a single assessment of tobacco use prior to diagnosis. Snus use was associated with increased risks of prostate cancer and total mortality among prostate cancer patients. This suggests that tobacco-related components such as nicotine or tobacco-specific carcinogens may promote cancer progression independent of tobacco's combustion products.

Snus undermines quit attempts but not abstinence: a randomised clinical trial among US smokers

BACKGROUND

Observational studies and a few clinical trials suggest that use of low nitrosamine smokeless tobacco (snus) can facilitate smoking cessation. To better understand the real-world impact of snus on smoking behaviour, a large-scale, long-term clinical trial of naturalistic snus use among smokers is needed.

STUDY DESIGN

A nationwide clinical trial compared abstinence outcomes among smokers who were randomised to receive free samples of snus versus not. Participants (N=1236) were recruited throughout the US and assessed for 1 year following a 6-week naturalistic sampling period, with high retention throughout. Primary outcomes included self-reported quit attempts, floating abstinence (any 7-day period of non-smoking) and 7-day point-prevalence abstinence at 6 months and 12 months. Secondary outcomes were changes in smoking, motivation and confidence to quit and adverse events. No tobacco industry support was provided.

RESULTS

Within snus group, 82% used at least once, and 16% were using regularly at end of sampling period. Compared to control participants, smokers in the snus group were less likely to make any quit attempt (RR=0.83; 95% CI 0.70 to 1.00), and any 24 h quit attempt (RR=0.77; 95% CI 0.63 to 0.95). There were no group differences on any measure of abstinence.

CONCLUSIONS

Provision of snus in a naturalistic context resulted in minimal uptake, and as a whole, undermined quit attempts and did not increase smoking abstinence. Results do not support the unguided, free provision of snus among smokers not motivated to quit as a means to facilitate quit attempts.

TRIAL REGISTRATION NUMBER

NCT01509586, Results.

Nicotine and Toxicant Exposure among U.S. Smokeless Tobacco Users: Results from 1999 to 2012 National Health and Nutrition Examination Survey Data

BACKGROUND

It has been suggested that smokeless tobacco users have high nicotine and toxicant exposure, but studies with nationally representative data have been limited.

METHODS

We analyzed biomarkers of tobacco exposure for 23,684 adult participants from the National Health and Nutrition Examination Survey from 1999 to 2012. The biomarkers analyzed were serum cotinine, urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), blood lead, blood cadmium, blood mercury, urinary arsenic, and urinary N-acetyl-S-(2-cyanoethyl)-L-cysteine. We calculated geometric mean concentrations for each biomarker by tobacco use category and geometric mean ratios adjusting for demographic factors.

RESULTS

Exclusive smokeless tobacco users had higher geometric mean concentrations of serum cotinine [178.9 ng/mL, 95% confidence interval (CI), 145.5-220.0] and NNAL (583.0 pg/mg creatinine, 95% CI, 445.2-763.5) than exclusive cigarette smokers (130.6 ng/mL, 95% CI, 122.3-139.6 and 217.6 pg/mg creatinine, 95% CI, 193.0-245.2, respectively). Smokeless tobacco users also had higher concentrations of blood lead compared with nontobacco users (adjusted geometric mean ratio = 1.30, 95% CI, 1.21-1.38). Based on limited sample sizes, NNAL concentrations for smokeless tobacco users appear to have declined from 2007 to 2008 (geometric mean = 1013.7 pg/mg creatinine, 95% CI, 738.9-1390.8) to 2011 to 2012 (geometric mean = 325.7 pg/mg creatinine, 95% CI, 159.6-664.9).

CONCLUSIONS

Exclusive smokeless tobacco users have higher observed levels of exposure to nicotine and carcinogenic tobacco-specific nitrosamines, as measured by cotinine and NNAL biomarker concentrations, than exclusive cigarette smokers. These patterns in NNAL levels for smokeless tobacco users may be changing over time.

IMPACT

High exposure to harmful constituents among smokeless tobacco users is a continuing health issue.

