ArticlePDF Available

Changes in the Frequency of Airway Infections in Smokers Who Switched To Vaping: Results of an Online Survey

Authors:
Joanna Astrid Miler at University of Stirling
Joanna Astrid Miler
Bernhard Mayer
Bernhard Mayer
Bernhard Mayer
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Download full-text PDFDownload full-text PDF
Read full-text
Download citation

Abstract

Background and aim: Cell and animal studies suggested that use of e-cigarettes may increase vulnerability to respiratory infection, though the available studies have serious limitations. Limited data are available on respiratory health of vapers. Methods: An on-line survey assessed subjective changes in respiratory symptoms in smokers who switched to vaping for at least two months. Results: Among 941 responders, 29% reported no change in respiratory symptoms, 5% reported worsening, and 66% reported an improvement. Among qualitative comments, 232 elaborated on positive and 15 on negative experiences. Conclusion: The switch from smoking to vaping was associated with a reduced incidence of self-reported respiratory infections. Further studies using objective measures in samples that are not self-selected are needed.
changes-in-the-frequency-of-airway-infections-in-smokers-who-switched-to-vaping-results-of-an-online-survey-2155-6105-10002
90.pdf
Content uploaded by Joanna Astrid Miler
Author content
All content in this area was uploaded by Joanna Astrid Miler on Jun 19, 2019
Content may be subject to copyright.
changes-in-the-frequency-of-airway-infections-in-smokers-who-switched-to-vaping-results-of-an-online-survey-2155-6105-10002
90.pdf
Content uploaded by Joanna Astrid Miler
Author content
All content in this area was uploaded by Joanna Astrid Miler on Jun 19, 2019
Content may be subject to copyright.
Changes in the Frequency of Airway Infections in Smokers Who Switched To
Vaping: Results of an Online Survey
Joanna Astrid Miler1*, Bernhard Mayer2 and Peter Hajek1
1Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK
2Department of Pharmacology and Toxicology, Institute of Pharmaceutical Sciences, University of Graz, Austria
*Corresponding author: Joanna Astrid Miler, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University
of London, Health and Lifestyle Research Unit, UK, Tel: (0044) 207 882 8230; Fax: (0044) 207 3777237; E-mail: j.miler@qmul.ac.uk
Received date: July 04, 2016; Accepted date: July 30, 2016; Published date: Aug 05, 2016
Copyright: © 2016 Miler JA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Background and aim: Cell and animal studies suggested that use of e-cigarettes may increase vulnerability to
respiratory infection, though the available studies have serious limitations. Limited data are available on respiratory
health of vapers.
Methods: An on-line survey assessed subjective changes in respiratory symptoms in smokers who switched to
vaping for at least two months.
Results: Among 941 responders, 29% reported no change in respiratory symptoms, 5% reported worsening, and
66% reported an improvement. Among qualitative comments, 232 elaborated on positive and 15 on negative
experiences.
Conclusion: The switch from smoking to vaping was associated with a reduced incidence of self-reported
respiratory infections. Further studies using objective measures in samples that are not self-selected are needed.
Keywords: E-cigarettes; Vaping; Airway infections; Smoking
cessation; Survey
Introduction
E-cigarettes (EC) deliver nicotine without combustion chemicals
and are therefore considered to be much safer than conventional
cigarettes [1,2]. Some potential risks however have been agged up in
cell and animal studies suggesting that vaping may increase
vulnerability to respiratory infections [3,4]. ere are only limited data
available on respiratory health of vapers. Human EC trials reported no
signicant adverse respiratory eects associated with EC use for up to
1.5 years and a follow-up study of smokers with asthma who switched
to vaping found signicant improvements. We conducted an on-line
survey to assess subjective changes in respiratory symptoms in
smokers who switched to vaping for at least two months [5,6].
Methods
Design
e survey was posted by BM on two large German vape forums
previously used by BM, E-Rauchen-Forum (http://www.e-rauchen-
forum.de/thread-82289.html) and Dampfertre-Forum (http://
www.dampfertre.de/t118747f1379-Umfrage-Haeugkeit-von-
Atemwegsinfektionen-quot-Schnupfen-quot-nach-Umstieg-auf-ECigs.html).
