Effect of Puffing Behavior on Particle Size Distributions and Respiratory Depositions From Pod-Style Electronic Cigarette, or Vaping, Products.
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ABSTRACT:
SUBMITTER: Ranpara A
PROVIDER: S-EPMC8671759 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:IntroductionSince the introduction of e-cigarettes into the U.S. market, the number and variety of vaping products has proliferated. E-hookahs are long, pen-like vaping devices that debuted in U.S. markets in 2014. By applying the Host, Agent, Vector, Environment (HAVE) Model, the objective of this exploratory study was to assess differences between e-cigarettes and e-hookahs to help inform tobacco regulatory science and practice.MethodsIn June-August 2014, a total of 54 unique manufactured e-cigarette and e-hookah products were identified at point of sales (POS) around three college campuses in Southeast U.S. Documented characteristics included brand name, disposable, rechargeable, nicotine containing, packaging, and flavor type. Statistical analyses were conducted October to November 2014 to assess frequency and percent of product type across POS and specific characteristics.ResultsAmong 54 products, 70.4% were e-cigarettes and 29.6% were e-hookahs. Across POS, drug stores and grocery stores carried e-cigarettes exclusively, while gas stations carried the greatest proportion of e-hookahs. Compared to e-hookahs, a greater proportion of e-cigarettes were non-disposable and contained nicotine; a greater proportion of e-hookahs came in fruit and other types of flavors compared to e-cigarettes.ConclusionsThe present study suggests that e-cigarettes and e-hookahs differ by specific product characteristics and by places where they are sold. Despite these differences, the products are used for similar purposes warranting careful monitoring of industry manufacturing and marketing, because the safety of both products is still undetermined. Additional research is needed to understand the uptake and continued use of these products.
| S-EPMC4698898 | biostudies-literature
Project description:IntroductionElectronic cigarettes (EC) have evolved rapidly toward higher powered devices that produce more vaping aerosol and a more satisfying vaping experience. This research characterized the particle size distribution and estimated the mass concentration of vaping aerosols produced at power outputs spanning the operating range typical of second generation variable voltage EC devices.MethodsEC aerosol was characterized from a single coil atomizer powered by a variable voltage EC battery at the minimum and maximum dial settings (3.3, 11.2 Watts, W), and a lab controlled power supply (3-11.9 W). Aerosol particle size distribution was measured by a Scanning Mobility Particle Sizer and Aerodynamic Particle Sizer, spanning 16 nm to 19.8 ?m. A mouth puff was simulated using a 100 mL glass syringe.ResultsConsistent with prior studies, sub-micron EC aerosol size distributions were bimodal, with peaks at 40 and 200 nm, however a previously unreported third mode was observed at approximately 1000 nm. The ~1000 nm mode accounted for 7-20x the aerosol mass of the smaller modes. Increasing atomizer power decreased count concentration of particles <600 nm but increased particle count >600 nm. Particle mass distribution shifted toward micron sized particles with increasing power and increased the respirable fraction of aerosol, likely due to increased coagulation and condensation around nano-sized particles.ConclusionsVaping power greatly affects EC aerosol count and mass distribution. Mouth puffed EC aerosol spans a much wider particle size range than previously reported, although the major portion of the mass is still well within the alveolar size range the larger particles will deposit within the oro-pharyngeal cavity at 2-3x greater efficiency than in alveoli. These observations have major clinical implications, as aerosol particle size distribution determines deposition sites along the respiratory tract. The results of this experiment stress the need for further research to inform the design, regulation and use of e-cigarette products.
| S-EPMC6312322 | biostudies-literature
Project description:E-cigarette use is dramatically increasing, particularly with adolescents. While the chemical composition of e-liquids and e-vapor is well characterized, the particle size distribution and the human airways deposition patterns of e-cigarette particles are understudied and poorly understood despite their likely contribution to adverse health effects from e-cigarette usage. In this study, we examined the impacts of e-cigarette device power, e-liquid composition, and vaping topography on e-cigarette particle sizes and their deposition in human airways. In addition, we observed that particle measurement conditions (dilution ratio, temperature, and humidity) significantly affect measured e-cigarette particle sizes. E-cigarette power output significantly increased particle count median diameters (CMD) from 174 ± 13 (particles generated under 6.4 W) to 236 ± 14 nm (particles generated under 31.1 W). E-cigarette particles generated from propylene glycol-based e-liquids (CMD = 145 ± 8 nm and mass median diameter [MMD] = 3.06 ± 0.17 ?m) were smaller than those generated from vegetable glycerin-based e-liquids (CMD = 182 ± 9 nm and MMD = 3.37 ± 0.21 ?m). Puff volume also impacted vapor particle size: CMD and MMD were 154 ± 11 nm and 3.50 ± 0.27 ?m, 163 ± 6 nm and 3.35 ± 0.24 ?m, and 146 ± 12 nm and 2.95 ± 0.14 ?m, respectively, for 35, 90, and 170 mL puffs. Estimated e-cigarette particle mass deposition fractions in tracheobronchial and bronchoalveolar regions were 0.504-0.541 and 0.073-0.306, respectively. Interestingly, e-cigarette particles are smaller than the particles generated from cigarette smoking but have similar human airway deposition patterns.
