Comparison of emissions across tobacco products: A slippery slope in tobacco control.

In this narrative review, we highlight the challenges of comparing emissions from different tobacco products under controlled laboratory settings (using smoking/vaping machines). We focus on tobacco products that generate inhalable smoke or aerosol, such as cigarettes, cigars, hookah, electronic cigarettes, and heated tobacco products. We discuss challenges associated with sample generation including variability of smoking/vaping machines, lack of standardized adaptors that connect smoking/vaping machines to different tobacco products, puffing protocols that are not representative of actual use, and sample generation session length (minutes or number of puffs) that depends on product characteristics. We also discuss the challenges of physically characterizing and trapping emissions from products with different aerosol characteristics. Challenges to analytical method development are also covered, highlighting matrix effects, order of magnitude differences in analyte levels, and the necessity of tailored quality control/quality assurance measures. The review highlights two approaches in selecting emissions to monitor across products, one focusing on toxicants that were detected and quantified with optimized methods for combustible cigarettes, and the other looking for product-specific toxicants using non-targeted analysis. The challenges of data reporting and statistical analysis that allow meaningful comparison across products are also discussed. We end the review by highlighting that even if the technical challenges are overcome, emission comparison may obscure the absolute exposure from novel products if we only focus on relative exposure compared to combustible products.

Menthol and filter ventilation in cigarettes: prevalence estimates and relationships with harm perception and smoking exposure.

INTRODUCTION: Menthol and filter ventilation (FV) contribute to cigarette appeal. This observational study examines the US prevalence of menthol versus non-menthol cigarette use by FV and how harm perceptions, cigarettes per day and biomarkers of exposure vary. METHODS: Population Assessment of Tobacco and Health Study (2013-2014) was merged with FV levels of cigarettes and restricted to daily smoking adults who had a usual cigarette variety and did not regularly use other tobacco (N=1614). Weighted descriptive statistics identified the prevalence of menthol and non-menthol use by low (0.02%-10.04%), moderate (10.05%-23.40%), high (23.41%-28.12%) and very high FV (28.13%-61.10%). Weighted linear regression was used to examine differences in outcomes by menthol/FV adjusted for potential confounders. RESULTS: The prevalence of a usual brand that was non-menthol, low FV was the lowest at 2.91%. Using non-menthol cigarettes with high and very high FV (≥23.4%) vs low FV (≤10.04%) was associated with a greater likeliness of misperceiving one's cigarette variety to be less harmful than other varieties (p values<0.05). Total nicotine equivalent, biomarker for nicotine exposure, was elevated (p values<0.05) among three non-menthol groups (low, moderate and very high FV) compared with two menthol groups (moderate, very high FV). CONCLUSION: The well-documented harm misperception linked to higher FV is more apparent in those using non-menthol than menthol cigarettes. Increased exposures were observed among some non-menthol cigarette users compared with some menthol cigarette users. These results should by no means delay a menthol ban but rather motivate concerted public health efforts to accompany the menthol ban to maximise smoking cessation.

Measurement of cigarette relighting: A common but understudied behavior.

OBJECTIVE: Relighting, i.e., extinguishing, saving, and later relighting and smoking unfinished cigarettes, appears prevalent, may be associated with nicotine dependence and negative health outcomes, yet is poorly understood. We estimate the prevalence, frequency, correlates of, and reasons for, cigarette relighting. METHODS: Survey respondents (n=676) were 18-45-year-old US-based Amazon Mechanical Turk (MTurk) participants who smoked cigarettes every/some days. Items assessed frequency of and reasons for relighting. Reported smoking sessions per day were compared to calculations based on reported cigarettes per day (CPD) and relighting frequency. RESULTS: Seventy-two percent of those who smoked reported relighting cigarettes. Reasons included not having time to finish (77%), not feeling like finishing (75%), saving money or avoiding wasting (70%), and making cigarettes last longer (59%). Nearly half (44%) relight to cut down and 34% to reduce harm. Hispanic (OR=1.73, CI:1.03-2.91) and non-Hispanic Black respondents (OR= 2.23, CI:1.20-4.10) had higher odds of relighting than others, as did those who smoke within 30minutes of waking (OR=2.45, CI:1.33-4.52) or wake up at night to smoke (OR=2.40, CI:1.68-3.44) (all ps <0.05). Respondents demonstrated low consistency in reporting the number of times they smoke (first-lit and relit) compared to calculations based on CPD and relighting frequency. CONCLUSIONS: Relighting is associated with race, ethnicity, nicotine dependence, and is often done to save money, cut down smoking, and reduce harm. Among those who relight, "smoking session" frequency seemed to be underestimated. Single item smoking frequency measures may not be ideal for individuals who smoke and relight.

