Similar uptake of lung carcinogens by smokers of regular, light, and ultralight cigarettes

Shedding 'light' on cigarette pack design: colour differences in product perceptions, use and exposure following the US descriptor ban

INTRODUCTION

Many countries removed misleading descriptors (eg, 'light,' 'mild') from cigarette packaging because they falsely conveyed messages of reduced risk. It is unclear if relabelled products currently promote misperceptions or differences in product use and toxicant exposure. We compared product perceptions, use and exposure between a US sample of Marlboro Gold (formerly 'light') and Red smokers.

METHODS

240 non-treatment-seeking adult daily Marlboro smokers (70% male, 71% White, mean cigarettes/day=16.4 (SD=8.3)) completed two laboratory sessions over a 5-day period. During sessions, participants smoked two cigarettes through a topography device to capture their puffing behaviour, provided precigarette and postcigarette carbon monoxide (CO) assessments, and completed risk perception and subjective rating questionnaires. Self-reported cigarettes per day were verified via daily filter collection; urine collected at the end of the period was assayed for nicotine metabolites.

RESULTS

Gold (n=49) smokers were more likely than Red (n=191) to incorrectly believe their cigarettes had less nicotine and tar than regular cigarettes (ps<0.001), and rated them as weaker, less harsh, and mild tasting (ps<0.05). Differences between Red and Gold smokers in cigarettes per day and puffing behaviours trended towards significance (ps<0.1). Notably, there were no group differences on CO boost or total nicotine equivalents (ps>0.1).

CONCLUSIONS

Misperceptions about nicotine and tar exist years after rebranding Marlboro Lights as Marlboro Gold. Biological results support that Gold smokers do not have lower toxicant exposure. The US should consider comprehensive packaging or product design regulations to properly inform smokers of product risks.Trial registeration number NCT02301351.

A review of the evidence on cigarettes with reduced addictiveness potential

BACKGROUND

In May 2018, the Secretariat for the World Health Organization Framework Convention on Tobacco Control convened a meeting to discuss the potential for reducing the addictiveness of tobacco products. A central focus was to review research findings on the behavioral effects of reducing the addictiveness of cigarettes.

METHODS

This manuscript reports the results of a review of the behavioral science literature, updated through April 2021, with special attention to both the potential benefits and unintended consequences of reducing nicotine in cigarettes.

RESULTS

Available evidence suggests that reducing nicotine content in cigarettes to very low levels could benefit public health in three primary ways, by 1) decreasing uptake of regular smoking, 2) decreasing the amount people smoke, and 3) increasing the likelihood of smoking cessation. Current evidence also suggests that reducing nicotine in cigarettes may produce similar benefits across many important subpopulations of people who smoke, including those with psychiatric comorbidities, those who use other substances, those with low socioeconomic status, young people, people who smoke infrequently and people who prefer menthol cigarettes. Cigarette nicotine reduction could also lead to some undesirable outcomes, such as experiencing withdrawal, product manipulation, an illicit market, and harm misperceptions; strategies that may mitigate each are discussed.

CONCLUSION

Overall, behavioral research suggests product standards that limit the nicotine content of combusted tobacco products could render cigarettes and similar products less addictive. The availability of legal, non-combusted products that effectively substitute for cigarettes and the dissemination of public health campaigns that clarify misperceptions about the relationship between nicotine, tobacco and disease may facilitate the extent to which a nicotine reduction policy reduces smoking.

Puff-resolved analysis and selected quantification of chemicals in the gas phase of E-Cigarettes, Heat-not-Burn devices and conventional cigarettes using single photon ionization time-of-flight mass spectrometry (SPI-TOFMS): A comparative study

INTRODUCTION

A wide array of alternative nicotine delivery devices (ANDD) has been developed and they are often described as less harmful than combustible cigarettes. This work compares the chemical emissions of three ANDD in comparison to cigarette smoke. All the tested ANDD are characterized by not involving combustion of tobacco.

METHOD

Single photon ionization time-of-flight mass spectrometry (SPI-TOFMS) is coupled to a linear smoking machine, which allows a comprehensive, online analysis of the gaseous phase of the ANDD aerosol and the conventional cigarette smoke (CC). The following devices were investigated in this study: a tobacco cigarette with a glowing piece of coal as a heating source, an electric device for heating tobacco and a first-generation electronic cigarette. Data obtained from a standard 2R4F research cigarette are taken as a reference.

RESULTS

The puff-by-puff profile of all products was recorded. The ANDD show a substantial reduction or complete absence of known harmful and potentially harmful substances compared to the CC. In addition, tar substances (i.e. semivolatile and low volatile aromatic and phenolic compounds) are formed to a much lower extent. Nicotine, however, is supplied in comparable amounts except for the investigated electronic cigarette.

CONCLUSIONS

The data shows that consumers switching from CC to ANDD are exposed to lower concentrations of harmful and potentially harmful substances. However, toxicological and epidemiological studies must deliver conclusive results if these reduced exposures are beneficial for users.

IMPLICATION

The comparison of puff-resolved profiles of emissions from different tobacco products, traditional and alternative, may help users switch to lower emission products. Puff-resolved comparison overcomes technical changes, use modes between products and may help in their regulation.

Can the Public Be Educated About Constituents in Smokeless Tobacco? A Three-Wave Randomized Controlled Trial

INTRODUCTION

The U.S. Food and Drug Administration (FDA) is required by law to inform the public about levels of harmful and potentially harmful tobacco constituents in a format that is "understandable and not misleading to a lay person." Our study addresses a critical gap in research on communicating such information for smokeless tobacco (SLT) products.

METHODS

The design included random assignment to one of the experimental (online interactive) conditions differing in presentation format or a control condition (receiving no information). Experimental respondents viewed information on levels and health risks of 5 harmful constituents in up to 79 products. Outcome measures included knowledge of health risks of constituents, perception of constituent variability in SLT products, disease risk ratings, self-reported SLT use, and side-by-side product comparisons. The sample of 333 SLT users, 535 cigarette smokers, and 663 nontobacco users participated at baseline, time of intervention, and 6 weeks postintervention.

RESULTS

Presentation formats showed few systematic differences so were combined in analyses. Experimental condition respondents increased their knowledge about constituent health effects and their perceptions of constituent variability in SLT products, from baseline to postintervention, and relative to the control condition. Changes in respondents' ratings of disease risk and their estimates of constituent exposure from specific products were observed, but not in self-reported SLT use.

CONCLUSIONS

Interactive online graphic and numeric presentation formats can be efficient in increasing people's knowledge of health effects and perceived variation of constituents in SLT products. Further research on longer-term behavioral assessment, and usefulness of this approach for regulatory agencies, is needed.

IMPLICATIONS

Research on communicating the information about harmful constituents in SLT products to lay persons is critically lacking. This study proposes novel formats for effective communication about the levels and the health effects of SLT constituents to multiple user groups. The lack of misperceptions among study participants that some tobacco products are safe suggests that such formats can potentially be used for public display of SLT constituent data by the FDA and regulatory agencies in other countries.

Tobacco harm reduction: Past history, current controversies and a proposed approach for the future

Tobacco harm reduction remains a controversial topic in tobacco control. Tobacco harm reduction involves providing tobacco users who are unwilling or unable to quit using nicotine products with less harmful nicotine-containing products for continued use. The skepticism towards harm reduction is based in part on the experience with low-yield tar/nicotine cigarettes, which were presumed to be associated with lower health risks than higher yield cigarettes and marketed as such by cigarette manufacturers. Only later did the field learn that these cigarettes were a deceptive way for cigarette manufacturers to allay the health concerns over cigarette smoking. Since this experience, there has been a proliferation of tobacco products that might potentially serve as a means to reduce tobacco harm. Some members of the tobacco control community believe that these products have great potential to reduce mortality and morbidity among smokers who completely switch to them. Others believe that we will be addicting another generation to tobacco products. This paper reviews the past history, the current tobacco landscape and controversies, and an approach that might rapidly reduce the yearly half-million deaths associated with cigarette smoking in the U.S.