Most of the active members of these forums are ex-smokers using
rellable ‘tank’ system EC products.
e pre-amble to the survey explained that a recent article suggested
that vaping could increase rates of common cold and respiratory
infections; that BM’s experience was the opposite; and that the purpose
of the survey is to nd out about any changes in rates of respiratory
infections vapers experience [3]. Responders were asked to respond
honestly and to note that the survey concerns respiratory infections
such as common cold and no other respiratory diseases such as asthma
or COPD. Responses were invited only from vapers who stopped
smoking completely or reduced smoking by at least 95% and who have
been vaping for at least 2 months. Appendix A includes verbatim
translation of the pre-amble and a screenshot of the survey page.
e question asked was: Since switching to e-cigarettes, the
frequency of any airways infections I get has: a) decreased; b) not
markedly changed; c) increased. We calculated proportions for each
answer and their condence intervals for each answer using SPSS.
Participants were able to elaborate on their answers with further
comments.
e survey was conducted between 24th of September 2014 and
31st December 2015. e soware identies responders and prevents
repeated responses. Vapers who are members of both were asked to
answer only once.
Results
Altogether 941 responses were received. Figure 1 presents the
results. Overall, 29% of responders reported no change in respiratory
symptoms, 5% reported worsening, and 66% reported an improvement
(95% CI=62.9-69.0).
Journal of Addiction Research &
Therapy Miler et al., J Addict Res Ther 2016, 7:4
DOI: 10.4172/2155-6105.1000290
Research Article Open Access
J Addict Res er, an open access journal
ISSN:2155-6105
Volume 7 • Issue 4 • 1000290
Figure 1: Self-reported changes in airway infections aer switching
from smoking to vaping (N=941).
ere were 247 qualitative responses commenting on improvements
or worsening in the rates of respiratory infections aer switching from
smoking to vaping. e total of 232 comments concerned positive and
15 concerned negative eects.
Here are some typical reports of positive changes: “As a smoker I
had an almost continuous cold. I’ve been a vaper for almost 2 years,
and for almost 2 years I’ve had no sning, no cough, nothing…”
“I’ve been vaping for 13 months and had none [infections] while
earlier I had colds and sore throat 2-3 times a year.”
“I’ve been vaping for 2 years and in this time I had one u-like
infection. As a smoker I used to have them at least twice a year, for
weeks at a time. I used to have to deal with a persistent cough and
mucus production. is year the infection had passed within 3 days.”
Here are some examples of negative reports:
“I smoked for 15 years and in those 15 years I was never really ill.
Aer quitting smoking I have already had 2 u-like infections […].”
“I have completely switched to vaping in 2009. At that time, the rst
3 smoke-free years I was denitely sick less oen than during my
smoking years. But I have observed that I have been sick more oen in
the last 3-4 years (a cold about 4-5 times a year). However, I must say
that I became a father 4 years ago. Maybe it has to do with my
daughter - she oen passes on her infections to me. I'm mostly ill aer
she has been ill.”
Discussion
e majority of smokers who switched to vaping reported a
reduction in the frequency of respiratory infections.
e survey has several limitations. e reports were subjective and
there is a possibility that vapers were trying to portray vaping in a
positive light to counteract the general anti-vaping ethos of public
health and media coverage of vaping in German speaking countries.
e survey pleaded for honesty, but it is possible that some responders
reported improvements in infection resistance even when the actual
change was small or none. Even with this caveat concerning the size of
the positive change, the results are reassuring in that only a small
proportion of respondents reported an increase in infections. If
switching to vaping generated a genuine problem, it could be expected
that aected vapers would report this. Another potential problem is
that smokers who experience adverse eects when vaping could be
expected to stop using e-cigarettes and so would not be in the sample.
is however also means that should such eects exist, they would be
self-limiting. Other limitations concern a possibility that some
respondents may have been still smoking, or may have been vaping for
less than two months, although if this were the case, it would make the
results more rather than less conservative.
e results seem to contradict the ndings from cell culture and
animal studies, but these studies have serious limitations. Regarding
the study that found a damage to epithelial cells harvested from 8-10
year old donors and incubated in e-liquid (not in e-cigarette aerosol)
for up to 48 h, it is unclear to what extent such exposure corresponds
to eects of vaping [3]. Also, no comparison with eects of cigarette
smoke was included. Regarding the mice study, it has been pointed out
that the increased morbidity and mortality in experimental animals
could have been caused by high levels of stress and nicotine poisoning
rather than by the presumed eects of free radicals [2,4]. e study did
not include a smoking control either, but it noted that the level of free
radicals was ‘several orders of magnitude lower than in cigarette
smoke’. As noted earlier, human studies did not detect any adverse
eects of vaping and benecial eects were noted on asthmatic patients
[6].
