Thirdhand smoke exposure promotes gastric tumor development in mouse and human.

The pollution of indoor environments and the consequent health risks associated with thirdhand smoke (THS) are increasingly recognized in recent years. However, the carcinogenic potential of THS and its underlying mechanisms have yet to be thoroughly explored. In this study, we examined the effects of short-term THS exposure on the development of gastric cancer (GC) in vitro and in vivo.

Remediation of Thirdhand Tobacco Smoke with Ozone: Probing Deep Reservoirs in Carpets.

We assessed the efficacy of ozonation as an indoor remediation strategy by evaluating how a carpet serves as a sink and long-term source of thirdhand tobacco smoke (THS) while protecting contaminants absorbed in deep reservoirs by scavenging ozone. Specimens from unused carpet that was exposed to smoke in the lab ("fresh THS") and contaminated carpets retrieved from smokers' homes ("aged THS") were treated with 1000 ppb ozone in bench-scale tests. Nicotine was partially removed from fresh THS specimens by volatilization and oxidation, but it was not significantly eliminated from aged THS samples.

Policy-relevant differences between secondhand and thirdhand smoke: strengthening protections from involuntary exposure to tobacco smoke pollutants.

Starting in the 1970s, individuals, businesses and the public have increasingly benefited from policies prohibiting smoking indoors, saving thousands of lives and billions of dollars in healthcare expenditures. Smokefree policies to protect against secondhand smoke exposure, however, do not fully protect the public from the persistent and toxic chemical residues from tobacco smoke (also known as thirdhand smoke) that linger in indoor environments for years after smoking stops. Nor do these policies address the economic costs that individuals, businesses and the public bear in their attempts to remediate this toxic residue.

Fraction of Free-Base Nicotine in Simulated Vaping Aerosol Particles Determined by X-ray Spectroscopies.

A new generation of electronic cigarettes is exacerbating the youth vaping epidemic by incorporating additives that increase the acidity of generated aerosols, which facilitate uptake of high nicotine levels. We need to better understand the chemical speciation of vaping aerosols to assess the impact of acidification. Here we used X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to probe the acid-base equilibria of nicotine in hydrated vaping aerosols.

Thirdhand Exposures to Tobacco-Specific Nitrosamines through Inhalation, Dust Ingestion, Dermal Uptake, and Epidermal Chemistry.

Tobacco-specific nitrosamines (TSNAs) are emitted during smoking and form indoors by nitrosation of nicotine. Two of them, '-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are human carcinogens with No Significant Risk Levels (NSRLs) of 500 and 14 ng day, respectively. Another TSNA, 4-(methylnitrosamino)-4-(3-pyridyl) butanal (NNA), shows genotoxic and mutagenic activity .

Volatile aldehyde emissions from "sub-ohm" vaping devices.

"Sub-ohm" atomizers with reduced resistance can deliver more power than conventional electronic cigarettes. Typical battery outputs are 100 W or more. These devices are particularly popular among young users, and can be a significant source of volatile carbonyls in the indoor environment.

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.

Chemical changes in thirdhand smoke associated with remediation using an ozone generator.

Ozonation is a common remediation approach to eliminate odors from mold, tobacco and fire damage in buildings. Little information exists to: 1) assess its effectiveness; 2) provide guidance on operation conditions; and 3) identify potential risks associated with the presence of indoor ozone and ozonation byproducts. The goal of this study is to evaluate chemical changes in thirdhand smoke (THS) aerosols induced by high levels of ozone, in comparison with THS aerosols aged under similar conditions in the absence of ozone.

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.

Short-term early exposure to thirdhand cigarette smoke increases lung cancer incidence in mice.

Exposure to thirdhand smoke (THS) is a recently described health concern that arises in many indoor environments. However, the carcinogenic potential of THS, a critical consideration in risk assessment, remains untested. Here we investigated the effects of short-term early exposure to THS on lung carcinogenesis in A/J mice.

Longitudinal association between mental disorders in childhood and subsequent depression - A nationwide prospective cohort study.

Background: Depression ranges among the most impairing mental disorders worldwide, and early detection is a global health priority. Little is known about the association between non-affective mental disorders in childhood/adolescence and later depression.

Methods: Nationwide register-based prospective cohort study, estimating cumulative incidences and incidence rate ratios (IRR) for later depression in individuals with and without non-affective mental disorders in early life.

Emissions from Electronic Cigarettes: Assessing Vapers' Intake of Toxic Compounds, Secondhand Exposures, and the Associated Health Impacts.

E-cigarettes likely represent a lower risk to health than traditional combustion cigarettes, but they are not innocuous. Recently reported emission rates of potentially harmful compounds were used to assess intake and predict health impacts for vapers and bystanders exposed passively. Vapers' toxicant intake was calculated for scenarios in which different e-liquids were used with various vaporizers, battery power settings and vaping regimes.

Early exposure to thirdhand cigarette smoke affects body mass and the development of immunity in mice.

