Second-hand smoke generated by combustion and electronic smoking devices used in real scenarios: Ultrafine particle pollution and age-related dose assessment

Impact of heat-not-burn cigarette passive smoking on children's oxidative stress, endothelial and platelet function

Growing global use of heat-not-burn cigarettes (HNBC) prompts investigation. Prior studies assessed HNBC's effects on cardiovascular health, revealing heightened oxidative stress, platelet activation, and endothelial dysfunction. However, limited understanding exists regarding passive smoking's impact on children exposed to HNBC. This study aims to assess levels of oxidative stress, endothelial and platelet function among children exposed to passive smoke from HNBC, traditional tobacco (TT) cigarettes and unexposed subjects. Seventy-eight children (2-18 years) were divided into three groups: HNBC passive smokers (n = 26), TT cigarette exposed (n = 26), and control (CNT) group (n = 26, unexposed). Oxidative stress was evaluated by serum NADPH oxidase-2 (NOX2) activity, assessed by soluble Nox2-derived peptide (sNOX2-dp), isoprostanes, hydrogen peroxide (H2O2) production, hydrogen break-down activity (HBA) and NO bioavailability. Endothelial function was assessed by brachial flow-mediated dilation (FMD). Platelet function was evaluated by soluble CD40 ligand (sCD40L), soluble P-selectin (sP-selectin) and thrombus formation by T-TAS analysis. Passive smoking-exposed children (both HNBC and TT) exhibited significantly increased serum sNOX2-dp, isoprostanes, H2O2, sCD40L sP-selectin and thrombus formation versus controls. Conversely, exposed children displayed reduced brachial FMD and serum NO bioavailability. No significant differences were found between children exposed to passive smoking of HNBC vs TT. Multivariable regression linked sNOX2 (standardized coefficient β: 0.284; SE: 0.040; p = 0.01) and H2O2 (standardized coefficient β: 0.243; SE: 0.0; p = 0.02) as independent predictors of FMD, and isoprostanes (standardized coefficient β:0.388; SE: 0.022; p < 0.001) and serum cotinine (standardized coefficient β:0.270; SE: 0.048; p = 0.01) with sNOX2-dp levels. Exposure to HNBC smoke heightened oxidative stress, endothelial dysfunction, platelet activation, and thrombus formation in children. Findings suggest avenues for interventions to curb childhood passive smoking exposure.

Secondhand electronic cigarette aerosol in vehicles impacts indoor air quality

BACKGROUND

Electronic cigarette (ECIG) use in vehicles represents a public health concern due to the potential for exposure to high concentrations of particulate matter (PM) and other toxicants. This study examined the impact of ECIG use on air quality in vehicles.

METHODS

People who reported current ECIG use (n=60; mean age=20.5, SD=2.3) completed a brief survey and a 30-min ECIG use session in their own vehicle. Using a protocol similar to clinical laboratory studies involving tobacco use, participants took 10 directed puffs (i.e., a directed bout with one puff every 30s for 5min) followed by a 25-min ad libitum period in which participants took as many puffs as desired. PM 2.5µm in diameter or smaller (PM2.5) were measured using aerosol monitors set up to sample air from the breathing zone of the passenger seat and total puffs were recorded. The association between peak PM2.5 concentration and puff count was examined.

RESULTS

Participants took a median 18 total puffs during the sessions. Median PM2.5 concentrations increased from 4.78µg/m3 at baseline to 107.40µg/m3 after the directed bout. Median peak PM2.5 concentration was 464.48µg/m3 and ranged from 9.56µg/m3 to 143,503.91µg/m3 (IQR=132.72-1604.68). After removing two extreme outliers for puff count and PM2.5 concentrations, puff count was significantly correlated with peak PM2.5 concentration during the ad libitum bout (r=0.32, p=0.015).

CONCLUSIONS

ECIG use in vehicles impacts air quality negatively and may pose health risks to those present in vehicles when ECIG use is occurring.

Impact of different ventilation conditions on tobacco smoke-associated particulate matter emissions in a car cabin using the TAPaC platform

Despite antagonizing attempts from the tobacco industry, passive inhalation of tobacco smoke is known to be cancerogenic and toxic to human health for decades. Nonetheless, millions of non-smoking adults and children are still victims of second-hand smoke. Accumulation of particulate matter (PM) in confined spaces such as the car are particularly harmful due to high concentrations. We here aimed to analyze the specific effects of ventilation conditions in the setting of a car. By the use of the measuring platform TAPaC (tobacco-associated particulate matter emissions inside a car cabin), 3R4F reference cigarettes, Marlboro red, and Marlboro gold were smoked in a car interior with a volume of 3.709 m3. Seven different ventilation conditions (C1-C7) were analyzed. Under C1, all windows were closed. Under C2-C7, the car ventilation was turned on power level 2/4 with the air directed towards the windshield. Only the passenger side window was opened, where an outer placed fan could create an airstream speed of 15.9-17.4 km/h at one meter distance to simulate a driving car. C2: Window 10 cm opened. C3: Window 10 cm opened with the fan turned on. C4: Window half-opened. C5: Window half-opened with the fan turned on. C6: Window fully opened. C7: Window fully opened with the fan turned on. Cigarettes were remotely smoked by an automatic environmental tobacco smoke emitter and a cigarette smoking device. Depending on the ventilation condition the cigarettes emitted different mean PM concentrations after 10 min under condition C1 (PM10: 1272-1697 µg/m3, PM2.5: 1253-1659 µg/m3, PM1: 964-1263 µg/m3) under C2, C4, and C6 (PM10: 68.7-196.2 µg/m3, PM2.5: 68.2-194.7 µg/m3, PM1: 66.1-183.8 µg/m3) C3, C5, and C7 (PM10: 73.7-139 µg/m3, PM2.5: 72-137.9 µg/m3, PM1:68.9-131.9 µg/m3). Vehicle ventilation is insufficient to protect passengers from toxic second-hand smoke completely. Brand-specific variations of tobacco ingredients and mixtures markedly influence PM emissions under ventilation conditions. The most efficient ventilation mode to reduce PM exposure was achieved by opening the passenger´s window 10 cm and turning the onboard ventilation on power level 2/4. In-vehicle smoking should be banned to preserve innocent risk groups (e.g., children) from harm.

An Exploratory Study on Strategies Adopted by Parents Who Use E-Cigarettes to Negotiate Risk Perceptions of Their Children's Secondhand Exposure and Parental Role Modeling

Existing health messages mainly targeted youth susceptible to vaping or parents who do not have much knowledge about e-cigarettes. This study makes a unique contribution by conducting the first in-depth investigation of e-cigarette-using parents' risk perceptions and parental role modeling and how these two factors affect their vaping behaviors at home or implementation of any strategies to reduce their children's risk. Fifteen parents who used e-cigarettes participated in a semi-structured interview. Interview transcripts were coded and analyzed through a deductive approach of thematic analysis. This study demonstrates the need to develop and disseminate future health messages for e-cigarette-using parents who may have low-risk perceptions of secondhand exposure or who have adopted ineffective strategies to reduce their children's exposure. This study also identifies some possible targets for future intervention efforts through these parents including increasing their knowledge about the health risk of secondhand exposure to e-cigarettes, emphasizing the caregiver role, and effective communications with children about the consequences of vaping.

Heat-not-burn tobacco products and cardiovascular risk reduction: A systematic review of randomized controlled trials

BACKGROUND

Heat-not-burn (HNB) technology by the U.S. Food and Drug Administration has been classified as a modified risk tobacco product, which can be a better option for those populations who cannot give up the habit of smoking. The outlook on the effects of these products is quite controversial in the scientific world.

OBJECTIVE

To present the effect of HNB tobacco products on the cardiovascular system, with reference to the existence of possible benefits of the technology.

METHODS

The literature search was conducted in PubMed/Medline, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov databases, with reliance on a well-defined guiding research statement. Quality appraisal was performed using the CASP checklist for randomized controlled trials.

