The Product Science of Electrically Heated Tobacco Products: An Updated Narrative Review of the Scientific Literature.

Heated tobacco products represent a novel category of tobacco products in which a tobacco consumable is heated to a temperature that releases nicotine from the tobacco leaf but not to a temperature sufficient to cause combustion. Heated tobacco products may therefore have the potential to be a less harmful alternative for adult smokers who would otherwise continue to smoke cigarettes, as their use should result in exposure to substantially fewer and lower levels of toxicants. This update represents a two-year extension to our previous narrative review, which covered peer-reviewed journal articles published up to August 31, 2021. The scientific evidence published between 2021 and 2023 continues to indicate that aerosols produced from heated tobacco products contain fewer and substantially lower levels of harmful and potentially harmful constituents and that these observed reductions consistently translate to reduced biological effects in both in vitro and in vivo toxicological studies. Biomarker and clinical data from studies in which product use is controlled within a clinical setting continue to suggest changes in levels of biomarkers of exposure, biomarkers of potential harm, and clinical endpoints indicating the potential for reduced harm with switching to exclusive use of heated tobacco products in adult smokers. Overall, the available peer-reviewed scientific evidence continues to indicate that heated tobacco products offer promise as a potentially less harmful alternative to cigarettes, and as such, the conclusions of our original narrative review remain valid.

Impact of Electronic Cigarettes, Heated Tobacco Products and Conventional Cigarettes on the Generation of Oxidative Stress and Genetic and Epigenetic Lesions in Human Bronchial Epithelial BEAS-2B Cells.

Electronic cigarettes (e-cig) and heated tobacco products (HTP) are often used as smoking cessation aids, while the harm reduction effects of these alternatives to cigarettes are still the subject of controversial debate, in particular regarding their carcinogenic potential. The objective of this study is to compare the effects of e-cig, HTP and conventional cigarette emissions on the generation of oxidative stress and genetic and epigenetic lesions in human bronchial epithelial BEAS-2B cells. Our results show that HTP were less cytotoxic than conventional cigarettes while e-cig were not substantially cytotoxic in BEAS-2B cells. E-cig had no significant effect on the Nrf2 pathway, whereas HTP and cigarettes increased the binding activity of Nrf2 to antioxidant response elements and the expression of its downstream targets HMOX1 and NQO1. Concordantly, only HTP and cigarettes induced oxidative DNA damage and significantly increased DNA strand breaks and chromosomal aberrations. Neither histone modulations nor global DNA methylation changes were found after acute exposure, regardless of the type of emissions. In conclusion, this study reveals that HTP, unlike e-cig, elicit a biological response very similar to that of cigarettes, but only after a more intensive exposure: both tobacco products induce cytotoxicity, Nrf2-dependent oxidative stress and genetic lesions in human epithelial pulmonary cells. Therefore, the health risk of HTP should not be underestimated and animal studies are required in order to determine the tumorigenic potential of these emerging products.

Total and bioavailable polycyclic aromatic hydrocarbons in unused and operated heat-not-burn tobacco products and conventional cigarettes.

Tobacco product waste poses a global environmental issue, affecting urban and coastal areas alike. The present studies report, for the first time, the total and bioavailable polycyclic aromatic hydrocarbons (PAHs) concentrations in unused and operated heat-not-burn (HnBs) tobacco products. To enable direct comparisons, identical sets of studies were conducted using conventional cigarettes (CCs). Five low-molecular PAHs were determined in HnBs at total concentrations that were of the same order before and after operation (Σ5PAH = 47.37 ± 3.44 ng unit-1 and Σ5PAH = 69.36 ± 5.78 ng unit-1 in unused and used HnBs, respectively). The incomplete combustion of organics during smoking of CCs, yielded substantially higher amounts of PAHs with their sum (Σ10PAHs = 1449 ± 113 ng unit-1) being >20 times larger than those in HnBs. The tobacco and filter were the most contaminated parts in HnBs. In unused CCs, tobacco had the highest PAHs load and after smoking, the spent filter was the most contaminated part, containing ∼80% of the total amount of PAHs. Naphthalene was the most abundant PAH detected in all tobacco products. Despite the high total PAH concentrations found in smoked CCs, the sums of the bioavailable PAH concentrations were of the same order in all tested tobacco products (Σ5PAH = 61.38 ± 1.79 ng unit-1 in unused HnBs, Σ5PAH = 70.87 ± 7.67 ng unit-1 in used HnBs, Σ4PAH = 66.92 ± 5.95 ng unit-1 in unused CCs, and Σ6PAH = 47.94 ± 1.26 ng unit-1 in smoked CCs). This finding was related to smoking affecting PAHs' leachability from CCs and delaying their desorption from the solid matrix. Adjusting the pH, salt and humic acids content at environmentally relevant values did not affect PAHs leaching at 24 h of soaking. Finally, the leaching behavior of PAHs in natural waters (river water, rainwater, and seawater) was found similar to that in ultrapure water, experimentally verifying the ability of tobacco product waste to leach PAHs into the aquatic environment.