e nding of an improvement in respiratory health in people who
quit smoking is not surprising because smoking causes increased
susceptibility to respiratory infections [7]. In addition to this however,
there is also a possibility that inhaled propylene glycol may further
magnify this eect. is is because this key ingredient of most e-liquids
has antimicrobial eects [8]. In a classical experiment, 1mg of
propylene glycol vapour in two to four million cc. of air produced
complete sterilisation of air into which pneumococci, streptococci,
staphylococci,
H. inuenzae
, and other microorganisms as well as
inuenza virus had been sprayed [9]. Vaping may provide a degree of
antimicrobial protection, but experimental evidence is needed to
conrm whether such an eect exists.
In summary, the switch from smoking to vaping seems associated
with a reduced incidence of airway infections, but further studies using
objective measures are needed.
Competing Interests
BM has provided commissioned reports on the pharmacology and
toxicology of nicotine containing products for manufacturers of e-
cigarettes and liquids, including Ryan®, Snoke®, Happy People GmbH,
InSmoke AG, CHV Pharma GmbH and Bündnis für Tabakfreien
Genuss e.V. PH received research funding from, and provided
consultancy to, pharmaceutical companies manufacturing smoking
cessation medications. JAM declares no competing interests.
Acknowledgement
We are grateful to vapers who responded to the survey. e survey
required no external funding.
References
1. McNeill A, Brose LS, Calder R, Hitchman SC, Hajek P, et al. (2015) E-
cigarettes: An evidence update. A report commissioned by Public Health
England. PHE, London, UK.
Citation: Miler JA, Mayer BM, Hajek P (2016) Changes in the Frequency of Airway Infections in Smokers Who Switched To Vaping: Results of an
Online Survey. J Addict Res Ther 7: 290. doi:10.4172/2155-6105.1000290
Page 2 of 3
J Addict Res er, an open access journal
ISSN:2155-6105
Volume 7 • Issue 4 • 1000290
2. Tobacco Advisory Group of the Royal College of Physicians (2016)
Nicotine without smoke-tobacco harm reduction. Royal College of
Physicians.
3. Wu Q, Jiang DJ, Minor M, Chu HW (2104) Electronic cigarette liquid
increases inammation and virus infection in primary human airway
epithelial cells. PLoS One e108342.
4. Sussan TE, Gajghate S, immulappa RK, Ma J, Kim JH, et al. (2015)
Exposure to electronic cigarettes impairs pulmonary anti-bacterial and
anti-viral defenses in a mouse model. PLoS One 10: e0116861.
5. McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P (2014) Electronic
cigarettes for smoking cessation and reduction. Cochrane Database Syst
Rev CD010216.
6. Polosa R, Morjaria J, Caponnetto P, Caruso M, Strano S, et al. (2014)
Eect of Smoking Abstinence and Reduction in Asthmatic Smokers
Switching to Electronic Cigarettes: Evidence for Harm Reversal. Int J
Environ Res Public Health 11: 4965-4977.
7. Feldman C, Anderson R (2013) Cigarette smoking and mechanisms of
susceptibility to infections of the respiratory tract and other organ
systems. J Infect 67: 169-184.
8. Nalawade TM, Bhat K, Sogi SH (2015) Bactericidal activity of propylene
glycol, glycerine, polyethylene glycol 400 and polyethylene glycol 1000
against selected microorganisms. J Int Soc Prevent Communit Dent
5:114-119.
9. Robertson OH, Bigg E, Puck TT, Miller BF (1942) Technical Assistance of
Elizabeth A Appell. e Bactericidal Action of Propylene Glycol Vapor on
Microorganisms Suspended in Air. I J Exp Med 75: 593-610.
