RESUMO
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. By contrast, most of the 24 polycyclic aromatic hydrocarbons detected in both samples were partially removed by ozone. One of the home-aged carpets was installed in an 18 m3 room-sized chamber, where its nicotine emission rate was 950 ng day-1 m-2. In a typical home, such daily emissions could amount to a non-negligible fraction of the nicotine released by smoking one cigarette. The operation of a commercial ozone generator for a total duration of 156 min, reaching concentrations up to 10,000 ppb, did not significantly reduce the carpet nicotine loading (26-122 mg m-2). Ozone reacted primarily with carpet fibers, rather than with THS, leading to short-term emissions of aldehydes and aerosol particles. Hence, by being absorbed deeply into carpet fibers, THS constituents can be partially shielded from ozonation.
Assuntos
Ozônio , Poluição por Fumaça de Tabaco , Nicotina/análise , Poluição por Fumaça de Tabaco/análise , Pisos e Cobertura de PisosRESUMO
Increasing evidence has shown that thirdhand smoke (THS) exposure is likely to induce adverse health effects. An important knowledge gap remains in our understanding of THS exposure related to cancer risk in the human population. Population-based animal models are useful and powerful in investigating the interplay between host genetics and THS exposure on cancer risk. Here, we used the Collaborative Cross (CC) mouse population-based model system, which recapitulates the genetic and phenotypic diversity observed in the human population, to assess cancer risk after a short period of exposure, between 4 and 9 weeks of age. Eight CC strains (CC001, CC019, CC026, CC036, CC037, CC041, CC042 and CC051) were included in our study. We quantified pan-tumor incidence, tumor burden per mouse, organ tumor spectrum and tumor-free survival until 18 months of age. At the population level, we observed a significantly increased pan-tumor incidence and tumor burden per mouse in THS-treated mice as compared to the control (p = 3.04E-06). Lung and liver tissues exhibited the largest risk of undergoing tumorigenesis after THS exposure. Tumor-free survival was significantly reduced in THS-treated mice compared to control (p = 0.044). At the individual strain level, we observed a large variation in tumor incidence across the 8 CC strains. CC036 and CC041 exhibited a significant increase in pan-tumor incidence (p = 0.0084 and p = 0.000066, respectively) after THS exposure compared to control. We conclude that early-life THS exposure increases tumor development in CC mice and that host genetic background plays an important role in individual susceptibility to THS-induced tumorigenesis. Genetic background is an important factor that should be taken into account when determining human cancer risk of THS exposure.
Assuntos
Neoplasias , Poluição por Fumaça de Tabaco , Humanos , Animais , Camundongos , Poluição por Fumaça de Tabaco/efeitos adversos , Camundongos de Cruzamento Colaborativo , Fatores de Risco , Neoplasias/etiologia , Neoplasias/genética , Carcinogênese/genética , Carcinogênese/induzido quimicamente , Transformação Celular NeoplásicaRESUMO
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. We show that, unlike the behavior observed in bulk water, nicotine in the core of aqueous particles was partially protonated when the pH of the nebulized solution was 10.4, with a fraction of free-base nicotine (αFB) of 0.34. Nicotine was further protonated by acidification with equimolar addition of benzoic acid (αFB = 0.17 at pH 6.2). By contrast, the degree of nicotine protonation at the particle surface was significantly lower, with 0.72 < αFB < 0.80 in the same pH range. The presence of propylene glycol and glycerol completely eliminated protonation of nicotine at the surface (αFB = 1) while not affecting significantly its acid-base equilibrium in the particle core. These results provide a better understanding of the role of acidifying additives in vaping aerosols, supporting public health policy interventions.
Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Vaping , Nicotina/química , Raios X , Aerossóis/química , Análise EspectralRESUMO
"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 next-generation sub-ohm vaping products were characterized by determining e-liquid consumption and volatile aldehydes emissions for several combinations of popular high-power configurations. Tests explored the effect of dilution air flow (air vent opening), puffing volume, and coil assembly configuration. The mass of liquid consumed per puff increased as the puff volume increased from 50 to 100 mL, then remained relatively constant for larger puff volumes up to 500 mL. This is likely due to mass transfer limitations at the wick and coil assembly, which reduced the vaporization rate at higher puff volumes. Carbonyl emission rates were systematically evaluated using a 0.15 Ω dual coil atomizer as a function of the puffing volume and dilution air flow, adjusted by setting the air vents to either 100% (fully open), 50%, 25%, or 0% (closed). The highest formaldehyde emissions were observed for the lowest puff volume (50 mL) when the vents were closed (48 ng mg-1), opened at 25% (39 ng mg-1) and at 50% (32 ng mg-1). By contrast, 50-mL puffs with 100% open vents, and puff volumes >100 mL for any vent aperture, generated formaldehyde yields of 20 ng mg-1 or lower, suggesting that a significant cooling effect resulted in limited carbonyl formation. Considering the effect of the coil resistance when operated at a voltage of 3.8 V, the amount of liquid evaporated per puff decreased as the resistance increased, in the order of 0.15 Ω > 0.25 Ω > 0.6 Ω, consistent with decreasing aerosol temperatures measured at the mouthpiece. Three different configurations of 0.15 Ω coils (dual, quadruple and octuple) were evaluated, observing significant variability. No clear trend was found between carbonyl emission rates and coil resistance or configuration, with highest emissions corresponding to a 0.25 Ω dual coil atomizer. Carbonyl emission rates were compared with those determined using the same methodology for conventional e-cigarettes (lower power tank systems), observing overall lower yields for the sub-ohm devices.
Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Vaping , Aerossóis , AldeídosRESUMO
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 PM1.0. 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 PM1.0 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.
Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Cannabis , Aerossóis , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Culinária , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , TerpenosRESUMO
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. Samples representing different stages of smoke aging in the absence of ozone, including freshly emitted secondhand smoke (SHS) and THS, were collected inside an 18-m3 room-sized chamber over a period of 42 h after six cigarettes were consumed. The experiments involved collection and analysis of gas phase species including volatile organic compounds (VOCs), volatile carbonyls, semivolatile organic compounds (SVOCs), and particulate matter. VOC analysis was carried out by gas chromatography/mass spectrometry with a thermal desorption inlet (TD-GC/MS), and volatile carbonyls were analyzed by on-line derivatization with dinitrophenylhydrazine (DNPH), followed by liquid chromatography with UV/VIS detection. SVOCs were extracted from XAD-coated denuders and Teflon-coated fiberglass filters in the absence of ozone. In those extracts, tobacco-specific nitrosamines (TSNAs) and other SVOCs were analyzed by gas chromatography with positive chemical ionization-triple quadrupole mass spectrometric detection (GC/PCI-QQQ-MS), and polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography with ion trap mass spectrometric detection (GC/IT-MS) in selected ion monitoring mode. Particulate matter concentration was determined gravimetrically. In a second experiment, a 300 mg h-1 commercial ozone generator was operated during 1 h, one day after smoke was generated, to evaluate the remediation of THS by ozonation. VOCs and volatile carbonyls were analyzed before and after ozonation. Extracts from fabrics that were exposed in the chamber before and after ozonation as surrogates for indoor furnishings were analyzed by GC/IT-MS, and aerosol size distribution was studied with a scanning mobility particle sizer. Ozone concentration was measured with a photometric detector. An estimated 175 mg ozone reacted with THS after 1 h of treatment, corresponding to 58% of the total O3 released during that period. Fabric-bound nicotine was depleted after ozonation, and the surface concentration of PAHs adsorbed to fabric specimens decreased by an order of magnitude due to reaction with ozone, reaching pre-smoking levels. These results suggest that ozonation has the potential to remove harmful THS chemicals from indoor surfaces. However, gas phase concentrations of volatile carbonyls, including formaldehyde, acetaldehyde and acetone were higher immediately after ozonation. Ultrafine particles (UFP, in most cases with size <60 nm) were a major ozonation byproduct. UFP number concentrations peaked shortly after ozonation ended, and remained at higher-than background levels for several hours. Based on these results, minimum re-entry times after ozone treatment were predicted for different indoor scenarios. Clearly defining re-entry times can serve as a practical measure to prevent acute exposures to ozone and harmful ozonation byproducts after treatment. This study evaluated potential benefits and risks associated with THS remediation using ozone, providing insights into this technology.