The Association of Tobacco Smoking, Second-hand Smoke, and Novel Tobacco Products With COVID-19 Severity and Mortality in Italy: Results From the COSMO-IT Study.

BACKGROUND: Despite the robust evidence of an excess risk of coronavirus disease 2019 (COVID-19) severity and mortality in ever smokers, the debate on the role of current and ex-smokers on COVID-19 progression remains open. Limited or no data are available on the link between electronic cigarette (e-cigarette), heated tobacco product (HTP) and second-hand smoke (SHS) exposure and COVID-19 progression. To fill this knowledge gap, we undertook the COvid19 and SMOking in ITaly (COSMO-IT) study. METHODS: A multi-centre longitudinal study was conducted in 2020-2021 in 24 Italian hospitals on a total of 1,820 laboratory-confirmed COVID-19 patients. We estimated multivariable odds ratios (OR) and 95% confidence intervals (CI) to quantify the association between smoking-related behaviours (ie, smoking status, e-cigarette and HTP use, and SHS exposure) and COVID-19 severity (composite outcome: intubation, intensive care unit admission and death) and mortality. RESULTS: Compared to never smokers, current smokers had an increased risk of COVID-19 mortality (OR 2.17; 95% CI, 1.06-4.41). E-cigarette use was non-significantly associated to an increased risk of COVID-19 severity (OR 1.60; 95% CI, 0.96-2.67). An increased risk of mortality was observed for exposure to SHS among non-smokers (OR 1.67; 95% CI, 1.04-2.68), the risk being particularly evident for exposures of ≥6 hours/day (OR 1.99; 95% CI, 1.15-3.44). CONCLUSION: This multicentric study from Italy shows a dismal COVID-19 progression in current smokers and, for the first time, in SHS exposed non-smokers. These data represent an additional reason to strengthen and enforce effective tobacco control measures and to support smokers in quitting.

Actualización sobre las nuevas formas de consumo de tabaco / Update on new forms of tobacco use

El tabaquismo sigue siendo la principal causa de morbimortalidad a nivel mundial. Por su clara influencia en las enfermedades cardiovasculares y respiratorias, es un factor importante en la consulta de medicina interna. Aunque la tasa de abandono del hábito tabáquico está ascendiendo en los últimos años, existe un porcentaje de pacientes que continúan fumando porque no pueden o no quieren cesar el hábito, a pesar de haber probado las terapias farmacológicas y no farmacológicas existentes. Para este grupo de paciente existen unas estrategias que se basan en intervenciones destinadas a reducir los efectos negativos del tabaco sin la necesidad de extinguir por completo su consumo. En esta revisión se contempla como gracias a la ausencia de combustión de la materia orgánica que se da en el cigarrillo convencional, en snus, cigarrillo electrónico y productos de tabaco calentado se genera un nivel significativamente inferior de sustancias tóxicas.(AU)

Smoking remains the leading cause of morbidity and mortality worldwide. Because of its clear influence on cardiovascular and respiratory diseases, it is an important factor in internal medicine consultations. Although the rate of smoking cessation has been increasing in recent years, there is a percentage of patients who continue to smoke because they are unable or unwilling to quit, despite having tried existing pharmacological and non-pharmacological therapies. For this group of patients there are strategies based on interventions aimed at reducing the negative effects of smoking without the need for complete cessation. In this review it is shown that due to the absence of combustion of organic matter in conventional cigarettes, snus, e-cigarettes and heated tobacco products generate significantly lower levels of toxic substances.(AU)

Diluted aqueous extract of heat-not-burn tobacco product smoke causes less oxidative damage in fibroblasts than conventional cigarette.

