Composition Of Smoke Research Articles

Effect of type and mode of zeolite application on the cigarette filters efficiency and sorption capacity

Filtration is one way of purification of tobacco smoke. The aim of this study was to examine the potential filtration effects of zeolites Y and ZSM-5, with different degree of crystallinity and in two modes of application (as a segment or as a powder added longitudinally with the filter fibers). Zeolites were added in the quantity of 60 mg. Degree of filter efficiency and sorption capacity has been determined in regard to several hazardous constituents of mainstream tobacco smoke such as: tar, carbon monoxide and nicotine. Composition of mainstream tobacco smoke was determined by using standard ISO methods. Experimental results showed that both, the type and the mode of the zeolite application affected the efficiency of smoke filtration. Zeolite Y, which was longitudinally applied to the filter, is shown to be the most effective. It was found 58.82% reduction of nicotine, 66.86% of tar and 86.24% of CO. During segmental application of zeolites, the blocking effect was observed.

Gynecological Endoscopic Society of Malaysia Statement and Recommendations on Gynecological Laparoscopic Surgery during COVID-19 Pandemic.

Objectives:While the issue of aerosolization of virus from the blood occurs during usage of energy sources scare practitioners, there have been no reported instances of healthcare workers (HCWs) being infected. COVID-19 virus is primarily transmitted via respiratory droplets and contact routes. Therefore, the ultimate decision for surgery, should be based on which is the safest, quickest route and concurrently ensuring that HCWs are protected during these surgeries. During the time of crisis, HCWs need to concentrate and channel resources to the care of those affected by the coronavirus hence judicious allocation of resources is mandatory. We present the guidelines and recommendations on gynecological laparoscopic surgery during this COVID-19 outbreak in Malaysia.Materials and Methods:Thorough search of articles and recommendations were done to look into the characteristics of the virus in terms of transmission and risks during surgery. Smoke plume characteristics, composition and risk of viral transmission were also studied. Search includes The WHO Library, Cochrane Library and electronic databases (PubMed, Google scholar and Science Direct).Conclusion:We concluded that there is no scientific basis of shunning laparoscopic approach in surgical intervention. Ultimately, the guiding principles would be of reducing the anesthetic and surgical duration, the availability of full protective gear for HCWs during the surgery and the status of the patient. It is mandatory for viral swab tests to be done within the shortest window period possible, for all cases planned for surgery.

Effect of benzo(a)pyrene on the expression of AhR-regulated microRNA in female and male rat lungs

Smoking is the main risk factor for lung cancer, mainly due to presence of nitrosamines and polycyclic aromatic hydrocarbons, including benzo[a]pyrene (BP) in tobacco smoke composition. The genotoxic effect of BP is based on the high DNA-binding ability of its metabolites, while the epigenetic effects are mediated by a change in the expression of cancer related genes or regulatory RNAs. It has been shown that women have a higher risk to develop lung cancer upon smoking rather than men. We hypothesized that crosstalk between signaling pathways activated by BP and estrogens could underlie the sex-dependent differences in miRNAs expression. To test this hypothesis, male and female rats were subjected to short-term or long-term BP exposure. Using in silico analysis, miRNAs containing the ER- and AhR-binding sites in the promoters of the genes (or host genes) were selected. During chronic exposure of BP the expression of miR-22-3p, -29a-3p, -126a-3p, -193b-5p in the lungs of male rats were significantly increased, while the level of miRNA-483-3p were decreased. Expression of miRNA-483-3p was up-regulated during chronic BP exposure in the lungs of female rats and the levels of other studied miRNAs were unchanged. In turn, changes in the expression of miRNAs were followed by changes in the expression of their target genes, including PTEN, EMP2, IGF1, ITGA6, SLC34A2, and the observed changes in female and male rat lungs were varied. Thus, our results suggest that sex-dependent epigenetic effects of BP may be based on different expression of AhR- and ER- regulated miRNAs.

