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.

Presence of the Carcinogen N'-Nitrosonornicotine in Saliva of E-cigarette Users.

Many harmful constituents are present in e-cigarettes at much lower levels than in cigarette smoke, and the results of analysis of urinary biomarkers in e-cigarette users are consistent with these findings. However, understanding the health effects of chronic exposures to e-cigarette aerosols may require thinking beyond these comparisons. In this study, we investigated the endogenous formation of the tobacco-specific oral and esophageal carcinogen N'-nitrosonornicotine (NNN) in e-cigarette users. Salivary NNN, nornicotine, and nicotine as well as urinary tobacco biomarkers, including total NNN, were analyzed in 20 e-cigarette users, 20 smokers, and 19 nonsmokers. Nornicotine and NNN levels in e-cigarettes used by the study participants were also analyzed. The mean of NNN in saliva of e-cigarette users was 14.6 (±23.1) pg/mL, ranging from nonquantifiable (below the limit of quantitation, LOQ) to 76.0 pg/mL. In smokers, salivary NNN ranged from below LOQ to 739 pg/mL, with 80% of smokers having salivary NNN in the range of levels found in e-cigarette users. Consistent with a previous report, very low levels of urinary total NNN were present in only 5 out of 20 e-cigarette users (ranging from 0.001 to 0.01 pmol/mL urine). Only trace levels of NNN were found in e-cigarette liquids. Together, our findings demonstrate that NNN is formed endogenously in e-cigarette users. While the overall exposure to NNN in e-cigarette users is dramatically lower than in smokers, the known carcinogenic potency of NNN warrants further investigations into the potential consequences of its endogenous formation. Salivary NNN, rather than urinary total NNN, which accounts for only 1-3% of the NNN dose, should be used to monitor e-cigarette users' exposure to this carcinogen.

Effects of nicotine-containing and "nicotine-free" e-cigarette refill liquids on intracranial self-stimulation in rats.

BACKGROUND: Animal models are needed to inform FDA regulation of electronic cigarettes (ECs) because they avoid limitations associated with human studies. We previously reported that an EC refill liquid produced less aversive/anhedonic effects at a high nicotine dose than nicotine alone as measured by elevations in intracranial self-stimulation (ICSS) thresholds, which may reflect the presence of behaviorally active non-nicotine constituents (e.g., propylene glycol) in the EC liquids. The primary objective of this study was to assess the generality of our prior ICSS findings to two additional EC liquids. We also compared effects of "nicotine-free" varieties of these EC liquids on ICSS, as well as binding affinity and/or functional activity of nicotine alone, nicotine-containing EC liquids, and "nicotine-free" EC liquids at nicotinic acetylcholine receptors (nAChRs). METHODS AND RESULTS: Nicotine alone and nicotine dose-equivalent concentrations of both nicotine-containing EC liquids produced similar lowering of ICSS thresholds at low to moderate nicotine doses, indicating similar reinforcement-enhancing effects. At high nicotine doses, nicotine alone elevated ICSS thresholds (a measure of anhedonia-like behavior) while the EC liquids did not. Nicotine-containing EC liquids did not differ from nicotine alone in terms of binding affinity or functional activity at nAChRs. "Nicotine-free" EC liquids did not affect ICSS, but bound with low affinity at some (e.g., α4ß2) nAChRs. CONCLUSIONS: These findings suggest that non-nicotine constituents in these EC liquids do not contribute to their reinforcement-enhancing effects. However, they may attenuate nicotine's acute aversive/anhedonic and/or toxic effects, which may moderate the abuse liability and/or toxicity of ECs.

Constituent Variations in Smokeless Tobacco Purchased in Mumbai, India.

OBJECTIVES: Worldwide, smokeless tobacco products vary greatly in their formulations and chemical composition. Understanding of toxic and carcinogenic constituent variations in such products can provide valuable insights for the development of effective tobacco control policies. In this study, we applied a standardized protocol to collect and analyze smokeless products sold in Mumbai, India. METHODS: Tobacco products were purchased at three markets in Mumbai, using standardized protocol for sample collection, labeling, and storage. Moisture content, pH, total and unprotonated nicotine, and five tobacco-specific N-nitrosamines (TSNA) were analyzed by validated methods. RESULTS: We purchased 39 samples representing eight varieties of manufactured and vendor-made smokeless tobacco products. Total nicotine ranged from 5.3 to 57.8 mg/g dry weight. Unprotonated nicotine content varied from 0.13% to 99.8% of total nicotine. Total TSNA content ranged from 0.17 to 81.0 µg/g dry weight. When expressed per wet weight of product, unprotonated nicotine varied more than 300-fold and TSNA content varied more than 650-fold across the products. Substantial vendor-to-vendor variations were also observed. CONCLUSIONS: Our findings emphasize the critical need for systematic smokeless tobacco surveillance in India, to improve understanding of exposures and cancer risks in users of these products.

Tobacco-specific N-nitrosamines and polycyclic aromatic hydrocarbons in cigarettes smoked by the participants of the Shanghai Cohort Study.

