Comparative assessment of HPHC yields in the Tobacco Heating System THS2.2 and commercial cigarettes

Cigarettes, heated tobacco products and dual use: exhaled carbon monoxide, saliva cotinine and total tobacco consumed by Hong Kong tobacco users

BACKGROUND

Independent studies on exhaled carbon monoxide (CO) and saliva cotinine levels in regular heated tobacco product (HTP) users, and how they compare with conventional cigarette (CC) smokers, are lacking.

METHODS

A total of 3294 current users of CCs, HTPs or electronic cigarettes (ECs) from a household survey and a smoking hotspot survey were classified into seven groups: exclusive users of CCs, HTPs, ECs; dual users of CCs and HTPs, CCs and ECs, HTPs and ECs; and triple users. We measured exhaled CO level using the piCo Smokerlyzer (n=780) and saliva cotinine using NicAlert cotinine test strips (n=620). Among the seven groups, the differences in (1) CO and cotinine levels were examined using Kruskal-Wallis test, and (2) the average daily tobacco consumption in the past 30 days was examined using multivariable linear regression.

RESULTS

Both exclusive and dual users of CCs had a higher CO level than exclusive HTP or EC users (p<0.05). Exhaled CO levels were similar between HTP and EC users, as were saliva cotinine levels among the seven groups. Compared with exclusive CC users, those who also used HTPs or ECs smoked fewer CCs (CCs+HTPs: adjusted coefficient -2.79, 95% CI -3.90 to -1.69; CCs+ECs: -1.34, 95% CI -2.34 to -0.34), but consumed more tobacco sticks equivalent in total (2.79 (95% CI 1.61 to 3.96); 1.95 (95% CI 0.79 to 3.12)).

CONCLUSIONS

HTP or EC use showed lower exhaled CO but similar saliva cotinine levels compared with CC use. Dual users of CCs and HTPs/ECs smoked fewer CCs than exclusive CC users, but consumed more tobacco in total.

Describing the Cellular Impact of IQOS™ Smoke Extract and Vibration on Human Vocal Fold Fibroblasts

OBJECTIVES

The isolated or combined effects of vibration and smoke extract (SE) from the IQOS™ "heat-not-burn" technology on human vocal fold fibroblasts (hVFF) were evaluated in an in vitro setting in order to elucidate their influence on vocal fold (patho-) physiology.

STUDY DESIGN

Experimental pilot study using intervention with IQOS™-SE in vitro.

METHODS

Immortalized hVFF were exposed to IQOS™-SE or control medium under static or vibrational conditions. A phonomimetic bioreactor was used to deliver vibrational patterns to hVFF over a period of 5days. Cytotoxicity was quantified by lactate dehydrogenase assay. Effects on extracellular matrix production, inflammation, fibrogenesis, and angiogenesis were assessed by reverse transcription-quantitative polymerase chain reaction, western blot, enzyme-linked immunosorbent assay, and Magnetic Luminex assays.

RESULTS

We observed significant changes induced either by IQOS™-SE exposure alone (matrix metalloproteinase 1, fibronectin, cyclooxygenase (COX)1, interleukin-8 gene expression), or by the combination of IQOS™-SE and vibration (hyaluronidase 2, COX2, interleukin-8 protein levels, vascular endothelial growth factor D).

CONCLUSION

Short-term in vitro exposure of hVFF to IQOS™-SE did not result in cytotoxicity and reduced the gene expression of measured inflammation mediators, but had no effect on their protein expression. However, the clinical effects of long-term IQOS™ use are still not known and further research is needed in order to assess, if IQOS™ is in fact less harmful than conventional cigarettes.

Impact of More Intense Smoking Parameters and Flavor Variety on Toxicant Levels in Emissions of a Heated Tobacco Product

INTRODUCTION

IQOS HEETS are promoted as reduced-risk alternatives to cigarettes. Although some studies have investigated the chemical composition of HEETS emissions, little is known on whether toxicant levels in such emissions are affected by different puffing parameters and flavor varieties. This has important implications when assessing actual human exposure, since IQOS users develop a specific and personalized puffing behavior and may use different HEETS variants.

METHODS

This study measured the levels of nicotine, total particulate matter, carbonyl compounds, and tobacco-specific nitrosamines (TSNAs) in the emissions of nine differently flavored HEETS and two cigarettes (1R6F and Marlboro Red, MR). Emissions from Yellow HEETS, 1R6F, and MR were collected using the World Health Organization Intense smoking regime and four more intense smoking regimes.

RESULTS

Yellow HEETS aerosol contained lower levels of toxicants compared to 1R6F and MR smoke. More intense smoking regimes increased carbonyl release in cigarette smoke, whereas only higher puff frequency led to lower levels of toxicants in Yellow HEETS aerosol. Some HEETS varieties exhibited higher levels of formaldehyde and TSNAs in their aerosols compared to Yellow HEETS.

CONCLUSIONS

Puff frequency was identified as the only smoking parameter that significantly lowered the release of almost all toxicants in Yellow HEETS, whereas a combination of higher puff volume and puff duration led to increased levels of some carbonyls. Differences in toxicant levels between various commercially available HEETS have important implications when assessing their health impact, as their consumption might induce different toxicant exposure and health effects.

IMPLICATIONS

HEETS release about half as much nicotine and substantially lower levels of toxicants compared to cigarettes. Literature data showed that puffing intensity is increased in cigarette smokers switching to HEETS, maybe in reaction to these lower nicotine levels. Our results show a differential impact of increased puff frequency, puff duration, and puff volume in the release of toxicants from HEETS. Thus, industry-independent studies on puff topography are critical to make choices for the most relevant puffing regime for heated tobacco product regulation. Regulators should consider evaluating the health impact of multiple HEETS varieties, as the tobacco filler composition significantly affects the release of certain toxicants.

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.

Use of heated tobacco products (IQOS) causes an acute increase in arterial stiffness and platelet thrombus formation

BACKGROUND AND AIMS

Heated tobacco products (HTPs) are novel alternative tobacco products being promoted as an alternative to cigarettes. To evaluate the impact of HTP use on vascular function, we investigated the effects of a brief HTP usage on arterial stiffness and platelet thrombus formation in healthy volunteers.

METHODS

In a randomised crossover study, twenty-four healthy young adults with occasional tobacco use smoked the HTP IQOS 3 Multi (Phillip Morris Int.) and "no-exposure" was used as a control, with a wash-out period of at least one week in-between. Arterial stiffness was assessed through pulse wave velocity and pulse wave analysis. Blood samples, collected at baseline and 5 min following exposure, were analysed with the Total-Thrombus-formation analysis system evaluating platelet and fibrin-rich thrombus formation tendency.

RESULTS

HTP exposure caused immediate heightened pulse wave velocity (+0.365 m/s, 95% CI: +0.188 to 0.543; p = 0.004) and enhanced augmentation index corrected to heart rate (+6.22%, 95% CI: +2.33 to 10.11; p = 0.003) compared to the no-exposure occasion. Similarly, blood pressure and heart rate transiently increased immediately following HTP inhalation. Platelet thrombus formation significantly increased following HTP exposure (area under the curve +59.5, 95% CI: +25.6 to 93.4; p < 0.001) compared to no-exposure. No effect was seen on fibrin-rich thrombus formation following HTP-exposure.

CONCLUSIONS

Brief HTP use in healthy young adults had immediate adverse effects on vascular function resulting in increased arterial stiffness and platelet thrombus formation, known risk factors for the development of atherosclerosis. Further research is needed to address long term health impacts.

Toxicological Aspects Associated with Consumption from Electronic Nicotine Delivery System (ENDS): Focus on Heavy Metals Exposure and Cancer Risk

Tobacco smoking remains one of the leading causes of premature death worldwide. Electronic Nicotine Delivery Systems (ENDSs) are proposed as a tool for smoking cessation. In the last few years, a growing number of different types of ENDSs were launched onto the market. Despite the manufacturing differences, ENDSs can be classified as "liquid e-cigarettes" (e-cigs) equipped with an atomizer that vaporizes a liquid composed of vegetable glycerin (VG), polypropylene glycol (PG), and nicotine, with the possible addition of flavorings; otherwise, the "heated tobacco products" (HTPs) heat tobacco sticks through contact with an electronic heating metal element. The presence of some metals in the heating systems, as well as in solder joints, involves the possibility that heavy metal ions can move from these components to the liquid, or they can be adsorbed into the tobacco stick from the heating blade in the case of HTPs. Recent evidence has indicated the presence of heavy metals in the refill liquids and in the mainstream such as arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), copper (Cu), and lead (Pb). The present review discusses the toxicological aspects associated with the exposition of heavy metals by consumption from ENDSs, focusing on metal carcinogenesis risk.