Możliwości realizacji programu redukcji szkód u osób palących tytoń. Stan aktualny i rekomendacje

On September 30, 2019, the editorial debate of the quarterly “Neuropsychiatry. Clinical Review” took place in Warsaw, dedicated to the possibilities of implementing the harm reduction programs in nicotine addiction. The scientific organizer was the Polish Neuropsychiatric Association. The publication is the result of this meeting. The debate was to establish the status praesens, to review research analyses and understand controversies, as well as to outline the perspectives of practical implementation of harm reduction programs. In addition, the possibilities of legal changes and new medical standards were indicated. Smoking is the most important, modifiable, cause of many diseases and premature mortality. Tobacco smokers become addicted not only to nicotine, but also to other substances included in cigarette smoke. Addiction is also influenced by cultural and social factors. A number of new tobacco products that do not work by smoking have a 90–95% reduction of toxic ingredients comparing to the composition of cigarette smoke. While lowering level of carcinogens is obviously beneficial, the long-term effects of these new products have not yet been established. The low effectiveness of the available methods of pharmacotherapy for nicotine addiction creates premises for the implementation of harm reduction programs using new products with modified risk. Such concepts are supported by state regulators in developed countries, creating special registration paths, taking into account the fact that the toxicity of new products is reduced. Precedent registrations of the products with reduced risk of harm (FDA, USA) create conditions to replace pragmatically smoking tobacco products – with other, less harmful ones.

Haze emissions from smouldering peat: The roles of inorganic content and bulk density

Smouldering peat fires are reported across continents and their emissions result in regional haze crisis (large scale accumulation of smoke at low altitudes) and large carbon foot prints. Inorganic content (IC) and bulk density vary naturally in peatlands and are among the important parameters governing peat fires. However, their roles in fire emissions remain unknown. In this work, bench-scale burning of sphagnum peat conditioned to different values of IC and bulk densities were conducted in the laboratory environment. Mass loss rate, spread rate and transient emissions of 20 gas species and particles (PM10, PM2.5 and PM1) were simultaneously investigated. We found that peat with 50% moisture content can self-sustain smouldering propagation if IC is less than 40%, or its bulk density is lower than 287.5 kg m−3. Increasing IC or bulk density decreases peat mass loss rate and spread rate. High IC peat releases lower gas fluxes (especially for CH4 and NH3) throughout the experiment. In the ignition stage, increasing IC leads to an increase in particles with diameter between 1 and 2.5 μm; in the fire spread stage, IC has no influence on the particle fluxes. In contrast, increasing bulk density delays both gas and particle emission fluxes without altering the smoke composition significantly. The fundamental understanding of how soil properties affect peat wildfires facilitates the development of mitigation technologies against haze.

Accessing the Life in Smoke: A New Application of Unmanned Aircraft Systems (UAS) to Sample Wildland Fire Bioaerosol Emissions and Their Environment

Wildland fire is a major producer of aerosols from combustion of vegetation and soils, but little is known about the abundance and composition of smoke’s biological content. Bioaerosols, or aerosols derived from biological sources, may be a significant component of the aerosol load vectored in wildland fire smoke. If bioaerosols are injected into the upper troposphere via high-intensity wildland fires and transported across continents, there may be consequences for the ecosystems they reach. Such transport would also alter the concept of a wildfire’s perimeter and the disturbance domain of its impact. Recent research has revealed that viable microorganisms are directly aerosolized during biomass combustion, but sampling systems and methodology for quantifying this phenomenon are poorly developed. Using a series of prescribed fires in frequently burned forest ecosystems, we report the results of employing a small rotary-wing unmanned aircraft system (UAS) to concurrently sample aerosolized bacteria and fungi, particulate matter, and micrometeorology in smoke plumes versus background conditions. Airborne impaction-based bioaerosol sampling indicated that microbial composition differed between background air and smoke, with seven unique organisms in smoke vs. three in background air. The air temperature was negatively correlated with the number of fungal colony-forming units detected. Our results demonstrate the utility of a UAS-based sampling platform for active sampling of viable aerosolized microbes in smoke arising from wildland fires. This methodology can be extended to sample viable microbes in a wide variety of emissions sampling pursuits, especially those in hazardous and inaccessible environments.