A Survey of N'-Nitrosonornicotine (NNN) and Total Water Content in Select Smokeless Tobacco Products Purchased in the United States in 2015

This investigation provides an updated survey measuring the levels of N'-nitrosonornicotine (NNN) and water content of a select number of smokeless tobacco products sold in the United States in 2015. A total of 34 smokeless tobacco products were collected and analyzed for NNN and water content using LC-MS/MS and GC-TCD, respectively. Smokeless tobacco products were chosen to obtain a representative sample of the different types of products on the U.S. market. These smokeless products represent 12 of the 25 top-selling smokeless tobacco products according to 2013 Nielsen net sales data while five of the smokeless tobacco products are of lower selling smokeless tobacco products. The NNN levels and the water content of the smokeless tobacco products were determined and compared to previous studies. Although the range of NNN levels found was broad for the examined smokeless tobacco products (0.64-12.0 μg/g dry weight), dry snuff had the highest levels of NNN observed (>5 μg/g dry weight). We observed a general decrease in NNN levels for the same six moist snuff products that were analyzed in 2004 compared to our current 2015 study. The water content of the smokeless tobacco products surveyed ranged from 3.92 to 54.8%.

Smokeless tobacco consumption impedes metabolic, cellular, apoptotic and systemic stress pattern: A study on Government employees in Kolkata, India

Smokeless tobacco (SLT) remains a threat amongst a large population across the globe and particularly in India. The oral use of tobacco has been implicated to cause physiological stress leading to extreme toxicological challenge. The study included 47 SLT-users and 44 non-users providing a spectrum of pathophysiological, clinico-biochemical, antioxidant parameters, cell cycle progression study of PBMC and morphological changes of red blood cells (RBC). The expressions of p53, p21, Bax, Bcl-2, IL-6, TNF- α, Cox-2, iNOS were analyzed from thirteen representative SLT-users and twelve non-users. Difference in CRP, random glucose, serum cholesterol, TG, HLDL-C, LDL-C, VLDL-C, neutrophil count, monocyte count, ESR, SOD (PBMC) and TBARS (RBC membrane) were found to be statistically significant (p < 0.05) between the studied groups. The current study confers crucial insight into SLT mediated effects on systemic toxicity and stress. This has challenged the metabolic condition leading to a rise in the inflammatory status, increased apoptosis and RBC membrane damage. The above findings were substantiated with metabolic, clinical and biochemical parameters. This is possibly the first ever in-depth report and remains an invaluable document on the fatal effects of SLT.

Assessing Constituent Levels in Smokeless Tobacco Products: A New Approach to Engaging and Educating the Public

INTRODUCTION

Providing accurate information about the constituents in nicotine-containing products may help tobacco users make informed decisions about product choices. An experimental study examined a novel approach for presenting accurate constituent information about brands and types of smokeless tobacco (SLT) that could be understood by the general public.

METHODS

Participants were recruited through Amazon's Mechanical Turk and presented information online about 2 constituent dimensions of SLT products-nicotine and/or toxicity (for simplicity, "toxicity" in this study refers to carcinogenic constituents) Participants completed measures of knowledge and tobacco health risks at 2 time points: before and after exposure to constituent information.

RESULTS

Participants were found to increase their knowledge that toxicity contributes to disease risk and nicotine contributes to addiction, that SLT products vary in their levels of nicotine and toxicity, and that both SLT and cigarette products have higher toxicity than medicinal nicotine replacement therapies (e.g., nicotine lozenges). Study results showed no differences when presenting toxicity information alone versus presenting it in conjunction with nicotine information, and found no misperceptions or confusions about the relative harmfulness of cigarettes, SLT, or nicotine replacement therapy.

CONCLUSIONS

Providing tobacco constituent information to smokers and nonsmokers will improve their knowledge about the relative toxicity across products and variations within a class of tobacco products without compromising the health risks associated with tobacco use.