Therapeutic Potential of Zinc Oxide-Loaded Syringic Acid Against in vitro and in vivo Model of Lung Cancer

Introduction

Lung cancer is one of the most aggressive forms of cancer that leads to a high mortality rate amongst several cancer types and it is a widely recurrent cancer globally. The use of zinc oxide nanoparticles (ZnONPs) in the formulation of sun cream, food flavors, and colorings due to its varied biological properties. The extensive significance of nanoparticles encourages their production but the approaches are a common challenge in concluding the direct beneficial effect for the disease treatment. Hence, in the present study, zinc oxide-loaded syringic acid (ZnO-SYR) phytochemical was used to elucidate the therapeutic effect against lung cancer.

Methods

The ZnO-SYR nanoparticles were synthesized and characterized by UV-visible spectroscopy, X-ray diffraction, dynamic light scattering, and FT-IR analysis. The characterized ZnO-SYR was tested on in vivo mouse model of lung cancer (benzo(a)pyrene (BAP)) and in vitro A549 cells.

Results

The results demonstrated the significant restoration of body weight with attenuated serum marker enzymes compared to BAP-treated animals. In addition, cytokine estimation revealed ameliorated levels of TNF-α, interleukins, IL-6, IL-1β with evidenced histological observations in ZnO-SYR-treated mice compared to BAP-induced lung cancer mice.

Discussion

Furthermore, cytotoxicity analysis demonstrated the altered mitochondrial membrane potential (MMP), with a profound increase in reactive oxygen species (ROS) levels, and apoptosis mechanism by ZnO-SYR compared to control cells. The conclusions of the present study put forward an evident confirmation of the protective and beneficial effects of zincoxide-loaded syringic acid against the BAP-induced lung cancer model.

Applying Tobacco, Environmental, and Dietary-Related Biomarkers to Understand Cancer Etiology and Evaluate Prevention Strategies

Many human cancers are caused by environmental and lifestyle factors. Biomarkers of exposure and risk developed by our team have provided critical data on internal exposure to toxic and genotoxic chemicals and their connection to cancer in humans. This review highlights our research using biomarkers to identify key factors influencing cancer risk as well as their application to assess the effectiveness of exposure intervention and chemoprevention protocols. The use of these biomarkers to understand individual susceptibility to the harmful effects of tobacco products is a powerful example of the value of this type of research and has provided key data confirming the link between tobacco smoke exposure and cancer risk. Furthermore, this information has led to policy changes that have reduced tobacco use and consequently, the tobacco-related cancer burden. Recent technological advances in mass spectrometry led to the ability to detect DNA damage in human tissues as well as the development of adductomic approaches. These new methods allowed for the detection of DNA adducts in tissues from patients with cancer, providing key evidence that exposure to carcinogens leads to DNA damage in the target tissue. These advances will provide valuable insights into the etiologic causes of cancer that are not tobacco-related.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."

Low Tar Level Does Not Reduce Human Exposure to Polycyclic Aromatic Hydrocarbons in Environmental Tobacco Smoke

Environmental tobacco smoke (ETS) is known to pose potential risk to human health, but the effects of tar level remain to be clarified. In the present study, ETS samples from two cigarette types with different tar levels in a 72.5 m3 room were collected for measurement of 16 polycyclic aromatic hydrocarbons (PAHs). Urine samples of volunteers participating in smoking events were collected and analyzed for eight hydroxyl-PAHs. The concentrations, compositions, and particle size distribution patterns of PAHs from higher-tar and lower-tar cigarettes were similar, while the emission factors of PAHs from higher-tar cigarettes were lower than those from lower-tar cigarettes. Furthermore, the change in the concentrations of PAH metabolites in urine samples before and after smoking was not attributed to tar level. Assuming that a single cigarette was smoked in a 100 m3 room, the estimated average inhalation cancer risks for different age groups from exposure to PAHs in ETS were below 1.0 × 10-6, but potential risks should not be overlooked, especially considering that only inhaled particle-bound PAHs in ETS were included in this assessment. Apparently, reduced tar levels would not necessarily lead to lowered risk of exposure to PAHs. Kicking the habit is perhaps the best choice to minimize any potential health risk.

Piloting a clinical laboratory method to evaluate the influence of potential modified risk tobacco products on smokers' quit-related motivation, choice, and behavior

Research methods are needed that can predict whether the availability of potential modified risk tobacco products (MRTPs) may influence smokers' quit-related motivation, choice, and behavior. This pilot study assessed the primary outcomes of feasibility and adherence to address this need using an electronic cigarette (ECIG) as a model MRTP. Cigarette smokers were randomly assigned to use only their own brand of cigarettes (OB-only) or a second-generation ECIG (18 ng/ml nicotine) plus their OB cigarettes (ECIG+OB) ad libitum for four weeks. Participants logged products using a mobile device, collected used cigarette filters, and provided saliva samples every day for analysis of cotinine. They returned to the lab once per week to provide a breath sample and accept or decline a choice to quit all tobacco products (i.e., cigarettes and/or ECIGs). They also returned for a one-month follow-up visit. Of those participants randomized (n = 60), 56.7% completed the 4-week intervention and 40.0% completed the follow-up visit. The primary reason for withdrawal was poor adherence with mobile device use. Comparable numbers of participants in each group chose to make a quit attempt, although more OB-only participants chose to quit during the first two weeks and more ECIG+OB participants during the last two weeks. With protocol modifications to reduce participation burden, the current method might ultimately be used by regulators to predict how smokers' quit-related motivation, choice, and behavior are influenced by current and future MRTPs.

Wearable Sensors for Monitoring of Cigarette Smoking in Free-Living: A Systematic Review

Globally, cigarette smoking is widespread among all ages, and smokers struggle to quit. The design of effective cessation interventions requires an accurate and objective assessment of smoking frequency and smoke exposure metrics. Recently, wearable devices have emerged as a means of assessing cigarette use. However, wearable technologies have inherent limitations, and their sensor responses are often influenced by wearers' behavior, motion and environmental factors. This paper presents a systematic review of current and forthcoming wearable technologies, with a focus on sensing elements, body placement, detection accuracy, underlying algorithms and applications. Full-texts of 86 scientific articles were reviewed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines to address three research questions oriented to cigarette smoking, in order to: (1) Investigate the behavioral and physiological manifestations of cigarette smoking targeted by wearable sensors for smoking detection; (2) explore sensor modalities employed for detecting these manifestations; (3) evaluate underlying signal processing and pattern recognition methodologies and key performance metrics. The review identified five specific smoking manifestations targeted by sensors. The results suggested that no system reached 100% accuracy in the detection or evaluation of smoking-related features. Also, the testing of these sensors was mostly limited to laboratory settings. For a realistic evaluation of accuracy metrics, wearable devices require thorough testing under free-living conditions.

Cigarette Filter Ventilation and Smoking Protocol Influence Aldehyde Smoke Yields

The WHO study group on tobacco product regulation (TobReg) advised regulating and lowering toxicant levels in cigarette smoke. Aldehydes are one of the chemical classes on the TobReg smoke toxicants priority list. To provide insight in factors determining aldehyde yields, the levels of 12 aldehydes in mainstream cigarette smoke of 11 Dutch brands were quantified. Variations in smoking behavior and cigarette design affecting human exposure to aldehydes were studied by using four different machine testing protocols. Machine smoking was based on the International Standardization Organization (ISO) and Health Canada Intense (HCI) regime, both with and without taping the filter vents. The 11 cigarette brands differed in (i) design and blend characteristics; (ii) tar, nicotine, and carbon monoxide (TNCO) levels; (iii) popularity; and (iv) manufacturer. Cigarette smoke was trapped on a Cambridge filter pad and carboxen cartridge. After being dissolved in methanol/CS2 and derivatization with DNPH, the aldehyde yields were determined using HPLC-DAD. Using an intense smoking regime (increased puff volume, shorter puff interval) significantly increased aldehyde yields, following the pattern: ISO < ISO-taped < HCI-untaped < HCI. For all of the regimes, acetaldehyde and acrolein yields were strongly correlated ( r = 0.804). The difference in TNCO and aldehyde levels between regular and highly ventilated low-TNCO cigarettes (as measured using ISO) diminished when smoking intensely; this effect is stronger when combined with taping filter vents. The highly ventilated low-TNCO brands showed six times more aldehyde production per mg nicotine for the intense smoking regimes. In conclusion, acetaldehyde and acrolein can be used as representatives for the class of volatile aldehydes for the different brands and smoking regimes. The aldehyde-to-nicotine ratio increased when highly ventilated cigarettes were smoked intensely, similar to real smokers. Thus, a smoker of highly ventilated low-TNCO cigarettes has an increased potential for higher aldehyde exposures compared to a smoker of regular cigarettes.