Citation: Miler JA, Mayer BM, Hajek P (2016) Changes in the Frequency of Airway Infections in Smokers Who Switched To Vaping: Results of an
Online Survey. J Addict Res Ther 7: 290. doi:10.4172/2155-6105.1000290
Page 3 of 3
J Addict Res er, an open access journal
ISSN:2155-6105
Volume 7 • Issue 4 • 1000290
... Each of the 37 studies only examined one of the listed health outcomes. There were 17 studies on respiratory disease [12-14, 22-35, 52] followed by CVD (6) [16][17][18][19][20][21] mental health (7), [37][38][39][40][41][42]54] and one each on oral health [43], two on cancer [15,36], self-reported chronic health conditions [44], tonsillitis [35] and nickel contact allergy [46]. Table 2 summarises that 27 (73%) of the studies reported only on harms, eight (22%) on benefits, two (2%) on both harm and benefits. ...
... In a cross-sectional study of 914 smokers who switched to e-cigarettes, 66% reported reductions in the frequency of respiratory infections and 6% reported worsening [35]. Single case studies reported on acute hypoxaemic respiratory failure and organizing pneumonia; organizing pneumonia; sensitivity pneumonitis and vesicular bronchial injury, but none specifically excluded other causes such as dual use, former smoking, other drug use or comorbidities. ...
... A 'poor' rated cross-sectional study reported an association between e-cigarette use and obesity (OR 4.4, p < 0.05) and alcohol abuse (OR 7.0, p < 0.05) [44]. There were two single case studies of e-cigarette use being linked to the improvement of recurrent tonsillitis [35,45] and occurrence of nickel contact allergy [46]. ...
A scoping review of studies on the health impact of electronic nicotine delivery systems
Article
Full-text available
  • Oct 2021
  • INTERN EMERG MED
We conducted a scoping review of studies on health outcomes from electronic nicotine delivery systems (ENDS). The objective was to identify, narratively synthesize, assess the strength and quality of evidence and critically appraise studies that have reported disease end points associated with the use of ENDS. We included published literature on the health impact of ENDS from 01/01/2015 until 01/02/2020 following the PRISMA guidelines using PubMed, Embase, Scopus and Google Scholar. The database search identified 755 studies, and other sources 265; 37 studies met final eligibility criteria. Levels of evidence included 24(65%) cross-sectional, one (2.7%) case-control and six (16%) case studies, four (11%) cohort studies , one (2.7%) randomized controlled trial (RCT) and one (2.7%) meta-analysis; 27(73%) studies reported only on harms, eight (22%) reported on benefits, two (2%) on benefits and harms. Quality ratings were poor in 20 (54%), fair in 9(24%) and good in 8(22%) of studies. In our review, ENDS was not shown to be causative for harmful cardiovascular disease (CVD) outcomes and shown to be beneficial for hypertensive patients. Switching from cigarettes to e-cigarettes resulted in reduced exacerbations of chronic obstructive pulmonary disease (COPD), with no evidence of long-term deterioration in lung function. Mental Health, cancer and mortality were not adequately studied to form any consensus. Our review has not demonstrated ENDS to be causative of harmful CVD outcomes; furthermore switching from cigarettes to e-cigarettes was associated with improved hypertensive control and reduced exacerbations of COPD, with no evidence of increased asthma risk or long-term respiratory harm. Mental health, cancer and mortality outcomes have not been adequately studied to form a conclusion. Overall, the findings of our review did not provide evidence to counter the consensus held by many that ENDS use is safer than the risks posed from smoking cigarettes.
View
... Clinical trials and surveys of smokers who completely switched to e-cigarettes have shown short-to medium-term improvements in asthma [18], chronic obstructive pulmonary disease (COPD) [19], blood pressure [20,21], muco-ciliary clearance [22], respiratory infections [23], lung function [24], respiratory symptoms [25,26], cardiovascular markers [27,28] and gum disease [29]. These changes are in the direction of less impairment and are likely to persist over the longer term. ...
A critique of the Australian National Health and Medical Research Council CEO statement on electronic cigarettes
Article
Full-text available
  • Feb 2023
This paper critically analyses a statement by Australia's National Health and Medical Research Council (NHMRC) on e‐cigarettes in May 2022 that will be used to guide national policy. We reviewed the evidence and the conclusions drawn in the NHMRC Statement. In our view, the Statement is not a balanced reflection of the benefits and risks of vaping because it exaggerates the risks of vaping and fails to compare them to the far greater risks of smoking; it uncritically accepts evidence of harms from e‐cigarettes while adopting a highly sceptical attitude towards evidence of their benefits; it incorrectly claims that the association between adolescent vaping and subsequent smoking is causal; and it understates the evidence of the benefits of e‐cigarettes in assisting smokers to quit. The Statement dismisses the evidence that vaping is probably already having a positive net public health effect and misapplies the precautionary principle. Several sources of evidence supporting our assessment were published after the NHMRC Statement's publication and are also referenced. The NHMRC Statement on e‐cigarettes does not present a balanced assessment of the available scientific literature and fails to meet the standard expected of a leading national scientific body.