A Randomized Control Study in Healthy Adult Smokers to Assess Reduced Exposure to Selected Cigarette Smoke Constituents in Switching to the Novel Heated Tobacco Product DT3.0a

This was a randomized, controlled, open-label, confinement study to assess change in exposure to selected cigarette smoke constituents in healthy adult cigarette smokers who switched to using a novel heated tobacco product (direct heating tobacco system, platform 3, generation 3, version a [DT3.0a]). Sixty nonmenthol cigarette smokers were randomized into 1 of the 4 study groups in which subjects switched to a nonmenthol type of tobacco stick used with DT3.0a, switched to a nonmenthol tobacco stick used with an in-market heated tobacco product device (THS), continued to smoke nonmenthol cigarettes, or stopped smoking. Furthermore, 30 menthol cigarette smokers were randomized into 1 of the 2 study groups in which subjects switched to a menthol tobacco stick used with DT3.0a (mDT3.0a) or continued to smoke menthol cigarettes. Fifteen biomarkers of exposure to selected harmful and potentially harmful constituents (HPHCs) were measured during the 5-day exposure period, followed by assessment of nicotine pharmacokinetics with the assigned product. Results indicated that switching to DT3.0a, THS, and mDT3.0a showed significant exposure reductions in most of the selected HPHCs as compared to continuing smoking cigarettes, with reductions being similar in magnitude to reductions observed with smoking cessation. For DT3.0a and mDT3.0a, nicotine pharmacokinetic parameters were not remarkably different from those obtained for cigarettes and the THS except that a longer time to maximum concentration was obtained following use of the mDT3.0a. In conclusion, switching from smoking cigarettes to DT3.0a or THS use reduced exposure to most of the selected HPHCs, and no remarkable differences were observed for the measurements obtained from different flavors of DT3.0a stick.

Aerosol Emissions from Heated Tobacco Products: A Review Focusing on Carbonyls, Analytical Methods, and Experimental Quality

We provide an extensive review of 17 independent and industry-funded studies targeting carbonyls in aerosol emissions of Heated Tobacco Products (HTPs), focusing on quality criteria based on the reproducibility of experiments, appropriate analytic methods, and puffing regimes. Most revised studies complied with these requirements, but some were unreproducible, while others failed to consider analytical variables that may have affected the results and/or produced unrealistic comparisons. We also provide a review of the literature on the physicochemical properties of heated tobacco and HTP aerosols, as well as the evaluation of HTPs by regulatory agencies, addressing various critiques of their relative safety profile. The outcomes from the revised studies and regulatory evaluations tend to agree with and converge to a general consensus that HTP aerosols expose users to significantly lower levels of toxicity than tobacco smoke.

Comparison of urinary mercapturic acid excretions in users of various tobacco/nicotine products

Urinary mercapturic acids (MAs) are detoxification products for electrophiles occurring in the human body. They are suitable biomarkers of exposure to directly acting electrophilic chemicals or to chemicals which generate the electrophile during its metabolism. We determined the urinary excretion of 19 MAs in habitual users of combustible cigarettes (CCs), electronic cigarettes (ECs), heated tobacco products (HTPs), oral tobacco (OT), and nicotine replacement therapy (NRT) products, and nonusers (NUs) of any tobacco/nicotine products. The 19 MAs are assumed to be physiologically formed primarily from 15 toxicants with three of them belonging to IARC Group 1 (human carcinogen), seven to Group 2A (probable human carcinogen), four to Group 2B (possible human carcinogen), and one to Group 3 (not classifiable as carcinogen). Smoking (CC) was found to be associated with significantly elevated exposure to ethylene oxide (or ethylene), 1,3-butadiene, benzene, dimethylformamide, acrolein, acrylamide, styrene, propylene oxide, acrylonitrile, crotonaldehyde, and isoprene compared with the other user groups and NU. Users of HTPs revealed slight elevation in the MAs related to acrolein, acrylamide, and crotonaldehyde compared with the other non-CC groups. Vaping (EC) was not found to be associated with any of the MAs studied. In conclusion, the determination of urinary MAs is a useful tool for assessing the exposure to toxicants (mainly potential carcinogens) in users of various tobacco/nicotine products. Our data also give cause to clarify the role of vaping (EC) in urinary excretion of DHPMA (precursor: glycidol).

An assessment of nicotine pharmacokinetics and subjective effects of the pulze heated tobacco system compared with cigarettes

Nicotine delivery and subjective effects are determinants of the ability of potentially less harmful tobacco products such as heated tobacco products (HTPs) to support adult smokers in switching away from cigarettes, and therefore to support tobacco harm reduction. This open-label, randomised, crossover, clinical study in 24 healthy adult smokers study assessed nicotine pharmacokinetics and subjective effects of the Pulze Heated Tobacco System (HTS; Pulze HTP device and three iD stick variants-Intense American Blend, Regular American Blend and Regular Menthol) compared with subjects' usual brand cigarettes (UBC). Cmax and AUCt were highest for UBC and significantly lower for each Pulze HTS variant. Cmax and AUCt were significantly higher for Intense American Blend compared with Regular American Blend, while AUCt was significantly higher for Intense American Blend compared with Regular Menthol. Median Tmax was lowest (i.e., nicotine delivery was fastest) for subjects' usual brand cigarettes and similar across the iD stick variants, although no between-product differences were statistically significant. All study products reduced urges to smoke; this effect was greatest for cigarettes although this was not statistically significant. Product evaluation scores for each Pulze HTS variant in the domains of 'satisfaction', 'psychological reward' and 'relief' were similar, and lower than those for UBC. These data demonstrate that the Pulze HTS effectively delivers nicotine and generates positive subjective effects, including satisfaction and reduced urge to smoke. This supports the conclusion that the Pulze HTS may be an acceptable alternative to cigarettes for adult smokers while having a lower abuse liability than cigarettes.

Heated Tobacco Products and Chronic Obstructive Pulmonary Disease: A Narrative Review of Peer-Reviewed Publications

An estimated 65 million people worldwide have moderate or severe chronic obstructive pulmonary disease (COPD), an umbrella term used to describe a group of progressive lung diseases that obstruct airflow such as emphysema and chronic bronchitis. Smoking contributes to an estimated 90% of COPD cases, as the harmful chemicals produced during tobacco combustion damage the lungs and airways. Although smoking cessation is the only intervention shown to improve COPD prognosis in smokers, many patients who try to quit continue to smoke. The continued use of conventional cigarettes exacerbates COPD symptoms, and globally more than 3 million people die from the disease every year. The last two decades have seen the introduction of combustion-free nicotine delivery alternatives that produce significantly lower levels of the harmful components in cigarette smoke, and researchers have begun to assess the impact of switching from cigarettes to these products. Several studies have examined how patients with COPD use e-cigarettes as assistance for quitting, but few have examined how heated tobacco products (HTP) may reduce risk. This narrative review summarises results from pre-clinical, clinical, and real-world evidence studies showing possible harm reduction benefits for patients with COPD who switch to HTPs rather than continuing to smoke cigarettes. Epidemiological studies, real-world data analyses, and randomised clinical trials must be conducted to determine whether switching from cigarettes to HTPs can improve health outcomes in patients with COPD who would otherwise continue to smoke combustible cigarettes.

Preliminary toxicological assessment of heated tobacco products: A review of the literature and proposed strategy

Heated tobacco products (HTP) have become increasingly common in many countries worldwide. The principle of heating tobacco, without combustion, to produce a nicotine-containing aerosol with remarkably reduced levels of other known toxins, compared to combusted tobacco cigarettes, is now well established. As these products are intended as alternatives to traditional combusted products, during the early stages of their development, it is important for manufacturers to ensure that the design of the product does not lead to any unintentionally increased or new risk for the consumer, compared to the traditional products that consumers seek to replace. There is limited guidance from tobacco product regulations concerning the requirements for performing such preliminary toxicological assessments. Here, we review the published literature on studies performed on HTPs in the pursuit of such data, outline a proposed approach that is consistent with regulatory requirements, and provide a logical approach to the preliminary toxicological assessment of HTPs.