Thirdhand smoke (THS) is the fraction of cigarette smoke that persists in indoor environments after smoking. We investigated the effects of neonatal and adult THS exposure on bodyweight and blood cell populations in C57BL/6 J mice. At the end of neonatal exposure, THS-treated male and female mice had significantly lower bodyweight than their respective control mice.

Thirdhand Smoke: New Evidence, Challenges, and Future Directions.

Thirdhand smoke (THS) is the contamination that persists after secondhand tobacco smoke has been emitted into air. It refers to the tobacco-related gases and particles that become embedded in materials, such as the carpet, walls, furniture, blankets, and toys. THS is not strictly smoke, but chemicals that adhere to surfaces from which they can be released back into the air, undergo chemical transformations and/or accumulate.

Emissions from Electronic Cigarettes: Key Parameters Affecting the Release of Harmful Chemicals.

Use of electronic cigarettes has grown exponentially over the past few years, raising concerns about harmful emissions. This study quantified potentially toxic compounds in the vapor and identified key parameters affecting emissions. Six principal constituents in three different refill "e-liquids" were propylene glycol (PG), glycerin, nicotine, ethanol, acetol, and propylene oxide.

Inhalable constituents of thirdhand tobacco smoke: chemical characterization and health impact considerations.

Tobacco smoke residues lingering in the indoor environment, also termed thirdhand smoke (THS), can be a source of long-term exposure to harmful pollutants. THS composition is affected by chemical transformations and by air-surface partitioning over time scales of minutes to months. This study identified and quantified airborne THS pollutants available for respiratory exposure, identified potential environmental tracers, and estimated health impacts to nonsmokers.

Impact of endobronchial coiling for lung volume reduction on pulmonary volume and attenuation: preinterventional and postinterventional computed tomography-quantification using separate lobe measurements.

Objective: The aim of this study was to objectify changes in volume and density of treated and untreated pulmonary lobes following endobronchial coiling for lung volume reduction by comparison with clinical (6-m walk test) and pulmonary function tests.

Methods: Twenty-two lobes in 17 patients (8 men, 9 women) were treated by endobronchial coiling and underwent preinterventional and postinterventional computed tomography examinations (inspiratory and expiratory phase) as well as pulmonary function test measurements.

Results: Responders (n = 14) presented a significant increase (70 ± 11 m) in the walking distance (6-m walk test) and FEV1 (forced expiratory volume in 1 second) values (61 ± 21 mL).

Cigarette smoke toxins deposited on surfaces: implications for human health.

Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered - Thirdhand smoke (THS) - the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic.

Solid-phase supported profluorescent nitroxide probe for the determination of aerosol-borne reactive oxygen species.

Reactive oxygen species (ROS) and free radicals play important roles in the chemical transformation and adverse health effects of environmental aerosols. This work presents a simple and sensitive method for sampling and analysis of ROS using a packed column coated with a profluorescent nitroxide scavenger, proxyl fluorescamine (PF). Quantification was performed by extraction and analysis using HPLC with fluorescence detection.

Thirdhand smoke causes DNA damage in human cells.

Exposure to thirdhand smoke (THS) is a newly described health risk. Evidence supports its widespread presence in indoor environments. However, its genotoxic potential, a critical aspect in risk assessment, is virtually untested.

Assessment of risk for asthma initiation and cancer and heart disease deaths among patrons and servers due to secondhand smoke exposure in restaurants and bars.

Background: Despite efforts to reduce exposure to secondhand smoke (SHS), only 5% of the world's population enjoy smoke-free restaurants and bars.

Methods: Lifetime excess risk (LER) of cancer death, ischaemic heart disease (IHD) death and asthma initiation among non-smoking restaurant and bar servers and patrons in Minnesota and the US were estimated using weighted field measurements of SHS constituents in Minnesota, existing data on tobacco use and multiple dose-response models.

Results: A continuous approach estimated a LER of lung cancer death (LCD) of 18 × 10(-6)(95% CI 13 to 23 × 10(-6)) for patrons visiting only designated non-smoking sections, 80 × 10(-6)(95% CI 66 to 95 × 10(-6)) for patrons visiting only smoking venues/sections and 802 × 10(-6)(95% CI 658 to 936 × 10(-6)) for servers in smoking-permitted venues.

Secondhand smoke exposure in the nonsmoking section: how much protection?

Introduction: Secondhand smoke (SHS) exposure continues to be a problem in bars and restaurants where smoking is permitted. This study measures the relative SHS exposure reduction in nonsmoking sections of establishments that allow some smoking.

Methods: Measurements were conducted simultaneously in the smoking and nonsmoking sections of 14 Minnesota hospitality venues.

Environmental monitoring of secondhand smoke exposure.

The complex composition of secondhand smoke (SHS) provides a range of constituents that can be measured in environmental samples (air, dust and on surfaces) and therefore used to assess non-smokers' exposure to tobacco smoke. Monitoring SHS exposure (SHSe) in indoor environments provides useful information on the extent and consequences of SHSe, implementing and evaluating tobacco control programmes and behavioural interventions, and estimating overall burden of disease caused by SHSe. The most widely used markers have been vapour-phase nicotine and respirable particulate matter (PM).