Nicotine: Carcinogenicity and Effects on Response to Cancer Treatment - A Review

Tobacco use is considered the single most important man-made cause of cancer that can be avoided. The evidence that nicotine is involved in cancer development is reviewed and discussed in this paper. Both tobacco smoke and tobacco products for oral use contain a number of carcinogenic substances, such as polycyclic hydrocarbons and tobacco-specific N-nitrosamines (TSNA), which undoubtedly contribute to tobacco related cancer. Recent studies have shown that nicotine can affect several important steps in the development of cancer, and suggest that it may cause aggravation and recurrence of the disease. TSNA may be formed from nicotine in the body. The role of nicotine as the major addictive component of tobacco products may have distracted our attention from toxicological effects on cell growth, angiogenesis, and tumor malignancy. Effects on cancer disease are important aspects in the evaluation of possible long-term effects from sources of nicotine, such as e-cigarettes and products for nicotine replacement therapy, which both have a potential for life-long use.

Fully automated analysis of four tobacco-specific N-nitrosamines in mainstream cigarette smoke using two-dimensional online solid phase extraction combined with liquid chromatography-tandem mass spectrometry

A fully automated method for the detection of four tobacco-specific nitrosamines (TSNAs) in mainstream cigarette smoke (MSS) has been developed. The new developed method is based on two-dimensional online solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE/LC-MS/MS). The two dimensional SPE was performed in the method utilizing two cartridges with different extraction mechanisms to cleanup disturbances of different polarity to minimize sample matrix effects on each analyte. Chromatographic separation was achieved using a UPLC C18 reversed phase analytical column. Under the optimum online SPE/LC-MS/MS conditions, N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were baseline separated with good peak shapes. This method appears to be the most sensitive method yet reported for determination of TSNAs in mainstream cigarette smoke. The limits of quantification for NNN, NNK, NAT and NAB reached the levels of 6.0, 1.0, 3.0 and 0.6 pg/cig, respectively, which were well below the lowest levels of TSNAs in MSS of current commercial cigarettes. The accuracy of the measurement of four TSNAs was from 92.8 to 107.3%. The relative standard deviations of intra-and inter-day analysis were less than 5.4% and 7.5%, respectively. The main advantages of the method developed are fairly high sensitivity, selectivity and accuracy of results, minimum sample pre-treatment, full automation, and high throughput. As a part of the validation procedure, the developed method was applied to evaluate TSNAs yields for 27 top-selling commercial cigarettes in China.

Tobacco-Specific Nitrosamines in Electronic Cigarettes: Comparison between Liquid and Aerosol Levels

INTRODUCTION

Although electronic cigarette (EC) liquids contain low levels of tobacco-specific nitrosamines (TSNAs), studies evaluating the levels emitted to the aerosol are scarce. The purpose of this study was to compare the levels of TSNAs between liquids and generated aerosol.

METHODS

Three EC liquids were obtained from the market. An additional (spiked) sample was prepared by adding known amounts of standard TSNAs solutions to one of the obtained liquids. N-nitrosonornicotine (NNN), N-nitrosoanatabine (NAT), N-nitrosoanabasine (NAB) and 4-(methylnitrosamino)1-(3-pyridyl)-1-butanone (NNK) were measured. Three 100-puff sets from each liquid were trapped in filter pads and were subsequently analyzed for the presence of TSNAs. The expected levels of TSNAs (calculated based on the liquid consumption) were compared with the measured levels in the aerosol.

RESULTS

Only NAB was found at trace levels in two commercial liquids (1.2 and 2.3 ng/g), while the third contained 1.5 ng/g NAB and 7.7 ng/g NNN. The 100-puff sets resulted in 336-515 mg liquid consumption, with no TSNAs being detected in the aerosol. The spiked sample contained 42.0-53.9 ng/g of each of the TSNAs. All TSNAs were detected in the aerosol with the measured levels being statistically similar to the expected amounts. A significant correlation between expected and measured levels of TSNAs in the aerosol was found (r = 0.83, p < 0.001).

CONCLUSION

The findings of this study show that exposure of EC users to TSNAs can be accurately assessed based on the levels present in the liquid, without the need to analyze the aerosol.