Twenty-eight day repeated exposure of human 3D bronchial epithelial model to heated tobacco aerosols indicates decreased toxicological responses compared to cigarette smoke

Tobacco harm reduction (THR) involves providing adult smokers with potentially reduced harm modes of nicotine delivery as alternatives to smoking combustible cigarettes. Heated tobacco products (HTPs) form a category with THR potential due to their ability to deliver nicotine and flavours through heating, not burning, tobacco. By eliminating burning, heated tobacco does not produce smoke but an aerosol which contains fewer and lower levels of harmful chemicals compared to cigarette smoke. In this study we assessed the in vitro toxicological profiles of two prototype HTPs' aerosols compared to the 1R6F reference cigarette using the 3D human (bronchial) MucilAir™ model. To increase consumer relevance, whole aerosol/smoke exposures were delivered repeatedly across a 28 day period (16, 32, or 48 puffs per exposure). Cytotoxicity (LDH secretion), histology (Alcian Blue/H&E; Muc5AC; FoxJ1 staining), cilia active area and beat frequency and inflammatory marker (IL-6; IL-8; MMP-1; MMP-3; MMP-9; TNFα) levels were assessed. Diluted 1R6F smoke consistently induced greater and earlier effects compared to the prototype HTP aerosols across the endpoints, and in a puff dependent manner. Although some significant changes across the endpoints were induced by exposure to the HTPs, these were substantially less pronounced and less frequently observed, with apparent adaptive responses occurring over the experimental period. Furthermore, these differences between the two product categories were observed at a greater dilution (and generally lower nicotine delivery range) for 1R6F (1R6F smoke diluted 1/14, HTP aerosols diluted 1/2, with air). Overall, the findings demonstrate the THR potential of the prototype HTPs through demonstrated substantial reductions in toxicological outcomes in in vitro 3D human lung models.

Comparative Health Risk Assessment of Heated Tobacco Products versus Conventional Cigarettes

BACKGROUND

Smoking is the largest preventable cause of death in the world with around eight million estimated premature deaths per year. In response to the harmful effects of conventional tobacco products the tobacco industry has launched a new type of products called Heated tobacco products (HTP) and e-cigarettes, which are considered safer for human health than conventional cigarettes.

MATERIALS AND METHODS

The research was conducted by searching the scientific literature using platforms "Google scholar," "PubMed" and "Science Direct." To compare the non-carcinogenic and carcinogenic risk of HTP products and conventional cigarettes, margin of exposure and lifetime excess cancer risk were calculated using data obtained from a scientific literature search.

HTP products have shown a reduced risk to human health compared to the conventional cigarettes, although they still contain compounds that can be dangerous to human health. There is not enough data obtained from independent studies that could safely indicate that these reduced amounts of toxic chemical entities in the composition of HTP do not induce any harmful effect.

CONCLUSION

Further research is needed to determine the harmful effects of HTP aerosol, as well as to tighten the legislation that would limit the production, import and distribution of these products worldwide until their safety for human health is confirmed with a sufficient number of transparent and representative results obtained in independent scientific studies.

Advancing New Approach Methodologies (NAMs) for Tobacco Harm Reduction: Synopsis from the 2021 CORESTA SSPT-NAMs Symposium

New approach methodologies (NAMs) are emerging chemical safety assessment tools consisting of in vitro and in silico (computational) methodologies intended to reduce, refine, or replace (3R) various in vivo animal testing methods traditionally used for risk assessment. Significant progress has been made toward the adoption of NAMs for human health and environmental toxicity assessment. However, additional efforts are needed to expand their development and their use in regulatory decision making. A virtual symposium was held during the 2021 Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) Smoke Science and Product Technology (SSPT) conference (titled "Advancing New Alternative Methods for Tobacco Harm Reduction"), with the goals of introducing the concepts and potential application of NAMs in the evaluation of potentially reduced-risk (PRR) tobacco products. At the symposium, experts from regulatory agencies, research organizations, and NGOs shared insights on the status of available tools, strengths, limitations, and opportunities in the application of NAMs using case examples from safety assessments of chemicals and tobacco products. Following seven presentations providing background and application of NAMs, a discussion was held where the presenters and audience discussed the outlook for extending the NAMs toxicological applications for tobacco products. The symposium, endorsed by the CORESTA In Vitro Tox Subgroup, Biomarker Subgroup, and NextG Tox Task Force, illustrated common ground and interest in science-based engagement across the scientific community and stakeholders in support of tobacco regulatory science. Highlights of the symposium are summarized in this paper.

Assessment of the Exposure to Aromatic Amines in Users of Various Tobacco/Nicotine Products

Aromatic amines such as ortho-toluidine (o-Tol), 2-aminonaphthalene (2-AN), and 4-aminobiphenyl (4-ABP) are human bladder carcinogens and occur at various workplaces, in ambient air, in food products, as well as in tobacco smoke. In a clinical study comprising a period of 74 h under confinement, we investigated the exposure to these three aromatic amines as well as to 3-aminobiphenyl (3-ABP) by measuring them in urine of habitual users of combustible cigarettes (CCs), electronic cigarettes (ECs), heated tobacco products (HTPs), oral tobacco (OT), and nicotine replacement therapy products (NRTs). Non-users (NU) of any tobacco/nicotine products served as (negative) control group. Smokers (CC) exhibited the highest levels for all four aromatic amines measured, significantly elevated compared to NU and non-CC users. Urinary levels in users of EC, HTP, NRT (mostly nicotine gum), and OT (mostly snus) were not significantly different from those in NU. Users of HTP showed slightly elevated urinary excretion levels of o-Tol, 3-ABP, and 4-ABP compared to some other non-CC groups. Dose markers such as daily consumption, urinary nicotine equivalents (Nequ), and plasma cotinine (CotP) were found to be consistently and significantly correlated with the excretion of aromatic amines for smokers (CC) only. Excretion levels of 3- and 4-ABP in smokers were significantly lower in the urine collected overnight compared to that collected during the day, which is just the opposite of what we observed for other biomarkers in this study. The possible reason for this observation is discussed. In conclusion, in contrast to smoking of CCs, the use of ECs, HTPs, nicotine gum, and oral tobacco was not observed to be associated with significant exposure to the aromatic amines o-Tol, 2-AN, 3-ABP, and 4-ABP. The observed slight increase in o-Tol, 3-ABP, and 4-ABP excretions in HTP users has to be verified in larger studies.

Assessment of the exposure to selected smoke constituents in adult smokers using in-market heated tobacco products: a randomized, controlled study

The objectives of this clinical study were to demonstrate a reduction in exposure to selected harmful and potentially harmful constituents (HPHCs) in Japanese healthy adult smokers who switched to four in-market heated tobacco products. Eighty-nine smokers were randomly assigned for five days to one of six study groups: four groups who switched to one of the commercially available heated tobacco products; a group who continued to smoke their own brand of combustible cigarettes (CC); or a group who stopped smoking (SS). Fifteen biomarkers of exposure (BoE) to 14 HPHCs and pyrene were measured at baseline, Day 3 and Day 5 in 24 h urine and breath, under clinical confinement. Product consumption, nicotine uptake and subjective effects were also measured before and after product switching. On Day 5, significant reductions in most BoE relative to the CC group were observed after switching to heated tobacco products. No changes in BoE were observed between baseline and Day 5 in the CC group. Significantly, the magnitude of the reduction in exposure to most of the selected HPHCs observed in the heated tobacco product groups was close to that observed in the SS group.

Chemical characterisation of the vapour emitted by an e-cigarette using a ceramic wick-based technology

Fourth-generation 'pod' e-cigarette devices have been driven by technological advances in electronic atomization of the e-liquid. Use of microporous ceramic as a wicking material improves heating efficiency, but how it affects the chemical emissions of these devices is unclear. We assessed the emissions of a pod e-cigarette with innovative ceramic wick-based technology and two flavoured e-liquids containing nicotine lactate and nicotine benzoate (57 and 18 mg mL-1 nicotine, respectively). Among the studied harmful and potentially harmful constituents (HPHCs) listed by the US FDA and/or WHO TobReg, only 5 (acetone, acetaldehyde, formaldehyde, naphthalene and nornicotine) were quantified at levels of 0.14 to 100 ng puff-1. In the combustible cigarette (Kentucky reference 1R6F), levels were from 0.131 to 168 µg puff-1. Nicotine levels ranged 0.10-0.32 mg puff-1 across the 3 study products. From the 19 proposed HPHCs specifically of concern in e-cigarettes, only 3 (glycerol, isoamyl acetate and propylene glycol) were quantified. The low/undetectable levels of HPHCs reflect not only the optimal operating conditions of the e-cigarette, including an efficient supply of e-liquid by the ceramic wick without overheating, but also the potential of the e-cigarettes to be used as an alternative to combustible cigarettes.