Our recent studies on tobacco smoke carcinogen and toxicant biomarkers and cancer risk among male smokers in the Shanghai Cohort Study showed that exposure to tobacco-specific nitrosamines (TSNA) and polycyclic aromatic hydrocarbons (PAH) is prospectively associated with the risk of cancer. These findings support the hypothesis that the smokers' cancer risk is a function of the dose of select tobacco carcinogens and highlight the importance of understanding the factors that affect the intake of these carcinogens by smokers. Given that tobacco constituent exposures are driven, at least in part, by the levels of these constituents in cigarette smoke, we measured mainstream smoke TSNA and PAH levels in 43 Chinese cigarette brands that participants of the Shanghai Cohort Study reported to smoke. In all brands analyzed here, mainstream smoke levels of NNN and NNK, the two carcinogenic TSNA, were generally relatively low, averaging (±SD) 16.8(±25.1) and 14.2(±9.5) ng/cigarette, respectively. The levels of PAH were comparable to those found in U.S. cigarettes, averaging 15(±9) ng/cigarette for benzo[a]pyrene, 119(±66) ng/cigarette for phenanthrene and 37(±19) ng/cigarette for pyrene. Our findings indicate that the generally low levels of NNN and NNK are most likely responsible for the relatively low levels of the corresponding biomarkers in the urine of the Shanghai Cohort Study participants as compared to those found in the U.S. smokers, supporting the role of the levels of these constituents in cigarette smoke in smokers' exposures. Our findings also suggest that, in addition to smoking, other sources contribute to Chinese smokers' exposure to PAH.

High levels of tobacco-specific N-nitrosamines and nicotine in Chaini Khaini, a product marketed as snus.

INTRODUCTION: Recently, a tobacco product, Chaini Khaini, identified as snus appeared in India. The product marketing emphasises its discreet nature and explicitly claims safety by referring to the existing evidence on Swedish snus. We analysed tobacco-specific nitrosamines and nicotine in 12 samples of Chaini Khaini purchased in 2013 at open markets in India. METHODS: Samples were purchased twice: in March 2013 from Mumbai and in November 2013 from Mumbai and Ahmedabad. Chemical constituents were measured by our routine validated methods. RESULTS: Levels of carcinogenic nitrosamines NNN, NNK and NNAL averaged 22.9 (±4.9), 2.6 (±1.0) and 3.1 (±1.5) µg/g tobacco (wet weight), respectively. The levels of NAB, which is normally present in trace levels in tobacco products, ranged from 3.9 to 12.9 µg/g tobacco. Total nicotine levels in all samples averaged 10.0 mg/g tobacco and unprotonated nicotine accounted for an average 95.4% of the total nicotine content. CONCLUSIONS: Chaini Khaini, which is labelled as snus and is marketed as a safe alternative to other tobacco products contains very high levels of carcinogenic nitrosamines and biologically available nicotine. Interventions are urgently needed to educate current and potential consumers of this product.

Monitoring tobacco-specific N-nitrosamines and nicotine in novel smokeless tobacco products: findings from round II of the new product watch.

INTRODUCTION: Analysis of novel smokeless tobacco products purchased in Round I of the New Product Watch (NPW)-a national tobacco monitoring network-demonstrated that some tobacco constituents vary not only across various brands but also regionally and over time within the same product. In this study, we analyzed snus and dissolvable tobacco products that were purchased in Round II of the NPW. METHODS: We analyzed tobacco-specific N-nitrosamines (TSNA) and nicotine in snus and dissolvable tobacco products that were purchased in various regions of the country during the spring and summer of 2011. The results were compared against the Round I data, across different U.S. regions, and among products. RESULTS: A total of 216 samples were received from different states representing 6 regions of the country. Compared with the previous analyses, TSNA levels increased significantly in Marlboro and Camel Snus and some dissolvable Camel products. The levels of unprotonated nicotine in Marlboro Snus and Camel Snus in this study were not different from Round I but varied significantly by regions; the differences between the highest and the lowest average regional levels were ~3.2-fold in Marlboro Snus ~1.7-fold in Camel Snus. CONCLUSIONS: Our results indicate that some novel smokeless tobacco products contain TSNA at the levels found in the conventional moist snuff. Observation of regional variations in unprotonated nicotine content in both Round I and Round II of NPW suggest that manufacturers may tailor the levels of this constituent consistently to different regions.

Levels of (S)-N'-nitrosonornicotine in U.S. tobacco products.

INTRODUCTION: N'-nitrosonornicotine (NNN), an esophageal and oral carcinogen present in tobacco products, has a chiral center in its structure. Of its two enantiomers, (S)-NNN exhibits higher tumorigenic potency than (R)-NNN. There is no information available on the levels of (S)-NNN in various tobacco products currently marketed in the United States. METHODS: We used chiral gas chromatography analysis to determine (S)-NNN levels in a convenience sample of 37 tobacco products currently marketed in the United States: conventional smokeless tobacco, novel smokeless tobacco products, and cigarette tobacco filler. RESULTS: Among all products analyzed here, (S)-NNN averaged 62.9 ± 6.3% (SD) of NNN. The absolute amount of (S)-NNN in conventional moist snuff averaged 1.26 ± 0.5 µg/g tobacco; in novel smokeless products 0.70 ± 0.2 µg/g tobacco; and in cigarette filler 1.36 ± 0.6 µg/g tobacco (all values are per wet weight). For each cigarette brand, the enantiomeric composition of NNN in cigarette smoke was similar to that of the corresponding tobacco filler. CONCLUSIONS: Our results demonstrate that (S)-NNN is the predominant NNN enantiomer in moist snuff, novel smokeless tobacco products, and cigarettes currently marketed in the United States. Efforts toward the reduction of NNN in U.S. tobacco products should take into account its enantiomeric composition, with particular focus on (S)-NNN as a causative agent for esophageal and oral cancers associated with tobacco use.