RESULTS

The search of three databases identified 167 records, and after selection process, 25 randomized controlled trials were eligible for our study's criteria. Twenty studies investigated the effects of HNB products on biomarkers of clinical relevance. Five studies evaluated other functional heart parameters rather than biomarkers.

CONCLUSION

With HNB tobacco products, significant reductions were found in biomarkers of exposure and biological effect related to pathways involved in cardiovascular disease, including inflammation, oxidative stress, lipid metabolism, platelet function, and endothelial dysfunction.

Xenobiotics Delivered by Electronic Nicotine Delivery Systems: Potential Cellular and Molecular Mechanisms on the Pathogenesis of Chronic Kidney Disease

Chronic kidney disease (CKD) is characterized as sustained damage to the renal parenchyma, leading to impaired renal functions and gradually progressing to end-stage renal disease (ESRD). Diabetes mellitus (DM) and arterial hypertension (AH) are underlying diseases of CKD. Genetic background, lifestyle, and xenobiotic exposures can favor CKD onset and trigger its underlying diseases. Cigarette smoking (CS) is a known modified risk factor for CKD. Compounds from tobacco combustion act through multi-mediated mechanisms that impair renal function. Electronic nicotine delivery systems (ENDS) consumption, such as e-cigarettes and heated tobacco devices, is growing worldwide. ENDS release mainly nicotine, humectants, and flavorings, which generate several byproducts when heated, including volatile organic compounds and ultrafine particles. The toxicity assessment of these products is emerging in human and experimental studies, but data are yet incipient to achieve truthful conclusions about their safety. To build up the knowledge about the effect of currently employed ENDS on the pathogenesis of CKD, cellular and molecular mechanisms of ENDS xenobiotic on DM, AH, and kidney functions were reviewed. Unraveling the toxic mechanisms of action and endpoints of ENDS exposures will contribute to the risk assessment and implementation of proper health and regulatory interventions.

Health risk assessment of particulate matter 2.5 in an academic metallurgy workshop

Exposure to indoor PM_2.5 is associated with allergies, eye and skin irritation, lung cancer, and cardiopulmonary diseases. To control indoor PM_2.5 and protect the health of occupants, exposure and health studies are necessary. In this study, exposure to PM_2.5 released in an academic metallurgy workshop was assessed and a health risk assessment was conducted for male and female students and technicians. Polycarbonate membrane filters and an active pump operating at a flow rate of 2.5 L/min were used to collect PM_2.5 from Monday to Friday for 3 months (August-October 2020) from 08:00-16:00. PM_2.5 mass concentrations were obtained gravimetrically, and the Multiple-Path Particle Dosimetry model was used to predict the deposition, retention, and clearance of PM_2.5 in the respiratory tract system. The risk of developing carcinogenic and non-carcinogenic effects among students and technicians was determined. The average PM_2.5 mass concentration for August was 32.6 μg/m³ 32.8 μg/m³ for September, and 32.2 μg/m³ for October. The head region accounted for the highest deposition fraction (49.02%), followed by the pulmonary (35.75%) and tracheobronchial regions (15.26%). Approximately 0.55 mg of PM_2.5 was still retained in the alveolar region 7 days after exposure. The HQ for male and female students was <1 while that of male and female technicians was >1, suggesting that technicians are at risk of developing non-carcinogenic health effects compared with students. The results showed a risk of developing carcinogenic health effects among male and female technicians (>1 × 10^-5 ); however, there was no excess cancer risk for students (<1 × 10^-6 ). This study highlights the importance of exposure and health studies in academic micro-environments such as metallurgy workshops which are often less researched, and exposure is underestimated. The results also indicated the need to implement control measures to protect the health of the occupants and ensure that the workshop rules are adhered to.

TAPaC-tobacco-associated particulate matter emissions inside a car cabin: establishment of a new measuring platform

Background

Particulate matter (PM) emission caused by tobacco combustion leads to severe health burdens worldwide. Second-hand smoke exposure is extraordinarily high in enclosed spaces (e.g., indoor rooms, car cabins) and poses a particular threat to the health of vulnerable individuals (e.g., children, elderly, etc.). This study aimed to establish a new measuring platform and investigate PM emissions under four different ventilation conditions inside a car cabin without exposing any person to harmful tobacco smoke.

Methods

PM concentrations were measured during the smoking of 3R4F reference cigarettes in a Mitsubishi Space Runner (interior volume 3.709 m³). The cigarettes were smoked with a machine, eliminating exposure of the researchers. Cigarettes were extinguished 4.5 min after ignition, and PM measurements continued until 10 min after ignition.

Results

High mean PM concentrations were measured for cigarettes without ventilation after 4.5 min (PM₁₀: 1150 µg/m³, PM_2.5: 1132 µg/m³, PM₁: 861.6 µg/m³) and after 10 min (PM₁₀: 1608 µg/m³, PM_2.5: 1583 µg/m³, PM₁: 1133 µg/m³). 3R4F smoked under conditions with turned on ventilation resulted in reduction of PM compared to those smoked without ventilation after 4.5 min (PM₁₀:-47.5 to -58.4%, PM_2.5:-47.2 to -58%, PM₁:-39.6 to -50.2%) and after 10 min (PM₁₀:-70.8 to -74.4%, PM_2.5:-70.6 to -74.3%, PM₁:-64.0 to -68.0%). Cigarettes smoked without ventilation generated high PM peaks at 4.5 min (PM₁₀: 2207 µg/m³, PM_2.5: 2166 µg/m³, PM₁: 1421 µg/m³) and at 10 min (PM₁₀: 1989 µg/m³, PM_2.5: 1959 µg/m³, PM₁: 1375 µg/m³). PM peaks of cigarettes smoked under different ventilation modes varied at 4.5 min (PM₁₀: 630-845 µg/m³, PM_2.5: 625-836 µg/m³, PM₁: 543 - 693 µg/m³) and 10 min (PM₁₀: 124 - 130 µg/m³, PM_2.5: 124 - 129 µg/m³, PM₁: 118 - 124 µg/m³).

Conclusion

The new measuring platform provides a safer way for researchers to investigate PM emissions of cigarettes. These data are comparable to published research and show that smoking in a parked vehicle with the windows closed generates harmful PM emissions even when the vehicle ventilation is in operation. Future studies should be carried out using the new measuring platform investigating PM exposure and PM distribution of in-vehicle smoking under a wide range of conditions.

Secondhand Aerosol Exposure From Heated Tobacco Products and Its Socioeconomic Inequalities in Japan: The JASTIS Study 2017-2020

INTRODUCTION

The growing use of heated tobacco products (HTPs) has raised concerns about secondhand aerosol (SHA) from HTPs, but few studies have been reported on it. This study aimed to investigate the trends in SHA exposure and their socioeconomic inequalities in Japan.

METHODS

The prevalence of SHA exposure from 2017 to 2020 was estimated using longitudinal internet survey data of 5221 participants, aged 20-69 years in 2017 (baseline), with adjustments using inverse probability weighting for "being a participant in an internet survey". Multivariable modified Poisson regression models were applied to examine the association between socioeconomic status (ie, educational attainment and equivalent income) at baseline and SHA exposure in 2020 with adjustments for sex and age.

RESULTS

The estimated prevalence of SHA exposure has consistently increased from 4.5% in 2017 to 10.8% in 2020. Lower educational attainment was associated with a higher risk of SHA exposure (p for trend = 0.010). The covariate-adjusted risks of SHA exposure in participants with a low-education and middle-education level were 1.57 and 1.34 times higher, respectively, than in those with a high-education level. However, significant differences in risks of SHA exposure between participants with low-, middle-, and high-income levels were not observed. Meanwhile, participants with a low-education and middle-education level also had 1.87 and 1.61 times higher risks of secondhand smoke (SHS) exposure from combustible cigarettes than those with a high-education level, respectively.

CONCLUSIONS

Our study revealed a rapid increase in SHA exposure and the existence of educational inequalities in both SHA and SHS exposure.