The Impact of Tobacco Cigarettes, Vaping Products and Tobacco Heating Products on Oxidative Stress

Cells constantly produce oxidizing species because of their metabolic activity, which is counteracted by the continuous production of antioxidant species to maintain the homeostasis of the redox balance. A deviation from the metabolic steady state leads to a condition of oxidative stress. The source of oxidative species can be endogenous or exogenous. A major exogenous source of these species is tobacco smoking. Oxidative damage can be induced in cells by chemical species contained in smoke through the generation of pro-inflammatory compounds and the modulation of intracellular pro-inflammatory pathways, resulting in a pathological condition. Cessation of smoking reduces the morbidity and mortality associated with cigarette use. Next-generation products (NGPs), as alternatives to combustible cigarettes, such as electronic cigarettes (e-cig) and tobacco heating products (THPs), have been proposed as a harm reduction strategy to reduce the deleterious impacts of cigarette smoking. In this review, we examine the impact of tobacco smoke and MRPs on oxidative stress in different pathologies, including respiratory and cardiovascular diseases and tumors. The impact of tobacco cigarette smoke on oxidative stress signaling in human health is well established, whereas the safety profile of MRPs seems to be higher than tobacco cigarettes, but further, well-conceived, studies are needed to better understand the oxidative effects of these products with long-term exposure.

Preliminary study on the effect of using heat-not-burn tobacco products on indoor air quality

In this study, the effect of the use of heat-not-burn (HnB) products on indoor air quality (IAQ) was evaluated. To do this, the concentrations of nicotine, propylene glycol (PG), and vegetable glycerin (VG) directly emitted when using HnB products were analyzed and compared to those from conventional cigarettes. Furthermore, the levels of VOCs, aldehydes, nanoparticle, and particulate matter (PM) detected when subjects used HnB products in the exposure chamber were evaluated the effect on IAQ. As a result, the range of nicotine levels transferred by HnB products (0.8-1.2 mg cigarette^-1) is lower than that by conventional cigarettes (2.4-3.6 mg cigarette^-1). On the other hand, the range of VG levels emitted from HnB products (3.1-5.9 mg cigarette^-1) were higher than that emitted from conventional cigarettes (0.6-3.0 mg cigarette^-1). In addition, although the amount generated from HnB products was small compared to those from conventional cigarettes, various kinds of VOCs, aldehydes, nanoparticle and PM were produced, and these were confirmed to affect IAQ.

Analysis of mainstream emissions, secondhand emissions and the environmental impact of IQOS waste: a systematic review on IQOS that accounts for data source

OBJECTIVE

To highlight the general features of IQOS literature focusing on the chemical analysis of IQOS emissions.

DATA SOURCES

PubMed, Web of Science and Scopus databases were searched on 8 November 2021 using the terms 'heated tobacco product', 'heat-not-burn', 'IQOS' and 'tobacco heating system' with time restriction (2010-2021). The search yielded 5480 records.

STUDY SELECTION

Relevant publications on topics related to IQOS assessment were retrieved (n=341). Two reviewers worked separately and reached agreement by consensus.

DATA EXTRACTION

Data on author affiliation and funding, article type and date of publication were extracted. Publications were categorised depending on their focus and outcomes. Data on IQOS emissions from the chemical analysis category were extracted.

DATA SYNTHESIS

Of the included publications, 25% were published by Philip Morris International (PMI) affiliates or PMI-funded studies. PMI-sponsored publications on emissions, toxicology assessments and health effects were comparable in number to those reported by independent research, in contrast to publications on IQOS use, market trends and regulation. Data on nicotine yield, carbonyl emissions, other mainstream emissions, secondhand emissions and IQOS waste were compared between data sources to highlight agreement or disagreement between PMI-sponsored and independent research.

CONCLUSIONS

Our analysis showed agreement between the data sources on nicotine yield from IQOS under the same puffing conditions. Also, both sources agreed that IQOS emits significantly reduced levels of some emissions compared with combustible cigarettes. However, independent studies and examination of PMI's data showed significant increases in other emissions from and beyond the Food and Drug Administration's harmful and potentially harmful constituents list.

Method Development and Applications for Reduced-Risk Products

Cigarette smoking remains the leading cause of preventable premature death and disease in the U [...]

NMR Spectroscopy Identifies Chemicals in Cigarette Smoke Condensate That Impair Skeletal Muscle Mitochondrial Function

Tobacco smoke-related diseases such as chronic obstructive pulmonary disease (COPD) are associated with high healthcare burden and mortality rates. Many COPD patients were reported to have muscle atrophy and weakness, with several studies suggesting intrinsic muscle mitochondrial impairment as a possible driver of this phenotype. Whereas much information has been learned about muscle pathology once a patient has COPD, little is known about how active tobacco smoking might impact skeletal muscle physiology or mitochondrial health. In this study, we examined the acute effects of cigarette smoke condensate (CSC) on muscle mitochondrial function and hypothesized that toxic chemicals present in CSC would impair mitochondrial respiratory function. Consistent with this hypothesis, we found that acute exposure of muscle mitochondria to CSC caused a dose-dependent decrease in skeletal muscle mitochondrial respiratory capacity. Next, we applied an analytical nuclear magnetic resonance (NMR)-based approach to identify 49 water-soluble and 12 lipid-soluble chemicals with high abundance in CSC. By using a chemical screening approach in the Seahorse XF96 analyzer, several CSC-chemicals, including nicotine, o-Cresol, phenylacetate, and decanoic acid, were found to impair ADP-stimulated respiration in murine muscle mitochondrial isolates significantly. Further to this, several chemicals, including nicotine, o-Cresol, quinoline, propylene glycol, myo-inositol, nitrosodimethylamine, niacinamide, decanoic acid, acrylonitrile, 2-naphthylamine, and arsenic acid, were found to significantly decrease the acceptor control ratio, an index of mitochondrial coupling efficiency.

Use of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes to Predict the Cardiotoxicity Potential of Next Generation Nicotine Products

Combustible cigarette smoking is an established risk factor for cardiovascular disease. By contrast, the cardiotoxicity potential of non-combustible next generation nicotine products (NGPs), which includes heated tobacco products (HTPs) and electronic vaping products (EVPs), and how this compares relative to combustible cigarettes is currently an area of scientific exploration. As such, there is a need for a rapid screening assay to assess this endpoint. The Cardio quickPredict is a metabolomics biomarker-based assay that uses human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) to screen for potential structural and functional cardiac toxicants based on the changes of four metabolites, lactic acid, arachidonic acid, thymidine, and 2'-deoxycytidine. The study aims were to investigate the cardiotoxicity potential of NGPs compared to cigarettes, in addition to nicotine. To accomplish this, hiPSC-CM were exposed to smoke or aerosol bubbled PBS samples: reference cigarette (1R6F); three variants of HTP; and three EVP variants. The 1R6F bPBS was the most active, having cardiotoxic potential at 0.3-0.6% bPBS (0.4-0.9 μg/mL nicotine), followed by HTP, which displayed cardiotoxic potential at a 10 times higher concentration, 3.3% bPBS (4.1 μg/mL nicotine). Both 1R6F and HTP bPBS (at 10-fold higher concentration than 1R6F) affected all four predictive metabolites, whereas none of the EVP bPBS samples were active in the assay up to the maximal concentration tested (10% bPBS). Nicotine tested on its own was predicted to have cardiotoxic potential at concentrations greater than 80 μg/mL, which is higher than expected physiological levels associated with combustible cigarette smoking. The application of this rapid screening assay to NGP research and the associated findings adds to the weight-of-evidence indicating that NGPs have a tobacco harm reduction potential when compared to combustible cigarettes. Additionally, this technique was shown to be sensitive and robust for the assessment of different NGPs and may be considered as part of a larger overall scientific framework for NGP assessments.

