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We thank Tobacco Control for the opportunity to respond to the comment above. Our study was obviously not looking into the harms of secondhand aerosol from e-cigarettes (SHA). Our paper departs from previous compelling research on the harms of SHA and assesses the prevalence and duration of such exposure among e-cigarette non-users, i.e., bystanders who are potentially exposed to the aerosols emitted by e-cigarette users.
Firstly, it is clear that we conducted the study on the basis of knowledge that bystanders were involuntarily exposed to potentially hazardous SHA in many places. We have clearly mentioned the growing evidence that supports our assertion about the potential harms of SHA in the Introduction and Discussion sections of the paper. SHA contains many toxicants, including nicotine, particulate matter and carcinogens (e.g., volatile organic compounds, polycyclic aromatic hydrocarbons, formaldehyde, acetaldehyde and tobacco specific nitrosamines-TSNAs). As mentioned, this evidence comes from previous scientific research (please, foresee the references 11 to 14 of our paper). Of special interest, fine particulate matter (PM2.5) concentration increased during e-cigarette use sessions with human volunteers in settings such as a room[1–3], during vapers’ conventions[4,5], and in vape shops and their neighbouring businesses[6]. Some TSNAs, such as N-nitrosonornicotine and nicotine-derived nitrosamine ketone, which are carcinogenic[7], hav...
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We thank Tobacco Control for the opportunity to respond to the comment above. Our study was obviously not looking into the harms of secondhand aerosol from e-cigarettes (SHA). Our paper departs from previous compelling research on the harms of SHA and assesses the prevalence and duration of such exposure among e-cigarette non-users, i.e., bystanders who are potentially exposed to the aerosols emitted by e-cigarette users.
Firstly, it is clear that we conducted the study on the basis of knowledge that bystanders were involuntarily exposed to potentially hazardous SHA in many places. We have clearly mentioned the growing evidence that supports our assertion about the potential harms of SHA in the Introduction and Discussion sections of the paper. SHA contains many toxicants, including nicotine, particulate matter and carcinogens (e.g., volatile organic compounds, polycyclic aromatic hydrocarbons, formaldehyde, acetaldehyde and tobacco specific nitrosamines-TSNAs). As mentioned, this evidence comes from previous scientific research (please, foresee the references 11 to 14 of our paper). Of special interest, fine particulate matter (PM2.5) concentration increased during e-cigarette use sessions with human volunteers in settings such as a room[1–3], during vapers’ conventions[4,5], and in vape shops and their neighbouring businesses[6]. Some TSNAs, such as N-nitrosonornicotine and nicotine-derived nitrosamine ketone, which are carcinogenic[7], have been identified in e-cigarette aerosol (reference 12 of our paper). Airborne nicotine concentration was found to increase after e-cigarette use in an experimental study in a room[1], in an observational study conducted in users’ and non-users’ homes (reference 13 of our paper), and in a study of vapers’ conventions[8]. Also, nicotine in SHA was found to be systematically absorbed by bystanders at levels comparable to secondhand tobacco smoke (references 10 and 42 of our paper), which is worrisome. Additionally, SHA may cause reduced lung function and asthma exacerbations among non-users exposed to it (references 15 and 16). Unfortunately, we are unable to review the study conducted by the California Department of Public Health that was mentioned in the comment, as the source is a blogsite without any specific reference to the scientific publication. Personal blogsites tend to be subjective and are dominantly used to express the bloggers’ personal views, even when these blogsites are maintained by academics. It is worth mentioning, our work was published in a peer-reviewed journal, developed by a team of researchers devoted to public health, and, importantly, who have no conflict of interests.
Secondly, the evidence available at the time of the writing of our paper shows that e-cigarette use and seeing e-cigarette use may renormalise tobacco smoking, induce relapse to smoking among former smokers and trigger initiation of e-cigarette use among non-smokers, particularly young people, by decreasing the harm perception of e-cigarettes (references 17 to 21, and 57). This means the concern around SHA is not only about the air quality but also the social norm it might shape.
In conclusion, based on the evidence mentioned, we wanted to know to what extent e-cigarette exposure was perceived among the general population in European countries; consequently, our study estimates the prevalence of passive exposure to SHA from e-cigarettes. Perhaps the “fear” (we prefer to say “concern”) should exist for selling or using products that may harm the health of people who use them and bystanders who are involuntarily exposed to their aerosols. Based on our results, current evidence, and arguments previously discussed[9], we continue to believe that governments should include e-cigarettes use in smoke-free laws.