The importance of the belief that "light" cigarettes are smoother in misperceptions of the harmfulness of "light" cigarettes in the Republic of Korea: a nationally representative cohort study

BACKGROUND

A number of countries have banned misleading cigarette descriptors such as "light" and "low-tar" as called for by the WHO Framework Convention on Tobacco Control. These laws, however, do not address the underlying cigarette design elements that contribute to misperceptions about harm. This is the first study to examine beliefs about "light" cigarettes among Korean smokers, and the first to identify factors related to cigarette design that are associated with the belief that "light" cigarettes are less harmful.

METHODS

We analysed data from Wave 3 of the ITC Korea Survey, a telephone survey of a nationally representative sample of 1,753 adult smokers, conducted October - December 2010. A multinomial logistic regression was used to examine which factors were associated with the belief that "light" cigarettes are less harmful than regular cigarettes.

RESULTS

One quarter (25.0 %) of smokers believed that "light" cigarettes are less harmful than regular cigarettes, 25.8 % believed that smokers of "light" brands take in less tar, and 15.5 % held both of these beliefs. By far the strongest predictor of the erroneous belief that "light" cigarettes are less harmful was the belief that "light" cigarettes are smoother on the throat and chest (p < 0.001, OR = 44.8, 95 % CI 23.6-84.9).

CONCLUSIONS

The strong association between the belief that "light" cigarettes are smoother on the throat and chest and the belief that "light" cigarettes are less harmful, which is consistent with previous research, provides further evidence of the need to not only ban "light" descriptors, but also prohibit cigarette design and packaging features that contribute to the perception of smoothness.

Environmental Smoking Restrictions and Light Cigarette Adoption Among Chinese Urban Smokers

Light cigarette adoption involves complex psychological and behavioral processes with many underlying factors. While numerous studies have shown that environmental restrictions on smoking are associated with higher probability of smoking cessation, it is also possible that some smokers may switch from regular to light cigarettes due to environmental pressures. The current study evaluates whether smoking restrictions in households, workplaces, and public places were respectively associated with light cigarette adoption. A cross-sectional multistage sampling process was used to recruit participants and collect data about demographics and smoking characteristics and environmental restriction variables. Multiple logistic models were employed to examine the association between environmental smoking restrictions and light cigarette adoption. Of 4735 respondents, 1592 (30.3 %) were current smokers, and 69.7 % (N = 1141) of the smokers were identified as light cigarette adopters. In a multivariate model, smoking restrictions in households, workplaces, and public places were significantly associated with higher light cigarette adoption. Under environmental smoking restrictions, which pose unique challenges to tobacco control efforts, light cigarette adoption may increase. The study findings are essential for health policy makers in designing and implementing targeted smoking cessation interventions and health education programs.

Application of CE-MS to a metabonomics study of human urine from cigarette smokers and non-smokers

BACKGROUND

Novel biomarkers of exposure and early adverse effects are needed for comparative studies of combustible and non-combustible tobacco products for regulatory authority evaluation. Metabolic biomarkers reflect both gene and environmental effects.

RESULTS

CE-MS has been applied to human urine samples from non-smokers and smokers of cigarettes at two tar levels. Validated chemometric models were able to separate smokers from non-smokers, with discrimination mainly based on the presence of nicotine metabolites. With these removed, it still proved possible to discriminate smokers from non-smokers with models now based on endogenous metabolites. The biochemical relevance of these biomarkers is discussed.

CONCLUSION

This proof-of-principle metabonomics study illustrates the potential of CE-MS to discover novel biomarkers in urine from tobacco users.

A longitudinal study of smokers' exposure to cigarette smoke and the effects of spontaneous product switching

A challenge in investigating the effect of public health policies on cigarette consumption and exposure arises from variation in a smoker's exposure from cigarette to cigarette and the considerable differences between smokers. In addition, limited data are available on the effects of spontaneous product switching on a smoker's cigarette consumption and exposure to smoke constituents. Over 1000 adult smokers of the same commercial 10mg International Organization for Standardization (ISO) tar yield cigarette were recruited into the non-residential, longitudinal study across 10 cities in Germany. Cigarette consumption, mouth level exposure to tar and nicotine and biomarkers of exposure to nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone were measured every 6months over a 3 and a half year period. Cigarette consumption remained stable through the study period and did not vary significantly when smokers spontaneously switched products. Mouth level exposure decreased for smokers (n=111) who switched to cigarettes of 7mg ISO tar yield or lower. In addition, downward trends in mouth level exposure estimates were observed for smokers who did not switch cigarettes. Data from this study illustrate some of the challenges in measuring smokers' long-term exposure to smoke constituents in their everyday environment.

Magnitudes of biomarker reductions in response to controlled reductions in cigarettes smoked per day: a one-week clinical confinement study

Tobacco toxicant-related exposure reduction is an important tool in harm reduction. Cigarette per day reduction (CPDR) occurs as smokers migrate from smoking cigarettes to using alternative tobacco/nicotine products, or quit smoking. Few reports characterize the dose-response relationships between CPDR and effects on exposure biomarkers, especially at the low end of CPD exposure (e.g., 5 CPD). We present data on CPDR by characterizing magnitudes of biomarker reductions. We present data from a well-controlled, one-week clinical confinement study in healthy smokers who were switched from smoking 19-25 CPD to smoking 20, 10, 5 or 0 CPD. Biomarkers were measured in blood, plasma, urine, and breath, and included smoke-related toxicants, urine mutagenicity, smoked cigarette filter analyses (mouth level exposure), and vital signs. Many of the biomarkers (e.g., plasma nicotine) showed strong CPDR dose-response reductions, while others (e.g., plasma thiocyanate) showed weaker dose-response reductions. Factors that lead to lower biomarker reductions include non-CPD related contributors to the measured response (e.g., other exposure sources from environment, life style, occupation; inter-individual variability). This study confirms CPDR dose-responsive biomarkers and suggests that a one-week design is appropriate for characterizing exposure reductions when smokers switch from cigarettes to new tobacco products.

Impact of the removal of light and mild descriptors from cigarette packages in Ontario, Canada: switching to "light replacement" brand variants

OBJECTIVE

This study assessed cessation and brand switching among smokers in Ontario, Canada after tobacco companies' voluntary removal of 'light' and 'mild' descriptors from cigarette packages.

METHOD

We analyzed longitudinal data on brand preference and cessation from a cohort of smokers (n=632) in the Ontario Tobacco Survey in Canada from 2006 to 2008 with a longitudinal regression model.

RESULTS

While cessation differed by brand variant prior to the ban (7% light vs. 3% regular; P<0.05), it did not differ by brand variant after the ban was implemented. In 2008, when light cigarette brand variants were no longer available, 33% of the sample still reported smoking lights and 31% smoked light replacement brand variants. During each subsequent follow-up, light brand smokers had 2 times the odds of smoking regular brand variants (Adjusted OR: 2.03, 95% CI 1.80,2.29), and almost 5 times the odds of using light replacement brand variants (Adjusted OR: 4.87, 95% CI 4.07,5.84), respectively, compared to continuing to smoke lights.

CONCLUSIONS

Even after removing misleading descriptors from cigarette packs, smokers continued to report using light brand variants, and many switched to newly introduced light replacement brand variants. After full implementation of the ban, cessation did not vary by brand variant.

Reduced nicotine cigarettes: smoking behavior and biomarkers of exposure among smokers not intending to quit

BACKGROUND

The U.S. FDA has the authority to limit the nicotine content of cigarettes; however, there are concerns that reduced nicotine cigarettes will be smoked more intensely and, therefore, will increase exposure to toxic chemicals in smoke. This study examined changes in consumer behavior and exposure in response to cigarettes with substantially reduced nicotine content.