Heterogeneity of Harmful Constituent Profiles in Smokeless Tobacco Products from Five African Countries.

Addictive, toxic, and carcinogenic constituents present in smokeless tobacco (SLT) products are responsible for the harmful effects associated with SLT use. There are limited data on levels of such constituents in SLT products used in Africa, a region with high prevalence of SLT use and the associated morbidity and mortality. Manufactured and custom-made SLT products were purchased from five African countries (South Africa, Uganda, Mauritania, Nigeria, and Zambia) using a standard approach for sample collection, labeling, and storage. Moisture content, pH, total and unprotonated (biologically available) nicotine, five tobacco-specific N-nitrosamines (TSNA), 10 polycyclic aromatic hydrocarbons (PAH), five metals and metalloids (As, Cd, Cr, Ni, and Pb), nitrate, and nitrite were analyzed. A total of 54 samples representing 15 varieties of manufactured SLT products and 13 varieties of custom-made SLT products were purchased and analyzed. In all samples, the total nicotine ranged from 1.6 to 20.5 mg/g product and unprotonated nicotine accounted for 5.3-99.6% of the total nicotine content. The sum of all five TSNA ranged from 1.6 to 100 µg/g product, with significant within-country variations observed across both the manufactured and custom-made varieties. Significant variations were also found for PAH, metals and metalloids, nitrates, and nitrites. This is the most comprehensive report on the chemical profiling of products from African countries. This is also the first study illustrating the variability of harmful constituents within the same types and brands of African SLT. Our findings emphasize the need for consumer education and interventions to reduce SLT use in Africa. The data reported here can be useful to regulators in considering measures to prevent the occurrence of high levels of known toxicants and carcinogens in manufactured products.

Illusion of filtration: Evidence from tobacco industry documents.

INTRODUCTION: We compared the design features of popular filtered and non-filtered cigarettes sold in the United States between 1960 and 1990, to assess the relationship between cigarette filter and tobacco weight. METHODS: We analyzed data on the design features of six popular filtered and three non-filtered cigarette brands sold in the US including the weight of tobacco used provided in the Cigarette Information Reports produced by Philip Morris Tobacco Company between 1960 and 1990. We also collected information on other design features such as stick length and circumference, the percentage of reconstituted tobacco in the blend, among other product parameters. We used joinpoint regression to test for trends in outcome variables for each brand assessed between 1960 and 1990. RESULTS: In all years, filtered cigarettes had less tobacco by weight compared to non-filtered cigarettes. The lower average weight of tobacco found in filtered cigarettes appears to be due to a combination of factors including stick and filter length, and the amount of reconstituted tobacco in the blend. The average percentages of total alkaloids and expanded tobacco increased over time but were similar between filtered and non-filtered brands. CONCLUSIONS: While various design features of popular filtered and non-filtered brands changed between 1960 and 1990, the observed reduction in tobacco weight among filtered brands was perhaps the most salient in terms of disease risk. Less tobacco in a filtered cigarette calls into question the presumed exclusive role of cigarette filter tips in the reduced health risks of filtered versus non-filtered cigarette smoking.

Switching to cigarette brand variants with different filter ventilation levels: a descriptive analysis.

BACKGROUND: Regulation of filter ventilation (FV) has been proposed to reduce misperceptions that ventilation reduces the health risks of smoking. We describe smoking behaviour and exposure after switching to a cigarette brand variant (CBV) with a different FV level. METHODS: Wave 1 (2013-2014) of the Population Assessment of Tobacco Use and Health Study was merged with FV levels of participants' CBV and restricted to adults with a usual CBV, smoked daily and included in wave 4 (2016-2017; n=371). Generalised estimation equations method modelled changes in FV and cigarettes per day (CPD), quit interest, total nicotine equivalents (TNE) and total NNAL (biomarker of a tobacco-specific carcinogen). FV change was defined as a change in CBV resulting in a ≥20% increase or decrease in FV. Secondary analyses used FV change based on an increase from <5% to >10% or a decrease from >10% to <5%. RESULTS: A non-significant pattern indicating an increase of 0.97 and 0.49 CPD was observed among those who switched to a CBV and increased FV by ≥20% and from <5% to >10%, respectively. A non-significant pattern indicating a decrease of 1.31 and 1.97 CPD was observed among those who decreased FV by ≥20% and from >10% to <5%, respectively. Changes in quit interest and biomarkers were also non-significant with one exception: greater reduction in TNE among those who decreased from >10% to <5% FV versus no change (-8.51 vs -0.25 nmol/mg creatinine; p=0.0447). CONCLUSIONS: Switching to CBV with lower FV does not appear to increase exposure and may even reduce exposure for some. Additional investigations are recommended to confirm these descriptive findings.