PaLS Study: Tobacco, Alcohol and Drugs Usage among Polish University Students in the Context of Stress Caused by the COVID-19 Pandemic

The COVID-19 pandemic and imposed restrictions were strong stress factors for young people, especially students. Increased alcohol consumption, smoking cigarettes, usage of heated tobacco products, and other stimulants are common methods of coping with anxiety. However, they can have serious negative health effects. A survey consisting of 12 questions related to mental health and psychoactive substance taking habits was distributed among Polish students between 22 February 2021 and 3 April 2021. A total of 1323 participants met all inclusion criteria (nfemales = 1021, nmales = 297, nother gender = 5). The mean age was 22 years old (±4.17); 47.62% were medical university students. A total of 71.92% reported negative impact, 8.25% did not notice changes, and 12.58% declared a positive pandemic impact on their mental health. A total of 12.58% declared an increase, 70.22% did not see any differences, and 17.20% reported a decrease in their psychoactive substance usage tendency due to the pandemic. Worse perceived psychologic well-being was correlated with a higher tendency to use tobacco (p < 0.001) and alcohol (p < 0.001), and not with marijuana and products containing tetrahydrocannabinol (p = 0.136), and hard drugs (p = 0.799). The majority of participants declared a negative pandemic impact on mental health and did not report significant changes in psychoactive substance taking habits. Medical personnel should be aware of the current situation and apply for proper prevention and treatment programs.

The Emission of VOCs and CO from Heated Tobacco Products, Electronic Cigarettes, and Conventional Cigarettes, and Their Health Risk

The differences in aerosol composition between new tobacco types (heated tobacco products and electronic cigarettes) and conventional cigarettes have not been systematically studied. In this study, the emissions of volatile organic compounds (VOCs), carbon monoxide (CO), nicotine, and tar from heated tobacco products (HTPs), electronic cigarettes (e-cigarettes) and conventional cigarettes were compared, and their health risks were evaluated by applying the same smoking regime and a loss mechanism of smoking. Twenty VOCs were identified in aerosols from HTPs, 18 VOCs were identified in aerosols from e-cigarettes, and 97 VOCs were identified in aerosols from cigarettes by GC–MS and HPLC analysis. The concentrations of total VOCs (TVOCs) emitted by the three types of tobacco products decreased as follows: e-cigarettes (795.4 mg/100 puffs) > cigarettes (83.29 mg/100 puffs) > HTPs (15.65 mg/100 puffs). The nicotine content was 24.63 ± 2.25 mg/100 puffs for e-cigarettes, 22.94 ± 0.03 mg/100 puffs for cigarettes, and 8.817 ± 0.500 mg/100 puffs for HTPs. When using cigarettes of the same brand, the mass concentrations of VOCs, tar, and CO emitted by HTPs were approximately 81.2%, 95.9%, and 97.5%, respectively, lower than the amounts emitted by cigarettes. The health risk results demonstrated that the noncarcinogenic risk of the three types of tobacco products decreased as follows: cigarettes (3609.05) > HTPs (2449.70) > acceptable level (1) > e-cigarettes (0.91). The lifetime cancer risk (LCR) decreased as follows: cigarettes (2.99 × 10⁻⁴) > HTPs (9.92 × 10⁻⁵) > e-cigarettes (4.80 × 10⁻⁵) > acceptable level (10⁻⁶). In general, HTPs and e-cigarettes were less harmful than cigarettes when the emission of VOCs and CO was considered.

Heated Tobacco Products Impair Cell Viability, Osteoblastic Differentiation, and Bone Fracture-Healing

BACKGROUND

The negative impact of cigarette smoking on bone union has been well documented. However, the impact of heated tobacco product (HTP) use on bone fracture-healing remains unclear. The present study investigated the effect of HTPs on preosteoblast viability, osteoblastic differentiation, and fracture-healing and compared the effects with those of conventional combustible cigarettes.

METHODS

Cigarette smoke extracts (CSEs) were generated from combustible cigarettes (cCSE) and HTPs (hCSE). CSE concentrations were standardized by assessing optical density. Preosteoblast (MC3T3-E1) cells were incubated with normal medium, cCSE, or hCSE. The cell viability was assessed via MTT assay. After osteoblastic differentiation of CSE-exposed cells, alkaline phosphatase (ALP) activity was assessed. To assess the in vivo effects of CSEs, a femoral midshaft osteotomy was performed in a rat model; thereafter, saline solution, cCSE, or hCSE was injected intraperitoneally, and bone union was assessed on the basis of micro-computed tomography (μCT) and biomechanical analysis 4 weeks later.

RESULTS

MC3T3-E1 cell viability was reduced in a time and concentration-dependent manner when treated with either cCSE or hCSE. ALP activity after osteoblastic differentiation of cCSE-treated cells was significantly lower than that of both untreated and hCSE-treated cells (mean and standard deviation, 452.4 ± 48.8 [untreated], 326.2 ± 26.2 [cCSE-treated], and 389.9 ± 26.6 [hCSE-treated] mol/L/min; p = 0.002). Moreover, the levels of osteoblastic differentiation in untreated and hCSE-treated cells differed significantly (p < 0.05). In vivo assessment of the femoral midshaft cortical region revealed that both cCSE and hCSE administration significantly decreased bone mineral content 4 weeks after surgery compared with levels observed in untreated animals (107.0 ± 11.9 [untreated], 94.5 ± 13.0 [cCSE-treated], and 89.0 ± 10.1 mg/cm3 [hCSE-treated]; p = 0.049). Additionally, cCSE and hCSE-exposed femora had significantly lower bone volumes than unexposed femora. Biomechanical analyses showed that both cCSE and hCSE administration significantly decreased femoral maximum load and elastic modulus (p = 0.015 and 0.019).

CONCLUSIONS

HTP use impairs cell viability, osteoblastic differentiation, and bone fracture-healing at levels comparable with those associated with combustible cigarette use.

CLINICAL RELEVANCE

HTP use negatively affects bone fracture-healing to a degree similar to that of combustible cigarettes. Orthopaedic surgeons should recommend HTP smoking cessation to improve bone union.

Comprehensive Air Quality Assessment of the Tobacco Heating System 2.2 under Simulated Indoor Environments

Despite the growing popularity of heated tobacco products, there are few comprehensive studies on their environmental aerosols. Therefore, the impact of the Tobacco Heating System 2.2 (THS 2.2) on indoor air quality was evaluated on the basis of a comprehensive list of 31 airborne constituents along with targeted screening of the gas–vapor and particulate phases of the environmental aerosol. The assessments were conducted at three ventilation rates. Indoor use of THS 2.2 increased the levels of nicotine, acetaldehyde, glycerin, and (if mentholated products were used) menthol relative to background levels, with a corresponding increase in total volatile organic compounds (TVOC) values. Moreover, a temporary increase in ultrafine particles was observed when two or more tobacco sticks were used simultaneously or with a short time lapse between usages, but the concentrations returned to close to background levels almost immediately. This is because THS 2.2 generates an aerosol of liquid droplets, which evaporate quickly. Nicotine, acetaldehyde, glycerin, and TVOC levels were measured in the low μg/m3 range and were below the existing guideline limits. A comparison of airborne constituent levels during indoor THS 2.2 use with emissions from combustion products and common everyday activities revealed a substantially lower impact of THS 2.2 on the indoor environment.

Exposure to Heated Tobacco Products and Adverse Health Effects, a Systematic Review

Heated tobacco products (HTP) are a form of nicotine delivery intended to be an alternative to traditional cigarettes. HTP tobacco products are sold to consumers as a less harmful alternative to traditional cigarettes, both for users and bystanders. The actual impact of HTP on the health of users and its overall impact on public health is still not fully known. A systematic search of the literature was carried out to identify relevant studies published in English from 2015 to February 2021. The following databases were used: PubMed, Scopus, Elsevier and ClinicalKey. 25 studies (independent and sponsored by the tobacco industry) were considered. The analysis of exposure biomarkers and cardiovascular and respiratory biomarkers showed differences between smokers and people using heated tobacco products. Improvements in clinically relevant risk markers, especially cholesterol, sICAM-1, 8-epi-PGF2α, 11-DTX-B2, HDL and FEV1, were observed compared to persistent cigarette smokers. On the other hand, exposure to IQOS has been reported to alter mitochondrial function, which may further exaggerate airway inflammation, airway remodeling and lung cancer. These products have the potential to increase oxidative stress and increase respiratory tract infections by increasing microbial adherence to the respiratory tract. Our review suggests that HTP products may be products with a reduced risk of chronic diseases, including respiratory and cardiovascular diseases and cancer compared to traditional smoking, although in the case of non-smokers so far, they may pose a risk of their occurrence. Research seems to be necessary to assess the frequency of HTP use and its potential negative health effects.