References mentioned in this response:
1 Schober W, Szendrei K, Matzen W, et al. Use of electronic cigarettes (e-cigarettes) impairs indoor air quality and increases FeNO levels of e-cigarette consumers. Int J Hyg Environ Health 2014;217:628–37. doi:10.1016/j.ijheh.2013.11.003
2 van Drooge BL, Marco E, Perez N, et al. Influence of electronic cigarette vaping on the composition of indoor organic pollutants, particles, and exhaled breath of bystanders. Environ Sci Pollut Res 2019;26:4654–66. doi:10.1007/s11356-018-3975-x
3 Volesky KD, Maki A, Scherf C, et al. The influence of three e-cigarette models on indoor fine and ultrafine particulate matter concentrations under real-world conditions. Environ Pollut 2018;243:882–9. doi:10.1016/j.envpol.2018.08.069
4 Chen R, Aherrera A, Isichei C, et al. Assessment of indoor air quality at an electronic cigarette (Vaping) convention. J Expo Sci Environ Epidemiol 2018;28:522–9. doi:10.1038/s41370-017-0005-x
5 Soule EK, Maloney SF, Spindle TR, et al. Electronic cigarette use and indoor air quality in a natural setting. Tob Control 2017;26:109–12. doi:10.1136/tobaccocontrol-2015-052772
6 Li L, Nguyen C, Lin Y, et al. Impacts of electronic cigarettes usage on air quality of vape shops and their nearby areas. Sci Total Environ 2021;760:143423. doi:10.1016/j.scitotenv.2020.143423
7 Hecht SS. Biochemistry, Biology, and Carcinogenicity of Tobacco-Specific N -Nitrosamines. Chem Res Toxicol 1998;11:559–603. doi:10.1021/tx980005y
8 Johnson JM, Naeher LP, Yu X, et al. A biomonitoring assessment of secondhand exposures to electronic cigarette emissions. Int J Hyg Environ Health 2019;222:816–23. doi:10.1016/j.ijheh.2019.04.013
9 Wilson N, Hoek J, Thomson G, et al. Should e-cigarette use be included in indoor smoking bans? Bull World Health Organ 2017;95:540–1. doi:10.2471/BLT.16.186536
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I wish to express my dismay with the clear and obvious intention to promote an agenda of fear. One might ask why you are not looking to see whether there actually are any harms from second hand aerosol as the study clearly acts upon a preface that this is the case. I would point you to the CDC's own testing of the air quality found here. Something smells a lot less like science and a lot more like virtue signalling funded by an agenda eager to skip the important part of knowing what you're dealing with before searching for potential victims. https://tobaccoanalysis.blogspot.com/2017/05/vape-shop-air-sampling-by-c...
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Recent work from Ilies et al. (1) is very informative toward understanding the degree to which heated tobacco products might confer less health risk than combusted cigarettes. This publication extends well beyond the existing HTP emissions evidence base, much of which was not conducted by independent groups. The authors should be commended for leveraging strong methodology, and for their comprehensive evaluation of toxicants generated by these products.
While the methodology and results of this publication appear sound, there are a number of inaccurate claims that warrant criticism in the second paragraph of the Introduction section:
• The second paragraph discusses nicotine vaping products (e-cigarettes), however citation #2 (Centers for Disease Control and Prevention (CDC). Use of cigarettes and other tobacco products among students aged 13-15 years--worldwide, 1999-2005. MMWR Morb Mortal Wkly Rep 2006;55:553) utilize data from 1999 through 2005, which mostly spans a time frame prior to the invention of the first e-cigarette in 2004 (2), and certainly spans a timeframe prior to their widespread marketing in the United States. The citation follows the sentence “However, the death toll provoked by their [e-cigarettes] consumption has increased significantly, reaching 650,000 annually, and it is likely to rise over the coming year…” This citation is clearly inapplicable to the unfounded claim being made about deaths attributable to e-ci...
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Recent work from Ilies et al. (1) is very informative toward understanding the degree to which heated tobacco products might confer less health risk than combusted cigarettes. This publication extends well beyond the existing HTP emissions evidence base, much of which was not conducted by independent groups. The authors should be commended for leveraging strong methodology, and for their comprehensive evaluation of toxicants generated by these products.
While the methodology and results of this publication appear sound, there are a number of inaccurate claims that warrant criticism in the second paragraph of the Introduction section:
• The second paragraph discusses nicotine vaping products (e-cigarettes), however citation #2 (Centers for Disease Control and Prevention (CDC). Use of cigarettes and other tobacco products among students aged 13-15 years--worldwide, 1999-2005. MMWR Morb Mortal Wkly Rep 2006;55:553) utilize data from 1999 through 2005, which mostly spans a time frame prior to the invention of the first e-cigarette in 2004 (2), and certainly spans a timeframe prior to their widespread marketing in the United States. The citation follows the sentence “However, the death toll provoked by their [e-cigarettes] consumption has increased significantly, reaching 650,000 annually, and it is likely to rise over the coming year…” This citation is clearly inapplicable to the unfounded claim being made about deaths attributable to e-cigarette use.
• Citation #3 also supports claims about e-cigarette use, however the cited paper (Sinha DN, Kumar A, Bhartiya D, et al. Smokeless tobacco use among adolescents in global perspective. Nicotine Tob Res 2017;19:1395–6) references non-combusted tobacco products in general, as opposed to the many publications which have looked explicitly at e-cigarette use in a more comprehensive fashion. After reading the Sinha et al. research letter, I am not sure that e-cigarettes were considered at all.
• Citation #4 (US Department of Commerce CB. National cancer Institute and centers for disease control and prevention Co-Sponsored tobacco use supplement to the current population survey 2007) does not provide a direct link to any supporting data/publication. It appears the authors are generally referring to the 2006-2007 Tobacco Use Supplement to the Current Population Survey (CPS-TUS), which was conducted in April 2006, August 2006, and January 2007 (3). The first report of an e-cigarette being imported to the United States is from August 2006 (https://rulings.cbp.gov/ruling/M85579), and the 2006-2007 CPS-TUS did not include any survey items related to e-cigarettes. As such, there is no data from the 2006-2007 CPS-TUS that supports the claim “[e-cigarettes] are highly addictive and can cause serious health problems”.