IMPLICATIONS

Using longitudinal internet cohort survey data, we found that the prevalence of exposure to secondhand aerosol (SHA) from heated tobacco products (HTPs) rapidly increased to 10.8% in 2020 in Japan. Furthermore, people with lower educational attainment were at higher risk of SHA exposure, suggesting that extensive educational interventions may be necessary to inform the public that although emissions from HTPs contain significantly lesser amounts of harmful and potentially harmful constituents and these compounds than cigarette smoke, they are not harmless and still entail risks, and its long-term effects are unknown. Therefore, future extensive monitoring of SHA exposure is needed.

Effects of inhalation frequency on inhalation/exposure dose of hazardous nanoparticles and toxic gases during cigarette smoking

In this study, we measured the pollutants generations during cigarette smoking under various inhalation frequency experiment scenarios by a self-developed smoking machine. Some concepts, the effective inhaled amount and exposure amount were proposed to quantitatively estimate emission rates. Important findings include: For interval 1 s, 2 s, 3 s, 4 s and 9 s (called from 1 s to 9 s herein), effective inhaled nano-scale PN (particle number) per cigarette was 8.43E+09 #, 7.24E+09 #, 5.74E+ 09 #, 3.82E+09 # and 1.15E+09 #, it decreased linearly with interval time; exposure amount of PN in side stream smoke was 1.06E+10 #, 1.2E+10 #, 1.48E+10 #, 1.84E+10 # and 8.74E+10 #, it increased with interval time. For toxic gases, all pollutants decreased with interval time in main stream smoke. In side stream smoke, NOx and CO firstly increased with interval time and then decreased (with the highest value at 3 s interval time), while HC always increased with interval time. So, this study is useful to understand the relationship between pollution and smoking habit.

Biomonitoring of Exposure to Urban Pollutants and Oxidative Stress during the COVID-19 Lockdown in Rome Residents

Background: The objective of this study is to evaluate the effects of traffic on human health comparing biomonitoring data measured during the COVID-19 lockdown, when restrictions led to a 40% reduction in airborne benzene in Rome and a 36% reduction in road traffic, to the same parameters measured in 2021. Methods: Biomonitoring was performed on 49 volunteers, determining the urinary metabolites of the most abundant traffic pollutants, such as benzene and PAHs, and oxidative stress biomarkers by HPLC/MS-MS, 28 elements by ICP/MS and metabolic phenotypes by NMR. Results: Means of s-phenylmercaputric acid (SPMA), metabolites of naphthalene and nitropyrene in 2020 are 20% lower than in 2021, while 1-OH-pyrene was 30% lower. A reduction of 40% for 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodGuo) and 60% for 8-oxo-7,8-dihydroguanine (8-oxoGua) were found in 2020 compared to 2021. The concentrations of B, Co, Cu and Sb in 2021 are significantly higher than in the 2020. NMR untargeted metabolomic analysis identified 35 urinary metabolites. Results show in 2021 a decrease in succinic acid, a product of the Krebs cycle promoting inflammation. Conclusions: Urban pollution due to traffic is partly responsible for oxidative stress of nucleic acids, but other factors also have a role, enhancing the importance of communication about a healthy lifestyle in the prevention of cancer diseases.

A filter-based system mimicking the particle deposition and penetration in human respiratory system for secondhand smoke generation and characterization

INTRODUCTION

Secondhand smoke endangers both the environment and the health of nonsmokers. Due to the scarcity of repeatable data generated by human subjects, a system capable of generating representative secondhand smoke is essential for studying smoke properties. This work presents the design and validation of a filter-based system that could mimic the particle deposition and penetration in human respiratory system for secondhand smoke generation and characterization.

METHODS

Guided by our study on characterizing size-dependent filtration efficiency of common materials, we identified three filter media that generate similar particle deposition efficiencies compared to different regions of the human respiratory system over a wide submicron size range. We demonstrated the performance of the proposed filter-based system using various operating conditions. Additionally, we compared the properties of secondhand smoke particles to those of primary smoke particles.

RESULTS

The difference in aerosol deposition efficiencies between the filter-based system and the International Commission on Radiological Protection (ICRP) model was less than 10% in the size range of 30 to 500 nm. High concentrations of metals were detected in the secondhand smoke. The contents of Ni and Cr generated from the secondhand electronic cigarettes are at least 20 and 5 times above the regulated daily maximum intake amount.

CONCLUSION

Given the agreement in aerosol respiratory deposition between the filter-based system and the ICRP model, such a system can facilitate laboratory studies of secondhand smoke due to its simple structure, high repeatability, and ease of control while remaining free of human subjects.

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.

Influence of E-Liquid Humectants, Nicotine, and Flavorings on Aerosol Particle Size Distribution and Implications for Modeling Respiratory Deposition

Electronic cigarette, or vaping, products are used to heat an e-liquid to form an aerosol (liquid droplets suspended in gas) that the user inhales; a portion of this aerosol deposits in their respiratory tract and the remainder is exhaled, thereby potentially creating opportunity for secondhand exposure to bystanders (e.g., in homes, automobiles, and workplaces). Particle size, a critical factor in respiratory deposition (and therefore potential for secondhand exposure), could be influenced by e-liquid composition. Hence, the purposes of this study were to (1) test the influence of laboratory-prepared e-liquid composition [ratio of propylene glycol (PG) to vegetable glycerin (VG) humectants, nicotine, and flavorings] on particle size distribution and (2) model respiratory dosimetry. All e-liquids were aerosolized using a second-generation reference e-cigarette. We measured particle size distribution based on mass using a low-flow cascade impactor (LFCI) and size distribution based on number using real-time mobility sizers. Mass median aerodynamic diameters (MMADs) of aerosol from e-liquids that contained only humectants were significantly larger compared with e-liquids that contained flavorings or nicotine (p = 0.005). Humectant ratio significantly influenced MMADs; all aerosols from e-liquids prepared with 70:30 PG:VG were significantly larger compared with e-liquids prepared with 30:70 PG:VG (p = 0.017). In contrast to the LFCI approach, the high dilution and sampling flow rate of a fast mobility particle sizer strongly influenced particle size measurements (i.e., all calculated MMAD values were &lt; 75 nm). Dosimetry modeling using LFCI data indicated that a portion of inhaled particles will deposit throughout the respiratory tract, though statistical differences in aerosol MMADs among e-liquid formulations did not translate into large differences in deposition estimates. A portion of inhaled aerosol will be exhaled and could be a source for secondhand exposure. Use of laboratory-prepared e-liquids and a reference e-cigarette to standardize aerosol generation and a LFCI to measure particle size distribution without dilution represents an improved method to characterize physical properties of volatile aerosol particles and permitted determination of MMAD values more representative of e-cigarette aerosol in situ, which in turn, can help to improve dose modeling for users and bystanders.

Laboratory Determination of Gravimetric Correction Factors for Real-time Area Measurements of Electronic Cigarette Aerosols

Research on secondhand electronic cigarette (ECIG) aerosol exposure using aerosol monitors has demonstrated that ECIG use can generate high concentrations of particulate matter (PM) and impact indoor air quality. However, quantifying indoor air PM concentrations using real-time optical monitors with on-site calibration specifically for different PM exposures has not been established. Therefore, the ECIG aerosol filter correction factors were calculated for different PM sizes (PM₁, PM_2.5, and PM₁₀) and different aerosol optical monitors, the MiniWRAS, pDR, and SidePak. ECIG aerosol generation was achieved using five ECIGs representing three ECIG types, disposable, pod-mod, and box mod. The aerosol size distribution by mass was measured for the five ECIGs during PM generation. Compared to the discrete filter measurements, the MiniWRAS performed the best when the concentrations were low, followed by the pDR and SidePak. The average PM concentrations and correction factor ranges for the different ECIGs were 323-1,775 μg/m³ and 0.64-6.01 for the MiniWRAS, 1,388-13,365 μg/m³ and 0.41-0.80 for the pDR, and 4,632-55,339 μg/m³ and 0.13-0.20 for the SidePak, respectively. The mass median diameter ranged from 0.41 and 0.62 μm, and most particles generated from the ECIGs were smaller than 1 μm. This study demonstrates that aerosol size distribution varies between ECIGs. Likewise, the correction factors developed for the real-time aerosol monitors are specific to the ECIG used. Thus, these data can help improve ECIG aerosol exposure measurement accuracy.