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.

Cancer potencies and margin of exposure used for comparative risk assessment of heated tobacco products and electronic cigarettes aerosols with cigarette smoke

Health risk associated with the use of combustible cigarettes is well characterized and numerous epidemiological studies have been published for many years. Since more than a decade, innovative non-combusted tobacco products have emerged like heated tobacco products (HTP) or electronic cigarettes (EC). Long-term effects of these new products on health remain, however, unknown and there is a need to characterize associated potential health risks. The time dedicated to epidemiological data generation (at least 20 to 40 years for cancer endpoint), though, is not compatible with innovative development. Surrogates need, therefore, to be developed. In this work, non-cancer and cancer risks were estimated in a range of HTP and commercial combustible cigarettes based upon their harmful and potentially harmful constituent yields in aerosols and smoke, respectively. It appears that mean lifetime cancer risk values were decreased by more than one order of magnitude when comparing HTPs and commercial cigarettes, and significantly higher margin of exposure for non-cancer risk was observed for HTPs when compared to commercial cigarettes. The same approach was applied to two commercial ECs. Similar results were also found for this category of products. Despite uncertainties related to the factors used for the calculations and methodological limitations, this approach is valuable to estimate health risks associated to the use of innovative products. Moreover, it acts as predictive tool in absence of long-term epidemiological data. Furthermore, both cancer and non-cancer risks estimated for HTPs and ECs highlight the potential of reduced risk for non-combusted products when compared to cigarette smoking.

A Method for Comparing the Impact on Carcinogenicity of Tobacco Products: A Case Study on Heated Tobacco Versus Cigarettes

Comparing the harmful health effects related to two different tobacco products by applying common risk assessment methods to each individual compound is problematic. We developed a method that circumvents some of these problems by focusing on the change in cumulative exposure (CCE) of the compounds emitted by the two products considered. The method consists of six steps. The first three steps encompass dose-response analysis of cancer data, resulting in relative potency factors with confidence intervals. The fourth step evaluates emission data, resulting in confidence intervals for the expected emission of each compound. The fifth step calculates the change in CCE, probabilistically, resulting in an uncertainty range for the CCE. The sixth step estimates the associated health impact by combining the CCE with relevant dose-response information. As an illustrative case study, we applied the method to eight carcinogens occurring both in the emissions of heated tobacco products (HTPs), a novel class of tobacco products, and tobacco smoke. The CCE was estimated to be 10- to 25-fold lower when using HTPs instead of cigarettes. Such a change indicates a substantially smaller reduction in expected life span, based on available dose-response information in smokers. However, this is a preliminary conclusion, as only eight carcinogens were considered so far. Furthermore, an unfavorable health impact related to HTPs remains as compared to complete abstinence. Our method results in useful information that may help policy makers in better understanding the potential health impact of new tobacco and related products. A similar approach can be used to compare the carcinogenicity of other mixtures.

In vitro long-term repeated exposure and exposure switching of a novel tobacco vapor product in a human organotypic culture of bronchial epithelial cells

Next‐generation tobacco products and nicotine delivery systems such as heat‐not‐burn tobacco products and electronic cigarettes, the usage of which is expected to have a beneficial impact on public health, have gained popularity over the past decade. However, the risks associated with the long‐term use of such products are still incompletely understood. Although the risks of these products should be clarified through epidemiological studies, such studies are normally performed based on each product category, not product‐by‐product. Therefore, investigation of the risk on a product‐by‐product basis is important to provide specific scientific evidence. In the current study, we performed the 40‐day repeated exposure of in vitro human bronchial epithelial tissues to cigarette smoke (CS) or vapor from our proprietary novel tobacco vapor product (NTV). In addition, tissue samples exposed to CS were switched to NTV or CS exposure was stopped at 20 days to reflect a situation where smokers switched to NTV or ceased to smoke. All tissue samples were assessed in terms of toxicity, inflammation and transcriptomic alterations. Tissue samples switched to NTV and the cessation of exposure samples showed recovery from CS‐induced damage although there was a time‐course difference. Moreover, repeated exposure to NTV produced negligible effects on the tissue samples while CS produced cumulative effects. Our results suggest that the use of NTV, including switching to NTV from cigarette smoking, has fewer effects on bronchial epithelial tissues than continuing smoking.

We carried out the 40‐day repeated exposure of in vitro bronchial epithelial tissues to cigarette smoke (CS) or vapor from novel tobacco vapor product (NTV) and intermediate switching from CS exposure to NTV exposure. Long‐term exposure to NTV resulted in negligible effect on the tissues. Moreover, the tissues that intermediately switched to NTV exposure showed recovery from CS‐induced damage similar to exposure cessation. These results implied that exposure to NTV showed few effects on bronchial epithelial tissues.

Statistical analysis plan for "A randomised, controlled study to evaluate the effects of switching from cigarette smoking to using a tobacco heating product on health effect indicators in healthy subjects"

Tobacco harm reduction strategies aim to substitute smoking with potentially reduced risk products (PRRPs) such as e-cigarettes and tobacco-heating products (THPs). The health benefits of switching from smoking to PRRPs is unknown. A randomised controlled trial is being conducted to increase understanding of the health effects of switching from smoking to a THP in a 12-month long ambulatory study (ISRCTN81075760). Here we describe the study endpoints and the statistical analysis plan. Endpoints are divided into biomarkers of exposure (BoE) to tobacco smoke constituents and health effect indicators related to risk of lung cancer, cardiovascular and obstructive lung disease. These have been selected on the basis of extensive literature evidence. Three primary endpoints, augmentation index (risk factor for cardiovascular disease), total NNAL (linked to lung cancer) and 8-Epi-PGF2α type III (indicator of oxidative stress linked to various diseases), and multiple secondary endpoints will be analysed at 90, 180, and 360 days. Changes from baseline will be compared between study arms by specific contrasts in mixed models. Study wise multiple comparisons adjustments will be performed to account for multiplicity of timepoints and comparisons within timepoints. Generalisability of outcomes will be tested by a sensitivity analysis adjusting for age and gender. Importantly, an ancillary analysis will be performed to assess product compliance during the study based on plasma levels of CEVal, a surrogate marker for acrylonitrile exposure. The rationale underlying the selection of BoEs and health effect indicators, coupled with the statistical analysis plan will be central to understanding the potential health effects of replacing smoking with THP use for one year.

State-of-the-art methods and devices for the generation, exposure, and collection of aerosols from heat-not-burn tobacco products

Tobacco harm reduction is increasingly recognized as a promising approach to accelerate the decline in smoking prevalence and smoking-related population harm. Potential modified risk tobacco products (MRTPs) must undergo a rigorous premarket toxicological risk assessment. The ability to reproducibly generate, collect, and use aerosols is critical for the characterization, and preclinical assessment of aerosol-based candidate MRTPs (cMRTPs), such as noncombusted cigarettes, also referred to as heated tobacco products, tobacco heating products, or heat-not-burn (HNB) tobacco products. HNB tobacco products generate a nicotine-containing aerosol by heating tobacco instead of burning it. The aerosols generated by HNB products are qualitatively and quantitatively highly different from cigarette smoke (CS). This constitutes technical and experimental challenges comparing the toxicity of HNB aerosols with CS. The methods and experimental setups that have been developed for the study of CS cannot be directly transposed to the study of HNB aerosols. Significant research efforts are dedicated to the development, characterization, and validation of experimental setups and methods suitable for HNB aerosols. They are described in this review, with a particular focus on the Tobacco Heating System version 2.2. This is intended to support further studies, the objective evaluation and verification of existing evidence, and the development of scientifically substantiated HNB MRTPs.

Informing iQOS Regulations in the United States: A Synthesis of What We Know

The tobacco industry offers various products, including heated tobacco products (HTPs). Philip Morris International's (PMI) "iQOS" has the greatest HTP market share, as well as research on its use and impact. iQOS was released in 2014 and is now in more than 40 countries. The U.S. Food and Drug Administration announced permission for PMI to sell iQOS in the United States in April 2019, and iQOS was launched in October 2019. Decisions pending its modified risk tobacco product (MRTP) application will occur subsequently. The U.S. regulatory efforts regarding iQOS could be informed by examining (a) Philip Morris USA other product marketing efforts and (b) the iQOS market in countries where it is available. This article briefly addresses these two points with extant literature and suggests that future research should address important gaps in what is currently known, including strategic international collaborations and research, which historically has been critical for advancing tobacco control globally.