Policy Options to Promote Smokefree Environments for Children and Adolescents

Secondhand smoke (SHS) exposure among children is associated with a wide variety of adverse health risks, including: asthma, otitis media, respiratory infections, impaired lung growth and function, decreased exercise tolerance, cognitive impairments, behavior problems, and sudden infant death syndrome. Unfortunately, over 40% of children aged 3-11 years-15.1 million children-are currently exposed to SHS, with nearly 70% of black children in this age group being exposed. Over the past three decades, great strides have been made in establishing smokefree environments for adults, ultimately reducing their SHS exposure. Regulations have been passed at the organizational, local, and state levels that increasingly ban smoking in the workplace and public places. Children's SHS exposure patterns, however, differ from adults' exposures, with greater time spent in the home and other potentially unregulated venues (school, child care, and car). This means that children have been afforded relatively less protection from SHS by these smokefree regulations. It is imperative, therefore, to seek alternative options for promoting smokefree environments for children throughout the United States. This article explores policy options that promote smokefree environments for children and adolescents: comprehensive smokefree/tobacco-free policies covering indoor/outdoor public places, housing, private vehicles, and child care, as well as Clinical Guidelines regarding patient/family interviews on smoking, SHS, cessation, and voluntary smokefree efforts. The policy section highlights the role of child and adolescent health practitioners in promoting these policies with the hope of fostering engagement of these key stakeholders in the policy process. Note, there are a wide range of important policy and regulatory strategies aimed at reducing tobacco initiation and use among children, adolescents, and young adults; while essential in tobacco prevention and control efforts, a discussion of these strategies is beyond the scope of this article.

Toxicity assessment of refill liquids for electronic cigarettes

We analyzed 42 models from 14 brands of refill liquids for e-cigarettes for the presence of micro-organisms, diethylene glycol, ethylene glycol, hydrocarbons, ethanol, aldehydes, tobacco-specific nitrosamines, and solvents. All the liquids under scrutiny complied with norms for the absence of yeast, mold, aerobic microbes, Staphylococcus aureus, and Pseudomonas aeruginosa. Diethylene glycol, ethylene glycol and ethanol were detected, but remained within limits authorized for food and pharmaceutical products. Terpenic compounds and aldehydes were found in the products, in particular formaldehyde and acrolein. No sample contained nitrosamines at levels above the limit of detection (1 μg/g). Residual solvents such as 1,3-butadiene, cyclohexane and acetone, to name a few, were found in some products. None of the products under scrutiny were totally exempt of potentially toxic compounds. However, for products other than nicotine, the oral acute toxicity of the e-liquids tested seems to be of minor concern. However, a minority of liquids, especially those with flavorings, showed particularly high ranges of chemicals, causing concerns about their potential toxicity in case of chronic oral exposure.

Nicotine levels and presence of selected tobacco-derived toxins in tobacco flavoured electronic cigarette refill liquids

BACKGROUND

Some electronic cigarette (EC) liquids of tobacco flavour contain extracts of cured tobacco leaves produced by a process of solvent extraction and steeping. These are commonly called Natural Extract of Tobacco (NET) liquids. The purpose of the study was to evaluate nicotine levels and the presence of tobacco-derived toxins in tobacco-flavoured conventional and NET liquids.

METHODS

Twenty-one samples (10 conventional and 11 NET liquids) were obtained from the US and Greek market. Nicotine levels were measured and compared with labelled values. The levels of tobacco-derived chemicals were compared with literature data on tobacco products.

RESULTS

Twelve samples had nicotine levels within 10% of the labelled value. Inconsistency ranged from -21% to 22.1%, with no difference observed between conventional and NET liquids. Tobacco-specific nitrosamines (TSNAs) were present in all samples at ng/mL levels. Nitrates were present almost exclusively in NET liquids. Acetaldehyde was present predominantly in conventional liquids while formaldehyde was detected in almost all EC liquids at trace levels. Phenols were present in trace amounts, mostly in NET liquids. Total TSNAs and nitrate, which are derived from the tobacco plant, were present at levels 200-300 times lower in 1 mL of NET liquids compared to 1 gram of tobacco products.

CONCLUSIONS

NET liquids contained higher levels of phenols and nitrates, but lower levels of acetaldehyde compared to conventional EC liquids. The lower levels of tobacco-derived toxins found in NET liquids compared to tobacco products indicate that the extraction process used to make these products did not transfer a significant amount of toxins to the NET. Overall, all EC liquids contained far lower (by 2-3 orders of magnitude) levels of the tobacco-derived toxins compared to tobacco products.