• The claim “More than 30 carcinogenic compounds in high concentrations were identified, leading to severe health hazards such as oral, pharyngeal, oesophageal and pancreatic cancers” is unfounded, as there is no longitudinal data linking e-cigarettes and cancer to date, nor am I aware of evidence that over 30 carcinogenic compounds in “high concentrations” have been identified in any studies of e-cigarette emissions. Additionally, the provided citation (citation #5: Hatsukami D, Zeller M, Gupta P, et al. Smokeless tobacco and public health: a global perspective 2014) does not talk about e-cigarettes even once.
• Citation #6 (Gupta R, Gupta S, Sharma S, et al. Risk of coronary heart disease among smokeless tobacco users: results of systematic review and meta-analysis of global data. Nicotine and Tobacco Research 2019;21:25–31) also does not pertain to e-cigarettes at all, and the accompanying claim “Cardiovascular death risks and stillbirths were also shown to increase up to four times, signalling real concerns regarding human health safety” is baseless with respect to the epidemiological literature on e-cigarettes.
While these concerns do not directly impact the study results or conclusions, e-cigarettes have become a polarizing topic in the tobacco control community and beyond. As such, claims about e-cigarettes must be made with the utmost care, based on rigorous scientific evidence and sound, balanced interpretations of relevant findings. This publication will be read and cited many times over as heated tobacco products continue to proliferate in tobacco markets across the globe, making it that much more important to address these misleading, and at times, blatantly false claims.
References:
1. Ilies BD, Moosakutty SP, Kharbatia NM, et al. Identification of volatile constituents released from IQOS heat-not-burn tobacco HeatSticks
using a direct sampling method. Tobacco Control. Published Online First: 26 May 2020. doi: 10.1136/tobaccocontrol-2019-055521
2. Henningfield JE & Zaatari GS. Electronic nicotine delivery systems: emerging science foundation for policy. Tobacco Control
2010;19:89e90. doi:10.1136/tc.2009.035279
3. US Department of Commerce, Census Bureau (2006-2007). National Cancer Institute and Food and Drug Administration co-sponsored
Tobacco Use Supplement to the Current Population Survey. 2006-2007. https://cancercontrol.cancer.gov/brp/tcrb/tus-cps/
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The meta-analysis by Khouja et al. confirms the strong association in young people between e-cigarette use and subsequent smoking.[1] The critical issue is whether the relationship is causal. If there is a causal relationship, there are several factors which diminish its impact.
Firstly, most of the studies used ‘ever smoking’ as the outcome. Ever smoking is a poor marker for smoking-related harm as most smoking by vapers who later smoke is experimental and infrequent and few progress to established smoking (100+ lifetime cigarettes). Shahab et al. found that only 2.7% of youth who tried e-cigarettes first progressed to established smoking. Only established smoking is linked to significant smoking-related death and disease.[2]
Secondly, the absolute number of non-smokers who progress from vaping to smoking is small as smoking precedes vaping in the vast majority of cases (70-85%).[3] If there is a gateway from vaping to smoking, this only affects a minority of young vapers.
Thirdly, the authors use Bradford Hill’s dose-response and specificity criteria to assess whether the association between vaping and subsequent smoking is likely to be causal.
They acknowledge that the dose-response criterion is mostly based on nicotine dependence, indicating that that nicotine dependent vapers are more likely to progress to smoking. However, nicotine dependence in non-smoking vapers is rare, less than 4% in the 2018 National Youth T...
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The meta-analysis by Khouja et al. confirms the strong association in young people between e-cigarette use and subsequent smoking.[1] The critical issue is whether the relationship is causal. If there is a causal relationship, there are several factors which diminish its impact.
Firstly, most of the studies used ‘ever smoking’ as the outcome. Ever smoking is a poor marker for smoking-related harm as most smoking by vapers who later smoke is experimental and infrequent and few progress to established smoking (100+ lifetime cigarettes). Shahab et al. found that only 2.7% of youth who tried e-cigarettes first progressed to established smoking. Only established smoking is linked to significant smoking-related death and disease.[2]
Secondly, the absolute number of non-smokers who progress from vaping to smoking is small as smoking precedes vaping in the vast majority of cases (70-85%).[3] If there is a gateway from vaping to smoking, this only affects a minority of young vapers.
Thirdly, the authors use Bradford Hill’s dose-response and specificity criteria to assess whether the association between vaping and subsequent smoking is likely to be causal.
They acknowledge that the dose-response criterion is mostly based on nicotine dependence, indicating that that nicotine dependent vapers are more likely to progress to smoking. However, nicotine dependence in non-smoking vapers is rare, less than 4% in the 2018 National Youth Tobacco Survey (NYTS).[4]
They point out that studies with ‘negative control outcomes’ would reduce specificity but do not cite any studies to demonstrate this. A number of studies have found that vaping also predicts other risky behaviors such as alcohol, marijuana and other substance use.[5,6] There is no biologically plausible mechanism for e-cigarette use being a causal factor for these other behaviours. We think that, like smoking, these associations are best explained by a common liability.[7]
Finally, the recent study by Shahab et al. using NYTS data found that nicotine vaping appears to be protective against future smoking.[2] Teens who vaped first were significantly less likely to subsequently become established smokers than 1) those who smoked first and 2) a matched group of non-vapers.