Is perception reality? Associations among "light" cigarettes and number of cigarettes smoked per day.

INTRODUCTION: Cigarette filter ventilation and light descriptors are associated with lowered perceptions of risk and smoking more cigarettes per day (CPD). This study examined the relationship between usual cigarette ventilation, perception, and CPD. METHODS: A crowdsourced sample (N = 995) of individuals who smoke higher-ventilated (=>20% ventilation) or lower-ventilated (=<10% ventilation) cigarettes identified their usual cigarette as "light" or "full flavor", and reported their average CPD. RESULTS: We found: 1) no association between ventilation status and perception of light versus full flavor (AUC=0.58), with the inaccurate perception being more prevalent in younger individuals (p = 0.041) and those who smoke L&M (73%, p < 0.001) and Camel (61%, p = 0.006) brands; and 2) perception, but not ventilation of usual cigarette, was significantly associated with CPD (p = 0.006), with individuals who perceived their cigarettes as light reporting an average of 13% more cigarettes per day (2.6 CPD), compared to those who perceived their cigarette as full flavor. CONCLUSIONS: Perceptions of light versus full-flavor, but not ventilation status, predicted CPD. These findings may inform anti-smoking health communication strategies and smoking cessation interventions. IMPLICATIONS: Tobacco control policies should eradicate the perception of cigarettes as light or full-flavored. Future research investigating the associations between cigarette filter ventilation and smoking behavior should consider the confounding effects that may lie in an individual's perceptions of their cigarettes.

Risk perceptions and continued smoking as a function of cigarette filter ventilation level among US youth and young adults who smoke.

BACKGROUND: While evidence demonstrates that the industry's marketing of cigarettes with higher filter ventilation (FV) misleads adults about their health risks, there is no research on the relationships between FV, risk perceptions and smoking trajectories among youth (ages 12-17) and young adults (ages 18-24). METHODS: Data on FV levels of major US cigarette brands/sub-brands were merged with the Population Assessment of Tobacco and Health Study to examine whether FV level in cigarettes used by wave 1 youth/young adults (n=1970) predicted continued smoking at waves 2-4, and whether those relationships were mediated by perceived risk of their cigarette brand. FV was modelled based on tertiles (0.2%-11.8%, low; 11.9%-23.2%, moderate; 23.3%-61.1%, high) to predict daily smoking, past 30-day smoking and change in number of days smoking at successive waves. RESULTS: The odds of perceiving one's brand as less harmful than other cigarette brands was 2.21 times higher in the high versus low FV group (p=0.0146). Relationships between FV and smoking outcomes at successive waves were non-significant (all p>0.05). CONCLUSION: Youth and young adults who use higher FV cigarettes perceived their brand as less harmful compared with other brands. However, level of FV was not associated with continued smoking.

Association of Urinary Biomarkers of Smoking-Related Toxicants with Lung Cancer Incidence in Smokers: The Multiethnic Cohort Study.