| S-EPMC7301609 | biostudies-literature
Project description:Many Electronic Nicotine Delivery Systems (ENDS) employ integrated sensors to detect user puffing behavior and activate the heating coil to initiate aerosol generation. The minimum puff flow rate and duration at which the ENDS device begins to generate aerosol are important parameters in quantifying the viable operating envelope of the device and are essential to formulating a design of experiments for comprehensive emissions characterization. An accurate and unbiased method for quantifying the flow condition operating envelope of ENDS is needed to quantify product characteristics across research laboratories. This study reports an accurate, unbiased method for measuring the minimum and maximum aerosolization puff flow rate and duration of seven pod-style, four pen-style and two disposable ENDS. The minimum aerosolization flow rate ranged from 2.5 to 23 (mL/s) and the minimum aerosolization duration ranged from 0.5 to 1.0 (s) across the ENDS studied. The maximum aerosolization flow rate was defined to be when the onset of liquid aspiration was evident, at flow rates ranging from 50 to 88 (mL/s). Results are presented which provide preliminary estimates for the effective maximum aerosolization flow rate and duration envelope of each ENDS. The variation in operating envelope observed between ENDS products of differing design by various manufacturers has implications for development of standardized emissions testing protocols and data reporting required for regulatory approval of new products.
| S-EPMC8415835 | biostudies-literature
Project description:To investigate passive vaping due to sub-ohm electronic cigarettes (e-cigs), aerosol number size distribution measurements (6 nm-10 µm) were performed during volunteer-vaping sessions. E-liquids, with vegetable glycerin (VG) and propylene glycol (PG), with a VG/PG ratio of 50/50 (with nicotine) and 80/20 (without nicotine), were vaped with a double-coil, single aerosol exit hole at 25-80 W electric power, corresponding to 130-365 kW m-2 heat fluxes and with an octa-coil, four aerosol exit holes atomizers, at 50-150 W electric power, corresponding to 133-398 kW m-2 heat fluxes. At the lowest heat flux, lower particle number concentrations (NTot) were observed for the nicotine-liquid than for the nicotine-free liquid, also due to its higher content of PG, more volatile than VG. For the octa-coil atomizer, at 265 and 398 kW m-2, NTot decreased below the first-generation e-cig, whereas volume concentrations greatly increased, due to the formation of super micron droplets. Higher volume concentrations were observed for the 80/20 VG/PG liquid, because of VG vaporization and of its decomposition products, greater than for PG. For the double coil atomizer, increasing the electric power from 40 W (208 kW m-2) to 80 W (365 kW m-2) possibly led to a critical heat flow condition, causing a reduction of the number concentrations for the VG/PG 50/50 liquid, an increase for the 80/20 VG/PG liquid and a decrease of the volume concentrations for both of them. Coherently, the main mode was at about 0.1 µm on both metrics for both liquids. For the other tests, two main modes (1 and 2 µm) were observed in the volume size distributions, the latter becoming wider at 100 and 150 W (265 and 398 kW m-2), suggesting the increased emission of light condensable decomposition products. The lower aerosol emissions observed at 150 W than at 100 W suggest the formation of gas-phase decomposition products. The observation of low-count high-volume aerosols addresses the relevance of the volume metric upon measuring the second-hand concentration of the aerosols released by sub-ohm e-cigarettes.