Air Quality Impacts of Smoke from Hazard Reduction Burns and Domestic Wood Heating in Western Sydney

Air quality was measured in Auburn, a western suburb of Sydney, Australia, for approximately eighteen months during 2016 and 2017. A long open-path infrared spectrometer sampled path-averaged concentrations of several gaseous species, while other pollutants such as PM 2.5 and PM 10 were sampled by a mobile air quality station. The measurement site was impacted by a number of indoor wood-heating smoke events during cold winter nights as well as some major smoke events from hazard reduction burning in the spring of 2017. In this paper we compare the atmospheric composition during these different smoke pollution events and assess the relative overall impact on air quality from domestic wood-heaters and prescribed forest fires during the campaign. No significant differences in the composition of smoke from these two sources were identified in this study. Despite the hazard reduction burning events causing worse peak pollution levels, we find that the overall exposure to air toxins was greater from domestic wood-heaters due to their higher frequency and total duration. Our results suggest that policy-makers should place a greater focus on reducing wood-smoke pollution in Sydney and on communicating the issue to the public.

Caracterization of Liquid Smoke Bamboo Waste with Pyrolysis Method

This research was aimed to produce and to analyze the quality and chemical composition of liquid smoke from bamboo waste by pyrolisis process. Temperatur of pyrolisis reactor were 140 oC, 180 oC, 220 oC, 260 oC and 300 oC for 5 hours to produce liquid smoke. Liquid smoke purified by filtration, distillation and adsorption. Resulted liquid smoke were analyzed yield, acidity, and density. Identifying the chemical composition of liquid smoke was by Gas Chromatography and Mass Spectrometry (GC-MS). Yield of liquid smoke 1,6977% up to 3,9713 %; Acidity of liquid smoke were 1.49 up to 1,9; the density of liquid smoke 1,004 up to 1,045. The results of GC-MS test showed that chemical composition of the liquid smoke have Phenolic compounds 0,5 – 0,6ppm and liquid smoke found not containing of carsinogenic Benz (a) Pyrene.

Analysis of chemical constituents in mainstream bidi smoke

Bidi, an indigenous form of cigarette in South Asian countries, is popular because of its low cost and multi-flavored variants. Although recent studies have shown that bidi smokers suffer from various adverse health effects including cancer, research on bidi smoke composition and exposure levels is still very limited. In this research, the vapor and particulate phases of bidi were characterized using gas chromatography coupled with mass spectrometry (GC–MS) and Fourier-transform infrared spectrometry (FTIR). The amounts of nicotine, cotinine, indole, substituted phenols, substituted pyridines, and phytol found in different size fractions of the particulate matter collected using a cascade impactor were reported. Due to the low combustibility of the tendu leaf in bidi, a six-second puff interval was used to sample the smoke constituents for analysis. Significant levels of carbon monoxide, hydrogen cyanide, and hydrocarbons like ethylene, methane and 1, 3-butadiene were detected in the mainstream bidi smoke. In addition, 3-methylpyridine, cotinine, α-amyrin, and β-amyrin were also present at high levels in bidi smoke. Despite having less tobacco compared to conventional cigarette, bidi smokers are potentially exposed to significantly higher concentrations of nicotine due to the greater puffing frequency. The non-porous nature and higher moisture content of tendu leaf in bidis compared to cigarette wrapping paper led to higher levels of carbon monoxide and tar in bidi smoke compared to regular cigarette smoke. Results of this study indicate the presence of harmful and carcinogenic chemicals in the mainstream bidi smoke that could be harmful to human health.