Assuntos
Ozônio , Intervenção Coronária Percutânea , Poluição por Fumaça de Tabaco , Cromatografia Gasosa-Espectrometria de Massas , Fumaça , Nicotiana , Poluição por Fumaça de Tabaco/análiseRESUMO
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.
Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Sistemas Eletrônicos de Liberação de Nicotina , Produtos do Tabaco , Poluição por Fumaça de Tabaco , Compostos Orgânicos Voláteis , Canadá , NicotianaRESUMO
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. Forty weeks after THS exposure from 4 to 7 weeks of age, the mice had increased incidence of lung adenocarcinoma, tumor size and, multiplicity, compared with controls. In vitro studies using cultured human lung cancer cells showed that THS exposure induced DNA double-strand breaks and increased cell proliferation and colony formation. RNA sequencing analysis revealed that THS exposure induced endoplasmic reticulum stress and activated p53 signaling. Activation of the p53 pathway was confirmed by an increase in its targets p21 and BAX. These data indicate that early exposure to THS is associated with increased lung cancer risk.
Assuntos
Neoplasias Pulmonares/induzido quimicamente , Fumar/efeitos adversos , Fatores de Tempo , Poluição por Fumaça de Tabaco/efeitos adversos , Animais , Proliferação de Células/fisiologia , Modelos Animais de Doenças , Incidência , Camundongos , Nicotiana/efeitos adversosRESUMO
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. For a high rate of 250 puff day-1 using a typical vaping regime and popular tank devices with battery voltages from 3.8 to 4.8 V, users were predicted to inhale formaldehyde (up to 49 mg day-1), acrolein (up to 10 mg day-1) and diacetyl (up to 0.5 mg day-1), at levels that exceeded U.S. occupational limits. Formaldehyde intake from 100 daily puffs was higher than the amount inhaled by a smoker consuming 10 conventional cigarettes per day. Secondhand exposures were predicted for two typical indoor scenarios: a home and a bar. Contributions from vaping to air pollutant concentrations in the home did not exceed the California OEHHA 8-h reference exposure levels (RELs), except when a high emitting device was used at 4.8 V. In that extreme scenario, the contributions from vaping amounted to as much as 12 µg m-3 formaldehyde and 2.6 µg m-3 acrolein. Pollutant concentrations in bars were modeled using indoor volumes, air exchange rates and the number of hourly users reported in the literature for U.S. bars in which smoking was allowed. Predicted contributions to indoor air levels were higher than those in the residential scenario. Formaldehyde (on average 135 µg m-3) and acrolein (28 µg m-3) exceeded the acute 1-h exposure REL for the highest emitting vaporizer/voltage combination. Predictions for these compounds also exceeded the 8-h REL in several bars when less intense vaping conditions were considered. Benzene concentrations in a few bars approached the 8-h REL, and diacetyl levels were close to the lower limit for occupational exposures. The integrated health damage from passive vaping was derived by computing disability-adjusted life years (DALYs) lost due to exposure to secondhand vapor. Acrolein was the dominant contributor to the aggregate harm. DALYs for the various device/voltage combinations were lower than-or comparable to-those estimated for exposures to secondhand and thirdhand tobacco smoke.
Assuntos
Poluentes Atmosféricos/análise , Sistemas Eletrônicos de Liberação de Nicotina , Formaldeído/análise , Poluição por Fumaça de Tabaco/análise , Poluição do Ar em Ambientes Fechados/análise , California , Substâncias Perigosas , Humanos , RiscoRESUMO
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. However, five weeks after neonatal exposure ended, THS-treated mice weighed the same as controls. In contrast, adult THS exposure did not change bodyweight of mice. On the other hand, both neonatal and adult THS exposure had profound effects on the hematopoietic system. Fourteen weeks after neonatal THS exposure ended, eosinophil number and platelet volume were significantly higher, while hematocrit, mean cell volume, and platelet counts were significantly lower compared to control. Similarly, adult THS exposure also decreased platelet counts and increased neutrophil counts. Moreover, both neonatal and adult THS exposure caused a significant increase in percentage of B-cells and significantly decreased percentage of myeloid cells. Our results demonstrate that neonatal THS exposure decreases bodyweight and that THS exposure induces persistent changes in the hematopoietic system independent of age at exposure. These results also suggest that THS exposure may have adverse effects on human health.