Electronic cigarettes in the USA: a summary of available toxicology data and suggestions for the future

OBJECTIVE

To review the available evidence evaluating the toxicological profiles of electronic cigarettes (e-cigarettes) in order to understand the potential impact of e-cigarettes on individual users and the public health.

METHODS

Systematic literature searches were conducted between October 2012 and October 2013 using five electronic databases. Search terms such as 'e-cigarettes' and 'electronic delivery devices' were used to identify the toxicology information for e-cigarettes.

RESULTS

As of October 2013, the scientific literature contains very limited information regarding the toxicity of e-cigarettes commercially available in the USA. While some preliminary toxicology data suggests that e-cigarette users are exposed to lower levels of toxicants relative to cigarette smokers, the data available is extremely limited at this time. At present, there is insufficient toxicological data available to perform thorough risk assessment analyses for e-cigarettes; few toxicology studies evaluating e-cigarettes have been conducted to date, and standard toxicological testing paradigms have not been developed for comparing disparate types of tobacco products such as e-cigarettes and traditional cigarettes.

CONCLUSIONS

Overall, the limited toxicology data on e-cigarettes in the public domain is insufficient to allow a thorough toxicological evaluation of this new type of tobacco product. In the future, the acquisition of scientific datasets that are derived from scientifically robust standard testing paradigms, include comprehensive chemical characterisation of the aerosol, provide information on users' toxicant exposure levels, and from studies replicated by independent researchers will improve the scientific community's ability to perform robust toxicological evaluations of e-cigarettes.

An analytical study on the common type of smokeless tobacco available in the Iranian market

Background:

The use of smokeless tobacco is considered as a risk factor for oral cancer.

Objectives:

The current study aimed to chemically analyze, separate and measure the existing substances in a type of chewing tobacco.

Materials and Methods:

In the current descriptive study, the investigated sample was a type of smokeless tobacco, known as BT, manufactured in India. First steam distillation method and Clevenger machine were used to separate and extract the essential oil of the sample. The presence of the desired compounds was evaluated in the essential oil, using gas chromatography (GC) and then gas chromatography coupled to mass spectrometry (GC/MS) analysis.

Results:

Based on the results obtained by the applied technique, the presence of carcinogenic compounds, N-nitrosomethyl-vinylamine (162 µg/g), N-nitrosonornicotine (6.3 µg/g), and Acetaldehyde (117 µg/g) was confirmed in the sample.

Conclusions:

Chemical analysis of the sample confirmed the existence of carcinogenic compounds.

The association between smokeless tobacco use and pancreatic adenocarcinoma: a systematic review

BACKGROUND

Smokeless tobacco is a possible risk factor for developing pancreatic adenocarcinoma. This systematic review addressed the question: Is there an association between smokeless tobacco use and pancreatic adenocarcinoma diagnosis?

METHODS

Five electronic databases, grey literature, and citations of relevant articles were searched to identify studies. Six researchers double-reviewed records for inclusion in the review. The information extracted from these studies was selected using criteria outlined in the Newcastle-Ottawa Quality Assessment Scale for observational studies. A qualitative synthesis of included studies was performed.

RESULTS

The search of electronic databases resulted in a total of 1747 citations. Eleven studies met the inclusion criteria for this review, including three cohort studies, seven case control studies and one study that pooled data from multiple case-control studies. Studies were heterogeneous in their assessment of exposure intensity and ascertainment of outcomes. Quality of the studies varied. Existing investigations of the association of interest appear to exhibit several types of biases including selection bias, information bias and bias in the analysis.

CONCLUSION

The association between smokeless tobacco use and pancreatic adenocarcinoma is inconclusive. More definitive conclusions regarding this relationship await the results of more methodologically rigorous epidemiologic studies.