Smoke from conventional cigarettes (C-cigarettes) contains various reactive oxygen species and toxic chemicals, which potentially cause oxidative damage not only to airways but also to the whole body, leading eventually to diseases, including emphysema, advanced atherosclerosis, and cancer. Many heat-not-burn tobacco products (HTPs) have been commercialized recently in Japan to maintain the smoking population by advertising that HTPs are less toxic. However, there were few studies reported from neutral organizations whether HTPs are indeed less damaging. To evaluate the potential capacity of HTPs to induce oxidative stress, we here compared two different HTPs with two types of C-cigarettes, using human fibroblast IMR90SV cells and 5% aqueous extracts in 10-ml phosphate-buffered saline (50-ml smoke/10 s). HTPs exhibited significantly lower oxidative toxicity in comparison to C-cigarettes. Whereas C-cigarettes induced ferroptosis in fibroblasts, the effects of HTPs were significantly reduced by measuring the levels of peroxides, pro-inflammatory cytokine expression, autophagy, catalytic Fe(II) and 8-hydroxy-2'-deoxyguanosine. Notably, major portions of C-cigarettes-induced pathogenic responses were inhibited by catalase. However, HTPs still induced p62 autophagy-adaptor at 5%-dilution and caused lethal effects to fibroblasts with undiluted solution. In conclusion, HTPs smoke per se can be toxic despite less toxicity in comparison to C-cigarettes, which warrants further investigation.

Update on new forms of tobacco use. / Actualización sobre las nuevas formas de consumo de tabaco.

Smoking remains the leading cause of morbidity and mortality worldwide. Because of its clear influence on cardiovascular and respiratory diseases, it is an important factor in internal medicine consultations. Although the rate of smoking cessation has been increasing in recent years, there is a percentage of patients who continue to smoke because they are unable or unwilling to quit, despite having tried existing pharmacological and non-pharmacological therapies. For this group of patients there are strategies based on interventions aimed at reducing the negative effects of smoking without the need for complete cessation. In this review it is shown that due to the absence of combustion of organic matter in conventional cigarettes, snus, e-cigarettes and heated tobacco products generate significantly lower levels of toxic substances.

Use and Awareness of Heated Tobacco Products in Europe.

BACKGROUND: Heated tobacco products (HTP) are new forms of tobacco consumption with limited information available on their use among the general population. Our objective was to analyze the prevalence and associations of use of HTP across 11 countries in Europe. METHODS: Within the TackSHS Project, in 2017-2018 we conducted a cross-sectional study with information on HTP use in the following countries: Bulgaria, England, France, Germany, Greece, Italy, Latvia, Poland, Portugal, Romania and Spain. In each country, face-to-face interviews were performed on a representative sample of around 1,000 subjects aged ≥15 years, for a total of 10,839 subjects. RESULTS: Overall, 27.8% of study participants were aware of HTPs, 1.8% were ever HTP users (ranging from 0.6% in Spain to 8.3% in Greece), and 0.1% were current users. Men were more frequently HTP ever users than women (adjusted odds ratio [aOR] 1.47; 95% confidence interval [CI], 1.11-1.95). Ever HTP use was inversely related to age (P for trend <0.001) and more frequent in ex-smokers (compared with never smokers, aOR 4.32; 95% CI, 2.69-6.95) and current smokers (aOR 8.35; 95% CI, 5.67-12.28), and in electronic cigarette past users (compared with never users, aOR 5.48; 95% CI, 3.46-8.68) and current users (aOR 5.92; 95% CI, 3.73-9.40). CONCLUSIONS: In 2017-2018, HTP use was still limited in Europe among the general population; however, the dual use of these products, their high use among younger generations, and the interest of non-smokers in these products are worrying and indicate the need for close monitoring in terms of prevalence and the characteristics of users.

Toxic mechanisms of cigarette smoke and heat-not-burn tobacco vapor inhalation on rheumatoid arthritis.