Assuntos
Peso Corporal , Hematopoese , Poluição por Fumaça de Tabaco/efeitos adversos , Animais , Contagem de Células Sanguíneas , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
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. The latter, with mass concentrations of 0.4-0.6%, is a possible carcinogen and respiratory irritant. Aerosols generated with vaporizers contained up to 31 compounds, including nicotine, nicotyrine, formaldehyde, acetaldehyde, glycidol, acrolein, acetol, and diacetyl. Glycidol is a probable carcinogen not previously identified in the vapor, and acrolein is a powerful irritant. Emission rates ranged from tens to thousands of nanograms of toxicants per milligram of e-liquid vaporized, and they were significantly higher for a single-coil vs a double-coil vaporizer (by up to an order of magnitude for aldehydes). By increasing the voltage applied to a single-coil device from 3.3 to 4.8 V, the mass of e-liquid consumed doubled from 3.7 to 7.5 mg puff(-1) and the total aldehyde emission rates tripled from 53 to 165 µg puff(-1), with acrolein rates growing by a factor of 10. Aldehyde emissions increased by more than 60% after the device was reused several times, likely due to the buildup of polymerization byproducts that degraded upon heating. These findings suggest that thermal degradation byproducts are formed during vapor generation. Glycidol and acrolein were primarily produced by glycerin degradation. Acetol and 2-propen-1-ol were produced mostly from PG, while other compounds (e.g., formaldehyde) originated from both. Because emissions originate from reaction of the most common e-liquid constituents (solvents), harmful emissions are expected to be ubiquitous when e-cigarette vapor is present.
Assuntos
Aerossóis , Sistemas Eletrônicos de Liberação de Nicotina , Acetaldeído , Formaldeído , NicotinaRESUMO
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. In a ventilated 18 m(3) laboratory chamber, six cigarettes were machine-smoked, and levels of particulate matter (PM2.5) and 58 volatile organic compounds (VOCs) were monitored during an aging period of 18 h. Results were compared with field measurements taken in a smoker's home 8 h after the last cigarette had been smoked. Initial chamber levels of individual VOCs in freshly emitted secondhand smoke (SHS) were in the range of 1-300 µg m(-3). The commonly used SHS tracers 3-ethenylpyridine (3-EP) and nicotine were no longer present in the gas phase after 2 h, likely due mostly to sorption to surfaces. By contrast, other VOCs persisted in the gas phase for at least 18 h, particularly furans, carbonyls, and nitriles. The concentration ratio of acetonitrile to 3-EP increased substantially with aging. This ratio may provide a useful metric for differentiating freshly emitted (SHS) from aged smoke (THS). Among the 29 VOCs detected in the smoker's home at moderate to high concentrations, 18 compounds were also detected in simultaneously sampled outdoor air, but acetonitrile, 2-methyl furan, and 2,5-dimethyl furan appeared to be specific to cigarette smoke. The levels of acrolein, methacrolein, and acrylonitrile exceeded concentrations considered harmful by the State of California. An initial exposure and impact assessment was conducted for a subset of pollutants by computing disability-adjusted life years lost, using available toxicological and epidemiological information. Exposure to PM2.5 contributed to more than 90% of the predicted harm. Acrolein, furan, acrylonitrile, and 1,3-butadiene were considered to be the most harmful VOCs. Depending on which criteria are used to establish the separation between SHS and THS, 5-60% of the predicted health damage could be attributed to THS exposure. Benefits and limitations of this approach are discussed.
Assuntos
Poluentes Atmosféricos/análise , Avaliação do Impacto na Saúde , Exposição por Inalação/análise , Nicotiana/efeitos adversos , Saúde Pública , Poluição por Fumaça de Tabaco/análise , California , Humanos , Material Particulado/análise , Anos de Vida Ajustados por Qualidade de Vida , Fatores de Tempo , Compostos Orgânicos Voláteis/análiseRESUMO
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. An attributable-risk (exposed/non-exposed) approach estimated a similar LER of LCD, a LER of IHD death about 10(-2) for non-smokers with average SHS exposure from all sources and a LER of asthma initiation about 5% for servers with SHS exposure at work only. These risks correspond to 214 LCDs and 3001 IHD deaths among the general non-smoking population and 1420 new asthma cases among non-smoking servers in the US each year due to SHS exposure in restaurants and bars alone. CONCLUSIONS: Health risks for patrons and servers from SHS exposure in restaurants and bars alone are well above the acceptable level. Restaurants and bars should be a priority for governments' effort to create smoke-free environments and should not be exempt from smoking bans.