| S-EPMC8583564 | biostudies-literature
Project description:Importance:Research indicates that electronic cigarette (e-cigarette) use (vaping) among adolescents is associated with the initiation and progression of combustible cigarette smoking. The reasons for this association are unknown. Objective:To evaluate whether use of e-cigarettes with higher nicotine concentrations is associated with subsequent increases in the frequency and intensity of combustible cigarette smoking and vaping. Design, Setting, and Participants:In this prospective cohort study involving students from 10 high schools in the Los Angeles, California, metropolitan area, surveys were administered during 10th grade in the spring (baseline) and 11th grade in the fall (6-month follow-up) of 2015 to students who reported using e-cigarettes within the past 30 days and the nicotine concentration level they used at baseline. Exposures:Self-report of baseline e-cigarette nicotine concentration of none (0 mg/mL), low (1-5 mg/mL), medium (6-17 mg/mL), or high (?18 mg/mL) typically used during the past 30 days. Main Outcomes and Measures:Frequency of combustible cigarette smoking and e-cigarette use within the past 30 days (0 days [none], 1-2 days [infrequent], or ?3 days [frequent]) and daily intensity of smoking and vaping (number of cigarettes smoked per day, number of vaping episodes per day, and number of puffs per vaping episode) at the 6-month follow-up. Results:The analytic sample included 181 students (96 boys [53.0%] and 85 girls [47.0%]; mean [SD] age, 16.1 [0.4] years). Each successive increase in nicotine concentration (none to low, low to medium, and medium to high) vaped was associated with a 2.26 (95% CI, 1.28-3.98) increase in the odds of frequent (vs no) smoking and a 1.65 (95% CI, 1.09-2.51) increase in the odds of frequent (vs no) vaping at follow-up after adjustment for baseline frequency of smoking and vaping and other relevant covariates. Use of e-cigarettes with high (vs no) nicotine concentration was associated with a greater number of cigarettes smoked per day at follow-up (adjusted rate ratio [RR], 7.03; 95% CI, 6.11-7.95). An association with a significantly greater number of vaping episodes per day was found with use of low (adjusted RR, 3.32; 95% CI, 2.61-4.03), medium (adjusted RR, 3.32; 95% CI, 2.54-4.10), and high (adjusted RR, 2.44; 95% CI, 1.63-3.24) nicotine concentrations (vs no nicotine) at baseline. Similar results were found for the number of puffs per vaping episode for low (adjusted RR, 2.05; 95% CI, 1.41-2.70), medium (adjusted RR, 3.39; 95% CI, 2.66-4.11), and high (adjusted RR, 2.23; 95% CI, 1.42-3.03) nicotine concentrations. Conclusions and Relevance:The results of this study provide preliminary evidence that use of e-cigarettes with higher nicotine concentrations by youths may increase subsequent frequency and intensity of smoking and vaping.
| S-EPMC5779618 | biostudies-literature
Project description:ImportanceSmoking is a known risk to wound healing, but whether electronic cigarettes present the same risk remains unknown.ObjectiveTo evaluate the rate of flap necrosis in the e-cigarette vapor-exposed group and the unexposed control and to detect a difference in the rate of flap necrosis between the traditional cigarette smoke-exposed group and the unexposed control.Design, setting, and participantsFrom March 10, 2018, to May 4, 2018, a cohort study was conducted on 45 male Sprague-Dawley rats at Boston University School of Medicine. Each rat weighed approximately 100 g at the beginning of the study and was randomized to 1 of 3 groups: negative control (n = 15), experimental (exposed to e-cigarette vapor; n = 15), and positive control (exposed to traditional cigarette smoke; n = 15). Rats in the experimental and positive control groups were exposed to electronic cigarette vapor and traditional cigarette smoke in a smoking chamber for 30 minutes twice a day for 30 consecutive days. Levels of serum cotinine were monitored and maintained between 150 ng/mL and 200 ng/mL. After 30 days, random pattern dorsal skin flaps were raised.Main outcomes and measuresPercentage of flap necrosis for each group.ResultsAll 45 rats survived the surgical procedure and postoperative recovery, and all rats thrived and gained weight over the course of the study. The highest rate of flap necrosis was found in the positive control cohort, with a mean (SD) of 68.7% (8.6%), followed by the experimental cohort, with a mean (SD) of 65.9% (11.8%); the negative control cohort had the least amount of flap necrosis, with a mean (SD) of 50.8% (9.4%). The percentage of flap necrosis in the negative control rats (95% CI, 46.0-55.6; P < .001) was substantially lower than that for both the positive control rats (95% CI, 64.3-73.0; P < .001) and the experimental rats (95% CI, 59.9-71.8; P < .001). No statistically significant difference in flap necrosis was noted between the rats in the experimental cohort and the rats in the positive control cohort (95% CI, 59.9-71.8 vs 95% CI, 64.3-73.0; P = .46).Conclusions and relevanceSmoking and vaping appear to be equally detrimental to wound healing and to be associated with a statistically significant increase in flap necrosis compared with the unexposed group. The results suggest that vaping should not be seen as a better alternative to cigarette smoking in the context of wound healing.Level of evidenceNA.