Their findings suggest that, if there is a gateway from vaping to smoking it is very small and is outweighed by a much larger effect of diverting youth away from cigarette smoking.
References
1. Khouja JN, Suddell SF, Peters SE, et al. Is e-cigarette use in non-smoking young adults associated with later smoking? A systematic review and meta-analysis. Tobacco control 2020 doi: 10.1136/tobaccocontrol-2019-055433 [published Online First: 2020/03/12]
2. Shahab L, Beard E, Brown J. Association of initial e-cigarette and other tobacco product use with subsequent cigarette smoking in adolescents: a cross-sectional, matched control study. Tobacco control 2020 doi: 10.1136/tobaccocontrol-2019-055283
3. Berry KM, Reynolds LM, Collins JM, et al. E-cigarette initiation and associated changes in smoking cessation and reduction: the Population Assessment of Tobacco and Health Study, 2013-2015. Tobacco control 2018;28(1):42-49. doi: 10.1136/tobaccocontrol-2017-054108
4. West R, Brown J, Jarvis M. Epidemic of youth nicotine addiction? What does the National Youth Tobacco Survey reveal about high school ecigarette use in the USA? 2019 [Available from: https://www.qeios.com/read/article/391 accessed 24 February 2020.
5. Park E, Livingston JA, Wang W, et al. Adolescent E-cigarette use trajectories and subsequent alcohol and marijuana use. Addictive behaviors 2020;103:106213. doi: 10.1016/j.addbeh.2019.106213 [published Online First: 2019/12/22]
6. Rigsby DC, Keim SA, Adesman A. Electronic Vapor Product Usage and Substance Use Risk Behaviors Among U.S. High School Students. J Child Adolesc Psychopharmacol 2019;29(7):545-53. doi: 10.1089/cap.2019.0047 [published Online First: 2019/07/26]
7. Vanyukov MM, Tarter RE, Kirillova GP, et al. Common liability to addiction and "gateway hypothesis": theoretical, empirical and evolutionary perspective. Drug and alcohol dependence 2012;123 Suppl 1:S3-17. doi: 10.1016/j.drugalcdep.2011.12.018 [published Online First: 2012/01/21]
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This is a well written original research about the burning issue of tobacco manufacturer lobbying. These manufacturing industries have developed strategies to undercut minimum price laws. By increasing tobacco taxes an effective policy has been designed to decrease tobacco use. In Pakistan currently, 209 million people smoke and about 83 billion cigarettes are smoked per year. As Pakistan has not ratified any anti-smoking policies, there should be great effort made to raise excise duties and taxes on tobacco companies to reduce the demand for cigarettes. In 2017 the local price of cigarettes was about 75 rupees of which half was excise duties [1].
With this expansion of taxes, there will be responses of reducing tobacco consumption, but the cigarette manufacturing industries developed specific promotions and lobbies to encourage their consumers to purchase lower taxed or lower priced tobacco products. It is the responsibility of health authorities to regulate the prices and promotion of such hazardous products [2]. According to WHO, “MPOWER” was the slogan in 2015, according to which M= monitor tobacco usage, P= Protect people from tobacco smoke, O= offering help to quit tobacco use, W= warning about its hazards, E= enforce to ban its advertisement, R = Raise tobacco taxes [3].
For smoke free Pakistan and all over the world four key factors should be instruments: Education, legislation, quitting support and financial policies.
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This is a well written original research about the burning issue of tobacco manufacturer lobbying. These manufacturing industries have developed strategies to undercut minimum price laws. By increasing tobacco taxes an effective policy has been designed to decrease tobacco use. In Pakistan currently, 209 million people smoke and about 83 billion cigarettes are smoked per year. As Pakistan has not ratified any anti-smoking policies, there should be great effort made to raise excise duties and taxes on tobacco companies to reduce the demand for cigarettes. In 2017 the local price of cigarettes was about 75 rupees of which half was excise duties [1].
With this expansion of taxes, there will be responses of reducing tobacco consumption, but the cigarette manufacturing industries developed specific promotions and lobbies to encourage their consumers to purchase lower taxed or lower priced tobacco products. It is the responsibility of health authorities to regulate the prices and promotion of such hazardous products [2]. According to WHO, “MPOWER” was the slogan in 2015, according to which M= monitor tobacco usage, P= Protect people from tobacco smoke, O= offering help to quit tobacco use, W= warning about its hazards, E= enforce to ban its advertisement, R = Raise tobacco taxes [3].
For smoke free Pakistan and all over the world four key factors should be instruments: Education, legislation, quitting support and financial policies.
1. Bate R. Large cigarette tax hikes, illicit producers, and organized crime: Lessons from Pakistan. AEI Paper & Studies. 2018 Jun 1:1.
2. Apollonio DE, Glantz SA. Tobacco industry promotions and pricing after tax increases: An analysis of internal industry documents.
3. World Health Organization. WHO report on the global tobacco epidemic 2015: raising taxes on tobacco. World Health Organization; 2015 Jul 31.
The atomizer used for testing has a maximum rating of 80 watts.