Passive Vaping from Sub-Ohm Electronic Cigarette Devices

To investigate passive vaping due to sub-ohm electronic cigarettes (e-cigs), aerosol number size distribution measurements (6 nm–10 µm) were performed during volunteer-vaping sessions. E-liquids, with vegetable glycerin (VG) and propylene glycol (PG), with a VG/PG ratio of 50/50 (with nicotine) and 80/20 (without nicotine), were vaped with a double-coil, single aerosol exit hole at 25–80 W electric power, corresponding to 130–365 kW m⁻² heat fluxes and with an octa-coil, four aerosol exit holes atomizers, at 50–150 W electric power, corresponding to 133–398 kW m⁻² heat fluxes. At the lowest heat flux, lower particle number concentrations (N_Tot) were observed for the nicotine-liquid than for the nicotine-free liquid, also due to its higher content of PG, more volatile than VG. For the octa-coil atomizer, at 265 and 398 kW m⁻², N_Tot decreased below the first-generation e-cig, whereas volume concentrations greatly increased, due to the formation of super micron droplets. Higher volume concentrations were observed for the 80/20 VG/PG liquid, because of VG vaporization and of its decomposition products, greater than for PG. For the double coil atomizer, increasing the electric power from 40 W (208 kW m⁻²) to 80 W (365 kW m⁻²) possibly led to a critical heat flow condition, causing a reduction of the number concentrations for the VG/PG 50/50 liquid, an increase for the 80/20 VG/PG liquid and a decrease of the volume concentrations for both of them. Coherently, the main mode was at about 0.1 µm on both metrics for both liquids. For the other tests, two main modes (1 and 2 µm) were observed in the volume size distributions, the latter becoming wider at 100 and 150 W (265 and 398 kW m⁻²), suggesting the increased emission of light condensable decomposition products. The lower aerosol emissions observed at 150 W than at 100 W suggest the formation of gas-phase decomposition products. The observation of low-count high-volume aerosols addresses the relevance of the volume metric upon measuring the second-hand concentration of the aerosols released by sub-ohm e-cigarettes.

Prediction of potential passive exposure from commercial electronic nicotine delivery systems using exhaled breath analysis and computational fluid dynamic techniques

Use of computational fluid dynamic (CFD) modeling to predict temporal and spatial constituent exposure for non-electronic nicotine delivery systems (ENDS) users (passive exposure) provides a more efficient methodology compared to conducting actual exposure studies. We conducted a clinical study measuring exhaled breath concentrations of glycerin, propylene glycol, nicotine, benzoic acid, formaldehyde, acetaldehyde, acrolein, menthol and carbon monoxide from use of eight different commercial ENDS devices and a non-menthol and menthol cigarette. Because baseline adjusted levels of other constituents were not consistently above the limit of detection, the mean minimum and maximum per puff exhaled breath concentrations (N= 20/product) of glycerin (158.7-260.9µg), propylene glycol (0.941-3.58µg), nicotine (0.10-1.06µg), and menthol (0.432-0.605µg) from use of the ENDS products were used as input parameters to predict temporal and spatial concentrations in an environmental chamber, office, restaurant, and car using different ENDS use scenarios. Among these indoor locations and ENDS use scenarios, the car with closed windows resulted in the greatest concentrations while opening the car windows produced the lowest concentrations. The CFD predicted average maximum glycerin and propylene glycol concentration ranged from 0.25 to 1068µg m^-3and 1.5 pg m^-3to 13.56µg m^-3,respectively. For nicotine and menthol the CFD predicted maximum concentration ranged from 0.16 pg m^-3to 4.02µg m^-3and 0.068 pg m^-3to 2.43µg m^-3, respectively. There was better agreement for CFD-predicted nicotine concentrations than glycerin and propylene glycol with published reports highlighting important experimental and computational variables. Maximum measured nicotine levels from environmental tobacco smoke in offices, restaurants, and cars exceeded our maximum average CFD predictions by 7-97 times. For all the measured exhaled breath constituents and CFD predicted constituents, except for propylene glycol and glycerin, concentrations were less from use of ENDS products compared to combustible cigarettes. NCT number: NCT04143256.

Beliefs of parents in Kuwait about thirdhand smoke and its relation to home smoking rules: A cross-sectional study

INTRODUCTION

Thirdhand smoke (THS) is the toxic residue of tobacco smoke that persists long after tobacco smoking on the clothing and hair of smokers and in the surrounding environment. This study aimed to assess parents' beliefs about THS in terms of harm and persistence in the environment and evaluate associations between parents' THS beliefs and home smoking rules.

METHODS

A sample of parents living in Kuwait were enrolled in a cross-sectional study. Parents reported home smoking rules (strict, partial, and no, home smoking ban) and completed the 9-item Beliefs About ThirdHand Smoke (BATHS) scale that assessed parents' overall, health, and persistence beliefs about THS. Associations between the quartiles of THS overall, health, and persistence beliefs scores and home smoking rules were evaluated using a modified Poisson regression, and adjusted prevalence ratios (APR) and 95% confidence intervals (CI) were estimated.

RESULTS

In total, 536 parents (404 females) were enrolled in the study, with 42.0% (n=225) and 43.6% (n=234) reporting a strict or partial home smoking ban, respectively. The prevalence of a strict home smoking ban was higher among never smokers than among ever smokers (49.1% vs 25.2%, p<0.001). The majority of participants indicated that THS exposure harms the health of children (67.2%) and adults (60.6%) and THS residue could remain for days in the environment (58.9%). The prevalence of a strict home smoking ban increased as THS overall (APR_{Q4 vs Q1} = 1.48; 95% CI: 1.12-1.96), health (APR_{Q4 vs Q1} = 1.22; 1.02-1.45), and persistence (APR_{Q4 vs Q1} = 1.55; 1.17-2.05) beliefs scores increased.

CONCLUSIONS

Parents' harm and persistence beliefs about THS were associated with enforcing a strict home smoking ban, which provides a safer environment for children and non-smokers. Therefore, tobacco prevention programs need to incorporate educational messages about the harm of THS in an attempt to promote smoke-free homes.

Environmental and individual exposure to secondhand aerosol of electronic cigarettes in confined spaces: Results from the TackSHS Project†

Secondhand electronic cigarette (e-cigarette) aerosol (SHA) might impair indoor air quality and expose bystanders. This study aims to investigate exposure to SHA in controlled conditions of enclosed settings simulating real-world scenario. An experiment was performed in a car and in a room, in which SHA was generated during a 30-minute ad libitum use of an e-cigarette. The experiment was replicated on five consecutive days in each setting. We measured PM_2.5 , airborne nicotine concentrations, and biomarkers of exposure to SHA, such as nicotine metabolites, tobacco-specific nitrosamines, propylene glycol, and glycerol in bystanders' saliva samples before, during, and after the exposure period. Self-reported health symptoms related to exposure to SHA were also recorded. The results showed that the highest median PM_2.5 concentration was recorded during the exposure period, being 21 µg/m³ in the room setting and 16 µg/m³ in the car setting-about twofold increase compared to the baseline. Most concentrations of the airborne nicotine and all biomarkers were below the limit of quantification in both settings. Bystanders in both settings experienced some short-term irritation symptoms, expressed as dry throat, nose, eyes, and phlegm. In conclusion, short-term use of an e-cigarette in confined spaces increased indoor PM_2.5 level and caused some irritation symptoms in bystanders.

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.