Tobacco combustion exposure worsens rheumatoid arthritis (RA). Non-combustible tobacco devices, as heat-not-burn tobacco (HNBT), are emerging as harm reduction to smokers by releasing nicotine and lower combustible tobacco products. Nevertheless, HNBT toxicity remains unclear. Hence, here we investigated the impacts of the tobacco combustible product (cigarette smoke; CS) or HNBT vapor exposures on antigen-induced arthritis (AIA) in C57BL/6 mice. Animals were exposed to airflow, HNBT vapor, or CS during 1 h/twice a day, under the Health Canada Intense (HCI) smoking regime, between days 14 to 20 after the first immunization. At day 21, 16 h after the last exposures, mice were i.a. challenged and the AIA effects were evaluated 24 h later. CS- or HNBT-exposed mice presented equivalent blood nicotine levels. CS exposure worsened articular symptoms, pulmonary inflammation, and expression of lung metallothioneins. Nevertheless, CS or HNBT exposures reduced lymphoid organs' cellularity, splenocyte proliferation and IL-2 secretion. Additional in vitro CS or HNBT exposures confirmed the harmful effects on splenocytes, which were partially mediated by the activation of nicotine/α7nAchR pathway. Associated, data demonstrate the toxic mechanisms of CS or HNBT inhalation at HCI regime on RA, and highlight that further investigations are fundamental to assure the toxicity of emerging tobacco products on the immune system during specific challenges.

The effect of emerging tobacco related products and their toxic constituents on thrombosis.

Although conventional cigarette smoking is declining, emerging tobacco related products (ETRPs) are currently gaining ground, especially among the youth. These products include electronic cigarettes, waterpipes/hookah, cigars/cigarillo, smokeless tobacco, and heat-not-burn cigarettes. The observed increase in the use of ETRPs is multifactorial and complex but appears to be mainly driven by efforts from the major tobacco companies to reinvent themselves, and present more appealing and allegedly safe(r) tobacco products. However, it is becoming apparent that these products produce substantial amounts of toxic chemicals, many of which have been shown to exert negative health effects, including in the context of the cardiovascular system. Thus, there has been research efforts, albeit limited in general, to characterize the health impact of these products on occlusive/thrombotic cardiovascular diseases (CVD). In this review, we will discuss the potential impact of ETRPs on thrombosis-based CVD. Specifically, we will review how these products and the major chemicals they produce and/or emit can trigger key players in the process of thrombosis, namely inflammation, oxidative stress, platelets, coagulation, and the vascular endothelium, and the relationship between these effects.

Effects of Heat-Not-Burn Cigarette Smoking on the Secretion of Saliva and Its Innate Immune System Components.

Saliva and salivary antimicrobial proteins play important roles in the innate immunity, which prevents infections of orally invading bacteria and viruses. In this study, we compared the secretion rates of salivary lactoferrin (Lac) and lysozyme (Lys) in heat-not-burn (HNB) cigarette smokers and non-smokers. The analysis population for this study included 212 members of the fire department, including 32 HNB cigarette smokers, 17 paper cigarette smokers, 14 combined HNB and paper cigarette smokers, and 149 non-smokers. Salivary Lac and Lys concentrations were assessed using enzyme immunoassay. Saliva secretion was significantly lower among HNB cigarette smokers (p < 0.01) than among non-smokers. Accompanying this result, salivary Lac and Lys secretion rates were significantly lower among smokers, particularly HNB cigarette smokers, than among non-smokers (all p < 0.01). Our findings suggest a possible adverse effect of HNB cigarette on the amount of Lac and Lys released into the oral cavity.

The Role of Novel (Tobacco) Products on Tobacco Control in Italy.