BACKGROUND: While cigarette smoking is the leading cause of lung cancer, the majority of smokers do not develop the disease over their lifetime. The inter-individual differences in risk among smokers may in part be due to variations in exposure to smoking-related toxicants. METHODS: Using data from a subcohort of 2,309 current smokers at the time of urine collection from the Multiethnic Cohort Study, we prospectively evaluated the association of ten urinary biomarkers of smoking-related toxicants [total nicotine equivalents (TNE), a ratio of total trans-3'-hydroxycotinine (3-HCOT)/cotinine (a phenotypic measure of CYP2A6 enzymatic activity), 4-(methylnitrosamino)-1-3-(pyridyl)-1-butanol (NNAL), S-phenylmercapturic acid (SPMA), 3-hydroxypropyl mercapturic acid (3-HPMA), phenanthrene tetraol (PheT), 3-hydroxyphenanthrene (PheOH), the ratio of PheT/PheOH, cadmium (Cd), and (Z)-7-(1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopenyl]hept-5-enoic acid (8-iso-PGF2α)] with lung cancer risk (n = 140 incident lung cancer cases over an average of 13.4 years of follow-up). Lung cancer risk was estimated using Cox proportional hazards models. RESULTS: After adjusting for decade of birth, sex, race/ethnicity, body mass index, self-reported pack-years, creatinine, and urinary TNE (a biomarker of internal smoking dose), a one SD increase in log total 3-HCOT/cotinine (HR, 1.33; 95% CI, 1.06-1.66), 3-HPMA (HR, 1.41; 95% CI, 1.07-1.85), and Cd (HR, 1.45; 95% CI, 1.18-1.79) were each associated with increased lung cancer risk. CONCLUSIONS: Our study demonstrates that urinary total 3-HCOT/cotinine, 3-HPMA, and Cd are positively associated with lung cancer risk. These findings warrant replication and consideration as potential biomarkers for smoking-related lung cancer risk. IMPACT: These biomarkers may provide additional information on lung cancer risk that is not captured by self-reported smoking history or TNE. See related commentary by Etemadi et al., p. 289.

Cigarette Smoke Extract, but Not Electronic Cigarette Aerosol Extract, Inhibits Monoamine Oxidase in vitro and Produces Greater Acute Aversive/Anhedonic Effects Than Nicotine Alone on Intracranial Self-Stimulation in Rats.

Conventional tobacco cigarettes appear to have greater abuse liability than non-combusted products such as electronic cigarettes (ECs) and nicotine replacement therapy (NRT). This may be due to the higher levels of behaviorally active non-nicotine constituents [e.g., monoamine oxidase (MAO) inhibitors such as ß-carbolines] in cigarette smoke (CS) compared to non-combusted products. To evaluate this hypothesis, the current studies compared the relative abuse liability of CS and EC aerosol extracts containing nicotine and a range of non-nicotine constituents to that of nicotine alone (NRT analog) using intracranial self-stimulation (ICSS) in rats. Effects of formulations on brain MAO activity in vitro and ex vivo were also studied to evaluate the potential role of MAO inhibition in the ICSS study. CS extract contained higher levels of several behaviorally active non-nicotine constituents (e.g., the ß-carbolines norharmane and harmane) than EC extract. Nicotine alone reduced ICSS thresholds at a moderate nicotine dose, suggesting a reinforcement-enhancing effect that may promote abuse liability, and elevated ICSS thresholds at a high nicotine dose, suggesting an aversive/anhedonic effect that may limit abuse liability. CS extract elevated ICSS thresholds to a greater degree than nicotine alone at high nicotine doses. Effects of EC extract on ICSS did not differ from those of nicotine alone. Finally, CS extract significantly inhibited MAO-A and MAO-B activity in vitro, whereas EC extract and nicotine alone did not. None of the formulations inhibited MAO measured ex vivo. These findings indicate greater acute aversive/anhedonic effects for CS extract compared to nicotine alone, suggesting lower abuse liability. Although confirmation of our findings using other dosing regimens, preclinical addiction models, and tobacco product extracts is needed, these findings suggest that the centrally-mediated effects of MAO inhibitors and other non-nicotine constituents may not account for the greater abuse liability of cigarettes compared to non-combusted products. Nonetheless, identifying the specific constituent(s) mediating the effects of CS extracts in this study could help clarify mechanisms mediating tobacco addiction and inform FDA product standards.

Simultaneous analysis of urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, N'-nitrosonornicotine, and cotinine by liquid chromatography-tandem mass-spectrometry.

Biomarkers of exposure to harmful tobacco constituents are key tools for identifying individuals at risk and developing interventions and tobacco control measures. However, tobacco biomarker studies are scarce in many parts of the world with high prevalence of tobacco use. Our goal was to establish a robust method for simultaneous analysis of urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), N'-nitrosonornicotine (NNN), and cotinine at the Advanced Centre for Treatment, Research and Education in Cancer (ACTREC) in Mumbai, India. These biomarkers are validated measures of exposure to the carcinogenic tobacco nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and NNN and the addictive alkaloid nicotine, respectively. The established method is characterized by excellent accuracy, linearity, and precision, and was successfully applied to the analysis of 15 smokeless tobacco (SLT) users and 15 non-users of tobacco recruited in Mumbai. This is the first report of establishment of such procedure in a laboratory in India, which offers the first in-country capacity for research on tobacco carcinogenesis in Indian SLT users.