Emissions from Heated Terpenoids Present in Vaporizable Cannabis Concentrates

Vaporizable cannabis concentrates (VCCs) consumed as a liquid (vaping) or a waxy solid (dabbing) are becoming increasingly popular. However, their associated emissions and impacts have not been fully described. Mixtures containing different proportions of 12 VCC terpenoids and high MW compounds were heated at 100-500 °C inside a room-sized chamber to simulate emissions. Terpenoids, thermal degradation byproducts, and ultrafine particles (UFPs) were quantified in the chamber air. Air samples contained over 50% of emitted monoterpenes and less than 40% of released sesquiterpenes and terpene alcohols. Eleven degradation byproducts were quantified, including acrolein (1.3-3.9 μg m^-3) and methacrolein (2.0 μg m^-3). A large amount of UFPs were released upon heating and remained airborne for at least 3 h. The mode diameter increased from 80 nm at 100 °C to 140 nm at 500 °C, and particles smaller than 250 nm contributed to 90% of PM_1.0. The presence of 0.5% of lignin, flavonoid, and triterpene additives in the heated mixtures resulted in a threefold increase in the particle formation rate and PM_1.0 concentration, suggesting that these high-molecular-weight compounds enhanced aerosol inception and growth. Predicted UFP emission rates in typical consumption scenarios (6 × 10¹¹-2 × 10¹³ # min^-1) were higher than, or comparable with, other common indoor sources such as smoking and cooking.

Aerial Transmission of the SARS-CoV-2 Virus through Environmental E-Cigarette Aerosols: Implications for Public Policies

We discuss the implications of possible contagion of COVID-19 through e-cigarette aerosol (ECA) for prevention and mitigation strategies during the current pandemic. This is a relevant issue when millions of vapers (and smokers) must remain under indoor confinement and/or share public outdoor spaces with non-users. The fact that the respiratory flow associated with vaping is visible (as opposed to other respiratory activities) clearly delineates a safety distance of 1-2 m along the exhaled jet to prevent direct exposure. Vaping is a relatively infrequent and intermittent respiratory activity for which we infer a mean emission rate of 79.82 droplets per puff (6-200, standard deviation 74.66) comparable to mouth breathing, it adds into shared indoor spaces (home and restaurant scenarios) a 1% extra risk of indirect COVID-19 contagion with respect to a "control case" of existing unavoidable risk from continuous breathing. As a comparative reference, this added relative risk increases to 44-176% for speaking 6-24 min per hour and 260% for coughing every 2 min. Mechanical ventilation decreases absolute emission levels but keeps the same relative risks. As long as direct exposure to the visible exhaled jet is avoided, wearing of face masks effectively protects bystanders and keeps risk estimates very low. As a consequence, protection from possible COVID-19 contagion through vaping emissions does not require extra interventions besides the standard recommendations to the general population: keeping a social separation distance of 2 m and wearing of face masks.

Room air constituent concentrations from use of electronic nicotine delivery systems and cigarettes using different ventilation conditions

To assess potential exposure of non-users to exhaled constituents from pod and cartridge electronic nicotine delivery systems (ENDS) products, an environmental clinical study was conducted with (n = 43) healthy adult smokers. Room air concentrations of 34 selected constituents (nicotine, propylene glycol, glycerin, 15 carbonyls, 12 volatile organic compounds, and 4 trace metals) and particle number concentration (0.3 to 25 µm) were compared from use of two ENDS products and conventional cigarettes using room ventilations representative of a residential, an office or a hospitality setting over a 4-h. exposure period. Products used were JUUL ENDS, Virginia Tobacco flavor (Group I), VUSE Solo, Original flavor (Group II) (5.0 and 4.8% nicotine by weight, respectively) and subjects' own conventional cigarettes (Group III). Cumulative 4-h room air sampling and particle counting were performed during prescribed (Groups I and II) and ad libitum product use (all Groups). Conventional cigarette use resulted in significantly more constituents detected and higher 4-h cumulative constituent concentrations compared to use of the ENDS products tested, except for the predominant ENDS ingredients, propylene glycol and glycerin. Use of conventional cigarettes also resulted in greater total particle number concentration than either prescribed or ad libitum use of either of the ENDS used in this study.

Prenatal and early life exposure to particulate matter, environmental tobacco smoke and respiratory symptoms in Mexican children

BACKGROUND

Exposure to particulate matter <2.5 μm in diameter (PM2.5) and environmental tobacco smoke (ETS) are associated with respiratory morbidity starting in utero. However, their potential synergistic effects have not been completely elucidated. Here, we examined the joint effects of prenatal and early life PM2.5 and prenatal ETS exposure on respiratory outcomes in children.

MATERIAL AND METHODS

We studied 536 mother-child dyads in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study in Mexico City. Exposure to PM2.5 was estimated using residence in pregnancy and child's first year of life with a satellite-based spatio-temporal model. ETS exposure was assessed by caregiver's report of any smoker in the household during the second or third trimester. Outcomes included report of ever wheeze and wheeze in the past 12 months (current wheeze) assessed when children were 6-8 years old considered in separate models. Associations were modeled using distributed lag models (DLM) with daily PM2.5 averages for pregnancy and the first year of life, adjusting for child's sex, birth weight z-score, mother's age and education at enrollment, maternal asthma, season of conception and stratified by prenatal ETS exposure (yes/no).

RESULTS

We identified a sensitive window from gestational week 14 through postnatal week 18 during which PM2.5 was associated with higher risk of ever wheeze at age 6-8 years. We also observed a critical window of PM2.5 exposure between postnatal weeks 6-39 and higher risk of current wheeze. We found significant associations between higher prenatal and early life PM2.5 exposure and higher cumulative risk ratios of ever wheeze (RR:3.76, 95%CI [1.41, 10.0] per 5 μg/m3) and current wheeze in the past year (RR:7.91, 95%CI [1.5, 41.6] per 5 μg/m3) only among children born to mothers exposed to ETS in pregnancy when compared to mothers who were not exposed.

CONCLUSIONS

Exposure to prenatal ETS modified the association between prenatal and early life PM2.5 exposure and respiratory outcomes at age 6-8 years. It is important to consider concurrent chemical exposures to more comprehensively characterize children's environmental risk. Interventions aimed at decreasing passive smoking might mitigate the effects of ambient air pollution.

Longitudinal association between environmental tobacco smoke exposure and behavioral problems in children from ages 5 to 9

Few studies have assessed the cumulative effects of exposure to environmental tobacco smoke (ETS¹) in relation to children's neurobehavioral problems over time. We assessed the longitudinal associations between ETS exposure at age 5 and behavioral problems at ages 5, 7, and 9 using the Ewha Birth and Growth Cohort, in Seoul, Korea. Children with available urinary cotinine levels at age 5 and one or more behavioral problem scores measured with the Korean Version of Child Behavior Checklist (CBCL²) at age 5, 7, and 9 were included in the study. Those whose mothers smoked during pregnancy were excluded, and a total of 179 children were included in the analysis. A linear mixed-model analysis using a REPEATED statement was conducted to assess whether ETS exposure was associated with the total, internalizing, and externalizing behavioral problem scores of the CBCL. The group with higher levels of cotinine showed continuously higher total and external behavioral problem scores from ages 5 to 9, which was seen after adjusting for preterm birth, father's education level, and television watching time. In addition, the difference in the total and external behavioral problem scores between the higher and lower cotinine groups at age 5 was statistically significant after a Bonferroni correction (p = 0.02 and 0.04, respectively), even though the fixed effect of cotinine level was almost but not statistically significant (p = 0.07 and 0.08, respectively). The results of this longitudinal cohort study provide evidence regarding the negative effects of ETS exposure in early childhood and their behavioral problems over time. This study supports the strengthening of anti-smoking policies used in educational interventions for parents, in order to reduce early ETS exposure in children.

Heat-not-burn tobacco products: an emerging threat to cardiovascular health

Cigarette smoking is at all-time lows globally, but the use of electronic cigarettes has increased profoundly. Recent reports of electronic cigarette or vaping use-associated lung injury may lead individuals to explore novel methods of nicotine consumption, such as heat-not-burn devices. IQOS from Philip Morris, a heat-not-burn device, became available for purchase in the United States in October 2019. Philip Morris claims that 8.8 million people have abandoned traditional cigarettes in favor of IQOS; however, evidence suggests that it may act as a gateway or complement to cigarette smoking, rather than a replacement. Surveys indicate that 96% of Korean IQOS users also smoke cigarettes, and 45% of Italian users of IQOS had never smoked cigarettes. In the United States, Canada, and England, susceptibility of youth to trying IQOS was slightly lower than electronic cigarettes, but higher than cigarette smoking. Heat-not-burn products produce mainstream and second-hand emissions of harmful chemicals, including nicotine, particulate matter, benzene, acrolein, and tobacco-specific nitrosamines. The levels of these emissions, despite being less than those of traditional cigarettes, are potentially harmful to cardiovascular health. A study of current smokers showed similar acute effects of heat-not-burn tobacco products and traditional cigarettes on heart rate, blood pressure, and arterial stiffness. Rats exposed to IQOS had similar vascular endothelial function impairment to those exposed to cigarettes. Heat-not-burn aerosol exposure of cultured macrophages elicited increased oxidative stress, although less than that induced by cigarette smoke. Further studies are needed to better understand the cardiovascular effects of heat-not-burn tobacco products.