METHODS

Seventy-two adult smokers completed an unblinded trial of reduced nicotine cigarettes. Participants completed a 7-day baseline period during which they smoked their usual cigarette brand, followed by consecutive 7-day periods smoking cigarettes with progressively lower nicotine levels (0.6, 0.3, and 0.05 mg emission Quest cigarettes). Nicotine dependence and withdrawal, smoking behavior, and biomarkers of exposure were assessed for each 7-day period.

RESULTS

Significant reductions in nicotine intake were observed between usual brand smoking (∼1.2 mg nicotine) and the 0.3 and 0.05 mg nicotine emission cigarettes, but not the 0.6 mg cigarette. The findings provide little evidence of compensatory smoking of Quest cigarettes, with no increases in exhaled breath carbon monoxide levels, smoking intensity, or levels of 1-hydroxypyrene across study periods. No significant differences were observed for smoking urges or measures of nicotine dependence.

CONCLUSIONS

The study adds to the evidence that cigarettes with markedly reduced nicotine content are not associated with increased smoking intensity or exposure to smoke toxicants.

IMPACT

The findings add to the evidence base on reduced nicotine content cigarettes and have the potential to inform FDA policy on nicotine levels.

Novel method to analysis benzo[a]pyrene in filter by liquid chromatography/tandem mass spectrometry: application to assess mouth level benzo[a]pyrene exposure

RATIONALE

Benzo[a]pyrene (B[a]P) is a well-known carcinogenic compound produced from incomplete combustion of organic compounds. During cigarette smoking, cigarette filters trap a portion of mainstream smoke B[a]P and accurate measurement of B[a]P levels in cigarette filter can be used to estimate human exposure level of this compound.

METHODS

A rapid and sensitive method to quantify B[a]P levels trapped by cigarette filter was developed. The method is based on liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry (LC/APPI-MS/MS). Validation was provided in smoked cigarette filter.

RESULTS

The method involved no extensive manual cleanup and concentration steps, hence is easy to use. The limit of detection was 0.064 ng/mL. The recovery ranged from 82.68% to 103.27% and the relative standard deviation (RSD) was less than 7%. A regression model between mainstream cigarette smoke and trapped B[a]P by cigarette filter was established (y = 2.5089x - 0.1851, R(2) = 0.999, n = 6). This model was applied to estimate mouth-level B[a]P exposure of smokers.

CONCLUSIONS

The LC/APPI-MS/MS method developed in this work had an excellent throughput in estimating the mouth-level exposure under natural human smoking conditions. Mouth-level B[a]P exposure based on a study of three cigarettes (8, 10 and 13 mg tar levels) showed significant positive correlations with B[a]P trapped by cigarette filter measured (y = 2.5456x - 0.5056, R(2) = 1, n = 249).

The predicted impact of reducing the nicotine content in cigarettes on alcohol use

INTRODUCTION

Product standards reducing the level of nicotine in cigarettes could significantly improve public health by reducing smoking behavior and toxicant exposure. However, relatively little is known about how the regulatory strategy could impact alcohol use, a closely related health behavior that is also a major contributor to morbidity and mortality. The primary objective of this paper is to predict the effect of nicotine reduction on alcohol use, identify priorities for future research, and highlight areas for mitigating any adverse outcomes.

METHODS

We critically reviewed and integrated literatures examining the effects of very low nicotine content (VLNC) cigarettes on smoking-related outcomes (nicotine exposure, nicotine withdrawal, and smoking as a cue to drink) and, in turn, the effects of those outcomes on alcohol use.

RESULTS

Current evidence suggests reducing the nicotine content of cigarettes may benefit public health by reducing alcohol use and problematic drinking over time as a consequence of reduced exposure to nicotine and the smoking cues associated with drinking. Nicotine withdrawal could increase risk of drinking, although these effects should be short-lived and could be mitigated by other sources of nicotine. Gender, hazardous drinking, and psychiatric comorbidities are likely to be important moderators of the effects of VLNC cigarettes.

CONCLUSIONS

It is imperative to broadly assess the public health impact of potential tobacco product regulations by including measures of closely related health behaviors that could be impacted by these interventions. Nicotine reduction in cigarettes may contribute to improved public health through reductions in alcohol use.

The changing face of tobacco use among United States youth

Tobacco use, primarily in the form of cigarettes, is the leading cause of preventable morbidity and mortality in the United States (U.S.). The adverse effects of tobacco use began to be recognized in the 1940's and new hazards of active smoking and secondhand smoke (SHS) exposure from cigarettes continue to be identified to this day. This has led to a sustained and wide-ranging array of highly effective regulatory, public health, and clinical efforts that have been informed by extensive scientific data, resulting in marked decreases in the use of cigarettes. Unfortunately, the dramatic recent decline in cigarette use in the U.S., has been accompanied by an upsurge in adolescent and young adult use of new, non-cigarette tobacco and nicotine-delivery products, commonly referred to as alternative tobacco products (ATPs). Commonly used ATPs include hookah, cigars, smokeless tobacco, and electronic cigarettes. While there have been a number of review articles that focus on adult ATP use, the purpose of this review is to provide an overview of what is, and is not known about emerging ATP use among U.S. adolescents on a national scale; as well as to identify research gaps in knowledge, and discuss future health and policy needs for this growing public health concern. This paper is not meant to systemically review all published survey data, but to present clear depiction of selected ATP usage in youth populations using national survey data.

The impact of cigarette branding and plain packaging on perceptions of product appeal and risk among young adults in Norway: A between-subjects experimental survey

OBJECTIVES

This study examined the perceptions of cigarette packaging and the potential impact of plain packaging regulations. The hypothesis was that the branded cigarette packages would be rated more positively than the corresponding plain packs with and without descriptors.

DESIGN

Between-subjects experimental online survey. Male and female participants were separately randomised to one of the three experimental conditions: fully branded cigarette packs, plain packs with descriptors and plain packs without descriptors; participants were asked to evaluate 12 individual cigarette packages. The participants were also asked to compare five pairs of packs from the same brand family.

SETTING

Norway.

PARTICIPANTS

1010 youths and adults aged 15-22.

PRIMARY OUTCOME MEASURES

Ratings of appeal, taste and harmfulness for individual packages. Ratings of taste, harm, quality, 'would rather try' and 'easier to quit' for pairs of packages.

RESULTS

Plain with and without descriptors packs were rated less positively than the branded packs on appeal (index score 1.63/1.61 vs 2.42, p<0.001), taste (index score 1.21/1.12 vs 1.70, p<0.001) and as less harmful (index score 1.0.34/0.36 vs 0.82, p<0.001) among females. Among males, the difference between the plain with and without descriptors versus branded condition was significant for appeal (index score 2.08/1.92 vs 2.58, p<0.005) and between the plain without descriptors versus branded condition for taste (index score 1.18 vs 1.70, p<0.00). The pack comparison task showed that the packs with descriptors suggesting a lower content of harmful substances, together with lighter colours, were more positively rated in the branded compared with the plain condition on dimensions less harmful (β -0.77, 95% CI -0.97 to -0.56), would rather try (β -0.32, 95% CI -0.50 to -0.14) and easier to quit (β -0.58, 95% CI -0.76 to -0.39).

CONCLUSIONS

The results indicate that a shift from branded to plain cigarette packaging could lead to a reduction in positive perceptions of cigarettes among young people.

Cigarette rod length and its impact on serum cotinine and urinary total NNAL levels, NHANES 2007-2010

INTRODUCTION

Research suggests that smokers of slim, long, or ultralong cigarettes may have a perception of reduced harm from their own brand. This study compared serum cotinine and urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol (NNAL) levels among smokers of regular-sized (68-72mm), king-sized (79-88mm), and long (94-101mm) or ultralong (110-121mm) cigarettes.