200 watts was applied. Needless to say, horrible results occurred.
This is not reputable science, it is a failed experiment, it should never have been published.
It should be noted that the Aspire Cleito coils used in this study have a manufacturer stated operating power range of between 55 and 75 watts. This is noted both on the box and laser etched into the side of the coil housing proper. it should be noted that the first data points in the graph ( to demonstrate the presence of CO in both liquid samples are in excess of the stated power range of the element.
"Strawnana" at 80 watts
"Black Ice" at 100 watts
This leads me to question the normalizing curve for the black ice sample as there are no data points in the graph (Figure 2) within the manufacturer noted operating range for that coil.
Furthermore, while this statement " ...though the bulk liquid temperature is controlled by boiling limits of the e-liquid component" would be accurate were the coil to be completely submerged in liquid, the mechanics of coil design will confound that principle. The resistance coils in electronic cigarettes are not, by design, submerged in liquid, they are in contact with a liquid saturated wick. Any heat energy applied to the coil whether in magnitude or duration, that exceeds the supply of liquid saturating the wick will result in a temperature spike which could cause the temperature to spike causing thermal degradation of what liquid does remain, and the singeing of the cotton wick.
It can be expected that where combustion occurs, carbon compounds will...
It should be noted that the Aspire Cleito coils used in this study have a manufacturer stated operating power range of between 55 and 75 watts. This is noted both on the box and laser etched into the side of the coil housing proper. it should be noted that the first data points in the graph ( to demonstrate the presence of CO in both liquid samples are in excess of the stated power range of the element.
"Strawnana" at 80 watts
"Black Ice" at 100 watts
This leads me to question the normalizing curve for the black ice sample as there are no data points in the graph (Figure 2) within the manufacturer noted operating range for that coil.
Furthermore, while this statement " ...though the bulk liquid temperature is controlled by boiling limits of the e-liquid component" would be accurate were the coil to be completely submerged in liquid, the mechanics of coil design will confound that principle. The resistance coils in electronic cigarettes are not, by design, submerged in liquid, they are in contact with a liquid saturated wick. Any heat energy applied to the coil whether in magnitude or duration, that exceeds the supply of liquid saturating the wick will result in a temperature spike which could cause the temperature to spike causing thermal degradation of what liquid does remain, and the singeing of the cotton wick.
It can be expected that where combustion occurs, carbon compounds will be present.
I would be interested in seeing the data sets to better understand exactly how far out of operating range CO began to manifest in the study.
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Miech and colleagues demonstrate declines in prevalence of non-medical use of prescription drugs among US high school students and show that these declines can be explained by trends in cigarette smoking.1 These observations are taken as support of the gateway hypothesis in which cigarette smoking increases the likelihood of subsequent other drug use. The authors further argue that these results are inconsistent with a ‘common liability’ model, and that the common liability model predicts that adolescent drug use would have “stayed steady or even increased as adolescents continued to use these drugs regardless of whether they smoked.” In this scenario, adolescents with a predilection toward substance might substitute cigarettes with other drugs as smoking rates decline.
However, this conceptualization of the common liability model is inconsistent with how such models are typically understood. Models that posit a common liability do not assert that the degree of liability is fixed in the population, such that changes in risk for use of one drug increases risk for other drug use. Instead, common liability can be influenced by environmental factors and environmental changes can coherently impact multiple outcomes, resulting in trends similar to those observed by Miech and colleagues.
For over 40 years, Problem Behavior Theory has provided a comprehensive theory and empirical approach to common liability. “Problem behaviors” (later termed...
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Miech and colleagues demonstrate declines in prevalence of non-medical use of prescription drugs among US high school students and show that these declines can be explained by trends in cigarette smoking.1 These observations are taken as support of the gateway hypothesis in which cigarette smoking increases the likelihood of subsequent other drug use. The authors further argue that these results are inconsistent with a ‘common liability’ model, and that the common liability model predicts that adolescent drug use would have “stayed steady or even increased as adolescents continued to use these drugs regardless of whether they smoked.” In this scenario, adolescents with a predilection toward substance might substitute cigarettes with other drugs as smoking rates decline.
However, this conceptualization of the common liability model is inconsistent with how such models are typically understood. Models that posit a common liability do not assert that the degree of liability is fixed in the population, such that changes in risk for use of one drug increases risk for other drug use. Instead, common liability can be influenced by environmental factors and environmental changes can coherently impact multiple outcomes, resulting in trends similar to those observed by Miech and colleagues.
For over 40 years, Problem Behavior Theory has provided a comprehensive theory and empirical approach to common liability. “Problem behaviors” (later termed “risk behaviors”) can be modeled as a latent factor that predisposes an adolescent to use of multiple substances, delinquency, and other health risk behaviors.2,3 The latent factor is influenced by the environment at multiple levels. We rely on this framework in two recent papers that demonstrate that that US declines in tobacco use, other substance use, substance use disorders, delinquency, and sexual promiscuity among adolescents are consistent with a population-level reduction in a latent factor that predisposes to risk for all of these outcomes.4,5 Similarly, the externalizing spectrum of personality and psychopathology is postulated to arise from a common liability to multiple substance use and other disinhibitory disorders.6 Externalizing liability has been shown to change in response to specific environmental stressors such as minority stress and child maltreatment.7–10
Although common liability models do not invoke causal gateway effects, they are consistent with commonly observed gateway patterns, in which easily available drugs such as alcohol, cigarettes and marijuana are usually used prior to use of other drugs.5 Thus, trends observed by Miech and colleagues do not contradict the common liability model.