In Italy, electronic cigarettes have spread since 2010 and heated tobacco products (HTP) since 2016. We investigated their public health consequences on conventional cigarette smoking, taking advantage of a series of cross-sectional studies annually conducted between 2001 and 2019 in Italy. Every year, the sample, including around 3000 individuals, was representative of the general Italian population aged ≥15 years. In Italy, smoking prevalence steadily declined from 29.1% in 2001 to 20.6% in 2013, then increased to 22.0% in 2019. In 2017-2019, current electronic cigarette users were 2.1% and in 2019 current HTP users were 1.1%. Among 498 ever electronic cigarette users, 23.2% started or re-started smoking and 15.7% quit smoking after electronic cigarette use; of 49 ever HTP users, 19.1% started or re-started smoking combusted cigarettes and 14.6% quit smoking after HTP use. The availability of novel products in Italy resulted in a halt of the decreasing trend in smoking prevalence. For the first time, we observed an increase of Italians inhaling nicotine, concurrently with the spread of novel (tobacco) products. More importantly, the use of novel products appears to increase-rather than decrease-the likelihood of smoking conventional cigarettes. Considering this evidence, we see no argument to justify the huge fiscal and regulatory benefits these products continue to have, at least in Italy.

Comparison of the chemical composition of aerosols from heated tobacco products, electronic cigarettes and tobacco cigarettes and their toxic impacts on the human bronchial epithelial BEAS-2B cells.

The electronic cigarettes (e-cigs) and more recently the heated tobacco products (HTP) provide alternatives for smokers as they are generally perceived to be less harmful than conventional cigarettes. However, it is crucial to compare the health risks of these different emergent devices, in order to determine which product should be preferred to substitute cigarette. The present study aimed to compare the composition of emissions from HTP, e-cigs and conventional cigarettes, regarding selected harmful or potentially harmful compounds, and their toxic impacts on the human bronchial epithelial BEAS-2B cells. The HTP emitted less polycyclic aromatic hydrocarbons and carbonyls than the conventional cigarette. However, amounts of these compounds in HTP aerosols were still higher than in e-cig vapours. Concordantly, HTP aerosol showed reduced cytotoxicity compared to cigarette smoke but higher than e-cig vapours. HTP and e-cig had the potential to increase oxidative stress and inflammatory response, in a manner similar to that of cigarette smoke, but after more intensive exposures. In addition, increasing e-cig power impacted levels of certain toxic compounds and related oxidative stress. This study provides important data necessary for risk assessment by demonstrating that HTP might be less harmful than tobacco cigarette but considerably more harmful than e-cig.

Effects of Fetal Exposure to Heat-Not-Burn Tobacco on Testicular Function in Male Offspring.

Several studies show that maternal conventional cigarette smoking during pregnancy has been associated with reduced sperm concentration in sons. The development of heat-not-burn (HnB) tobacco has gained a growing following. However, the effects of prenatal HnB tobacco smoking on male offspring are as yet unknown. Pregnant CD-1 mice were exposed to I-Quit-Ordinary-Smoking (IQOS) (HnB tobacco) aerosol from heat sticks, mainstream smoke from 3R4F (conventional cigarettes) or clean air, using a whole-body exposure system. Adult male offspring mice were divided into six groups: control (5- and 15-weeks-old offspring), IQOS (5 and 15-weeks-old) and 3R4F (5 and 15-weeks-old). Spermatogenesis, sperm characteristics, serum testosterone, and seminiferous tubule morphology were evaluated. Prenatal IQOS exposure increased abnormal seminiferous tubule morphology and decreased sperm production at 5 weeks, but 3R4F exposure did not. Prenatal exposure to IQOS aerosol delays sexual maturation of male offspring or adversely affects the male testicular function of the offspring more than smoke from a combustion cigarette.

Ceramide ratios are affected by cigarette smoke but not heat-not-burn or e-vapor aerosols across four independent mouse studies.