View
... [147][148][149][150] On the other hand, respiratory benefits have been reported for smokers who switched to e-cigarettes. This includes reduced incidence of self-reported respiratory infections, 151 and reduction in annual COPD exacerbation at 1, 2, and 3 years after switching to e-cigarettes. 152, 153 ...
Clinical Pharmacology of Electronic Nicotine Delivery Systems (ENDS): Implications for Benefits and Risks in the Promotion of the Combusted Tobacco Endgame
Article
  • Aug 2021
Electronic nicotine delivery systems (ENDS) such as e‐cigarettes and heated tobacco products are novel battery‐operated devices that deliver nicotine without combustion of tobacco. Because cigarette smoking is sustained by nicotine addiction and the toxic combustion products are mainly responsible for the harmful effects of smoking, ENDS could be used to promote smoking cessation while exposing users to lower levels of toxicants compared with conventional cigarettes. The currently available evidence from clinical and observational studies indicates a potential role of e‐cigarettes as smoking cessation aids, although many continue to use e‐cigarettes long after quitting smoking. Nicotine and toxicant delivery vary considerably by device and depend on the characteristics of the e‐liquid formulation. Because smokers tend to titrate their nicotine intake to maintain their desired pharmacologic effects, device and liquid characteristics need to be considered when using ENDS as an aid to quit smoking. Factors potentially limiting their use are the currently still unknown long‐term safety of these products and concerns regarding widespread use among youth. Implications of clinical pharmacology data on ENDS for the cigarette endgame and regulation by the U.S. Food and Drug administration are discussed.
View
... Studies of cells and animals have suggested that vaping may result in respiratory infections; 35,36 however, a large internet survey of vapers found that the switch from smoking to vaping was accompanied by reduction in respiratory infections. 37 It was proposed that this could be because of the antibacterial properties of propylene glycol, which is usually one of the constituents of e-liquid. Respiratory symptoms were monitored to see if vaping has any negative or positive effects. ...
E-cigarettes compared with nicotine replacement therapy within the UK Stop Smoking Services: the TEC RCT
Article
Full-text available
  • Aug 2019
Background Over the past few years, a large number of smokers in the UK have stopped smoking with the help of e-cigarettes. So far, UK Stop Smoking Services (SSSs) have been reluctant to include e-cigarettes among their treatment options because data on their efficacy compared with the licensed medications are lacking. Objective The objective was to compare the efficacy of refillable e-cigarettes and nicotine replacement therapy (NRT) products, when accompanied by weekly behavioural support. Design A randomised controlled trial comparing e-cigarettes and NRT. Setting Three sites that provide local SSSs. Participants The participants were 886 smokers seeking help to quit smoking, aged ≥ 18 years, not pregnant or breastfeeding, with no strong preference to use or not to use NRT or e-cigarettes in their quit attempt, and currently not using NRT or e-cigarettes. A total of 886 participants were randomised but two died during the study (one in each study arm) and were not included in the analysis. Interventions The NRT arm ( n = 446) received NRT of their choice (single or combination), provided for up to 12 weeks. The e-cigarette arm ( n = 438) received an e-cigarette starter pack and were encouraged to buy addtional e-liquids and e-cigarette products of their choice. Both arms received the same standard behavioural support. Participants attended weekly sessions at their SSS and provided outcome data at 4 weeks. They were then followed up by telephone at 6 and 12 months. Participants reporting abstinence or at least 50% reduction in cigarette consumption at 12 months were invited to attend for carbon monoxide (CO) validation. Participants/researchers could not be blinded to the intervention. Main outcome measures The primary outcome was CO-validated sustained abstinence rates at 52 weeks. Participants lost to follow-up or not providing biochemical validation were included as non-abstainers. Secondary outcomes included abstinence at other time