1. Miech R, Keyes KM, O’Malley PM, Johnston LD. The great decline in adolescent cigarette smoking since 2000: consequences for drug use among US adolescents. Tob Control. January 2020:tobaccocontrol-2019-055052.
2. Jessor R, Jessor SL. Problem Behavior and Psychosocial Development: A Longitudinal Study of Youth. Academic Press; 1977.
3. Jessor R. Risk behavior in adolescence: A psychosocial framework for understanding and action. Journal of adolescent Health. 1991;12(8):597-605.
4. Grucza RA, Krueger RF, Agrawal A, et al. Declines in prevalence of adolescent substance use disorders and delinquent behaviors in the USA: a unitary trend? Psychological Medicine. 2018;48(9):1494-1503.
5. Borodovsky JT, Krueger RF, Agrawal A, Grucza RA. A Decline in Propensity Toward Risk Behaviors Among U.S. Adolescents. Journal of Adolescent Health. 2019;65(6):745-751.
6. Krueger RF, Markon KE, Patrick CJ, Benning SD, Kramer MD. Linking antisocial behavior, substance use, and personality: an integrative quantitative model of the adult externalizing spectrum. J Abnorm Psychol. 2007;116(4):645-666.
7. Lehavot K, Simoni JM. The impact of minority stress on mental health and substance use among sexual minority women. Journal of Consulting and Clinical Psychology. 2011;79(2):159-170.
8. Eaton NR. Transdiagnostic psychopathology factors and sexual minority mental health: Evidence of disparities and associations with minority stressors. Psychology of Sexual Orientation and Gender Diversity. 2014;1(3):244-254.
9. Rodriguez-Seijas C, Stohl M, Hasin DS, Eaton NR. Transdiagnostic Factors and Mediation of the Relationship Between Perceived Racial Discrimination and Mental Disorders. JAMA Psychiatry. 2015;72(7):706.
10. Vachon DD, Krueger RF, Rogosch FA, Cicchetti D. Assessment of the Harmful Psychiatric and Behavioral Effects of Different Forms of Child Maltreatment. JAMA Psychiatry. 2015;72(11):1135.
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A key finding of this paper does not find its way into the abstract namely, "no significant differences in wheezing and related respiratory symptoms was found when comparing current vapers who never smoked with never smokers. " This tends to suggest, unsurprisingly, that it is the prior smoking history that is the critical factor in current wheeze. The paper supports the harm reduction hypothesis for switching to vaping completely from smoking as per the conclusion. But the conclusion also states in the first line, "Vaping was associated with increased risk of wheezing and related respiratory symptoms, " which is incorrect without adding "in current smokers." Vapers who previously smoked have lower risk than those who continue to smoke, including dual users, and those who never smoked have no increased risk.
We read with interest a recent publication by Li, et. al, entitled Association of smoking and electronic cigarette use with wheezing and related respiratory problems in adults: cross-sectional results from the Population Assessment of Tobacco and Health (PATH) study, wave 2. The primary finding, reported in the abstract, was that risk of wheezing and related respiratory symptoms was significantly increased in current exclusive e-cigarette users compared to never users, with an adjusted odds ratio of 1.67 (1.23, 2.15). We think the report is misleading for several reasons.
First, the main multivariable analysis (Table 2) did not adequately adjust for important confounders that impact wheeze, most importantly, cigarette smoking history. In most analyses of medical outcomes in adults, pack-years of smoking has a strong relation to smoking-related diseases, over-and-above current smoking status. Since three quarters of vapers in the main model were ex-smokers, cigarette smoking history is almost certainly contributing to the size and significance of the main reported finding. Other combustible tobacco use and current marijuana smoking would also be expected to exacerbate cough and wheeze. Our bet is that large numbers of e-cigarette users also use marijuana.
The authors partially addressed smoking history with a secondary analysis (Table 3), in which they stratified by former smoking status. In that analysis, vaping was not significantl...
We read with interest a recent publication by Li, et. al, entitled Association of smoking and electronic cigarette use with wheezing and related respiratory problems in adults: cross-sectional results from the Population Assessment of Tobacco and Health (PATH) study, wave 2. The primary finding, reported in the abstract, was that risk of wheezing and related respiratory symptoms was significantly increased in current exclusive e-cigarette users compared to never users, with an adjusted odds ratio of 1.67 (1.23, 2.15). We think the report is misleading for several reasons.
First, the main multivariable analysis (Table 2) did not adequately adjust for important confounders that impact wheeze, most importantly, cigarette smoking history. In most analyses of medical outcomes in adults, pack-years of smoking has a strong relation to smoking-related diseases, over-and-above current smoking status. Since three quarters of vapers in the main model were ex-smokers, cigarette smoking history is almost certainly contributing to the size and significance of the main reported finding. Other combustible tobacco use and current marijuana smoking would also be expected to exacerbate cough and wheeze. Our bet is that large numbers of e-cigarette users also use marijuana.