METHODS

Nationally representative data from the 2007-2008 and 2009-2010 National Health and Nutrition Examination Survey were analyzed for 3,699 current smokers aged ≥20 years. Biomarker levels were summarized using geometric means (GMs). Multivariate linear regression analyses were performed to assess the effect of cigarette rod length on log-transformed serum cotinine and creatinine-adjusted urinary total NNAL levels.

RESULTS

The GM of serum cotinine level was higher among smokers of long/ultralong cigarettes (263.15ng/ml) compared with smokers of regular-sized (173.13ng/ml) or king-sized (213.79ng/ml) cigarettes. Similarly, the GM of creatinine-adjusted NNAL levels was higher among smokers of long/ultralong cigarettes (0.48ng NNAL/mg of creatinine) compared with smokers of regular-sized (0.34ng NNAL/mg of creatinine) or king-sized (0.33ng NNAL/mg of creatinine) cigarettes. After adjusting for potential confounders, mean cotinine and NNAL levels were both significantly higher among smokers of long/ultralong cigarettes compared with levels observed in smokers of either regular-sized or king-sized cigarettes. However, no significant differences were observed between smokers of regular-sized and king-sized cigarettes in mean levels of cotinine or NNAL.

CONCLUSIONS

Significantly elevated tobacco biomarker levels were observed among smokers of long/ultralong cigarettes compared with smokers of regular-sized or king-sized cigarettes. This underscores the need to educate the public about the dangers of all tobacco products.

Relationship between knowledge about the harms of smoking and smoking status in the 2010 Global Adult Tobacco China Survey

BACKGROUND

This analysis estimates the association between smoking-related knowledge and smoking behaviour in a Chinese context. To identify the specific knowledge most directly related to smoking status, we used a novel latent variable analysis approach to adjust for the high correlations between different measures of knowledge about tobacco smoking.

METHOD

Data are from the Global Adult Tobacco China Survey, a nationally representative sample of 13 354 household-dwelling individuals 15 years of age or older. Multinomial logistic regressions estimated the association between smoking status (ie, never smoked, current smoker or past smoker) and four smoking-related beliefs: whether or not smoking causes lung cancer, heart attack and stroke, and whether or not low-tar cigarettes are less harmful. A latent variable approach reassessed these associations while taking into account the general level of knowledge about smoking.

RESULTS

After demographic variables and general knowledge about smoking had been controlled for, the belief that low-tar cigarettes are not less harmful was more prevalent in persons who had never smoked than in current smokers (OR=1.3 (95% CI 1.0 to 1.7) in men and OR=2.8 (95% CI 1.3 to 5.9) in women); this association was even stronger when past smokers and current smokers were compared (OR=2.1 (95% CI 1.5 to 3.0) in men and OR=5.0 (95% CI 1.3 to 20.1) in women).

CONCLUSIONS

Compared with those who have never smoked and those who have ceased smoking, current smokers in China are more likely to believe that low-tar cigarettes are less harmful than regular cigarettes.

Body mass index, lifetime smoking intensity and lung cancer risk

There is as yet no generally accepted explanation for the common finding that low body mass index (BMI) is associated with an increased risk of lung cancer. We investigated this association in a Canadian population-based case-control study (1996-2002) with a particular view to assessing the hypothesis that the observed association was due to residual confounding by smoking. Analyses were based on 1,076 cases and 1,439 controls who provided their height at enrollment and their weight at two points in time, at age 20 and 2 years before enrollment. BMI, in kg/m(2) , was classified into underweight (<18.5), normal (18.5-24.9), overweight (25.0-29.9), and obese (≥30). Smoking history was synthesized into a comprehensive smoking index (CSI) that integrated duration, intensity and time since quitting. Odds ratios (ORs) and 95% confidence intervals (CIs) for BMI-lung cancer associations were estimated, adjusting for CSI as well as several sociodemographic, lifestyle and occupational factors. The normal BMI category was used as the reference. Among those who were underweight at age 20, there was a lower risk of lung cancer (OR = 0.69, 95% CI: 0.50-0.95). Conversely, lung cancer risk was increased among those who were underweight 2 years before enrollment (OR = 2.30, 95% CI: 1.30-4.10). The results were almost identical when stratifying analyses based on smoking history into never/lighter and heavier smokers. The inverse association between recent BMI and lung cancer is unlikely to be largely attributable to residual confounding by smoking. Reverse causality or a true relationship between BMI and lung cancer remain plausible.

Genetic toxicology and toxicogenomic analysis of three cigarette smoke condensates in vitro reveals few differences among full-flavor, blonde, and light products

Cigarette smoking leads to various detrimental health outcomes. Tobacco companies produce different brands of cigarettes that are marketed as reduced harm tobacco products. Early examples included "light" cigarettes, which differ from regular cigarettes due to filter ventilation and/or differences in chemical constituents. In order to establish baseline similarities and differences among different tobacco brands available in Canada, the present study examined the cytotoxicity, mutagenicity, clastogenicity, and gene expression profiles of cigarette smoke condensate (CSC) from three tobacco products, encompassing a full-flavor, blonde, and "light" variety. Using the Salmonella mutagenicity assay, we confirmed that the three CSCs are mutagenic, and that the potency is related to the presence of aromatic amines. Using the Muta™Mouse FE1 cell line we determined that the CSCs were clastogenic and cytotoxic, but nonmutagenic, and the results showed few differences in potencies among the three brands. There were no clear brand-specific changes in gene expression; each brand yielded highly similar expression profiles within a time point and concentration. The molecular pathways and biological functions affected by exposure included xenobiotic metabolism, oxidative stress, DNA damage response, cell cycle arrest and apoptosis, as well as inflammation. Thus, there was no appreciable difference in toxicity or gene expression profiles between regular brands and products marketed as "light," and hence no evidence of reduced harm. The work establishes baseline CSC cytotoxicity, mutagenicity, and expression profiles that can be used as a point of reference for comparison with data generated for products marketed as reduced harm and/or modified risk tobacco products.

Tobacco carcinogen metabolites and DNA adducts as biomarkers in head and neck cancer: potential screening tools and prognostic indicators

Head and neck squamous cell carcinoma (HNSCC) is one of many cancers that are strongly associated with tobacco use. Whereas HNSCC is often seen in tobacco users, many tobacco users do not develop carcinoma; and the differences between smokers with and without HNSCC are poorly studied to date. Some smokers may be inherently more susceptible to developing carcinoma due to patterns of tobacco use, innate metabolism of carcinogens, or altered excretion. Identifying those smokers at greatest risk for HNSCC would have great benefit through targeted smoking cessation efforts and enhanced surveillance. One approach to better understand the extent of exposure to, and metabolism of, tobacco carcinogens is through the use of tobacco-specific metabolites. Tobacco-specific metabolites can identify patterns of dose, exposure, and metabolism, and perhaps ultimately characterize the important differences between smokers who develop HNSCC and smokers who do not.

Do smokers in Europe think all cigarettes are equally harmful?

BACKGROUND

Despite the ban on misleading descriptors such as light or mild cigarettes in Europe, there are still widespread misperceptions of the relative harmfulness of different brands of cigarettes among smokers. This study examined the extent to which smokers in three European countries believed that some cigarette brands are less harmful and why, using data from the International Tobacco Control (ITC) Europe surveys.

METHODS

Cross-sectional analyses were completed among nationally representative samples of 4,956 current smokers (aged ≥ 18) from Germany (n = 1,515), France (n = 1,735) and the United Kingdom (n = 1,706) conducted between September 2006 and November 2007. Logistic regression models examined whether outcomes, including beliefs that some cigarettes could be less harmful than others, varied by socio-demographic and country of residence.

FINDINGS

Around a quarter of smokers in the UK and France, and a third in Germany believed some cigarettes are less harmful than others. Overall, of smokers who falsely believed that some cigarettes are less harmful, 86.3% thought that tar/nicotine yields, 48.7% taste, and 40.4% terms on packs such as 'smooth' or 'ultra' indicated less harmful brands. About a fifth of smokers across all countries chose their brand based on health reasons, and a similar proportion gave tar yields as a reason for choosing brands.