points, reduction in smoke intake, treatment adherence and ratings, elicited adverse reactions, and changes in self-reported respiratory health. A cost-efficacy analysis of the intervention was also conducted. Results The 1-year quit rate was 9.9% in the NRT arm and 18.0% in the e-cigarette arm (risk ratio 1.83, 95% confidence interval 1.30 to 2.58; p < 0.001). The e-cigarette arm had significantly higher validated quit rates at all time points. Participants in the e-cigarette arm showed significantly better adherence and experienced fewer urges to smoke throughout the initial 4 weeks of their quit attempt than those in the NRT arm, and gave their allocated product more favourable ratings. They were also more likely to be still using their allocated product at 1 year (39.5% vs. 4.3%, χ ² = 161.4; p < 0.001). Participants assigned to e-cigarettes reported significantly less coughing and phlegm at 1 year than those assigned to NRT (controlling for smoking status). A detailed economic analysis confirmed that, because e-cigarettes incur lower NHS costs than NRT and generate a higher quit rate, e-cigarette use is more cost-effective. Limitations The results may not be generalisable to other types of smokers or settings, or to cartridge-based e-cigarettes. Conclusions Within the context of multisession treatment for smokers seeking help, e-cigarettes were significantly more effective than NRT. If SSSs provide e-cigarette starter packs, it is likely to boost their success rates and improve their cost-efficacy. Future work The efficacy of e-cigarettes provided with different levels of support will show whether smokers should be encouraged to switch to vaping within support services or whether e-cigarettes can be recommended with less intensive or no support. Trial registration Current Controlled Trials ISRCTN60477608. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 23, No. 43. See the NIHR Journals Library website for further project information. The trial was supported by the Cancer Research UK Prevention Trials Unit (grant A16893).
View
Safety of e-cigarettes and nicotine patches as stop-smoking aids in pregnancy: Secondary analysis of the Pregnancy Trial of E-cigarettes and Patches (PREP) randomized controlled trial
Article
  • Jan 2024
  • ADDICTION
Aims The aim of this study was to examine the safety of e‐cigarettes (EC) and nicotine patches (NRT) when used to help pregnant smokers quit. Design A recent trial of EC versus NRT reported safety outcomes in the randomized arms. We conducted a further analysis based on product use. Setting Twenty‐three hospitals in England and a stop‐smoking service in Scotland took part. Participants The participants comprised 1140 pregnant smokers. Interventions We compared women using and not using EC and NRT regularly during pregnancy. Measurements Measurements included nicotine intake compared with baseline, birth weight, other pregnancy outcomes, adverse events, maternal respiratory symptoms and relapse in early abstainers. Findings Use of EC was more common than use of NRT (47.3% vs 21.6%, P < 0.001). Women who stopped smoking (abstainers) and used EC at the end‐of‐pregnancy (EOP) reduced their salivary cotinine by 45% [49.3 ng/ml, 95% confidence interval (CI) = −79.8 to −10]. Only one abstainer used NRT at EOP. In dual users, cotinine increased by 19% (24 ng/ml, 95% CI = 3.5–68). In women reporting a reduction of at least 50% in cigarette consumption, cotinine levels increased by 10% in those using nicotine products and by 9% in those who did not. Birth weights in dual users and exclusive smokers were the same (3.1 kg). Birth weight in abstainers using either nicotine product was higher than in smokers [3.3 kg, standard deviation (SD) = 0.7] versus 3.1 kg, SD = 0.6; difference = 0.15 kg, 95% CI = 0.05–0.25) and not different from abstainers not using nicotine products (3.1 kg, SD = 0.8). Abstainers and smokers using nicotine products had no worse pregnancy outcomes or more adverse events than abstainers and smokers not using them. EC users reported more improvements than non‐users in cough [adjusted relative risk (aRR) = 0.59, 95% CI = 0.37–0.93] and phlegm (aRR = 0.53, 95% CI = 0.31–0.92), controlling for smoking status. EC or NRT use had no association with relapse. Conclusions Regular use of e‐cigarettes or nicotine patches by pregnant smokers does not appear to be associated with any adverse outcomes.