Cigarette Relighting: A Series of Pilot Studies Investigating a Common Yet Understudied Smoking Behavior.

BACKGROUND: The act of extinguishing, saving, and later relighting unfinished cigarettes is a common yet understudied behavior that may have implications for tobacco treatment and health. METHODS: This paper presents four pilot studies investigating various aspects of this topic: (1) the prevalence of relighting among NJ and NY Quitline callers (n = 20,984); (2) the prevalence and correlates of relighting in two national surveys (n = 1008, n = 1018); (3) a within-subject (n = 16) laboratory experiment comparing cigarettes smoked per day and exhaled carbon monoxide when relighting and not relighting cigarettes; and (4) a national survey of tobacco treatment providers' (n = 150) perceptions of relighting. RESULTS: Relighting was found to be common (approximately 45% of smokers), and associated with lower socioeconomic status, heavier smoking and nicotine dependence, greater smoking-related concerns, as well as high levels of exhaled carbon monoxide. Providers noted the potential importance of relighting but reported that they do not regularly incorporate it into their assessment or tobacco treatment planning. CONCLUSIONS: These findings address a major research gap in the emerging research on this common behavior. Future research is needed to better understand the potential implications of relighting for policies and clinical practices related to tobacco cessation and health.

Ethnic Differences of Urinary Cadmium in Cigarette Smokers from the Multiethnic Cohort Study.

The Multiethnic Cohort Study (MEC) has demonstrated racial/ethnic differences in smoking-associated lung cancer risk. As part of the ongoing effort to characterize exposure to cigarette smoke constituents and better understand risk differences, we evaluated Cd exposure as it is a known lung carcinogen. We quantified urinary cadmium (Cd) by inductively coupled plasma mass spectrometry in a subset of 1956 current smokers from MEC. Ethnic-specific geometric means (GM) were compared adjusting for age at urine collection, sex, creatinine (natural log), education, and smoking (urinary total nicotine equivalents [TNE] and smoking duration). Self-reported questionnaire data, including occupation, were also considered. Latinos and Native Hawaiians had the highest GM urinary Cd (0.871 and 0.836 ng/mL, respectively) followed by Japanese Americans and African Americans (0.811 ng/mL and 0.807, respectively) and Whites (0.736 ng/mL). Patterns in race/ethnicity were consistent by sex such that females had the highest GM urinary Cd. When further adjusting for categorical occupational Cd exposure, racial/ethnic differences of Cd remained (p = 0.009). Findings suggest differences in urinary Cd among smokers across different racial/ethnic groups exist and highlight the importance in considering environmental sources of Cd exposure beyond smoking. These finding lay ground for future studies of individual characteristics that are associated with lower risk for cancer despite higher carcinogenic exposures.

Harm Perceptions of Tobacco/Nicotine Products and Child Exposure: Differences between Non-Users, Cigarette-Exclusive, and Electronic Cigarette-Exclusive Users.

OBJECTIVE: This study examined caregiver perception of harm and child secondhand exposure to nicotine in a sample of e-cigarette-exclusive, cigarette-exclusive, and non-tobacco/nicotine users (non-users). METHODS: Cigarette-exclusive (n = 19), e-cigarette-exclusive (n = 12), and non-users (n = 20) and their children (N = 51, Mage = 10.47) completed self-report questionnaires about perceptions of harm, child secondhand exposure, and provided urine to assess child nicotine exposure (cotinine). ANOVAs examined differences between caregiver use status on tobacco harm perceptions and child cotinine levels. Independent samples t-test compared differences in caregiver-reported child secondhand exposure in the home and car. RESULTS: All 3 caregiver groups rated cigarettes as highly harmful (P = .14), but e-cigarette users rated all 3 types of e-cigarette products (Cartridge-based: P < .001; Tank: P < .001; Box Mod: P < .001) as less harmful than cigarette users and non-users. Caregivers from the e-cigarette user group reported greater child secondhand exposure than caregivers using cigarettes (past 7-day in-home exposure (P = .03); past 7-day exposure in-home + in-car exposure (P = .02); in-home exposure by caregivers and other people exposure (P = .02)). Children from the cigarette user group had significantly higher levels of cotinine (M = 16.6, SD = 21.7) compared to children from the Non-User group (M = .43, SD = .95; P = .001), but no significant difference when compared to children from the E-Cigarette User group (M = 6.5, SD = 13.5). DISCUSSION: In this sample, caregivers who used e-cigarettes perceived them as less harmful, reported using them more frequently at home and in the car, even when their children were present, compared to cigarette users. As a result, children appear to be exposed to nicotine at levels similar to children living with cigarette users. Future caregiver prevention and intervention efforts should target education around the potential harms of secondhand e-cigarette aerosol to children.