The effects of beliefs regarding drug assignment in experimental and field studies of nicotine delivery devices: a review

The placebo effect of a psychoactive drug can be defined as the effect of expecting the drug in the absence of its pharmacological actions. As nicotine is widely believed to be the primary factor driving cigarette smoking, smokers are likely to expect nicotine to alleviate craving and withdrawal. The present review examines the extent to which any observed effects of nicotine, and especially its craving- and withdrawal-reducing effects, can be attributed to placebo. We begin by reviewing studies that examined the placebo effects of nicotine in the laboratory and follow with a review of potential placebo effects that are typically not controlled in placebo-controlled studies of nicotine replacement therapy (NRT). In laboratory studies, nicotine instructions decrease tobacco smoking, craving and/or withdrawal, while nicotine-specific effects have not been consistently reported. In field trials of NRT, there is a general failure to assess smokers' beliefs regarding their drug assignment. This omission makes it difficult to unequivocally attribute findings of placebo-controlled NRT studies to the physiological effects of nicotine. In sum, our review indicates that the placebo effects of nicotine, and specifically nicotine content expectations, may account for many of the benefits associated with nicotine delivery devices in both laboratory and field studies.

Non-cigarette tobacco and the lung

Cigarette smoking is known to cause a wide range of damaging health outcomes; however, the effects of non-cigarette tobacco products are either unknown or perceived as less harmful than cigarettes. Smokeless tobacco, cigar smoking, and waterpipe smoking have increased in usage over the past few decades. Some experts believe that their use is reaching epidemic proportions. Factors such as a perception of harm reduction, targeted advertising, and unrecognized addiction may drive the increased consumption of non-cigarette tobacco products. In particular, the need for social acceptance, enjoyment of communal smoking activities, and exotic nature of waterpipe smoking fuels, in part, its popularity. The public is looking for "safer" alternatives to smoking cigarettes, and some groups advertise products such as smokeless tobacco and electronic cigarettes as the alternatives they seek. Though it is clear that cigar and waterpipe tobacco smoking are probably as dangerous to health as cigarette smoking, there is an opinion among users that the health risks are less compared to cigarette smoking. This is particularly true in younger age groups. In the cases of smokeless tobacco and electronic cigarettes, the risks to health are less clear and there may be evidence of a harm reduction compared to cigarettes. In this article, we discuss commonly used forms of non-cigarette tobacco products, their impacts on lung health, and relevant controversies surrounding their use.

Public education about the relative harm of tobacco products: an intervention for tobacco control professionals

BACKGROUND

In the USA, new regulations require the collection of information on tobacco constituents by brand and variety and publication of this information in a way not likely to be misconstrued by consumers. Understanding of such information becomes increasingly important as new tobacco products are marketed and modifications are made to reduce the toxicity of some products. This pilot study assessed the current knowledge of tobacco control professionals regarding the relative harmfulness of several tobacco products, and evaluated an online educational intervention aimed at improving understanding of variations in nicotine and tobacco-specific N-nitrosamines (TSNAs).

METHODS

Fifty-two tobacco control professionals participated in an online intervention which presented and discussed the results of constituent analyses of Camel Snus and Marlboro Snus compared to several conventional smokeless tobacco products. Comparisons with cigarettes were also discussed. Pre- and post-intervention questions assessed understanding of the concepts.

RESULTS

Pre-intervention responses demonstrated that 31% did not know that cigarettes are more harmful than smokeless tobacco, 67% did not know that smokeless products higher in nicotine are likely to be more effective substitutes for cigarettes, 52% did not know TSNAs are the major carcinogens in tobacco and 81% did not know new snus products tend to be lower in TSNAs than conventional spit tobacco. After intervention participation, knowledge increased on all points except one where pretest results were 100% correct.

CONCLUSIONS

Public education campaigns are urgently needed for tobacco control professionals and consumers to increase awareness and understanding of the continuum of risk among tobacco products.

Youth tobacco use type and associations with substance use disorders

AIMS

To examine the associations between youth poly-tobacco use and substance use disorders.

DESIGN

Analysis of data from the 2007-11 US National Survey on Drug Use and Health.

SETTING

Randomly selected, household-dwelling adolescents from the non-institutionalized, civilian population of the United States.

PARTICIPANTS

A total of 91 152 adolescents (aged 12-17 years).