View
Vergleichende Untersuchungen von Schlüsselkomponenten aus Dämpfen der E-Zigarette
Thesis
  • Jan 2022
Respiratorische Erkrankungen stellen zunehmend eine relevante globale Problematik dar. Die Erweiterung bzw. Modifizierung von Applikationswegen möglicher Arzneimittel für gezielte topische Anwendungen ist dabei von größter Bedeutung. Die Variation eines bekannten Applikationsweges durch unterschiedliche technologische Umsetzungen kann die Vielfalt der Anwendungsmöglichkeiten, aber auch die Patienten-Compliance erhöhen. Die einfache und flexible Verfahrensweise durch schnelle Verfügbarkeit und eine handliche Technologie sind heutzutage wichtige Eigenschaften im Entwicklungsprozess eines Produktes. Eine direkte topische Behandlung von Atemwegserkrankungen am Wirkort in Form einer inhalativen Applikation bietet dabei viele Vorteile gegenüber einer systemischen Therapie. Die medizinische Inhalation von Wirkstoffen über die Lunge ist jedoch eine komplexe Herausforderung. Inhalatoren gehören zu den erklärungsbedürftigen Applikationsformen, die zur Erhöhung der konsequenten Einhaltung der Verordnung so einfach, wie möglich gestaltet werden müssen. Parallel besitzen und nutzen weltweit annähernd 68 Millionen Menschen die Technologie eines inhalativen Applikators zur bewussten Schädigung ihrer Gesundheit in Form einer elektronischen Zigarette. Diese bekannte Anwendung bietet die potentielle Möglichkeit einer verfügbaren, kostengünstigen und qualitätsgeprüften Gesundheitsmaßnahme zur Kontrolle, Prävention und Heilung von Atemwegserkrankungen. Sie erzeugt ein Aerosol durch elektrothermische Erwärmung eines sogenannten Liquids, das durch Kapillarkräfte eines Trägermaterials an ein Heizelement gelangt und verdampft. Ihr Bekanntheitsgrad zeigt, dass eine beabsichtigte Wirkung in den Atemwegen eintritt. Diese Wirkung könnte jedoch auch auf potentielle pharmazeutische Einsatzgebiete übertragbar sein. Die Vorteile der pulmonalen Verabreichung sind dabei vielfältig. Im Vergleich zur peroralen Applikation gelangt der Wirkstoff gezielt zum Wirkort. Wenn eine systemische Applikation zu Arzneimittelkonzentrationen unterhalb der therapeutischen Wirksamkeit in der Lunge führt, könnte eine inhalative Darreichung bereits bei niedriger Dosierung die gewünschten höheren Konzentrationen am Wirkort hervorrufen. Aufgrund der großen Resorptionsfläche der Lunge sind eine höhere Bioverfügbarkeit und ein schnellerer Wirkungseintritt infolge des fehlenden First-Pass-Effektes möglich. Es kommt ebenfalls zu minimalen systemischen Nebenwirkungen. Die elektronische Zigarette erzeugt wie die medizinischen Inhalatoren lungengängige Partikel. Die atemzuggesteuerte Technik ermöglicht eine unkomplizierte und intuitive Anwendung. Der prinzipielle Aufbau besteht aus einer elektrisch beheizten Wendel und einem Akku. Die Heizwendel ist von einem sogenannten Liquid in einem Tank umgeben und erzeugt das Aerosol. Das Liquid beinhaltet eine Basismischung bestehend aus Propylenglycol, Glycerin und reinem Wasser in unterschiedlichen prozentualen Anteilen. Es besteht die Annahme, dass das Basisliquid auch mit pharmazeutischen Wirkstoffen für die pulmonale Applikation beladen werden kann. Aufgrund der thermischen Belastung durch die e-Zigarette müssen potentielle Wirkstoffe sowie das Vehikel eine thermische Stabilität aufweisen. Die potentielle medizinische Anwendung der Technologie einer handelsüblichen e-Zigarette wurde anhand von drei Schwerpunkten an vier Wirkstoffen untersucht. Die drei ätherischen Öle Eucalyptusöl, Minzöl und Nelkenöl wurden aufgrund ihrer leichten Flüchtigkeit und der historischen pharmazeutischen Anwendung anhand von Inhalationen bei Erkältungssymptomen bzw. im zahnmedizinischen Bereich gewählt. Das eingesetzte Cannabinoid Cannabidiol (CBD) hat einen