Impact of Cigarette Filter Ventilation on U.S. Smokers' Perceptions and Biomarkers of Exposure and Potential Harm.

BACKGROUND: Relationships between cigarette filter ventilation levels, biomarkers of exposure (BOE) and potential harm (BOPH), and harm perceptions were examined. METHODS: Filter ventilation levels in cigarette brands were merged with Wave 1 (2013-2014) Population Assessment of Tobacco Use and Health study. Data were restricted to smokers who reported a usual brand and not regular users of other tobacco products. BOEs included nicotine, tobacco-specific nitrosamines, volatile organic compounds (VOC), and polycyclic aromatic hydrocarbons. BOPHs measured inflammation and oxidative stress. Perceived harm was assessed as self-reported risk of one's usual brand compared with other brands. RESULTS: Filter ventilation ranged from 0.2% to 61.1% (n = 1,503). Adjusted relationships between filter ventilation and BOE or BOPH were nonsignificant except for VOC N-acetyl-S-(phenyl)-L-cysteine (PHMA) and high-sensitivity C-reactive protein (hsCRP). In pairwise comparisons, PHMA was higher in quartile (Q) 4 (4.23 vs. 3.36 pmol/mg; P = 0.0103) and Q3 (4.48 vs. 3.36 pmol/mg; P = 0.0038) versus Q1 of filter ventilation and hsCRP comparisons were nonsignificant. Adjusted odds of perceiving one's own brand as less harmful was 26.87 (95% confidence interval: 4.31-167.66), 12.55 (3.01-52.32), and 19.18 (3.87-95.02) times higher in the Q2, Q3, and Q4 of filter ventilation compared with Q1 (P = 0.0037). CONCLUSIONS: Filter ventilation was not associated with BOE or BOPH, yet smokers of higher ventilated cigarettes perceived their brand as less harmful than other brands compared with smokers of lower ventilated cigarettes. IMPACT: Research to understand the impact of this misperception is needed, and remedial strategies, potentially including a ban on filter ventilation, are recommended.

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.

Relationships Between Race, Gender, and Spot Urine Levels of Biomarkers of Tobacco Exposure Vary Based on How Creatinine Is Handled in Analyses.

INTRODUCTION: We illustrate the differential impact of common analysis approaches to handling urinary creatinine, a measure for urine dilution, on relationships between race, gender, and biomarkers of exposure measured in spot urine. METHODS: In smokers, spot urine levels of total nicotine equivalents (TNE, sum of total nicotine, total cotinine, and total 3'-hydroxycotinine) and total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) overall and per cigarette were examined. Relationships between race (African Americans [AA] n = 373, Whites n = 758) or gender (males n = 629, females n = 502) and TNE or NNAL were examined using the following approaches to handling creatinine: (1) unadjusted/unstandardized; (2) standardization; (3) adjustment as a covariate. Significance was considered at p < .05. RESULTS: Creatinine was higher in AA versus Whites (1.19 vs. 0.96 mg/mL; p < .0001) and in males versus females (1.21 vs. 0.84 mg/mL; p < .0001). Independent of how creatinine was handled, TNE was lower among AA than Whites (TNE ratios AA vs. Whites: 0.67-0.84; p's < .05). Unadjusted TNE per cigarette was higher among AA versus Whites (ratio 1.12; p = .0411); however, the relationship flipped with standardization (ratio 0.90; p = .0360) and adjustment (ratio 0.95; p = .3165). Regarding gender, unadjusted TNE was higher among males versus females (ratio 1.13; p = .0063), but the relationship flipped with standardization (ratio 0.79; p < .0001) or adjustment (ratio 0.89; p = .0018). Unadjusted TNE per cigarette did not differ across gender (ratio 0.98; p = .6591), but lower levels were found in males versus females with standardization (ratio 0.68; p < .0001) and adjustment (ratio 0.74; p < .0001). NNAL displayed similar patterns. CONCLUSIONS: Relationships between race, gender, and spot urine levels of biomarkers of exposure can vary greatly based on how creatinine is handled in analyses. IMPLICATIONS: Lack of appropriate methods can lead to discrepancies across reports on variability of urinary biomarkers by race and gender. We recommend that for any analyses of biomarkers of exposure measure in spot urine samples across race, gender, or other population subgroups that differ in urinary creatinine levels, sensitivity analyses comparing the different methods for handling urinary creatinine should be conducted. If methods result in discrepant findings, this should be clearly noted and discussed.