Comparative Indoor Pollution from Glo, Iqos, and Juul, Using Traditional Combustion Cigarettes as Benchmark: Evidence from the Randomized SUR-VAPES AIR Trial

Modified risk products (MRP) such as electronic vaping cigarettes (EVC) and heat-not-burn cigarettes (HNBC) are appealing alternatives to combustion cigarettes. Limited between- and within-device comparative data are available on MRP. We aimed at comparing indoor particulate matter (PM) emissions measured in a randomized trial enforcing standardized smoking sessions, testing different devices and flavors of MRP, using traditional combustion cigarettes (TCC) as benchmark. Overall, MRP yielded significantly lower levels of indoor PM in comparison to TCC (with median PM levels during smoking for MRP < 100 μg/m³, and for TCC > 1000 μg/m³). Despite this, significant differences among MRP were found, with Iqos appearing associated with a significantly lower burden of emissions for all the monitored fractions of PM, including total PM (all p < 0.05). Precisely, during use, PM ≤1 µm (PM₁) emissions were 28 (16; 28) μg/m³ for Glo, 25 (15; 57) μg/m³ for Iqos, and 73 (15; 559) μg/m³ for Juul (p < 0.001 for Glo vs. Iqos, p < 0.001 for Glo vs. Juul, and p = 0.045 for Iqos vs. Juul). Exploratory within-MRP analyses suggested significant differences between flavors, favoring, for instance, Ultramarine for Glo, Bronze for Iqos, and Mango for Juul, even if results varied substantially according to individual smoker. In conclusion, leading MRP have significantly less intense and persistent effects on indoor pollution in comparison to TCC. Yet, when focusing solely on MRP, between-product and between-flavor differences appear, with quantitative estimates suggesting lower polluting effects with Iqos. These results, if confirmed externally, could be used to individualize product and flavor choice to minimize the untoward effects of EVC and HNBC on indoor pollution.

Where Do Ultrafine Particles and Nano-Sized Particles Come From?

This paper presents an overview of the literature studies on the sources of ultrafine particles (UFPs), nanomaterials (NMs), and nanoparticles (NPs) occurring in indoor (occupational and residential) and outdoor environments. Information on the relevant emission factors, particle concentrations, size, and compositions is provided, and health relevance of UFPs and NPs is discussed. Particular attention is focused on the fraction of particles that upon inhalation deposit on the olfactory bulb, because these particles can possibly translocate to brain and their possible role in neurodegenerative diseases is an important issue emerging in the recent literature.

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, PM_2.5, 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.

A randomized trial comparing the acute coronary, systemic, and environmental effects of electronic vaping cigarettes versus heat-not-burn cigarettes in smokers of combustible cigarettes undergoing invasive coronary assessment: rationale and design of the SUR-VAPES 3 trial

BACKGROUND

Traditional combustible cigarette (TCC) smoking remains a major cause of preventable cardiovascular morbidity and mortality. Modified risk products (MRP) such as electronic vaping cigarettes (EVC) and heat-not-burn cigarettes (HNBC) may be safer than TCC but may still have detrimental oxidative, platelet and vascular effects of particular importance to people with symptomatic coronary artery disease (CAD).

METHODS

We aimed to compare the acute coronary, systemic and environmental effects of two leading MRP in 20 TCC smokers admitted for invasive coronary assessment of CAD and willing to quit or after prior failed quitting attempts. After confirmation at angiography of an intermediate coronary stenosis, coronary flow reserve (CFR) will be appraised. Patients will then be randomized 1:1 to use a single EVC or a single HNBC in the catheterization laboratory, followed by repeat CFR measurement. The primary endpoint will be the change in CFR before and after product use. Quantitative coronary angiography, fractional flow reserve (FFR), and instantaneous wave-free ratio (iFR) will also be measured.

RESULTS

We expected to accrue results able to: 1) test whether MRP have in general a detrimental impact on coronary vascular function in TCC smokers; 2) test whether EVC have a different impact than HNBC on coronary function; 3) provide ancillary pathophysiologic and translational insights on the acute risk and safety profile of MRP in TCC smokers with established cardiovascular disease, including complex correlations between coronary, cardiac, systemic and environmental effects. In addition, by directly informing participants of their individual results, they will be further empowered to quit TCC.

CONCLUSIONS

The Sapienza University of Rome-Vascular Assessment of Proatherosclerotic Effects of Smoking (SUR-VAPES) 3 trial will provide important insights into the pathophysiologic cardiovascular impact of EVC and HNBC, also suitable to inform patients and individualize their smoking cessation strategy.

Exposure to Environmental Tobacco Smoke (ETS) among Employees of Hospitality Venues in the Light of Changes in Anti-Tobacco Legislation in Poland

Introduction: Numerous studies conducted in Europe and worldwide have indicated that employees of hospitality venues are the most exposed professional group to environmental tobacco smoke (ETS) in the workplace. The purpose of this study was to assess the exposure of employees of hospitality venues to ETS in the light of changes in anti-tobacco legislation in Poland. Materials and methods: The study consisted of two stages. The first stage was conducted in 2010, while the second in 2015. The study was conducted among employees of 300 randomly selected hospitality venues in the city of Łódź (Poland). In total, 2607 questionnaires were analysed. The study used two survey questionnaires created and recommended by the Institute for Global Tobacco Control to study exposure to ETS. Statistical analysis was made with Statistica 13.1 PL (StatSoft, Poland). Results: In the group of all nonsmoking employees, individuals exposed to ETS at work in 2010 accounted for 72.6%; while in 2015 it was 51.8%. Factors affecting exposure to ETS in the workplace included, among others: age, marital status, education, position held, presence of a smoking room on the premises, and noncompliance with the provisions of the anti-tobacco laws. Conclusions: The prevalence of tobacco smoking among employees of hospitality venues decreased in 2010–2015, however, it remained high. More than half of nonsmoking employees were exposed to ETS at work.

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, PM_2.5 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.

Assessment of indoor air exposure at residential homes: Inhalation dose and lung deposition of PM10, PM2.5 and ultrafine particles among newborn children and their mothers

Accurate assessment of particulate matter (PM) dose and respiratory deposition is essential to better understand the risks of exposure to PM and, consequently, to develop the respective risk-control strategies. In homes, this is especially relevant in regards to ultrafine particles (UFP; <0.1 μm) which origin in these environments is mostly due to indoor sources. Thus, this study aimed to estimate inhalation doses for different PM mass/number size fractions (i.e., PM₁₀, PM_2.5 and UFP) in indoor air of residential homes and to quantify the deposition (total, regional and lobar) in human respiratory tract for both newborn children and mothers. Indoor real-time measurements of PM₁₀, PM_2.5 and UFP were conducted in 65 residential homes situated in Oporto metropolitan area (Portugal). Inhalation doses were estimated based on the physical characteristics of individual subjects and their activity patterns. The multi-path particle dosimetry model was used to quantify age-specific depositions in human respiratory tract. The results showed that 3-month old infants exhibited 4-fold higher inhalation doses than their mothers. PM₁₀ were primarily deposited in the head region (87%), while PM_2.5 and UFP depositions mainly occurred in the pulmonary area (39% and 43%, respectively). Subject age affected the pulmonary region and the total lung deposition; higher deposition being observed among the newborns. Similarly, lower lobes (left lobe: 37% and right lobe: 30%) received higher PM deposition than upper and middle lobes; right lobes lung are prone to be more susceptible to respiratory problems, since asymmetric deposition was observed. Considering that PM-related diseases occur at specific sites of respiratory system, quantification of site-specific particle deposition should be predicted in order to better evidence the respective health outcomes resulting from inhaled PM.