The authors partially addressed smoking history with a secondary analysis (Table 3), in which they stratified by former smoking status. In that analysis, vaping was not significantly associated with any respiratory symptom among persons with no previous cigarette smoking history. The secondary analysis strongly suggests that if a measure capturing extent of former smoking was entered as a covariate in the main model, the primary reported finding of an association between e-cigarette use and pulmonary symptoms would have been null.
Second, the analyses did not adjust for conditions that exacerbate wheeze (chronic obstructive pulmonary disease, congestive heart failure and certain cardiac medications), another potential source of residual confounding. These conditions may also cause declining health, prompting the person to quit smoking or switch from smoking to vaping, adding to a cross sectional association through reverse causality.
While addressing this last issue requires longitudinal data, we believe adding former smoking status and marijuana smoking to the main analysis should be done. The inclusion of these covariates would provide a less biased estimate of the cross-sectional association between vaping and respiratory symptoms and perhaps reach entirely different conclusions. We hope the authors will publish updated results in their response to this comment.
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We thank Tobacco Control for the opportunity to respond to the comment above. Our study was obviously not looking into the harms of secondhand aerosol from e-cigarettes (SHA). Our paper departs from previous compelling research on the harms of SHA and assesses the prevalence and duration of such exposure among e-cigarette non-users, i.e., bystanders who are potentially exposed to the aerosols emitted by e-cigarette users.
Firstly, it is clear that we conducted the study on the basis of knowledge that bystanders were involuntarily exposed to potentially hazardous SHA in many places. We have clearly mentioned the growing evidence that supports our assertion about the potential harms of SHA in the Introduction and Discussion sections of the paper. SHA contains many toxicants, including nicotine, particulate matter and carcinogens (e.g., volatile organic compounds, polycyclic aromatic hydrocarbons, formaldehyde, acetaldehyde and tobacco specific nitrosamines-TSNAs). As mentioned, this evidence comes from previous scientific research (please, foresee the references 11 to 14 of our paper). Of special interest, fine particulate matter (PM2.5) concentration increased during e-cigarette use sessions with human volunteers in settings such as a room[1–3], during vapers’ conventions[4,5], and in vape shops and their neighbouring businesses[6]. Some TSNAs, such as N-nitrosonornicotine and nicotine-derived nitrosamine ketone, which are carcinogenic[7], hav...
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I wish to express my dismay with the clear and obvious intention to promote an agenda of fear. One might ask why you are not looking to see whether there actually are any harms from second hand aerosol as the study clearly acts upon a preface that this is the case. I would point you to the CDC's own testing of the air quality found here. Something smells a lot less like science and a lot more like virtue signalling funded by an agenda eager to skip the important part of knowing what you're dealing with before searching for potential victims.
https://tobaccoanalysis.blogspot.com/2017/05/vape-shop-air-sampling-by-c...
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Recent work from Ilies et al. (1) is very informative toward understanding the degree to which heated tobacco products might confer less health risk than combusted cigarettes. This publication extends well beyond the existing HTP emissions evidence base, much of which was not conducted by independent groups. The authors should be commended for leveraging strong methodology, and for their comprehensive evaluation of toxicants generated by these products.
While the methodology and results of this publication appear sound, there are a number of inaccurate claims that warrant criticism in the second paragraph of the Introduction section:
• The second paragraph discusses nicotine vaping products (e-cigarettes), however citation #2 (Centers for Disease Control and Prevention (CDC). Use of cigarettes and other tobacco products among students aged 13-15 years--worldwide, 1999-2005. MMWR Morb Mortal Wkly Rep 2006;55:553) utilize data from 1999 through 2005, which mostly spans a time frame prior to the invention of the first e-cigarette in 2004 (2), and certainly spans a timeframe prior to their widespread marketing in the United States. The citation follows the sentence “However, the death toll provoked by their [e-cigarettes] consumption has increased significantly, reaching 650,000 annually, and it is likely to rise over the coming year…” This citation is clearly inapplicable to the unfounded claim being made about deaths attributable to e-ci...
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The meta-analysis by Khouja et al. confirms the strong association in young people between e-cigarette use and subsequent smoking.[1] The critical issue is whether the relationship is causal. If there is a causal relationship, there are several factors which diminish its impact.
Firstly, most of the studies used ‘ever smoking’ as the outcome. Ever smoking is a poor marker for smoking-related harm as most smoking by vapers who later smoke is experimental and infrequent and few progress to established smoking (100+ lifetime cigarettes). Shahab et al. found that only 2.7% of youth who tried e-cigarettes first progressed to established smoking. Only established smoking is linked to significant smoking-related death and disease.[2]
Secondly, the absolute number of non-smokers who progress from vaping to smoking is small as smoking precedes vaping in the vast majority of cases (70-85%).[3] If there is a gateway from vaping to smoking, this only affects a minority of young vapers.
Thirdly, the authors use Bradford Hill’s dose-response and specificity criteria to assess whether the association between vaping and subsequent smoking is likely to be causal.
They acknowledge that the dose-response criterion is mostly based on nicotine dependence, indicating that that nicotine dependent vapers are more likely to progress to smoking. However, nicotine dependence in non-smoking vapers is rare, less than 4% in the 2018 National Youth T...