| S-EPMC6439741 | biostudies-literature
Project description:BACKGROUND:Former combustible cigarette smokers who vape e-cigarettes after quitting smoking may experience health benefits if post-quit vaping prevents smoking relapse. METHODS:Former combustible cigarette smokers aged >18 that were recent (quit???12 months) or long-term (quit?>?12 months) quitters at baseline were re-surveyed at 1-year follow-up in the Population Assessment of Tobacco and Health (PATH) U.S. nationally-representative longitudinal study. Associations of baseline e-cigarette vaping status (never use, prior use, current occasional use, and current regular use) and smoking relapse (vs. abstinence) at follow-up were estimated. RESULTS:Among recent quitters (N?=?884), the prevalence of follow-up smoking relapse was 31.6%, 39.0%, 51.6%, and 31.9% among never (N?=?233), prior (N?=?399), current occasional (N?=?56), and current regular (N?=?196) baseline e-cigarette users, respectively. Baseline e-cigarette use was not associated with smoking relapse at follow-up after covariate adjustment. In long-term quitters (n?=?3210), follow-up smoking relapse was 1.8%, 10.4%, 9.6%, and 15.0% among never (N?=?2479), prior (N?=?588), current occasional (N?=?45), and current regular (N?=?98) baseline e-cigarette users, respectively. Both prior use (AOR?=?2.00, CI [1.25-3.20]) and current regular use of e-cigarettes (AOR?=?3.77, CI [1.48-9.65]) had higher odds of subsequent smoking relapse as compared to never e-cigarette users after covariate adjustment. Among relapsers, baseline e-cigarette vaping was not associated with smoking frequency or intensity at follow-up. CONCLUSIONS:Vaping more than one year after quitting smoking was associated with smoking relapse at 12-month follow-up in a nationally-representative sample. Further studies are needed to evaluate whether this association is causal.
| S-EPMC6743978 | biostudies-literature
Project description:BackgroundThe use of electronic cigarettes (e-cigarettes), also known as vaping, has risen exponentially among North American youth in recent years and has become a critical public health concern. The marketing strategies used by e-cigarette companies have been associated with the uptick in use among youth, with video advertisements on television and other electronic platforms being the most pervasive strategy. It is unknown how these advertisements may be tapping into youth needs and preferences.ObjectiveThe aim of this 2-phase study was to examine the marketing strategies that underpin e-cigarette advertisements, specifically in the context of television.MethodsIn phase 1, a scoping review was conducted to identify various influences on e-cigarette uptake among youth. Results of this scoping review informed the development of a coding framework. In phase 2, this framework was used to analyze the content of e-cigarette advertisements as seen on 2 popular television channels (Discovery and AMC).ResultsIn phase 1, a total of 20 articles met the inclusion criteria. The resultant framework consisted of 16 key influences on e-cigarette uptake among youth, which were categorized under 4 headings: personal, relational, environmental, and product-related. In phase 2, 38 e-cigarette advertisements were collected from iSpot.tv and represented 11 popular e-cigarette brands. All of the advertisements tapped into the cited influences of youth e-cigarette uptake, with the most commonly cited influences (product and relational) tapping into the most, at 97% (37/38) and 53% (20/38), respectively.ConclusionsThe findings highlight the multidimensional influences on youth uptake of e-cigarettes, which has important implications for developing effective antivaping messages, and assist public health professionals in providing more comprehensive prevention and cessation support as it relates to e-cigarette use. The findings also bring forward tangible strategies employed by e-cigarette companies to recruit youth into vaping. Understanding this is vital to the development of cohesive strategies that combat these provaping messages.
| S-EPMC7455879 | biostudies-literature
Project description:Objectives:We compared nicotine concentrations in one brand of refill fluids that were purchased in 4 countries and labeled 0 mg of nicotine/mL. We then identified counterfeit e-cigarette products from these countries. Methods:Overall, 125 e-cigarette refill fluids were purchased in Nigeria, the United States (US), England, and China. Nicotine concentrations were measured using high performance liquid chromatography and compared to labeled concentrations. Refill fluids were examined to identify physical differences and grouped into authentic and counterfeit products. Results:Whereas nicotine was in 51.7% (15/29) of the Nigerian, 3.7% (1/27) of the Chinese and 1.6% (1/61) of the American refill fluids (range = 0.4 - 20.4 mg/mL), 8 British products did not contain nicotine. Products from China, the US, and Nigeria with trace amounts of nicotine (0.4 to 0.6 mg/mL) were authentic; however, all products from Nigeria with more than 3.7 mg/mL were counterfeit. Conclusions:We introduce 2 novel issues in the e-cigarette industry, the production of counterfeit refill fluids under a brandjacked label and inclusion of nicotine in 81.3% of the counterfeit products labeled 0 mg/mL. This study emphasizes the need for better control and monitoring of nicotine containing products and sales outlets.
| S-EPMC5937541 | biostudies-literature