CONCLUSIONS

Our research suggests that the current European Tobacco Products Directive is inadequate in eliminating misperceptions about the relative risk of brand descriptors on cigarettes. There is therefore an urgent need to protect smokers in Europe from these misperceptions via stronger measures such as plain packaging regulations.

A study to evaluate the effect on Mouth Level Exposure and biomarkers of exposure estimates of cigarette smoke exposure following a forced switch to a lower ISO tar yield cigarette

A forced switch to a lower ISO tar yield cigarette was used in a clinical study, conducted in Germany, that compared two methods of estimating exposure to cigarette smoke. Pre- and post-switch estimates of Mouth Level Exposure (MLE) to nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), pyrene and acrolein were obtained by chemical analysis of spent cigarette filters for nicotine content. Similarly, pre- and post-switch estimates of uptake of these smoke constituents were achieved by analysis of corresponding urinary biomarkers of exposure (BoE): total nicotine equivalents; total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL); total 1-hydroxypyrene (1-OHP), and 3-hydroxypropyl-mercapturic acid (3-HPMA), plus the nicotine metabolite cotinine, in plasma and saliva. Three hundred healthy volunteers were recruited comprising 100 smokers of each of 9-10 and 4-6 mg ISO tar yield cigarettes and 50 smokers of 1-2mg ISO tar yield cigarettes and 50 non-smokers. Fifty smokers of each of the 9-10 and 4-6 mg ISO tar yield cigarettes took part in the switching aspects of this study whilst the remaining smokers formed non-switching control groups who smoked their usual ISO tar yield cigarette throughout the study. After 5 days, all subjects were admitted into a clinic where baseline measures of MLE and BoE were obtained. The 10mg switching group was then switched to the 4 mg ISO tar yield cigarette and the 4 mg ISO tar yield switching group switched to the 1mg cigarette. Subjects returned home for 12 days, continuing to smoke the supplied cigarettes before being readmitted into the clinic where samples were collected for MLE and BoE analysis. Changes in daily exposure estimates were determined on a group and individual basis for both methods. The pre- to post-switch directional changes in MLEs and their corresponding BoEs were generally consistent and the MLE/BoE relationship maintained. Switching to a lower yield cigarette generally resulted in reductions in exposure with the resultant exposure level being similar to that seen in regular smokers of the lower yield cigarette.

Mouth level smoke exposure using analysis of filters from smoked cigarettes: a study of eight countries

The analysis of spent cigarette filters enables the estimation of the nicotine and tar (nicotine-free dry particulate matter) yields obtained by smokers in their everyday environment and has been shown to correlate well with biomarkers of exposure. Leading products across the range of ISO tar yields were selected from Australia, Brazil, Canada, Germany, Japan, New Zealand, South Africa and Switzerland. At least fifty demographically representative smokers were recruited per product. Subjects, ≥ 21 years of age and smoking ≥ 5 cigarettes per day, were asked to collect ≥ 15 filters from cigarettes they had smoked. The collected filters were analysed for nicotine and UV absorbance to enable the smokers' mouth level exposure to nicotine and tar to be estimated and a comparison of countries and tobacco blend styles to be made. Smoking history data were also collected. More than 80,000 filters were collected from 5703 smokers of 106 products from eight countries. Mean ± SD estimated nicotine exposures per cigarette and per day ranged from 0.93 ± 0.34 mg/cigarette (Brazil) to 1.77 ± 0.69 mg/cigarette (South Africa) and from 16.4 ± 11.1mg/day (Germany) to 31.5 ± 14.8 mg/day (South Africa), respectively. Male smokers obtained higher mean estimated tar and nicotine exposures than female smokers. These gender differences were statistically significant for six countries. Significant correlations were found between estimated nicotine exposure and ISO nicotine yield, and between estimated tar exposure and ISO tar yield (p<0.001).

Estimation and correlation of cigarette smoke exposure in Canadian smokers as determined by filter analysis and biomarkers of exposure

A clinical study conducted in Canada compared two methods of estimating exposure to cigarette smoke in 192 volunteer subjects: 43 smokers of 4-6 mg, 49 of 8-12 mg and 50 of 14-15 mg ISO tar yield cigarettes and 50 non-smokers. Estimates of mouth level exposure (MLE) to nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), pyrene and acrolein were obtained by chemical analysis of spent cigarette filters. Estimates of smoke constituent uptake were achieved by analysis of urinary biomarkers for total nicotine equivalents (nicotine, cotinine, trans-3'-hydroxycotinine plus their glucuronide conjugates), NNK (total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) plus glucuronide), pyrene (1-hydroxy pyrene plus glucuronide) and acrolein (3-hydroxylpropyl-mercapturic acid) plus the nicotine metabolite cotinine in plasma and saliva. The objective of our study was to confirm the correlations between measures of human exposure obtained by filter analysis and biomarkers. Significant correlations (p<0.001) were found between MLE and the relevant biomarker for each smoke constituent. The adjusted values of the Pearson correlation coefficients (r) were 0.80 (nicotine), 0.77 (acrolein) and 0.44 (pyrene). NNK correlations could not be obtained because of the low NNK yield of Canadian cigarettes. Unexpectedly high levels of acrolein biomarker found in non-smokers urine on one of the two days sampled emphasised the need for more than one sampling occasion per period and an awareness of non-tobacco sources of smoke constituents under investigation. No consistent dose response, in line with ISO tar yield smoked, of MLE estimates was found for nicotine, pyrene and acrolein and respective biomarkers. The influence of demographics on our results has also been examined.

A survey of mouth level exposure to cigarette smoke in the United States

Smoke yields determined by a machine-based smoking method cannot adequately predict exposures experienced by human smokers. In this work, a filter analysis technique which addresses this fundamental limitation was used to measure mouth level exposures (MLE) to tar and nicotine in 1330 smokers of 26 brand-styles of US cigarettes covering a wide range of machine-generated yields. Despite the high degree of variability observed among individual smokers, MLEs were significantly correlated with machine-derived tar and nicotine yields (r=0.423 for nicotine MLE/cigarette; r=0.493 for tar MLE/cigarette; p<0.001 for both). Mean tar and nicotine MLE was higher for males than for females. Mean MLE across races was generally similar. Menthol cigarettes tended toward lower MLE than non-menthol cigarettes and King-Size cigarettes (≈ 83 mm) tended toward lower MLE than 100's cigarettes (≈ 100 mm), though those trends were not statistically significant. There were good agreements between MLEs measured in a group of 159 subjects smoking their usual cigarette brand-style on two separate occasions and between two independent groups of subjects smoking the same brand-styles. The results indicated that the filter analysis method used had sufficient precision to show similarity among groups.

Impact of the removal of misleading terms on cigarette pack on smokers' beliefs about 'light/mild' cigarettes: cross-country comparisons

AIM

This paper examines how smokers' beliefs about 'light/mild' cigarettes in Australia, Canada and the United Kingdom were affected by the removal of misleading 'light/mild' terms from packs.

DESIGN, SETTING AND PARTICIPANTS

  The data come from the first seven waves (2002-09) of the International Tobacco Control Policy Evaluation (ITC) Four-Country Survey, an annual cohort telephone survey of adult smokers in Canada, the United States, the United Kingdom and Australia (21 613 individual cases). 'Light' and 'mild' descriptors were removed in 2003 in the United Kingdom, in 2006 in Australia and in 2007 in Canada. We compare beliefs about 'light' cigarettes both before and after the bans, with those of smokers in the United States serving as the control condition.

MEASURES

  Smokers' beliefs about 'light' cigarettes were assessed using a set of statements rated on a five-point 'agree'-'disagree' scale.

FINDINGS

  The proportions of respondents reporting misperceptions about light cigarettes declined between 2002 and 2009 in all four countries. There were marked temporary reductions in reported misperceptions in the United Kingdom and Australia, but not in Canada, following the removal of 'light/mild' descriptors.

CONCLUSIONS

  Removal of 'light/mild' descriptors and tar, nicotine and carbon monoxide yield information from cigarette packs is insufficient to effectively eliminate false beliefs. The combination of alternative descriptors and design features that produce differences in taste strength and harshness, independent of actual intakes, are sufficient to produce or sustain the same misbeliefs.