Assuntos
Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Asma/mortalidade , Exposição Ambiental/estatística & dados numéricos , Neoplasias Pulmonares/mortalidade , Isquemia Miocárdica/mortalidade , Restaurantes , Poluição por Fumaça de Tabaco/estatística & dados numéricos , Adulto , Poluentes Atmosféricos , Comorbidade , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Masculino , Micronésia , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Fumar/epidemiologia , Poluição por Fumaça de Tabaco/efeitos adversos , Estados Unidos , Adulto JovemRESUMO
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. For comparison, the conventional method of collecting aerosols into dichlorofluorescin (DCFH) aqueous solution was used as a reference. The method was successfully applied to the determination of ROS in a model secondary organic aerosol (SOA) system generated by ozonolysis of nicotine, as well as in secondhand tobacco smoke (SHS). ROS concentrations between 50-565 nmol m(-3) were detected in fresh SOA and SHS samples. After SHS aging for 22 h, 13-18% of the initial ROS mass remained, suggesting the presence of persistent ROS. The new method offers better stability and reproducibility along with sensitivity comparable to that of DCFH (method detection limit of 3.2 and 1.4 nmol m(-3) of equivalent H2O2 for PF and DCFH respectively). The PF probe was stable during storage at room temperature and not reactive with ozone or NOx, whereas DCFH in the particle-collecting liquid system was strongly influenced by ozone and NOx interferences. This case study provides a good basis for employing solid-phase supported PF for field measurement of specific ROS in other combustion systems (i.e. biomass burning, candles, and diesel exhaust) and environmental aerosols.
Assuntos
Aerossóis/química , Fluorescamina/química , Sequestradores de Radicais Livres/química , Nicotina/análise , Espécies Reativas de Oxigênio/análise , Poluição por Fumaça de Tabaco/análise , Cromatografia Líquida de Alta Pressão , Fluorescamina/análogos & derivados , Fluoresceínas/química , Fluorescência , Vidro/química , Humanos , Limite de Detecção , Ozônio/química , Reprodutibilidade dos TestesRESUMO
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. An important characteristic of THS is its ability to undergo chemical transformations during aging periods, as demonstrated in a recent study showing that sorbed nicotine reacts with the indoor pollutant nitrous acid (HONO) to form tobacco-specific nitrosamines (TSNAs) such as 4-(methylnitrosamino)-4-(3-pyridyl)butanal (NNA) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The goal of this study was to assess the genotoxicity of THS in human cell lines using two in vitro assays. THS was generated in laboratory systems that simulated short (acute)- and long (chronic)-term exposures. Analysis by liquid chromatography-tandem mass spectrometry quantified TSNAs and common tobacco alkaloids in extracts of THS that had sorbed onto cellulose substrates. Exposure of human HepG2 cells to either acute or chronic THS for 24h resulted in significant increases in DNA strand breaks in the alkaline Comet assay. Cell cultures exposed to NNA alone showed significantly higher levels of DNA damage in the same assay. NNA is absent in freshly emitted secondhand smoke, but it is the main TSNA formed in THS when nicotine reacts with HONO long after smoking takes place. The long amplicon-quantitative PCR assay quantified significantly higher levels of oxidative DNA damage in hypoxanthine phosphoribosyltransferase 1 (HPRT) and polymerase ß (POLB) genes of cultured human cells exposed to chronic THS for 24h compared with untreated cells, suggesting that THS exposure is related to increased oxidative stress and could be an important contributing factor in THS-mediated toxicity. The findings of this study demonstrate for the first time that exposure to THS is genotoxic in human cell lines.