AIMS: Smoking is an important risk factor for the development of chronic obstructive pulmonary disease and cardiovascular diseases. This study aimed to further elucidate the role of ceramides, as a key lipid class dysregulated in disease states. MAIN METHODS: In this article we developed and validated LC-MS/MS method for ceramides (Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1(15Z)) for the absolute quantification. We deployed it together with proteomics and transcriptomic analysis to assess the effects of cigarette smoke (CS) from the reference cigarette as well as aerosols from heat-not-burn (HnB) tobacco and e-vapor products in apolipoprotein E-deficient (ApoE-/-) mice over several time points. KEY FINDINGS: In the lungs, CS exposure substantially elevated the ratios of Cer(d18:1/24:0) and Cer(d18:1/24:1) to Cer(d18:1/18:0) in two independent ApoE-/- mouse inhalation studies. Data from previous studies, in both ApoE-/- and wild-type mice, further confirmed the reproducibility of this finding. Elevation of these ceramide ratios was also observed in plasma/serum, the liver, and-for the Cer(d18:1/24:1(15Z)) to Cer(d18:1/18:0) ratio-the abdominal aorta. Also, the levels of acid ceramidase (Asah1) and glucocerebrosidase (Gba)-lysosomal enzymes involved in the hydrolysis of glucosylceramides-were consistently elevated in the lungs after CS exposure. In contrast, exposure to HnB tobacco product and e-vapor aerosols did not induce significant changes in the ceramide profiles or associated enzymes. SIGNIFICANCE: Our work in mice contributes to the accumulating evidence on the importance of ceramide ratios as biologically relevant markers for respiratory disorders, adding to their already demonstrated role in cardiovascular disease risk assessment in humans.

How Do Combustion and Non-Combustion Products Used Outdoors Affect Outdoor and Indoor Particulate Matter Levels? A Field Evaluation Near the Entrance of an Italian University Library.

Particulate Matter (PM) is a well-known health risk factor and pollutes both outdoor and indoor air. Using PM as an air pollution indicator, the aims were to assess outdoor and indoor air pollution due to combustion and/or non-combustion products used outdoors and to compare the PM levels emitted by different products. PM with an aerodynamic diameter ≤10, 4, 2.5 and 1 µm (PM10, PM4, PM2.5, PM1) was simultaneously measured in two areas, respectively, indoors (with smoking ban) and outdoors (where people commonly smoke) of a university library during the morning and the afternoon of two weekdays. Both combustion and non-combustion products determined a relevant worsening of outdoor air quality, with the highest PM1 levels achieved when a single traditional cigarette (9920 µg m-3), a single e-cigarette (9810 µg m-3) and three simultaneous traditional cigarettes (8700 µg m-3) were smoked. An increase of indoor PM1 levels was found during outdoor smoking/vaping sessions, persisting also after the end of sessions. The results highlighted the need for a revision of smoke-free laws, especially for outdoor areas, to include non-combustion products. In addition, it is essential to make society aware of the dangers of smoking outdoors by implementing health promotion interventions.

Comparing Factors Related to Any Conventional Cigarette Smokers, Exclusive New Alternative Product Users, and Non-Users among Japanese Youth: A Nationwide Survey.

The impact of heated-tobacco-products (HTPs) and electronic cigarettes (e-cigarettes) on youth is a controversial public health issue, as it is unknown whether alternative products result in more youth using such products or smoking. In Japan, e-cigarettes with nicotine are prohibited, but e-cigarettes without nicotine are available. HTPs are marketed as tobacco products. Within this unique context, we aimed to compare any conventional cigarette smokers (including those who also used alternative products) with exclusive users of alternative products and examine factors relating to their use in Japan. In 2017, 22,275 students in grades 7-9 (age 12-15) and 42,142 in grades 10-12 (age 15-18) nationwide were surveyed. Overall, 1.8% were current users of any of the three products over the last month. Multivariable analysis revealed that risk factors for alternative product use were the same as those for cigarette use. Among all users, exclusive new product users were more likely to participate in club activities and intend to continue to higher education; any conventional cigarette users (including those who also used alternative products) were more likely to be exposed to secondhand smoke at home and to drink alcohol. Reducing adult smoking and disseminating health education remain relevant as strategies for preventing adolescents' future tobacco use.

Passive Exposure to Pollutants from a New Generation of Cigarettes in Real Life Scenarios.