Comparison of Mainstream Smoke Composition from CR20 Resin Filter and Empty-Cavity Filter Cigarettes by Headspace SPME Coupled with GC×GC TOFMS and Chemometric Analysis

Summary A previously established method based on headspace solidphase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography (GC×GC) coupled to time-of-flight mass spectrometry (TOFMS) has been used to evaluate and compare the profiles of semi-volatile compounds present in mainstream tobacco smoke particulate matter trapped on glass fibre filters for two types of cigarettes differing only in filter design. In the first cigarette, the filter cavity contained approximately 60 mg of a weakly basic macroporous polystyrene resin cross-linked with divinyl benzene and with surface amine functionality (CR20), whereas in the second cigarette, it was empty. Relative quantitative analysis, chemical identification, and chemical grouping allowed the use of both parametric and non-parametric analyses to identify differences in the chemical composition of the smokes from these cigarettes. The analysis demonstrated that in addition to the selective partial removal of volatile carbonyls and HCN demonstrated previously, CR20 selectively, but incompletely removed 316 compounds from the particulate phase of cigarette smoke, mainly aryl and aromatic hydrocarbons as well as other more volatile species. In contrast, the relative proportion of amines, hydroxylated aromatic compounds and less volatile species was increased in the smoke from the cigarette containing CR20 in the filter. Our findings show that high resolution GC techniques combined with mass spectrometry and chemometric approaches are powerful tools for deconvoluting the complexity of combustion aerosols, as well as helping to identify changes in chemical composition resulting from modifications to cigarette designs. [Beitr. Tabakforsch. Int. 28 (2019) 231–249]

Study of the mainstream cigarette smoke aerosols by Fourier transform ion cyclotron resonance mass spectrometry coupled to laser/desorption and electrospray ionization - Additional insights on the heteroaromatic components.

The chemical composition of the particulate phase of cigarette smoke inhaled by the active smoker is still poorly known in spite of its importance from a health point of view. A non-targeted approach is applied to cigarette smoke particles collected on a quartz filter to obtain an as complete as possible description of this complex mixture. A home-made smoking machine including devices for volatile organic compounds (VOCs) and particle sampling was used. The validation of the cigarette smoking and cigarette smoke collection procedures was conducted by the quantification of some compounds by gas chromatography/mass spectrometry (GC/MS). The particles were investigated by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) directly after their collection on quartz filters by laser/desorption ionization (LDI) or after extraction with CH2 Cl2 by electrospray ionization (ESI). The determination of the benzene, toluene, ethylbenzene and xylenes (from 2 to 35 μg/cigarette) and nicotine (0.68 ± 0.05 mg/cigarette) validated the used sampling method. The complementarity of the LDI and ESI sources for the cigarette smoke analysis was established. The ESI analyses evidenced polar compounds and components with a pyridine group and LDI ensured the detection of poly-condensed heteroaromatic species. Finally, this methodology was employed to characterize particles from cigarettes with or without flavoring additives. Some insights into the composition of cigarette smoke inhaled by active smokers have been obtained. The ~1750 observed features revealed the huge complexity of cigarette smoke particles and the diversity of the possible associated health issues. Both heteroaromatic and highly oxygenated compounds produced by combustion and pyrolysis have been highlighted.

Importance of Experimental Tests for the Determination of Modeling Parameters in Fire Safety Engineering

In the field of Fire Safety Engineering, the application of mathematical models is crucial in order to properly estimate the severity of eventual fires occurring inside workplaces. Such models (like CFast, Ozone, FDS, CFX, Fluent), require a notable amount of specific parameters in order to work. Such parameters are usually available in the current literature, or they can be estimated via experimental tests. In this work, several experimental setups have been performed in order to evaluate such data in the burning of a wide range of materials: cotton, polyethylene and polyester in industrial rollers, flour, sugar, feed for dairy cows, and wood pallets. Cone Calorimeter, Mahler bomb, and real-scale tests have been performed in order to evaluate parameters such as Calorific Values, Total Heat Released, Heat Released Rate and smoke composition analysis. The real-scale tests have been performed with the aim of addressing fire occurring in warehouses, focusing then on an industrial environment. All the values have been compared with theoretical estimations made with the ClaRaf 2.0 software, and it was noticed that they tend to give overestimated values in comparison with empirical results.