Comparison of End Tidal Carbon Monoxide Levels between Conventional Cigarette, Electronic Cigarette and Heated Tobacco Product among Asiatic Smokers

Electronic nicotine delivery systems (ENDS) and heated tobacco products (HTPs) are noncombustible tobacco products which have been found to generate aerosols containing lower levels of Harmful and Potentially Harmful Constituents (HPHCs) in comparison to conventional cigarettes. Objective: This quasi experimental study measured and compared the end tidal carbon monoxide (eCO) levels of participants after use of ENDS, HTPs and conventional cigarettes. Methods: In total 45 smokers, each smoking at least 10 conventional cigarettes per day for 5 years participated in the study. Based on their preference, participants used only one of the tobacco products (ENDS, HTPs, or conventional cigarette) and were briefed about the product use based on manufacturer's instructions. The eCO levels were obtained at baseline, followed by 5, 10, 15, 30 and 45 min respectively after the product use. Results: There was significant increase in eCO levels for conventional cigarettes as compared to other modes. Peak eCO levels of 20.2 ± 0.86 ppm, 8.8 ± 1.56 ppm and 6.0 ± 1.36 ppm was achieved at 30 min, 15 min and 10 min for conventional cigarettes, ENDS and HTPs respectively. However, the levels were significantly lower in ENDS and HTPs. Conclusion: Even though ENDS and HTPs may have produced significantly lower eCO than conventional cigarettes, the significantly increasing levels over time from baseline which was not shown before is a cause of concern. As of now, their use as an alternate to cigarettes needs to be considered under regulatory framework.

Exhaled Carbon Monoxide Levels in Forty Resistant to Cessation Male Smokers after Six Months of Full Switch to Electronic Cigarettes (e-Cigs) or to A Tobacco Heating Systems (THS)

Cigarette smoke releases several toxic chemicals and carcinogens including carbon monoxide (CO). This study examined the levels of exhaled CO in smokers switching to electronic cigarettes (e-Cigs) or a tobacco heating system (THS) and their level of compliance six months after switching. On the basis of their own preferences, 40 male smokers unwilling or unable to stop smoking were switched to e-Cigs or THSs for six months (20 subjects in each group). Nicotine addiction and levels of carbon monoxide in the exhaled breath (eCO) were measured at baseline (the latter also at six months). The Shapiro Wilk test, graphical methods, Student T test or Mann-Whitney test were used to assess the normal distribution of variables and differences between the two groups after six months. The two groups showed no difference at baseline, but a significant higher addiction score in smokers choosing THS. E-Cig and THS showed significant reduced levels of eCO (both %COHb and COppm) after six months, which were within the range of non-smoker status. Reduced levels of %COHb did not significantly differ between the two groups, whilst the THS group had a significantly lower reduction in levels of COppm vs the e-Cig group (p < 0.05). Both e-Cigs and THSs are capable of significantly reducing eCO at least in the medium term, hence constituting a viable tobacco harm reduction approach in smokers who are unwilling or unable to stop smoking.

Heat-not-burn tobacco products: a systematic literature review

OBJECTIVE

To review peer-reviewed evidence on heat-not-burn tobacco products (HnB), their secondhand emissions and use by humans; to identify differences between independent and industry-funded studies.

DATA SOURCES

Medline, Embase, PsycINFO, ProQuest, Scopus and Web of Science databases were searched up to 6 November 2017 for studies on HnB published after December 2009; reference lists were screened and other researchers contacted, yielding 637 records.

STUDY SELECTION

Thirty-one publications on HnB secondhand emissions (n=16) or use by humans (n=15) were selected by two reviewers with excellent agreement (k=0.75).

DATA EXTRACTION

Data on authors' affiliations, HnB products, secondhand emissions and human exposure were extracted by one reviewer. Two reviewers assessed the quality of experimental HnB studies using the Effective Public Health Practice Project tool.

DATA SYNTHESIS

Twenty out of 31 studies were affiliated with tobacco industry. Studies on secondhand emissions varied by methodology, products and comparators. Compared with cigarettes, HnB delivered up to 83% of nicotine and reduced levels of harmful and potentially harmful toxicants by at least 62% and particulate matter by at least 75%. Experimental HnB use studies were limited to one product, reductions of human exposure to toxicants varied between 42% and 96%. HnB use suppressed urges to smoke, but participants rated HnB less satisfying than cigarettes. While limited by methodological heterogeneity, findings were largely similar for independent and industry-funded studies.

CONCLUSIONS

Studies on HnB secondhand emissions and human use were heterogeneous and largely affiliated with the manufacturers. HnB exposed users and bystanders to toxicants, although at substantially lower levels than cigarettes.

Evaluating the effects of switching from cigarette smoking to using a heated tobacco product on health effect indicators in healthy subjects: study protocol for a randomized controlled trial

Tobacco heating products (THPs) are a potentially safer alternative to combustible cigarette smoking. Through continued use, THPs may reduce smoking-related disease risk, whilst maintaining the sensorial experience and nicotine delivery sought by smokers. While literature evidence of the biological effects of THP aerosol exposure is increasing, there remains a knowledge gap with respect to substantiation of THP reduced risk potential in longer term real-life use. This randomized, multi-centre, controlled clinical study will test the hypotheses that following a switch from combustible cigarettes to a THP for 1 year, participants will experience a sustained reduction in exposure to tobacco-related toxicants that will lead to favourable changes in health effect indicators associated with smoking-related disease development. Changes in such indicators will be contextualized against smoking cessation and never-smoker cohorts. Up to 280 participants who do not intend to quit smoking will be randomized to continued combustible smoking (arm A, up to n = 80) or a commercially available THP (arm B n = 200). Furthermore, up to 190 participants with a high intent to quit smoking will undergo smoking cessation (arm D), and 40 never smokers will serve as a control group (arm E). Recruitment numbers were determined to be sufficient to achieve n = 50 in arms A, B and D, at study end. Enrolment started in March 2018 and the trial is scheduled to be completed in March 2020. Data from this study will be a valuable addition to the growing body of evidence in the field of understanding the individual and public health impact of THPs.Clinical Trial Registration: https://www.isrctn.com/ISRCTN81075760.

Changes in Biomarkers of Exposure on Switching From a Conventional Cigarette to Tobacco Heating Products: A Randomized, Controlled Study in Healthy Japanese Subjects

BACKGROUND

Smoking is a leading cause of numerous human disorders including pulmonary disease, cardiovascular disease, and cancer. Disease development is primarily caused by exposure to cigarette smoke constituents, many of which are known toxicants. Switching smokers to modified risk tobacco products (MRTPs) has been suggested as a potential means to reduce the risks of tobacco use, by reducing such exposure.

METHODS

This randomized, controlled study investigated whether biomarkers of toxicant exposure (BoE) were reduced when smokers switched from smoking combustible cigarettes to using a novel (glo™/THP1.0) or in-market comparator (iQOS/THS) tobacco heating product (THP). One hundred eighty Japanese smokers smoked combustible cigarettes during a 2-day baseline period, followed by randomization to either continue smoking cigarettes, switch to using mentholated or non-mentholated variants of glo™, switch to using a non-mentholated variant of iQOS, or quit nicotine and tobacco product use completely for 5 days. Baseline and post-randomization 24-h urine samples were collected for BoE analysis. Carbon monoxide was measured daily in exhaled breath (eCO).

RESULTS

On day 5 after switching, urinary BoE (excluding for nicotine) and eCO levels were significantly (p < .05) reduced by medians between 20.9% and 92.1% compared with baseline in all groups either using glo™ or iQOS or quitting tobacco use. Between-group comparisons revealed that the reductions in the glo™ groups were similar (p > .05) to quitting in many cases.

CONCLUSIONS

glo™ or iQOS use for 5 days reduced exposure to smoke toxicants in a manner comparable to quitting tobacco use. THPs are reduced exposure tobacco products with the potential to be MRTPs.

IMPLICATIONS

This clinical study demonstrates that when smokers switched from smoking combustible cigarettes to using tobacco heating products their exposure to smoke toxicants was significantly decreased. In many cases, this was to the same extent as that seen when they quit smoking completely. This may indicate that these products have the potential to be reduced exposure and/or reduced risk tobacco products when used by smokers whose cigarette consumption is displaced completely.

CLINICAL TRIAL REGISTRATIONS

ISRCTN14301360 and UMIN000024988.