Metabolomics Profiles of Smokers from Two Ethnic Groups with Differing Lung Cancer Risk.

African American (AA) smokers are at a higher risk of developing lung cancer compared to whites. The variations in the metabolism of nicotine and tobacco-derived carcinogens in these groups were reported previously with the levels of nicotine metabolites and carcinogen-derived metabolites measured using targeted approaches. While useful, these targeted strategies are not able to detect global metabolic changes for use in predicting the detrimental effects of tobacco use and ultimately lung cancer susceptibility among smokers. To address this limitation, we have performed global untargeted metabolomics profiling in urine of AA and white smokers to characterize the pattern of metabolites, identify differentially regulated pathways, and correlate these profiles with the observed variations in lung cancer risk between these two populations. Urine samples from AA (n = 30) and white (n = 30) smokers were used for metabolomics analysis acquired in both positive and negative electrospray ionization modes. LC-MS data were uploaded onto the cloud-based XCMS online (http://xcmsonline.scripps.edu) platform for retention time correction, alignment, feature detection, annotation, statistical analysis, data visualization, and automated systems biology pathway analysis. The latter identified global differences in the metabolic pathways in the two groups including the metabolism of carbohydrates, amino acids, nucleotides, fatty acids, and nicotine. Significant differences in the nicotine degradation pathway (cotinine glucuronidation) in the two groups were observed and confirmed using a targeted LC-MS/MS approach. These results are consistent with previous studies demonstrating AA smokers with lower glucuronidation capacity compared to whites. Furthermore, the d-glucuronate degradation pathway was found to be significantly different between the two populations, with lower amounts of the putative metabolites detected in AA compared to whites. We hypothesize that the differential regulation of the d-glucuronate degradation pathway is a consequence of the variations in the glucuronidation capacity observed in the two groups. Other pathways including the metabolism of amino acids, nucleic acids, and fatty acids were also identified, however, the biological relevance and implications of these differences across ethnic groups need further investigation. Overall, the applied metabolomics approach revealed global differences in the metabolic networks and endogenous metabolites in AA and whites, which could be used and validated as a new potential panel of biomarkers that could be used to predict lung cancer susceptibility among smokers in population-based studies.

Oral Microbiome Profiling in Smokers with and without Head and Neck Cancer Reveals Variations Between Health and Disease.

While smoking is inextricably linked to oral/head and neck cancer (HNSCC), only a small fraction of smokers develop HNSCC. Thus, we have sought to identify other factors, which may influence the development of HNSCC in smokers including microbiology. To determine microbial associations with HNSCC among tobacco users, we characterized oral microbiome composition in smokers with and without HNSCC. 16S rRNA MiSeq sequencing was used to examine the oral mucosa microbiome of 27 smokers with (cases) and 24 without HNSCC (controls). In addition, we correlated previously reported levels of DNA damage with the microbiome data. Smokers with HNSCC showed lower microbiome richness compared with controls (q = 0.012). Beta-diversity analyses, assessed as UniFrac (weighted and unweighted) and Bray-Curtis distances, showed significant differences in oral mucosal microbiome signatures between cases and controls (r 2 = 0.03; P = 0.03) and higher interindividual microbiome heterogeneity in the former (q ≤ 0.01). Higher relative abundance of Stenotrophomonas and Comamonadaceae and predicted bacterial pathways mainly involved in xenobiotic and amine degradation were found in cases compared with controls. The latter, in contrast, exhibited higher abundance of common oral commensals and predicted sugar degradation pathways. Finally, levels of DNA damage in the oral cavity were correlated with the microbiome profiles above. Oral microbiome traits differ in smokers with and without HNSCC, potentially informing the risk of eventual HNSCC and shedding light into possible microbially mediated mechanisms of disease. These findings present data that may be useful in screening efforts for HNSCC among smokers who are unable to quit.

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."