Simultaneous determination of tobacco minor alkaloids and tobacco-specific nitrosamines in mainstream smoke by dispersive solid-phase extraction coupled with ultra-performance liquid chromatography/tandem orbitrap mass spectrometry.

The minor alkaloids in tobacco play an important role in the chemical composition of cigarette smoke, and they are precursors of tobacco-specific nitrosamines (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), N-nitrosoanabasine (NAB) and N-nitrosoanatabine (NAT)). NNN and NNK are classified as group 1 carcinogens. A method quantitating both tobacco minor alkaloids and tobacco-specific nitrosamines in mainstream smoke has not been reported. Tobacco minor alkaloids and tobacco-specific nitrosamines in cigarette mainstream smoke were extracted by sonication. The extract was cleaned up by dispersive solid-phase extraction, and separation was achieved via ultra-performance liquid chromatography/tandem orbitrap mass spectrometry. The method was validated by analysis of six replicate samples spiked with three levels of the analyses. The mean recoveries for the six replicates were from 84.7% to 118% with less than 15% relative standard deviation except myosmine at the low spiked level and the calculated detection limits were 0.066 to 13.2ng/cig, respectively. The mean concentrations of nicotyrine, anabasine, nornicotine, anatabine, myosmine, 2,3-bipyridine, cotinine, nicotelline, N-formylnornicotine, NNK, NNN, NAB and NAT in 30 different brands of commercial cigarette smoke under the ISO smoking regimen were 2.50μg/cig, 2.34μg/cig, 3.21μg/cig, 5.78μg/cig, 2.83μg/cig, 1.05μg/cig, 1.55μg/cig, 0.55μg/cig, 2.48μg/cig, 6.06ng/cig, 3.62ng/cig, 0.40ng/cig and 6.15ng/cig, respectively. The proposed method was suitable for analysis of tobacco minor alkaloids and tobacco-specific nitrosamines in cigarette mainstream smoke.

Production of Phenol From Liquid Smoke Resulted by the Pyrolysis of Cashew Nut Shells

Cashew nut shell is a waste from cashew nut industry. It contains liquid known as Cashew Nut Shell Liquid (CNSL) which has similar molecule structure with synthetic phenol Phenol is a material for phenolic resin in preparation of varnish. The aims of this research are to determine the optimum temperature of pyrolysis for producing phenol liquid smoke and knowing the chemical composition of liquid smoke. This research used pyrolysis method at various pyrolysis temperatures were 200, 300, 400 and 500°C, respectively. The gas from the pyrolysis process was then condensed by the condenser until liquid was obtained. The liquid was deposited for 1 week in a separating funnel and then separated to obtain liquid smoke and residue. The volatile compounds of liquid smoke from a cashew nut shell were analyzed using gas chromatography and mass spectrometry (GC-MS). The results showed that the optimum pyrolysis temperature was at 400°C with a yield of 53.4% liquid smoke and the chemical composition of liquid smoke percentage: phenol (36,6%), carbonyl (7,1%), acid (18.8%) respectively. Phenol from liquid smoke resulted by the pyrolysis of cashew nut shells is an alternative material potential for substituting or replacing synthetic phenol from petroleum derivates.

Simple Determination of Gaseous and Particulate Compounds Generated from Heated Tobacco Products.