The use of electronic cigarettes (e-cigarettes) and heat-not-burn tobacco (HNBT), as popular nicotine delivery systems (NDS), has increased among adult demographics. This study aims to assess the effects on indoor air quality of traditional tobacco cigarettes (TCs) and new smoking alternatives, to determine the differences between their potential impacts on human health. Measurements of particulate matter (PM1, PM2.5 and PM10), black carbon, carbon monoxide (CO) and carbon dioxide (CO2) were performed in two real life scenarios, in the home and in the car. The results indicated that the particle emissions from the different NDS devices were significantly different. In the home and car, the use of TCs resulted in higher PM10 and ultrafine particle concentrations than when e-cigarettes were smoked, while the lowest concentrations were associated with HNBT. As black carbon and CO are released by combustion processes, the concentrations of these two pollutants were significantly lower for e-cigarettes and HNBT because no combustion occurs when they are smoked. CO2 showed no increase directly associated with the NDS but a trend linked to a higher respiration rate connected with smoking. The results showed that although the levels of pollutants emitted by e-cigarettes and HNBT are substantially lower compared to those from TCs, the new smoking devices are still a source of indoor air pollutants.

Heat-not-burn tobacco, electronic cigarettes, and combustible cigarette use among Japanese adolescents: a nationwide population survey 2017.

BACKGROUND: From among the global public health concerns, smoking remains one of the most crucial challenges. Especially for adolescents, the increase in the use of electronic cigarettes is controversial, as its use may lead to established smoking. In Japan, where a unique tobacco regulation system exists, the heat-not-burn tobacco market has been growing. However, the prevalence and association of combustible cigarettes and new tobacco-related products have not yet been closely investigated among Japanese adolescents. This study aimed to clarify the prevalence of smoking among adolescents, including new types of tobacco-related products, and to compare the characteristics of their users. METHODS: The 2017 Lifestyle Survey of Adolescents is a nationally-representative survey collected in Japan. From the national school directory, 98 junior high schools and 86 high schools were randomly sampled throughout Japan. The students completed an anonymous questionnaire at school. We calculated the prevalence of use for each type of tobacco product. Then, the use of a combination of products and the characteristics of different types of products were examined. RESULTS: In total, 64,152 students from 48 junior high schools and 55 high schools were included the analysis (school response rate = 56%, Mage = 15.7 years, 53.9% boys). The age-adjusted rate of ever (current) use of electronic cigarettes was 2.1% (0.7%) in junior high school and 3.5% (1.0%) in high school; that of combustible cigarettes was 2.6% (0.6%) in junior high school and 5.1% (1.5%) in high school. The rate of heat-not-burn tobacco use was lower relative to other products: 1.1% (0.5%) in junior high school and 2.2% (0.9%) in high school. An examination of the combined use of the three products identified a high number of dual users. Comparisons between different types of users indicated different backgrounds for combustible cigarette users and new product users. CONCLUSIONS: The prevalence of new tobacco-alternative products is growing in popularity among Japanese adolescents. Dual use is common, and many adolescents use new products only. Moreover, e-cigarettes might attract a broader range of groups to smoking. Continuous monitoring and research are needed to investigate their influence as a possible gateway to tobacco smoking.

IQOS - a heat-not-burn (HnB) tobacco product - chemical composition and possible impact on oxidative stress and inflammatory response. A systematic review.

Objectives: This work attempts to summarize current knowledge about IQOS, the heat-not-burn tobacco products, their chemical composition and possible impact on oxidative stress and inflammatory response.Materials and Methods: The literature search was performed between January and April 2019 by a combination of terms: 'IQOS smoking', 'IQOS cigarette', 'I quit original smoking cigarette', 'heat-not-burn products', 'HnB tobacco products'.Results: The aim of IQOS system is to minimalize the exposure of its smokers to dangerous substances present in cigarette smoke and to lower the probability of development of tobacco-related diseases. As current studies suggest, this new heat-not-burn tobacco product emits significantly lower concentrations of tar, carbonyls, VOCs, CO, free radicals or nitrosamines when compared to conventional cigarette, and thus it may reduce health risk for smokers. However, it does not eliminate this risk of development of tobacco-related diseases.Discussion: For conventional tobacco smokers the IQOS products may be an alternative option, which helps to reduce exposure to hazardous and potentially hazardous constituents. However, for never-smokers using the IQOS cigarettes may develop an addiction or increase exposition to some substances, which may increase probability of tobacco-related diseases. Moreover, emission of unexpected substances depends on device cleaning strategy and puff regiments.Conclusions: There is only limited data about IQOS effect on smokers' health. The future investigation, especially comparison with healthy never-smokers or study of chronic exposure to IQOS, is needed.