Molecular changes in the esophageal epithelium after a subchronic exposure to cigarette smoke in the presence of bile-acid reflux

BACKGROUND

Gastroesophageal reflux of bile acids plays an important role in the development of Barrett's esophagus (BE)-associated esophageal adenocarcinoma (EAC). Cigarette smoke has been demonstrated to exacerbate the effects of reflux and thus the initial stages of EAC carcinogenesis. To date, no in vivo studies have been conducted to look at the concomitant effects of cigarette smoke and bile acids on EAC incidence.

METHODS

In this pilot study, rats that underwent esophagoduodenal anastomosis (EDA) surgery to induce reflux were exposed to whole-body cigarette smoke 3 weeks after surgery. Smoke exposure (135 mg/m³/day) was done for 4 h/day for 5 consecutive days and animals were euthanized after a 48-h recovery period.

RESULTS

Exposure to EDA-smoke accelerated the development of BE when compared to EDA-air. The presence of reflux caused a significant 3.5-fold increase in nuclear factor-κB-inducing kinase (NIK) staining (1.47 ± 0.6; p = 0.01). Animals with both reflux and smoking had the highest (10-fold; 4 ± 0.9) induction of cyclooxygenase-2 (COX-2) expression (p < 0.05). Similarly, there was a 10-fold increase in 4-aminobiphenyl (4-ABP) protein adducts identified in all smoke-exposed animals (p < 0.01).

CONCLUSION

Cigarette smoke aggravates reflux-induced BE and potentially accelerates the progression of BE to EAC through the loss of manganese superoxide dismutase (MnSOD), and overexpression of NF-κB- and COX-2-mediated factors.

Tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in smokers in the United States: NHANES 2007-2008

The tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), has been measured in urine samples from all participants aged 6 years and older from the National Health and Nutrition Examination Survey 2007-2008. Participants with a serum cotinine concentration of ≥ 10 ng/mL were identified as tobacco users, primarily cigarette smokers. Regression models were developed to calculate geometric mean NNAL concentrations adjusted for serum cotinine, urinary creatinine, cigarettes per day, and Federal Trade Commission tar values of the cigarettes smoked. Significant differences were found by gender (p=0.003) and race/ethnicity (p=0.022 for non-Hispanic white versus non-Hispanic black smokers), but not by menthol type of the cigarettes. Females and non-Hispanic white smokers had the highest adjusted means for urinary NNAL (353 and 336 pg/mL, respectively). The results from this study demonstrated significant relationships between NNAL concentrations and serum cotinine (p<0.001) and urine creatinine (p<0.001). The joint effect of linear and quadratic terms for number of cigarettes smoked per day was also statistically significant (p=0.001). In addition to addressing current NNK exposure levels, these results will form a baseline for future estimates of tobacco users' exposure to this carcinogen.

Mutagenicity of 11 cigarette smoke condensates in two versions of the mouse lymphoma assay

Cigarette smoke condensate (CSC) is genotoxic in nearly all assays in which it has been tested. In this study, we investigated the mutagenicity of 11 CSCs using the microwell and soft-agar versions of the mouse lymphoma assay (MLA). These CSCs were prepared from commercial or experimental cigarettes, 10 of them were produced using International Organisation for Standardisation (ISO) conditions and one CSC was generated using intense Massachusetts Department of Public Health (MDPH) conditions. In the presence of rat liver S9, the L5178Y/Tk(+/-) mouse lymphoma cells were treated with 11 CSCs at different concentrations (25-200 μg/ml) for 4 h. All CSCs resulted in dose-dependent increases of both cytotoxicity and mutagenicity in both versions of the MLA. The mutagenic potencies of the CSCs were calculated as mutant frequency per microgram CSC from the slope of the linear regression of the dose-response curves and showed no correlations with the tar yield of the cigarette or nicotine concentrations of the CSCs. Comparing two CSCs produced from the same commercial cigarettes using two different smoking conditions, the one generated under ISO conditions was more mutagenic than the other generated under intense conditions on a per microgram CSC basis. We also examined the loss of heterozygosity (LOH) at four microsatellite loci spanning the entire chromosome 11 for the mutants induced by 11 CSCs. The most common type of mutation observed was LOH with chromosome damage spanning less than ∼34 Mbp. These results indicate that the MLA identifies different genotoxic potencies among a variety of CSCs and that the results from both versions of the assay are comparable.

Urinary metabolites of polycyclic aromatic hydrocarbons in workers exposed to vapours and aerosols of bitumen

Urinary hydroxylated metabolites of polycyclic aromatic hydrocarbons (PAH) were investigated as potential biomarkers of bitumen exposure in a cross-shift study in 317 exposed and 117 non-exposed workers. Personal measurements of the airborne concentration of vapours and aerosols of bitumen during a working shift were weakly associated with post-shift concentrations of 1-hydroxypyrene (1-OHP) and 1-, 2+9-, 3- and 4-hydroxyphenanthrenes (further referred to their sum as OHPHE), but not 1- and 2-hydroxynaphthalene (OHNA). Smoking showed a strong influence on the metabolite concentrations, in particular on OHNA. Pre-shift concentrations of 1-OHP and OHPHE did not differ between the study groups (P = 0.16 and P = 0.89, respectively). During shift, PAH metabolite concentrations increased in exposed workers and non-exposed smokers. Statistical modelling of post-shift concentrations revealed a small increase in 1-OHP by a factor of 1.02 per 1 mg/m(3) bitumen (P = 0.02) and 1.04 for OHPHE (P < 0.001). A group difference was observed that was diminished in non-smokers. Exposed non-smokers had a median post-shift 1-OHP concentration of 0.42 μg/l, and non-smoking referents 0.13 μg/l. Although post-shift concentrations of 1-OHP and OHPHE were slightly higher than those in the general population, they were much lower than in coke-oven workers. The small content of PAHs in vapours and aerosols of bitumen, the increasing use of additives to asphalt mixtures, the strong impact of smoking and their weak association with airborne bitumen limit the use of PAH metabolites as specific biomarkers of bitumen exposure.

Beliefs about the relative harm of "light" and "low tar" cigarettes: findings from the International Tobacco Control (ITC) China Survey

BACKGROUND

Many smokers in Western countries perceive "light" or "low tar" cigarettes as less harmful and less addictive than "regular" or "full flavoured" cigarettes. However, there is little research on whether similar perceptions exist among smokers in low and middle incomes, including China.

OBJECTIVE

To characterise beliefs about "light" and "low tar" cigarettes among adult urban smokers in China.

METHODS

We analysed data from Wave 1 of the ITC China Survey, a face-to-face household survey of 4732 adult Chinese smokers randomly selected from six cities in China in 2006. Households were sampled using a stratified multistage design.

FINDINGS

Half (50.0%) of smokers in our sample reported having ever tried a cigarette described as "light," "mild" or "low tar". The majority of smokers in our sample (71%) believed that "light" and/or "low tar" cigarettes are less harmful compared to "full flavoured" cigarettes. By far the strongest predictor of the belief that "light" and/or "low tar" cigarettes are less harmful was the belief that "light" and/or "low tar" cigarettes feel smoother on the respiratory system (p<0.001, OR=53.87, 95% CI 41.28 to 70.31).

CONCLUSION

Misperceptions about "light" and/or "low tar" cigarettes were strongly related to the belief that these cigarettes are smoother on the respiratory system. Future tobacco control policies should go beyond eliminating labelling and marketing that promotes "light" and "low tar" cigarettes by regulation of product characteristics (for example, additives, filter vents) that reinforce perceptions that "light" and "low tar" cigarettes are smoother on the respiratory system and therefore less harmful.

Applying tobacco carcinogen and toxicant biomarkers in product regulation and cancer prevention

Tobacco carcinogen and toxicant biomarkers are metabolites or protein or DNA adducts of specific compounds in tobacco products. Highly reliable analytical methods, based mainly on mass spectrometry, have been developed and applied in large studies of many of these biomarkers. A panel of tobacco carcinogen and toxicant biomarkers is suggested here, and typical values for smokers and nonsmokers are summarized. This panel of biomarkers has potential applications in the new and challenging area of tobacco product regulation and in the development of rational approaches to cancer prevention by establishing carcinogen and toxicant uptake and excretion in people exposed to tobacco products.