As a new form of cigarettes, heated tobacco products (HTPs) have been rapidly distributed worldwide. In this study, an improved method for analyzing gaseous and particulate compounds generated from HTPs is described. Smoke is collected using a GF-CX572 sorbent cartridge with 300 mg of carbon molecular sieves, that is, Carboxen 572 (CX572), and a 9 mm glass-fiber filter (GF). After collection, the CX572 particles from the cartridge are transferred along with the GF and deposited into a vial containing two phases of carbon disulfide and methanol. The CX572 particles settle into the lower carbon disulfide phase, while nonpolar compounds are desorbed. After the sample is allowed to stand, the solution is slowly stirred. The two-phase mixture of carbon disulfide and methanol is combined into a homogeneous solution. Polar compounds are then desorbed, while the desorbed nonpolar compounds remain in solution. For the analysis of carbonyl compounds, an enriched 2,4-dinitrophenylhydrazine solution is added to a portion of the combined solution for derivatization and subsequent high-performance liquid chromatography analysis. For the analysis of volatile organic compounds and water, a portion of the combined solution is analyzed by gas chromatography-mass spectrometry or equipped with a thermal conductivity detector. By applying the proposed GF-CX572 one-cartridge method to the analysis of the mainstream smoke generated from HTPs and traditional cigarettes, several chemical compounds are detected, and the chemical composition of smoke is revealed. The GF-CX572 one-cartridge method can analyze gaseous and particulate chemical compounds from the HTP smoke by utilizing not only the entire puff volume but also one puff volume because the GF-CX-572 cartridge can be replaced with a new cartridge within 3 s. An overview of the chemicals generated from HTPs is obtained in detail by one-puff volume sampling. In addition, the generated chemical compounds strongly depend on the temperature of tobacco leaves in HTPs.

Constraints on Meteoric Smoke Composition and Meteoric Influx Using SOFIE Observations With Models

AbstractThe composition of meteoric smoke particles in the mesosphere is constrained using measurements from the Solar Occultation For Ice Experiment (SOFIE) in conjunction with models. Comparing the multiwavelength observations with models suggests smoke compositions of magnetite, wüstite, magnesiowüstite, or iron‐rich olivine. Smoke compositions of pure pyroxene, hematite, iron‐poor olivine, magnesium silicate, and silica are excluded, although this may be because these materials have weak signatures at the SOFIE wavelengths. Information concerning smoke composition allows the SOFIE extinction measurements to be converted to smoke volume density. Comparing the observed volume density with model results for varying meteoric influx (MI) provides constraints on the ablated fraction of incoming meteoric material. The results indicate a global ablated MI of 3.3 ± 1.9 t d−1, which represents only iron, magnesium, and possibly silica, given the smoke compositions indicated here. Considering the optics and iron content of individual smoke compositions gives an ablated Fe influx of 1.8 ± 0.9 t d−1. Finally, the global total meteoric influx (ablated plus surviving) is estimated to be 30 ± 18 t d−1, when considering the present results and a recent description of the speciation of meteoric material.

Hazardous aerosol emissions during agriculture biomass burning season in Son La and Ba Vi regions, Vietnam

Major national emission sources are assessed by characterization of smoke pollution arising due to traditional agriculture, domestic, and cooking activities in the regions of the biggest biomass burning. Measurement campaigns were carried in Son La and Ba Vi regions, Vietnam, during the dry seasons of 2013 and 2015-2016. PM and BC monitoring, aerosol sampling, chemical speciation were conducted to evaluate ambient smoke level, to relate the characteristics of local on-field emissions to regional aerosols, and to identify the dangerous components of smoke composition. The regions Son La and Ba Vi in February-June faced severe levels of air pollution, with critical PM2.5 and PM10 concentrations up to 130 and 167 µg/m3, respectively, significantly exceeding the air quality standards. A wide range of PM mass concentrations was categorized according to the smoke level, supported by the evolution of carbon (OC, EC) fractions as well as ionic species and molecular markers. The level of PM and BC concentrations was seen to be dependent on factors such as weather conditions and precipitation. Non-acid carbonyls, carboxylates, and aliphatic carbon compounds were evolved with increasing smoke intensity, together with carbonates in coarse size fractions, indicating a large impact of smoke emissions and soil lifted up by the intense fires. On-field emissions in both smoldering and flaming phases were assessed in near-source measurements.