Impact of Electronic Alternatives to Tobacco Cigarettes on Indoor Air Particular Matter Levels

An aerosol study was carried out in a test room measuring particulate matter (PM) with an aerodynamic diameter smaller than 10, 4, 2.5 and 1 µm (PM10, PM4, PM2.5, PM1) before and during the use of electronic alternatives to tobacco cigarettes (EATC) IQOS®, GLO®, JUUL®, with different kinds of sticks/pods, as well as during the smoking of a conventional tobacco cigarette. The aerosol was mainly in the PM1 size range (>95%). All studied EATCs caused lower indoor PM1 concentrations than conventional tobacco cigarettes. Nevertheless, they determined a worsening of indoor-PM1 concentration that ranged from very mild for JUUL®-depending on the pod used-to considerably severe for IQOS® and GLO®. Median values ranged from 11.00 (Iqos3 and Juul2) to 337.5 µg m-3 (Iqos4). The high variability of particle loadings was attributed both to the type of stick/pod used and to the different way of smoking of volunteers who smoked/vaped during the experiments. Moreover, during vaping IQOS® and GLO® indoor PM1 concentrations reach levels by far higher than outdoor concentrations that range from 14 to 21 µg m-3, especially during the exhalation of the smoke. From these results emerge an urgent need of a legislative regulation limiting the use of such devices in public places.

Effect of ventilation strategies and air purifiers on the children's exposure to airborne particles and gaseous pollutants in school gyms

Indoor school gyms are environments characterized by high concentrations of different airborne particulate and gaseous pollutants. In particular, like other naturally-ventilated school environments, in addition to indoor pollutants children can be exposed to sub-micron particles and gaseous pollutants emitted by outdoor sources and penetrating the building envelope; moreover, high concentrations of super-micron particles can be reached due to the resuspension phenomena related to the physical activity performed therein. The present paper aims to evaluate the effect of different ventilation methods (natural ventilation, manual airing) and the use of air purifiers in reducing the indoor concentrations of different airborne particles and gaseous pollutants in school gyms. To this end, an experimental campaign was performed in two naturally-ventilated school gyms in Barcelona (Spain) of different volumes and different distance to major urban roads. Indoor and outdoor measurements of particle number, black carbon and PM_1-10 concentrations were performed as well as indoor measurements of CO₂ and NO₂ concentrations. The study revealed that the use of air purifiers with windows kept closed (natural ventilation) can lead to a significant reduction in terms of indoor-to-outdoor concentration ratios. In the smaller gym (air changes per hour of the purifiers, ACH, equal to 9.2 h^-1) the I/O ratios were reduced by 93% and 95% in terms of particle number and PM_1-10, respectively; whereas in the larger school gym (ACH = 1.7 h^-1) the corresponding reductions were 70% and 84%. For manual airing scenarios, the effect of the air purifiers on outdoor-generated sub-micron particles is reduced; in particular, for low ACH values (i.e. ACH = 1.7 h^-1), the reduction is quite negligible (6%).

High Particulate Matter Burden of Cigarettes from the United Arab Emirates and Germany: Are There Country-Specific Differences?

Although the big tobacco companies offer the same cigarette brands across countries, little is known about the potential regional differences of the particulate matter (PM) emissions of apparently equal brands. PM emissions of three cigarette brands (Marlboro Gold, Winston Red resp. Classic, Parliament Platinum resp. Night Blue) from the United Arab Emirates (UAE) and Germany were analysed. Second-hand smoke was produced in a 2.88 m³ measuring cabin by an automatic environmental tobacco smoke emitter. PM size fractions PM₁₀, PM_2.5, and PM₁ were detected in real-time using laser aerosol spectrometry. Depending on the PM fraction Marlboro cigarettes from UAE showed 33%-35% higher PM amounts. Moreover, Winston cigarettes from UAE showed distinctly higher PM values (28-31%) than the German counterparts. The "lighter" Parliament from UAE emitted 3%-9% more PM than the German one. The measured mean PM₁₀ values laid between 778 and 1163 µg/m³ (mean PM_2.5: 777-1161 µg/m³; mean PM₁: 724-1074 µg/m³). That means smoking in enclosed rooms causes massive PM burden. The PM emission of equal or similar tobacco products from different countries can differ distinctly. Hence, the declaration of PM emission values, besides nicotine, tar, and carbon monoxide amounts, should be obligatory worldwide. Furthermore, complete information about the ingredients and production processes of tobacco products should be provided to health officials and the public. This can help to minimise or ban substances or product designs that make smoking even more harmful, and to enhance the awareness of the risks of smoking.

Ultrafine particles: unique physicochemical properties relevant to health and disease

Ultrafine particles (UFPs) are aerosols with an aerodynamic diameter of 0.1 µm (100 nm) or less. There is a growing concern in the public health community about the contribution of UFPs to human health. Despite their modest mass and size, they dominate in terms of the number of particles in the ambient air. A particular concern about UFPs is their ability to reach the most distal lung regions (alveoli) and circumvent primary airway defenses. Moreover, UFPs have a high surface area and a capacity to adsorb a substantial amount of toxic organic compounds. Harmful systemic health effects of PM₁₀ or PM_2.5 are often attributable to the UFP fraction. In this review, we examine the physicochemical characteristics of UFPs to enable a better understanding of the effects of these particles on human health. The characteristics of UFPs from diesel combustion will be discussed in the greatest detail because road vehicles are the primary source of UFP emissions in urban pollution hotspots. Finally, we will elaborate on the role of UFPs on global climate change, since the adverse effects of UFPs on meteorological processes and the hydrological cycle may even be more harmful to human health than their direct toxic effects.

Ultrafine particles (UFPs) from auto exhaust, factory emissions, and woodburning negatively affect human health and can alter weather patterns. UFPs, particles less than 100 nanometers, smaller than the smallest bacterium, are the most common airborne particles. Their size allows them to penetrate the deepest lung passageways, sometimes carrying toxic metals or organic compounds that trigger inflammation and disease. Hyouk-Soo Kwon at the University of Ulsan, Seoul, South Korea, and coworkers have reviewed the sources and effects of UFPs. Auto engines are a primary source; recent improvements in combustion technology have resulted in production of smaller particles, with worse effects on health. UFPs have also been found to affect cloud formation and behavior, altering rainfall patterns and potentially causing flooding or drought. Understanding the properties of UFPs will help find ways to mitigate their effects.

Size-segregated deposition of atmospheric elemental carbon (EC) in the human respiratory system: A case study of the Pearl River Delta, China

It has increasingly become apparent in recent years that atmospheric elemental carbon (EC) is potentially a more sensitive indicator of human health risks from ambient aerosol exposure compared to particulate mass. However, a comprehensive evaluation of the factors affecting EC exposure is lacking so far. To address this, we performed measurements of size-segregated EC in Guangzhou, China, followed by an estimation of deposition in the human respiratory system. Most ambient EC was in the fine mode suggesting significant cloud processing, and ~40% was deposited in the human respiratory tract, with predominant deposition in the head region (47%), followed by the pulmonary (30%) and tracheobronchial (23%) regions. A significant fraction (36%) of deposited EC were coarse particles indicating the need to consider coarse-mode EC in future health effect studies. Infants and children exhibited greater vulnerability to EC exposure than adults, and the deposition amount varied linearly with breathing rate, a proxy for physical exertion. The nature of breathing was found to constrain EC inhalation significantly, with oronasal breathing associated with lower total deposition and nasal breathing leading to lower deposition in the tracheobronchial and pulmonary regions. Overall, these observations strengthen the need to include EC as an additional air quality indicator.