Assuntos
Dano ao DNA , Poluição por Fumaça de Tabaco/efeitos adversos , Linhagem Celular , Ensaio Cometa , Quebras de DNA/efeitos dos fármacos , Humanos , Mutagênicos/análise , Mutagênicos/química , Mutagênicos/toxicidade , Ácido Nitroso/análise , Ácido Nitroso/química , Ácido Nitroso/toxicidade , Estresse OxidativoRESUMO
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. All of the 16 two-hr visits included photometer measurements of fine particles (PM2.5) and 12 of the visits also included measurements of 4 gas-phase tracers of SHS. RESULTS: The median ratio of nonsmoking/smoking section PM2.5 concentrations was 0.65 with an interquartile range (IQR) of 0.49-0.72. Measurements conducted after implementation of a smoking ban at 13 of the venues resulted in a smoking section PM2.5 post-ban/pre-ban ratio of 0.06 (IQR = 0.02-0.16). The median nonsmoking/smoking section ratios for gas-phase compound were 0.67 (IQR = 0.35-0.78) for pyridine, 0.52 (IQR = 0.30-0.70) for pyrrole, 0.43 (IQR = 0.35-0.84) for 3-EP, and 0.27 (IQR = 0.16-0.47) for nicotine. These results are consistent with the expectations of differential removal: the lowest ratios are for the least volatile, most strongly sorbing gases and the highest ratios for less sorbing gases and PM2.5. CONCLUSIONS: Designated nonsmoking sections in establishments that allow some smoking resulted in a median PM2.5 reduction of 35% compared with a 94% reduction after a smoking ban. The only adequate protection from cigarette smoke exposure is to eliminate smoking in indoor spaces.
Assuntos
Poluição do Ar em Ambientes Fechados/análise , Poluição por Fumaça de Tabaco/análise , Poluição por Fumaça de Tabaco/prevenção & controle , Humanos , Minnesota , RestaurantesRESUMO
BACKGROUND: There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). OBJECTIVES: We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. DISCUSSION: Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include the creation of secondary pollutants that in some cases are more toxic (e.g., tobacco-specific nitrosamines). THS persists in real-world residential settings in the air, dust, and surfaces and is associated with elevated levels of nicotine on hands and cotinine in urine of nonsmokers residing in homes previously occupied by smokers. Much still needs to be learned about the chemistry, exposure, toxicology, health risks, and policy implications of THS. CONCLUSION: The existing evidence on THS provides strong support for pursuing a programmatic research agenda to close gaps in our current understanding of the chemistry, exposure, toxicology, and health effects of THS, as well as its behavioral, economic, and sociocultural considerations and consequences. Such a research agenda is necessary to illuminate the role of THS in existing and future tobacco control efforts to decrease smoking initiation and smoking levels, to increase cessation attempts and sustained cessation, and to reduce the cumulative effects of tobacco use on morbidity and mortality.
Assuntos
Poluentes Atmosféricos/química , Poluentes Atmosféricos/toxicidade , Exposição Ambiental , Nicotiana/química , Nicotiana/toxicidade , Poluição por Fumaça de Tabaco/efeitos adversos , Poluição do Ar em Ambientes Fechados/efeitos adversos , Poluição do Ar em Ambientes Fechados/prevenção & controle , Cotinina/análise , Cotinina/toxicidade , Avaliação de Medicamentos , Política de Saúde , Humanos , Nicotina/análise , Nicotina/toxicidade , Nitrosaminas/análise , Nitrosaminas/toxicidade , Poluição por Fumaça de Tabaco/prevenção & controleRESUMO
BACKGROUND: Smoking bans in bars and restaurants have been shown to improve worker health and reduce hospital admissions for acute myocardial infarction. Several studies have also reported improved indoor air quality, although these studies generally used single visits before and after a ban for a convenience sample of venues. PURPOSE: The primary objective of this study was to provide detailed time-of-day and day-of-week secondhand smoke-exposure data for representative bars and restaurants in Minnesota. METHODS: This study improved on previous approaches by using a statistically representative sample of three venue types (drinking places, limited-service restaurants, and full-service restaurants), conducting repeat visits to the same venue prior to the ban, and matching the day of week and time of day for the before- and after-ban monitoring. The repeat visits included laser photometer fine particulate (PM2.5) concentration measurements, lit cigarette counts, and customer counts for 19 drinking places, eight limited-service restaurants, and 35 full-service restaurants in the Minneapolis/St. Paul metropolitan area. The more rigorous design of this study provides improved confidence in the findings and reduces the likelihood of systematic bias. RESULTS: The median reduction in PM2.5 was greater than 95% for all three venue types. Examination of data from repeated visits shows that making only one pre-ban visit to each venue would greatly increase the range of computed percentage reductions and lower the statistical power of pre-post tests. Variations in PM2.5 concentrations were found based on time of day and day of week when monitoring occurred. CONCLUSIONS: These comprehensive measurements confirm that smoking bans provide significant reductions in SHS constituents, protecting customers and workers from PM2.5 in bars and restaurants.
