Identification of Cytotoxic Flavor Chemicals in Top-Selling Electronic Cigarette Refill Fluids.

We identified the most popular electronic cigarette (EC) refill fluids using an Internet survey and local and online sales information, quantified their flavor chemicals, and evaluated cytotoxicities of the fluids and flavor chemicals. "Berries/Fruits/Citrus" was the most popular EC refill fluid flavor category. Twenty popular EC refill fluids were purchased from local shops, and the ingredient flavor chemicals were identified and quantified by gas chromatography-mass spectrometry. Total flavor chemical concentrations ranged from 0.6 to 27.9 mg/ml, and in 95% of the fluids, total flavor concentration was greater than nicotine concentration. The 20 most popular refill fluids contained 99 quantifiable flavor chemicals; each refill fluid contained 22 to 47 flavor chemicals, most being esters. Some chemicals were found frequently, and several were present in most products. At a 1% concentration, 80% of the refill fluids were cytotoxic in the MTT assay. Six pure standards of the flavor chemicals found at the highest concentrations in the two most cytotoxic refill fluids were effective in the MTT assay, and ethyl maltol, which was in over 50% of the products, was the most cytotoxic. These data show that the cytotoxicity of some popular refill fluids can be attributed to their high concentrations of flavor chemicals

Measurement of Enantiomer Percentages for Five Monoterpenes from six conifer species by cartridge-tube-based passive sampling adsorption–Thermal Desorption (ps-ATD)

Many monoterpenes have at least two different stereochemical forms, and many biosynthetic pathways are known to favor one product over the other(s). A rapid method was developed and used in the determination of the (-/+ role= presentation style= box-sizing: border-box; border-radius: 0px; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3e)-enantiomeric distributions for α-pinene, β-pinene, camphene, limonene, and β-phellandrene as emitted by plant material from six conifer species. The six species included the two pine species Pseudotsuga menziesii and Pinus ponderosa, as well as the four cypress species Chamaecyparis lawsoniana, Thuja plilcata, Juniperus chinensis, and Thuja occidentalis. The method involved passive sampling adsorption–thermal desorption (ps-ATD). During sampling, the cartridge tube was placed in a 60 mL glass vial with plant material for 1 h. Sample analytes were thermally transferred to a chiral gas chromatography (GC) column. Detection was by mass spectrometry (MS). The six species exhibited different emission patterns for the five monoterpenes in the -/+ role= presentation style= box-sizing: border-box; border-radius: 0px; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3e totals, although within a given species the distributions among the five monoterpenes were similar across multiple plants. β-pinene dominated in P. menziesii and P. ponderosa, and α-pinene dominated in T. plicata and T. occidentalis. The chiral separations revealed differences in the -/+ role= presentation style= box-sizing: border-box; border-radius: 0px; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3e enantiomeric distributions among the species. The (−)-enantiomers of α-pinene and β-pinene dominated strongly in P. menziesii and P. ponderosa; the (−)-enantiomer of β-phellandrene dominated in C. lawsoniana. The dependence of the method precision on percent enantiomer abundance is discussed

Transportation System Impacts on Bicyclists\u27 Air Pollution Risks: Considerations for System Design and Use

Health risks associated with air pollution uptake while bicycling are often cited as a potential drawback to increased bicycling in cities. This seminar will provide an overview of how roadway and travel characteristics impact bicyclists\u27 uptake of traffic-related air pollution. Specific considerations for planners and designers of urban transportation systems to mitigate risks for travelers will be discussed. In addition, the extent to which bicyclists themselves can unilaterally reduce their pollution uptake will be described. This seminar synthesizes findings from a recently completed doctoral dissertation at Portland State University and from the broader literature.https://pdxscholar.library.pdx.edu/trec_seminar/1017/thumbnail.jp

Eugenol, Menthol and other Flavour Chemicals in Kreteks and ‘white’ cigarettes purchased in Indonesia

Background Flavoured tobacco products are not restricted in Indonesia, a country with about 68 million adults who smoke. Most use clove-mixed tobacco cigarettes (‘kreteks’); non-clove (‘white’) cigarettes are also available. Although the use of flavour chemicals has been identified by WHO as promoting tobacco use, little has been reported for Indonesia about the levels of flavourants in either kreteks or ‘white cigarettes’. Methods 22 kretek brand variants and nine ‘white’ cigarette brand variants were purchased in Indonesia during 2021/2022; one of the kretek packs contained three colour-coded variants, giving a total sample number of 24 for the kreteks. Chemical analyses gave the mg/stick (=mg/(filter+rod)) values for 180 individual flavour chemicals that included eugenol (a clove-flavoured compound), four other clove-related compounds and menthol. Results Eugenol was present at significant levels in all 24 kreteks (2.8–33.8 mg/stick), but was essentially absent in all of the cigarettes. Menthol was present in 14 of 24 kreteks, with levels ranging from 2.8 to 12.9 mg/stick, and in five of the nine cigarettes, with levels ranging from 3.6 to 10.8 mg/stick. Other flavour chemicals were also found in many of the kretek and cigarette samples. Conclusions In this small sample, we found numerous variations of flavoured tobacco products offered by multinational and national companies in Indonesia. Given the body of evidence that flavours make tobacco products more appealing, regulation of clove-related compounds, menthol and other flavour chemicals should be considered in Indonesia

Ethyl Maltol, Vanillin, Corylone and other Conventional Confectionery-related Flavour Chemicals Dominate in Some E-cigarette Liquids Labelled ‘tobacco’ flavoured

Background The increased popularity of electronic cigarettes (e-cigarettes) has been linked to the abundance of flavoured products that are attractive to adolescents and young adults. In the last decade, e-cigarette designs have evolved through four generations that include modifications in battery power, e-cigarette liquid (e-liquid) reservoirs and atomiser units. E-liquids have likewise evolved in terms of solvent use/ratios, concentration and number of flavour chemicals, use of nicotine salts and acids, the recent increased use of synthetic cooling agents and the introduction of synthetic nicotine. Our current objective was to evaluate and compare the evolving composition of tobacco-flavoured e-liquids over the last 10 years. Methods Our extensive database of flavour chemicals in e-liquids was used to identify trends and changes in flavour chemical composition and concentrations. Results Tobacco-flavoured products purchased in 2010 and 2011 generally had very few flavour chemicals, and their concentrations were generally very low. In tobacco-flavoured refill fluids purchased in 2019 and Puff Bar Tobacco e-cigarettes, the total number and concentration of flavour chemicals were higher than expected. Products with total flavour chemicals \u3e10 mg/mL contained one to five dominant flavour chemicals (\u3e1 mg/mL). The most frequently used flavour chemicals in tobacco e-liquids were fruity and caramellic. Conclusions There is a need for continuous surveillance of e-liquids, which are evolving in often subtle and harmful ways. Chemical constituents of tobacco flavours should be monitored as they clearly can be doctored by manufacturers to have a taste that would appeal to young users

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. In a ventilated 18 m3 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