Effects of Exposure to Tobacco Cigarette, Electronic Cigarette and Heated Tobacco Product on Adipocyte Survival and Differentiation In Vitro

Cigarette smoking (CS) causes significant morbidity worldwide, attributed to the numerous toxicants generated by tobacco combustion. Electronic cigarettes (ECIG) and heated tobacco products (HTP) are considered alternative smoking/vaping products that deliver nicotine through an inhaled aerosol and emit fewer harmful constituents than CS. However, their long-term impacts on human health are not well established. Nicotine exposure has been linked to lipolysis and body weight loss, while smoking has been associated with insulin resistance and hyperinsulinemia. Enhanced function of beige (thermogenic) adipocytes has been proposed as a means to reduce obesity and metabolic disorders. In this study, we compared the effect of extract-enriched media via exposure of culture medium to CS, HTP aerosol, and ECIG aerosol on the viability and the differentiation of 3T3-L1 pre-adipocytes to beige adipocytes. Only CS extract caused a decrease in cell viability in a dose- and time-dependent manner. Furthermore, relative lipid accumulation and expression levels of the adipocyte markers Pgc-1α, Ppar-γ and Resistin were significantly decreased in cells exposed to CS extract. Our results demonstrate that CS extract, in contrast to HTP and ECIG extracts, significantly impairs differentiation of pre-adipocytes to beige adipocytes and may therefore impact significantly adipose tissue metabolic function.

Exposure to ultrafine particles in children until 18 years of age: A systematic review

Airborne ultrafine particles (UFP) have been related to adverse health effects, but exposure in vulnerable population groups such as children is still not well understood. We aim to review the scientific literature regarding personal exposure to UFP in different microenvironments in populations until 18 years of age. The bibliographical search was carried out in July 2019 using the online database PubMed and was completed with references in articles found in the search. We selected the studies that used continuous counters and measured UFP levels in both specific microenvironment (houses, schools, transport, etc) and personal exposure. Finally, 32 studies fulfilled the criteria: of these, 10 analyzed personal exposure and 22 examined UFP levels in the microenvironment (especially in schools or nurseries (18/22)) and five in various microenvironments (including dwellings and means of transport, where exposure levels were higher). The characteristics of the microenvironments with the greatest levels of UFP were being close to heavy traffic or near cooking and cleaning activities. This review revealed the wide differences in exposure assessment methodologies that could lead to a lack of uniform and comparable information about the real UFP exposure in children.

Nanoparticle Behaviour in an Urban Street Canyon at Different Heights and Implications on Indoor Respiratory Doses

The amount of outdoor particles that indoor environments receive depends on the particle infiltration factors (Fin), peculiar of each environment, and on the outdoor aerosol concentrations and size distributions. The respiratory doses received, while residing indoor, will change accordingly. This study aims to ascertain to what extent such doses are affected by the vertical distance from the traffic sources. Particle number size distributions have been simultaneously measured at street level and at about 20 m height in a street canyon in downtown Rome. The same Fin have been adopted to estimate indoor aerosol concentrations, due to the infiltration of outdoor particles and then the relevant daily respiratory doses. Aerosol concentrations at ground floor were more than double than at 20 m height and richer in ultrafine particles. Thus, although aerosol infiltration efficiency was on average higher at 20 m height than at ground floor, particles more abundantly infiltrated at ground level. On a daily basis, this involved a 2.5-fold higher dose at ground level than at 20 m height. At both levels, such doses were greater than those estimated over the period of activity of some indoor aerosol sources; therefore, they represent an important contribution to the total daily dose.

Evaluation of Second-Hand Exposure to Electronic Cigarette Vaping under a Real Scenario: Measurements of Ultrafine Particle Number Concentration and Size Distribution and Comparison with Traditional Tobacco Smoke

The present study aims to evaluate the impact of e-cig second-hand aerosol on indoor air quality in terms of ultrafine particles (UFPs) and potential inhalation exposure levels of passive bystanders. E-cig second-hand aerosol characteristics in terms of UFPs number concentration and size distribution exhaled by two volunteers vaping 15 different e-liquids inside a 49 m3 room and comparison with tobacco smoke are discussed. High temporal resolution measurements were performed under natural ventilation conditions to simulate a realistic exposure scenario. Results showed a systematic increase in UFPs number concentration (part cm-3) related to a 20-min vaping session (from 6.56 × 103 to 4.01 × 104 part cm-3), although this was one up to two order of magnitude lower than that produced by one tobacco cigarette consumption (from 1.12 × 105 to 1.46 × 105 part cm-3). E-cig second-hand aerosol size distribution exhibits a bimodal behavior with modes at 10.8 and 29.4 nm in contrast with the unimodal typical size distribution of tobacco smoke with peak mode at 100 nm. In the size range 6-26 nm, particles concentration in e-cig second-hand aerosol were from 2- (Dp = 25.5 nm) to 3800-fold (Dp = 9.31 nm) higher than in tobacco smoke highlighting that particles exhaled by users and potentially inhaled by bystanders are nano-sized with high penetration capacity into human airways.

Further Insights on Predictors of Environmental Tobacco Smoke Exposure during the Pediatric Age

Background: The smoking ban in public places has reduced Environmental Tobacco Smoke (ETS) exposure for non-smokers, but despite this, domestic environments still remain places at high risk of exposure, and, today, about 40% of children worldwide are exposed to ETS at home. The aims of the study are to investigate the contribution of several factors on ETS exposure among a group of Italian children and to evaluate the changes in smoking precautions adopted at home when the smoker is the mother, the father, or both parents, respectively. Methods: A cross-sectional study was performed on a sample of 519 Italian schoolchildren. Information was collected via a questionnaire. Results: 41.4% of the participants lived with at least one smoker. Almost half of the children exposed to ETS lived with one or more smokers who do not observe any home smoking ban. Lower maternal or paternal educational levels significantly increase the risk of ETS exposure at home and the "worst case" is represented by both parents who smoke. Conclusions: More effective preventive interventions are needed to protect children from ETS exposure. Some interventions should be specifically dedicated to smokers with a low educational level and to mothers that smoke.

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.

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.

A narrative review evaluating the safety and efficacy of e-cigarettes as a newly marketed smoking cessation tool

Introduction:

E-cigarettes are an alternative to traditional tobacco-based cigarettes. While having considerable societal awareness, conflicting evidence exists to support their claims that they are an effective smoking cessation tool and are safe. Currently >7000 flavours exist with evidence that they exhibit detrimental cellular and tissue effects. A literature review was conducted utilising PubMed and Google Scholar Databases identifying papers between 2014 and 2019. The aims of this study were to accurately gauge the safety and efficacy of e-cigarettes as a smoking cessation tool.

Methods:

Search terms including ‘electronic cigarettes’ and ‘vaping’ were used to identify suitable references. A total of 314 articles were identified from which papers were excluded due to risk of bias, insufficient detail or were duplicate from which 58 papers were used in the final review.

Results:

Evidence shows that e-cigarettes can have detrimental effects on several cell lines and animal models with their flavourings and nicotine content implicated; this has, however, not translated into major health outcomes after 3.5 years follow-up but has been linked to chronic lung disease and cardiovascular disease. While advertised as an effective smoking cessation tool, no consensus can be made regarding their effectiveness although the first robust randomised controlled trial reports some success. This, however, is offset by the fact that the most common e-cigarette use is as a dual user and that there is evidence of threefold increased risk of future tobacco smoking.

Conclusion:

Future research is needed to evaluate the long-term health outcomes and efficacy of e-cigarettes as a smoking cessation tool with greater discussion between patients and clinicians regarding this smoking cessation tool.

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.

Indoor Sources of Air Pollutants

People spend an average of 90% of their time in indoor environments. There is a long list of indoor sources that can contribute to increased pollutant concentrations, some of them related to human activities (e.g. people's movement, cooking, cleaning, smoking), but also to surface chemistry reactions with human skin and building and furniture surfaces. The result of all these emissions is a heterogeneous cocktail of pollutants with varying degrees of toxicity, which makes indoor air quality a complex system. Good characterization of the sources that affect indoor air pollution levels is of major importance for quantifying (and reducing) the associated health risks. This chapter reviews some of the more significant indoor sources that can be found in the most common non-occupational indoor environments.