Micronuclei frequencies in peripheral blood and buccal exfoliated cells of young smokers and non-smokers

Cytogenetic biomarkers, such as micronuclei in peripheral blood or oral mucosa, are widely used for evaluation of exposure to genotoxins or carcinogens. Tobacco is one of the strongest carcinogens, responsible for development of different types of cancers. The aim of this study was to assess the genotoxicity of cigarette consumption in young smokers and to correlate results of cytogenetic analysis in peripheral blood lymphocytes and exfoliated buccal cells. The study was conducted on samples taken from 43 smokers and 44 non-smokers, young individuals from Bosnia and Herzegovina. Significantly higher frequency of micronuclei in peripheral blood lymphocytes was observed in smokers (p < 0.05). No significant correlations were found for age, duration and intensity of smoking, and frequency of micronuclei in lymphocytes. Significantly higher frequency of degenerated (apoptotic) buccal cells was also revealed in smokers (p < 0.05). The frequency of apoptotic cells in smokers was significantly influenced by the age of participants (F = 8.649; p < 0.01) and duration of smoking (F = 5.389; p < 0.05). Results of cytogenetic analysis conducted in peripheral blood and exfoliated buccal cells are in significant positive correlation, indicating complementarities of those analyses.

DNA damage response induced by exposure of human lung adenocarcinoma cells to smoke from tobacco- and nicotine-free cigarettes

Cigarette smoke (CS) is the major cause of lung cancer and contributes to the development of other malignancies. Attempts have been made to construct reduced toxicity cigarettes, presumed to have diminished genotoxic potential. One such product on the market is the tobacco and nicotine free (T&N-free) cigarette type made from lettuce and herbal extracts. We have recently developed a sensitive assay of the genotoxicity of CS based on cytometric analysis of induction of the DNA damage response (DDR) in normal human pulmonary endothelial or A549 pulmonary adenocarcinoma cells. In the present study, we observed that exposure of A549 cells to CS from T/N-free cigarettes induced a smoke-dose dependent DDR as evidenced by phosphorylation (activation) of the Ataxia telangiectasia mutated (ATM) protein kinase and of the histone H2AX (γH2AX). The extent of DDR induced by T&N-free smoke was distinctly greater than that induced by comparable doses of CS from reference cigarettes (2R4F) containing tobacco and nicotine. The pattern of DDR induced by T&N-free smoke was similar to that of 2R4F cigarettes in terms of the cell cycle phase specificity and involvement of reactive oxygen species (ROS). The data also imply that similar to 2R4F exposure of cells to T/N-free smoke leads to formation of double-strand DNA breaks (DSBs) resulting from collapse of replication forks upon collision with the primary ssDNA lesions induced by smoke. Since DSBs are potentially carcinogenic our data indicate that smoking tobacco and nicotine-free cigarettes is at least as hazardous as smoking cigarettes containing tobacco and nicotine.

Cigarette filter-based assays as proxies for toxicant exposure and smoking behavior--a literature review

BACKGROUND

Cigarettes are being marketed with filters that differ in composition and design. The filters have different toxicant trapping efficiencies, and smoking stains reflect variations in smoking behavior. Presented herein are the results of a structured literature review that was done to identify cigarette filter-based assays that may serve as proxies for mouth-level exposure and assessing smoking methods.

METHODS

A search of the published scientific literature and internal tobacco company documents from 1954 to 2009 was carried out.

RESULTS

The literature search identified diverse schemes for assessing cigarette filters, including visual inspection and digital imaging of smoked-stained spent filters, and quantitative determinations for total particulate matter (TPM), nicotine, and solanesol. The results also showed that: (a) there are sufficient data to link filter-based chemical measures to standardized smoking machine-measured yields of tar and nicotine; (b) TPM eluted from filters or in chemical digest of filters can be used to estimate the efficiency of the filter for trapping smoke solids; (c) visual and digital inspection of spent filters is useful in finding indicators of variations in smoking behaviors; and (d) there is a correlation between solanesol and nicotine measured in filters and exposure biomarkers in smokers.

CONCLUSIONS

The cigarette filter may prove useful in estimating smoking behaviors such as filter vent blocking and puffing intensity, and may have utility as proxy measures of mouth-level smoke exposure in clinical trials. Additional investigations are needed to compare the different proposed assay schemes and the assay results with measurements of human biomarker assays of smoke exposure.

Reduced nicotine content cigarettes: effects on toxicant exposure, dependence and cessation

AIMS

To examine the effects of reduced nicotine cigarettes on smoking behavior, toxicant exposure, dependence and abstinence.

DESIGN

Randomized, parallel arm, semi-blinded study. Setting University of Minnesota Tobacco Use Research Center.

INTERVENTIONS

Six weeks of: (i) 0.05 mg nicotine yield cigarettes; (ii) 0.3 mg nicotine yield cigarettes; or (iii) 4 mg nicotine lozenge; 6 weeks of follow-up. Measurements Compensatory smoking behavior, biomarkers of exposure, tobacco dependence, tobacco withdrawal and abstinence rate.

FINDINGS

Unlike the 0.3 mg cigarettes, 0.05 mg cigarettes were not associated with compensatory smoking behaviors. Furthermore, the 0.05 mg cigarettes and nicotine lozenge were associated with reduced carcinogen exposure, nicotine dependence and product withdrawal scores. The 0.05 mg cigarette was associated with greater relief of withdrawal from usual brand cigarettes than the nicotine lozenge. The 0.05 mg cigarette led to a significantly higher rate of cessation than the 0.3 mg cigarette and a similar rate as nicotine lozenge.

CONCLUSION

The 0.05 mg nicotine yield cigarettes may be a tobacco product that can facilitate cessation; however, future research is clearly needed to support these preliminary findings.

Clinical trials methods for evaluation of potential reduced exposure products

Potential reduced exposure products (PREPs) to tobacco toxicants may have promise in reducing tobacco-related morbidity or mortality or may promote greater harm to individuals or the population. Critical to determining the risks or benefits from these products are valid human clinical trial PREP assessment methods. Such an assessment involves determining the effects of these products on biomarkers of exposure and effect, which serve as proxies for harm, and assessing the potential for consumer uptake and abuse of the product. This article identifies critical methodologic issues associated with PREP assessments, reviews the methods that have been used to assess PREPs, and describes the strengths and limitations of these methods. Additionally, recommendations are provided for clinical trial PREP assessment methods and future research directions in this area based on this review and on the deliberations from a National Cancer Institute sponsored Clinical Trials PREP Methods Workshop.

Evaluation of in vitro assays for assessing the toxicity of cigarette smoke and smokeless tobacco

BACKGROUND

In vitro toxicology studies of tobacco and tobacco smoke have been used to understand why tobacco use causes cancer and to assess the toxicologic impact of tobacco product design changes. The need for toxicology studies has been heightened given the Food and Drug Administration's newly granted authority over tobacco products for mandating tobacco product performance standards and evaluate manufacturers' health claims about modified tobacco products. The goal of this review is to critically evaluate in vitro toxicology methods related to cancer for assessing tobacco products and to identify related research gaps.

METHODS

PubMed database searches were used to identify tobacco-related in vitro toxicology studies published since 1980. Articles published before 1980 with high relevance also were identified. The data were compiled to examine (a) the goals of the study, (b) the methods for collecting test substances, (c) experimental designs, (d) toxicologic end points, and (e) relevance to cancer risk.

RESULTS

A variety of in vitro assays are available to assess tobacco smoke that address different modes of action, mostly using non-human cell models. However, smokeless tobacco products perform poorly in these assays. Although reliable as a screening tool for qualitative assessments, the available in vitro assays have been poorly validated for quantitative comparisons of different tobacco products. Assay batteries have not been developed, although they exist for nontobacco assessments. Extrapolating data from in vitro studies to human risks remains hypothetical.

CONCLUSIONS

In vitro toxicology methods are useful for screening toxicity, but better methods are needed for today's context of regulation and evaluation of health claims.