METHODS

Logistic regression models were used to examine the associations between type of tobacco user (non-user, users of alternative tobacco products only, users of cigarettes only and users of cigarettes plus alternative tobacco products) with past year alcohol, marijuana or other illicit drug use disorders, adjusting for demographic and social variables.

FINDINGS

Compared with non-users of tobacco, the greatest risk for substance use disorders was among users of cigarettes plus alternative tobacco products [alcohol disorder adjusted odds ratio (aOR) = 18.3, 95% confidence interval (CI) = 16.2-20.6; marijuana disorder aOR = 37.2, 95% CI = 32.5-42.7; other drug disorder aOR = 18.4, 95% CI = 15.4-21.8], followed by users of cigarettes only (alcohol disorder aOR = 9.6, 95% CI = 8.8-10.6; marijuana disorder aOR = 20.4, 95% CI = 18.1-23.0; other drug disorder aOR = 9.4, 95% CI = 7.8-11.4), then users of alternative tobacco products only (alcohol disorder aOR = 8.1, 95% CI = 6.7-9.6; marijuana disorder aOR = 9.2, 95% CI = 7.5-11.4; other drug disorder aOR = 3.2, 95% CI = 2.4-4.3).

CONCLUSIONS

Tobacco use in adolescence is associated with higher rates of substance use disorders across all tobacco users, especially among those who use cigarettes plus other tobacco products.

Combusted but not smokeless tobacco products cause DNA damage in oral cavity cells

The aim of this work was to investigate genomic DNA damage in human oral cavity cells after exposure to different tobacco product preparations (TPPs). The oral carcinoma cell line 101A, gingival epithelial cells HGEC, and gingival fibroblasts HGF were exposed to TPM (total particulate matter from 3R4F cigarettes), ST/CAS (2S3 smokeless tobacco extract in complete artificial saliva), and NIC (nicotine). Treatments were for 24 h using TPM at its EC-50 doses, ST/CAS and NIC at doses with equi-nicotine units, and high doses for ST/CAS and NIC. Comet assays showed that TPM, but not ST/CAS or NIC, caused substantial DNA breaks in cells; only the high ST/CAS dose caused weak DNA damage. These results were confirmed by immunofluorescence for γ-H2AX protein. These data revealed that the combusted TPP caused substantial DNA damage in all cell types, whereas the two non-combusted TPPs exerted no or only minimal DNA damage. They support epidemiologic evidence on the relative risk associated with consumption of non-combusted versus combusted tobacco products, and help to understand potential genotoxic effects of such products on oral cavity cells.

Electronic cigarettes and vaping: a new challenge in clinical medicine and public health. A literature review

Electronic cigarette (e-cigarette) use, or vaping, in the United States and worldwide is increasing. Their use is highly controversial from scientific, political, financial, psychological, and sociological ideologies. Given the controversial nature of e-cigarettes and vaping, how should medical care providers advise their patients? To effectively face this new challenge, health care professionals need to become more familiar with the existing literature concerning e-cigarettes and vaping, especially the scientific literature. Thus, the aim of this article is to present a review of the scientific evidence-based primary literature concerning electronic cigarettes and vaping. A search of the most current literature using the pubmed database dating back to 2008, and using electronic cigarette(s) or e-cigarette(s) as key words, yielded a total of 66 highly relevant articles. These articles primarily deal with (1) consumer-based surveys regarding personal views on vaping, (2) chemical analysis of e-cigarette cartridges, solutions, and mist, (3) nicotine content, delivery, and pharmacokinetics, and (4) clinical and physiological studies investigating the effects of acute vaping. When compared to the effects of smoking, the scant available literature suggests that vaping could be a “harm reduction” alternative to smoking and a possible means for smoking cessation, at least to the same degree as other Food and Drug Administration-approved nicotine replacement therapies. However, it is unclear if vaping e-cigarettes will reduce or increase nicotine addiction. It is obvious that more rigorous investigations of the acute and long-term health effects of vaping are required to establish the safety and efficacy of these devices; especially parallel experiments comparing the cardiopulmonary effects of vaping to smoking. Only then will the medical community be able to adequately meet the new challenge e-cigarettes and vaping present to clinical medicine and public health.