Heated Tobacco Products: Volatile Emissions and Their Predicted Impact on Indoor Air Quality

This study characterized emissions from IQOS, a heated tobacco product promoted as a less harmful alternative to cigarettes. Consumable tobacco plugs were analyzed by headspace GC/MS to assess the influence of heating temperature on the emission profile. Yields of major chemical constituents increased from 4.1 mg per unit at 180 °C to 6.2 mg at 200 °C, and 10.5 mg at 220 °C. The Health Canada Intense smoking regime was used to operate IQOS in an environmental chamber, quantifying 33 volatile organic compounds in mainstream and sidestream emissions. Aldehydes, nitrogenated species, and aromatic species were found, along with other harmful and potentially harmful compounds. Compared with combustion cigarettes, IQOS yields were in most cases 1-2 orders of magnitude lower. However, yields were closer to, and sometimes higher than electronic cigarettes. Predicted users' daily average intake of benzene, formaldehyde, acetaldehyde and acrolein were 39 μg, 32 μg, 2.2 mg and 71 μg, respectively. Indoor air concentrations were estimated for commonly encountered scenarios, with acrolein levels of concern (over 0.35 μg m-3) derived from IQOS used in homes and public spaces. Heated tobacco products are a weaker indoor pollution source than conventional cigarettes, but their impacts are neither negligible nor yet fully understood.

Household Surveys in the General Population and Web-Based Surveys in IQOS Users Registered at the Philip Morris International IQOS User Database: Protocols on the Use of Tobacco- and Nicotine-Containing Products in Germany, Italy, and the United Kingdom (Greater London), 2018-2020

BACKGROUND

Philip Morris International (PMI) has developed a novel heat-not-burn tobacco product, Tobacco Heating System (THS), which is marketed under the brand name of IQOS with HEETS (IQOS). The aerosol generated by THS has substantially fewer toxicants than combustible cigarette smoke, although the extent of the reduction of harmful and potentially harmful constituents reported varies between studies. To evaluate the potential harm reduction associated with IQOS use, the assessment of the uptake and continued use of IQOS in the context of all other tobacco- and nicotine-containing products is crucial. In March 2018, PMI launched cross-sectional surveys in Germany, Italy, and the United Kingdom (Greater London) to estimate the prevalence and use patterns of IQOS and other tobacco- and nicotine-containing products use in these 3 markets following the commercialization of IQOS. This study describes the protocol of the surveys.

OBJECTIVE

The objectives of these surveys are to estimate the prevalence of tobacco- and nicotine-containing products use; describe past and current patterns of use; and explore their associations with self-reported health, motivation to use, risk perceptions, and perceived aesthetic changes.

METHODS

The overall design of the surveys is similar in all 3 countries. Repeated cross-sectional surveys are being conducted annually over 3 consecutive years (2018 to 2020) and in 2 samples: a representative sample of the general population and a sample of IQOS users. A total of 6085 adults per year will be selected from the general population for each survey through multistage stratified sampling, and participants will respond to face-to-face computer-assisted personal interviews. In addition, 1404, 1384, and 1246 IQOS users per year in Germany, Italy, and Greater London, respectively, will be randomly selected from the PMI IQOS user database and will be invited to complete the Web-based survey using computer-assisted self-interviews. The Smoking Questionnaire is used to assess the tobacco use patterns of the participants.

RESULTS

The recruitment of the general population sample began in March 2018 and that of the IQOS user sample began in April 2018. The data collection is ongoing, and the results of the first year data analysis are expected to be available by June 2019.

CONCLUSIONS

As the design of the 3 surveys is similar, the results will allow for cross-countries comparison of the prevalence of IQOS and other tobacco- and nicotine-containing products use as well as patterns of use and associated factors.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/12061.

Mainstream smoke constituents and in vitro toxicity comparative analysis of 3R4F and 1R6F reference cigarettes

A new Kentucky reference cigarette, 1R6F, has been manufactured to replace the depleting 3R4F reference cigarette. The 3R4F Kentucky reference cigarettes have been widely used as monitor or comparator cigarettes for mainstream smoke analysis and in vitro and in vivo toxicological data of cigarettes and novel tobacco products. Both reference cigarettes were analyzed in the same laboratory during the same period of time with the goal of performing a comparison of 3R4F and 1R6F. On the basis of the results obtained from aerosol chemistry and in vitro assays, we consider that the 1R6F reference cigarette is a suitable replacement for the 3R4F reference cigarette as a comparator/monitor cigarette. Its specific use as a comparator for novel tobacco products was checked on the basis of a comparative test with the Tobacco Heating System 2.2 as an example.

Investigation of menthol content and transfer rates in cigarettes and Tobacco Heating System 2.2

Menthol cigarettes account for a significant market share in many countries. However, little recent data exists on menthol levels in cigarettes and in mainstream smoke, limited to some markets or specific cigarette designs, such as cigarettes containing capsules filled with flavoring liquids. Samples of mentholated cigarettes bought worldwide with a variety of cigarette designs were analyzed for menthol content in cigarettes and in cigarette mainstream smoke with two analytical machine smoking regimes. A wide range of menthol content in cigarettes, from 1 to 22 mg/cigarette, was observed. The transfer of menthol to the cigarette mainstream smoke was generally slightly higher than the transfer of nicotine, with a range of 17%-40% using an intense smoking regime and 1%-17% using the ISO smoking regime. For the Tobacco Heating System (THS) 2.2, the menthol content was 12.8 mg/stick, and the transfer of menthol into the aerosol was about 17% with the ISO intense smoking regime, similar to the transfer of nicotine. The menthol content of the novel product THS 2.2 corresponds to the midpoint of the menthol content range of cigarettes, and the transfer of menthol to its aerosol is in the low range of cigarette menthol transfer.

Multi-omics analysis: Repeated exposure of a 3D bronchial tissue culture to whole-cigarette smoke

Cigarette smoke (CS) is a major risk factor in the development of chronic inflammatory lung diseases such as chronic obstructive pulmonary disease. A comprehensive investigation of the biological impacts of chronic CS exposure on lung tissue is therefore important for understanding the pathogenesis of lung disease. We used three-dimensional (3D) organotypic human bronchial tissue cultures and metabolomics, transcriptomics, and proteomics to investigate changes in biological processes affected by repeated whole-CS exposure. We found that CS perturbed central carbon metabolism in relation with oxidative stress responses. Epidermal growth factor receptor, which is involved in the early-stage pathogenesis of airway diseases, was identified as a key regulator of the perturbed processes. Proteomic analysis of proteins in the apical surface liquid of the 3D bronchial tissue cultures indicated that repeated whole-CS exposure induced alterations in the secretion of several known biomarkers of airway diseases, including mucins and matrix metalloproteinases. These findings are consistent with observations from lung disease patients. Overall, our results suggest that 3D bronchial tissue cultures can provide valuable information on tissue-specific alterations in biological processes induced by chronic exposure to CS.

[Systematic analysis of the scientific literature on heated tobacco]

INTRODUCTION

The tobacco industry (TI) reports that heated tobacco reduces risk of tobacco use and will replace cigarettes. An analysis of the scientific literature was conducted in order to enlighten professionals and decision-makers.

METHOD

After a Medline query in February 2018, a systematic analysis was conducted.

RESULTS

Of the 100 papers published in 2008-2018, 75 have authors affiliated or linked to TI. Emissions contain gases, droplets and solid particles, so are smokes. The main products are: THS2.2 (Iqos®) which heats mini-cigarettes at 340°C, the THP1.0 (Glo®) which heats at 240°C sticks delivering about half as much nicotine, Ploom® which uses reconstituted tobacco microcapsules heated at 180°C. Under the experimental conditions, there is a reduction of toxic emissions and biological effects, but the expected risk reduction is not demonstrated. Symptoms related to passive smoking are described. The 4 epidemiological articles report that heated tobacco is used in 10 to 45% of cases by non-smokers and demonstrate the effectiveness of TI promotion campaigns. Thus, the THS2.2 is more a gateway to smoking (20%) than an exit door (11%); moreover, it is not expected risk reduction among the 69% who are mixed users.

CONCLUSIONS

While reducing emissions is documented, reducing the risk to the smoker who switches to heated-tobacco remains to be demonstrated. On the other hand, the worsening of the global tobacco risk related to the promotion of the products by the TI is anticipated, justifying that the authorities take the appropriate measures to control the promotion of heated tobacco.