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.

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.

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.

Heated Tobacco Product Smokers in Japan Identified by a Population-Based Survey.

BACKGROUND: In this study, we aim to estimate the prevalence of heated tobacco product (HTP) smokers 3 years after the launch of HTPs in Japan. METHODS: Our study, performed in February 2018 in Japan, had a cross-sectional population-based design. A total of 4,628 adult participants (2,121 men and 2,507 women) were randomly sampled from all regions of Japan. The response rate was 57.9%. Interviews were conducted by trained investigators who visited participants' homes. A survey on current (past 30 days) and lifetime tobacco use (including e-cigarettes and HTPs), as well as numerous sociodemographic factors, was conducted. RESULTS: The age-adjusted rates and estimated number of lifetime-HTP smokers were 14.1% (95% confidence interval [CI], 12.5-15.6%; 7.11 million men) and 3.7% (95% CI, 2.9-4.4%; 1.99 million women). The age-adjusted rates for current HTP smokers were 8.3% (95% CI, 7.1-9.6%; 4.21 million men) and 1.9% (95% CI, 1.3-2.4%; 1.02 million women). Multiple variables were found to be associated with a higher prevalence of current HTP use, including being male, aged 20-39 years, a current Internet user, a risky drinker, or a heavy episodic drinker. HTP use was also higher among men with 10 years or more of education, women with 15 years or less of education, and men with middle- or high-level household incomes. CONCLUSION: We concluded that HTP use has increased substantially in Japan. However, regulations for HTPs are weaker than those for combustible cigarettes in Japan. Thus, HTPs should be subjected to the same regulations as combustible tobacco products.

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.

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.

Study Profile: The Japan "Society and New Tobacco" Internet Survey (JASTIS): A Longitudinal Internet Cohort Study of Heat-Not-Burn Tobacco Products, Electronic Cigarettes, and Conventional Tobacco Products in Japan.

BACKGROUND: Japan became the first country where heat-not-burn tobacco products were sold. Therefore, there was no information for actual status on the actual use status or the harms of heat-not-burn tobacco products. The objectives of the study profile are to generate data that can be freely available to external researchers, and to create collaborative research projects in the future. METHODS: The Japan "Society and New Tobacco" Internet Survey (JASTIS) is a longitudinal internet cohort study which investigates perception, attitude, and use of heat-not-burn tobacco, electronic cigarettes (e-cigarettes), and conventional tobacco products in Japan. The survey also includes demographic, health-related, and socioeconomic factors. Participants were randomly selected and invited from internet panelists. The baseline survey was closed when the target number of respondents who had answered the questionnaire was met. RESULTS: The study includes three cohorts (1-3) from the 2015 baseline survey and a cohort (4) from the 2017 baseline survey: cohorts 1 and 4 were recruited based on sex and age: men and women aged 15-69 years (n = 8,240 for cohort 1 and n = 5,897 for cohort 4); cohorts 2 and 3 were created using status-based recruiting: e-cigarette and/or heat-not-burn tobacco ever users (n = 2,188; cohort 2) and combustible cigarette smokers without e-cigarette/heat-not-burn tobacco experience (n = 724; cohort 3). The completion rates were 8.5% to 9.9%. All subjects were followed and assessed annually. Response rates for the follow-up survey were 65.5% in 2016, 55.3% in 2017, and 50.9% in 2018. Because Internet-based responders are not a representative sample of the general population of Japan, we conducted adjustment to account for "being an internet survey respondent" and reported tobacco product use in Japan. A recent JASTIS study reported that prevalence of IQOS current-use among Japanese adults had rapidly increased from 0.3% in 2015 to 3.6% in 2017. CONCLUSION: The JASTIS study provides the first estimates for heat-not-burn tobacco use in the world and e-cigarette use in Japan. For information on collaboration, please contact the corresponding author.

iQOS: evidence of pyrolysis and release of a toxicant from plastic.

OBJECTIVE: To evaluate performance of the I quit original smoking (iQOS) heat-not-burn system as a function of cleaning and puffing topography, investigate the validity of manufacturer's claims that this device does not burn tobacco and determine if the polymer-film filter is potentially harmful. METHODS: iQOS performance was evaluated using five running conditions incorporating two different cleaning protocols. Heatsticks were visually and stereomicroscopically inspected preuse and postuse to determine the extent of tobacco plug charring (from pyrolysis) and polymer-film filter melting, and to elucidate the effects of cleaning on charring. Gas chromatography-mass spectrometry headspace analysis was conducted on unused polymer-film filters to determine if potentially toxic chemicals are emitted from the filter during heating. RESULTS: For all testing protocols, pressure drop decreased as puff number increased. Changes in testing protocols did not affect aerosol density. Charring due to pyrolysis (a form of organic matter thermochemical decomposition) was observed in the tobacco plug after use. When the manufacturer's cleaning instructions were followed, both charring of the tobacco plug and melting of the polymer-film filter increased. Headspace analysis of the polymer-film filter revealed the release of formaldehyde cyanohydrin at 90°C, which is well below the maximum temperature reached during normal usage. DISCUSSION: Device usage limitations may contribute to decreases in interpuff intervals, potentially increasing user's intake of nicotine and other harmful chemicals. This study found that the tobacco plug does char and that charring increases when the device is not cleaned between heatsticks. Release of formaldehyde cyanohydrin is a concern as it is highly toxic at very low concentrations.

Comparison of Chemicals in Mainstream Smoke in Heat-not-burn Tobacco and Combustion Cigarettes.

Because of the health effects of secondhand smoke, the Japanese government is trying to establish an effective law for total avoidance of secondhand smoke in indoor environments for tobacco-free Tokyo Olympic and Paralympic games 2020, as requested by the International Olympic Committee (IOC) and the World Health Organization (WHO). Meanwhile, Philip Morris International has begun selling a new heat-not-burn tobacco, iQOS, which it claims is designed not to produce secondhand smoke. There is little scientific data, however, of the hazards and toxicity of iQOS. In this study, we evaluated several harmful compounds (nicotine, tar, carbon monoxide (CO) and tobacco-specific nitrosamines (TSNAs)) in the mainstream smoke and fillers of iQOS, and compared their concentrations with those from conventional combustion cigarettes. The concentrations of nicotine in tobacco fillers and the mainstream smoke of iQOS were almost the same as those of conventional combustion cigarettes, while the concentration of TSNAs was one fifth and CO was one hundredth of those of conventional combustion cigarettes. These toxic compounds are not completely removed from the mainstream smoke of iQOS, making it necessary to consider the health effects and regulation of iQOS.

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.

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 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.

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.

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.

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.