Effect of Adding 5-Aminotetrazole to a Modified U.S. Army Terephthalic Acid White Smoke Composition

Military visible obscuration compositions (obscurants, smokes) play an important role on today's battlefield. For many years, the known toxicity or ageing problems of established formulations were commonly accepted since there was a lack of alternatives. Since the U.S. Army stopped producing the AN-M8 hexachloroethane (HC) smoke grenade, the M83 terephthalic acid (TA) smoke grenade has been used in its place. This cool-burning, less toxic, but also low efficiency white smoke formulation cannot compete with HC-based formulations in terms of obscuration performance. In this context, we have explored the use of 5-aminotetrazole (5-AT) as an additive and fuel in the known TA system. Remarkably, it has been found that sugar is not necessarily required in the formulations, which has implications for the future improvement of sublimation-condensation smoke compositions, including coloured smoke compositions. In small-scale tests, it was found that replacing sucrose with 5-AT in the formulations resulted in significantly improved smoke persistence.

Initiation, Progression, and Sustained Waterpipe Use: A Nationally Representative Longitudinal Study of U.S. Young Adults.

Background: Waterpipe tobacco smoking (WTS) is increasing in popularity despite evidence of harm and potential for dependence. Intervention development has been hampered by a lack of longitudinal, nationally representative data on usage patterns and factors independently associated with WTS initiation. Therefore, we aimed to characterize key transitions between WTS states in a nationally representative group of young adults, with particular attention to factors independently associated with initiation.Methods: Participants were randomly selected from a national probability-based panel representing 97% of the United States. A total of 1,785 adults ages 18 to 30 at baseline completed two Web-based surveys 18 months apart in 2013 and 2014. Assessments included knowledge of waterpipe tobacco smoke composition, positive and negative attitudes toward WTS, normative beliefs, intention to use waterpipe, and WTS behavior. We used multivariable logistic regression to assess the association between predictive factors and subsequent WTS initiation.Results: In fully adjusted models, overall knowledge about toxicants associated with WTS was not associated with subsequent WTS initiation. Similarly, negative attitudes and normative beliefs were not associated with WTS uptake. However, baseline positive attitudes were strongly and significantly associated with WTS initiation [adjusted OR (AOR) = 1.7; 95% confidence interval (CI), 1.2-2.3]. Similarly, baseline intention to use WTS was strongly associated with subsequent initiation (AOR = 7.0; 95% CI, 3.5-13.7).Conclusions: Prevention efforts may be most successful if they target individuals with clear intentions to use WTS and challenge positive attitudes surrounding WTS.Impact: Surveillance of WTS trajectories will help inform health care and policy surrounding this emerging risk behavior among U.S. young adults. Cancer Epidemiol Biomarkers Prev; 26(5); 748-55. ©2017 AACR.

Pressure and Gas Flow Distribution Inside the Filter of a Non-Filter Ventilated Lit Cigarette During Puffing

Summary Establishing a realistic gas flow velocity distribution inside a cigarette filter during smoking is important to understand filtration mechanisms of different mainstream smoke species and the overall effect of filter designs on mainstream smoke composition. In this paper, an experimental method is described which directly measures the gas pressure field inside a cellulose acetate filter during cigarette smoking. This was demonstrated by using 3R4F research reference cigarettes smoked under a 35 mL puff of 6 s duration. In addition, filter temperature measurements were also carried out at multiple locations within the filter. Both the temperature and pressure sensing locations were selected to match the radial and longitudinal directions of the cigarette filter. The temperature and pressure measurements were then used to calculate the velocity according to Darcy’s Law along the mainstream flow direction in the cigarette filter at each puff. The spatially resolved maps of temperature, pressure and flow velocity on a puff-by-puff basis provide useful insights into the dynamic filtration of smoke aerosol under the influence of the approaching burning coal and progressive accumulation of smoke particulate matter.