Assuntos
Poluição do Ar em Ambientes Fechados/análise , Material Particulado/análise , Restaurantes/legislação & jurisprudência , Fumar/legislação & jurisprudência , Poluição por Fumaça de Tabaco/legislação & jurisprudência , Poluição do Ar em Ambientes Fechados/legislação & jurisprudência , Poluição do Ar em Ambientes Fechados/prevenção & controle , Humanos , Minnesota , Restaurantes/classificação , Restaurantes/estatística & dados numéricos , Estudos de Amostragem , Prevenção do Hábito de Fumar , Poluição por Fumaça de Tabaco/prevenção & controleRESUMO
This study shows that residual nicotine from tobacco smoke sorbed to indoor surfaces reacts with ambient nitrous acid (HONO) to form carcinogenic tobacco-specific nitrosamines (TSNAs). Substantial levels of TSNAs were measured on surfaces inside a smoker's vehicle. Laboratory experiments using cellulose as a model indoor material yielded a > 10-fold increase of surface-bound TSNAs when sorbed secondhand smoke was exposed to 60 ppbv HONO for 3 hours. In both cases we identified 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal, a TSNA absent in freshly emitted tobacco smoke, as the major product. The potent carcinogens 4-(methylnitrosamino)-1-(3-pyridinyl)-1-butanone and N-nitroso nornicotine were also detected. Time-course measurements revealed fast TSNA formation, with up to 0.4% conversion of nicotine. Given the rapid sorption and persistence of high levels of nicotine on indoor surfaces-including clothing and human skin-this recently identified process represents an unappreciated health hazard through dermal exposure, dust inhalation, and ingestion. These findings raise concerns about exposures to the tobacco smoke residue that has been recently dubbed "thirdhand smoke." Our work highlights the importance of reactions at indoor interfaces, particularly those involving amines and NO(x)/HONO cycling, with potential health impacts.
Assuntos
Carcinógenos/química , Nicotina/química , Ácido Nitroso/química , Poluição por Fumaça de Tabaco , Adsorção , Celulose/química , Química/métodos , Cromatografia Gasosa/métodos , Gases , Humanos , Cinética , Óxidos de Nitrogênio/química , Propriedades de Superfície , Espectrometria de Massas em Tandem/métodos , NicotianaRESUMO
Tobacco-specific nitrosamines (TSNAs) are some of the most potent carcinogens in tobacco and cigarette smoke. Accurate quantification of these chemicals is needed to help assess public health risks. We developed and validated a specific and sensitive method to measure four TSNAs adsorbed to model surfaces and secondhand smoke (SHS) particles using gas chromatography-ion-trap tandem mass spectrometry. In an 18-m(3) room-sized chamber, a smoking machine generated realistic concentrations of SHS that were actively sampled on Teflon-coated fiber glass (TCFG) filters, and passively sampled on cellulose substrates. A simple solid-liquid extraction protocol using methanol as solvent was successfully applied to both substrates with recoveries ranging from 85 to 115%. For each TSNA, tandem MS parameters were optimized and the major fragmentation pathways were elucidated. The method showed excellent performance, with a linear dynamic range from 2 to 1000ngmL(-1), low detection limits (S/N>3) of 30-300pgmL(-1) and precision with experimental errors below 10% for all compounds. Moreover, no interfering peaks were observed, indicating a high selectivity of MS/MS without the need for a sample clean-up step. This method provides a suitable analytical tool to detect and quantify traces of TSNA in indoor environments polluted with SHS.