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This is a well written original research about the burning issue of tobacco manufacturer lobbying. These manufacturing industries have developed strategies to undercut minimum price laws. By increasing tobacco taxes an effective policy has been designed to decrease tobacco use. In Pakistan currently, 209 million people smoke and about 83 billion cigarettes are smoked per year. As Pakistan has not ratified any anti-smoking policies, there should be great effort made to raise excise duties and taxes on tobacco companies to reduce the demand for cigarettes. In 2017 the local price of cigarettes was about 75 rupees of which half was excise duties [1].
With this expansion of taxes, there will be responses of reducing tobacco consumption, but the cigarette manufacturing industries developed specific promotions and lobbies to encourage their consumers to purchase lower taxed or lower priced tobacco products. It is the responsibility of health authorities to regulate the prices and promotion of such hazardous products [2]. According to WHO, “MPOWER” was the slogan in 2015, according to which M= monitor tobacco usage, P= Protect people from tobacco smoke, O= offering help to quit tobacco use, W= warning about its hazards, E= enforce to ban its advertisement, R = Raise tobacco taxes [3].
For smoke free Pakistan and all over the world four key factors should be instruments: Education, legislation, quitting support and financial policies.
1....
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The atomizer used for testing has a maximum rating of 80 watts.
200 watts was applied. Needless to say, horrible results occurred.
This is not reputable science, it is a failed experiment, it should never have been published.
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It should be noted that the Aspire Cleito coils used in this study have a manufacturer stated operating power range of between 55 and 75 watts. This is noted both on the box and laser etched into the side of the coil housing proper. it should be noted that the first data points in the graph ( to demonstrate the presence of CO in both liquid samples are in excess of the stated power range of the element.
"Strawnana" at 80 watts
"Black Ice" at 100 watts
This leads me to question the normalizing curve for the black ice sample as there are no data points in the graph (Figure 2) within the manufacturer noted operating range for that coil.
Furthermore, while this statement " ...though the bulk liquid temperature is controlled by boiling limits of the e-liquid component" would be accurate were the coil to be completely submerged in liquid, the mechanics of coil design will confound that principle. The resistance coils in electronic cigarettes are not, by design, submerged in liquid, they are in contact with a liquid saturated wick. Any heat energy applied to the coil whether in magnitude or duration, that exceeds the supply of liquid saturating the wick will result in a temperature spike which could cause the temperature to spike causing thermal degradation of what liquid does remain, and the singeing of the cotton wick.
It can be expected that where combustion occurs, carbon compounds will...
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Miech and colleagues demonstrate declines in prevalence of non-medical use of prescription drugs among US high school students and show that these declines can be explained by trends in cigarette smoking.1 These observations are taken as support of the gateway hypothesis in which cigarette smoking increases the likelihood of subsequent other drug use. The authors further argue that these results are inconsistent with a ‘common liability’ model, and that the common liability model predicts that adolescent drug use would have “stayed steady or even increased as adolescents continued to use these drugs regardless of whether they smoked.” In this scenario, adolescents with a predilection toward substance might substitute cigarettes with other drugs as smoking rates decline.
However, this conceptualization of the common liability model is inconsistent with how such models are typically understood. Models that posit a common liability do not assert that the degree of liability is fixed in the population, such that changes in risk for use of one drug increases risk for other drug use. Instead, common liability can be influenced by environmental factors and environmental changes can coherently impact multiple outcomes, resulting in trends similar to those observed by Miech and colleagues.
For over 40 years, Problem Behavior Theory has provided a comprehensive theory and empirical approach to common liability. “Problem behaviors” (later termed...
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A key finding of this paper does not find its way into the abstract namely, "no significant differences in wheezing and related respiratory symptoms was found when comparing current vapers who never smoked with never smokers. " This tends to suggest, unsurprisingly, that it is the prior smoking history that is the critical factor in current wheeze. The paper supports the harm reduction hypothesis for switching to vaping completely from smoking as per the conclusion. But the conclusion also states in the first line, "Vaping was associated with increased risk of wheezing and related respiratory symptoms, " which is incorrect without adding "in current smokers." Vapers who previously smoked have lower risk than those who continue to smoke, including dual users, and those who never smoked have no increased risk.
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We read with interest a recent publication by Li, et. al, entitled Association of smoking and electronic cigarette use with wheezing and related respiratory problems in adults: cross-sectional results from the Population Assessment of Tobacco and Health (PATH) study, wave 2. The primary finding, reported in the abstract, was that risk of wheezing and related respiratory symptoms was significantly increased in current exclusive e-cigarette users compared to never users, with an adjusted odds ratio of 1.67 (1.23, 2.15). We think the report is misleading for several reasons.
First, the main multivariable analysis (Table 2) did not adequately adjust for important confounders that impact wheeze, most importantly, cigarette smoking history. In most analyses of medical outcomes in adults, pack-years of smoking has a strong relation to smoking-related diseases, over-and-above current smoking status. Since three quarters of vapers in the main model were ex-smokers, cigarette smoking history is almost certainly contributing to the size and significance of the main reported finding. Other combustible tobacco use and current marijuana smoking would also be expected to exacerbate cough and wheeze. Our bet is that large numbers of e-cigarette users also use marijuana.
The authors partially addressed smoking history with a secondary analysis (Table 3), in which they stratified by former smoking status. In that analysis, vaping was not significantl...
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