aktuellen Bezug zu dem pharmazeutischen Markt Deutschlands zur Legalisierung von cannabishaltigen Produkten und der medizinischen Forschung zum inhalativen Konsum. Es wurden relevante wirkstoffhaltige Flüssigformulierungen entwickelt und hinsichtlich ihrer Verdampfbarkeit zu Aerosolen bewertet. In den quantitativen und qualitativen chromatographischen Untersuchungen konnten spezifische Verdampfungsprofile der Wirkstoffe erfasst und bewertet werden. Dabei stieg die verdampfte Masse der Leitsubstanzen 1,8-Cineol (Eucalyptusöl), Menthol (Minzöl) und Eugenol (Nelkenöl) zwischen 33,6 µg und 156,2 µg pro Zug proportional zur Konzentration im Liquid im Bereich zwischen 0,5% und 1,5% bei einer Leistung von 20 Watt. Die Freisetzungsrate von Cannabidiol hingegen schien unabhängig von der Konzentration im Liquid im Mittelwert bei 13,3 µg pro Zug zu liegen. Dieses konnte an fünf CBD-haltigen Liquids im Konzentrationsbereich zwischen 31 µg/g und 5120 µg/g Liquid gezeigt werden. Außerdem konnte eine Steigerung der verdampften Massen mit Zunahme der Leistung der e-Zigarette festgestellt werden. Die Interaktion der Liquids bzw. Aerosole mit den Bestandteilen des Speichels sowie weiterer gastrointestinaler Flüssigkeiten wurde über die Anwendung von zugehörigen in vitro Modellen und Einsatz von Enzymaktivitäts-Assays geprüft. In den Untersuchungen wurden Änderungen von Enzymaktivitäten anhand des oralen Schlüsselenzyms α-Amylase sowie von Proteasen ermittelt. Damit sollte exemplarisch ein möglicher Einfluss auf physiologische bzw. metabolische Prozesse im humanen Organismus geprüft werden. Das Bedampfen von biologischen Suspensionen führte bei niedriger Leistung der e-Zigarette (20 Watt) zu keiner bzw. einer leichten Änderung der Enzymaktivität. Die Anwendung einer hohen Leistung (80 Watt) bewirkte tendenziell das Herabsetzen der Enzymaktivitäten. Die Erhöhung der Enzymaktivitäten könnte zu einem enzymatischen Abbau von Schleimstoffen wie Mucinen führen, was wiederum die effektive, mechanische Abwehr gegenüber bakteriellen Infektionen zur Folge hätte. Da eine Anwendung der Applikation insbesondere bei bakteriellen Atemwegserkrankungen denkbar wäre, folgten abschließend Untersuchungen der antibakteriellen Eigenschaften der Liquids bzw. Aerosole in vitro. Es wurden sechs klinisch relevante bakterielle Krankheitserreger ausgewählt, die nach zwei Charakteristika gruppiert werden können. Die drei multiresistenten Bakterien Pseudomonas aeruginosa, Klebsiella pneumoniae und Methicillin-resistenter Staphylococcus aureus können mithilfe von üblichen Therapien mit Antibiotika nicht abgetötet werden und haben vor allem eine nosokomiale Relevanz. Die zweite Gruppe weist Eigenschaften auf, die vordergründig assoziiert sind mit respiratorischen Erkrankungen. Die Bakterien Streptococcus pneumoniae, Moraxella catarrhalis und Haemophilus influenzae sind repräsentativ beteiligt an Atemwegserkrankungen mit diverser Symptomatik. Die Bakterienarten wurden mit den jeweiligen Liquids behandelt bzw. bedampft und deren grundlegende Dosis-Wirkungsbeziehung charakterisiert. Dabei konnte eine antibakterielle Aktivität der Formulierungen ermittelt werden, die durch Zugabe eines Wirkstoffes die bereits antibakterielle Wirkung der Bestandteile Glycerin und Propylenglycol verstärkte. Die hygroskopischen Eigenschaften dieser Substanzen sind vermutlich für eine Wirkung in aerosolierter Form verantwortlich. Sie entziehen die Feuchtigkeit aus der Luft und haben einen austrocknenden Effekt auf die Bakterien. Das Bedampfen der Bakterienarten Streptococcus pneumoniae, Moraxella catarrhalis und Haemophilus influenzae hatte einen antibakteriellen Effekt, der zeitlich abhängig von der Leistung der e-Zigarette war. Die Ergebnisse der Untersuchungen führen zu dem Schluss, dass jeder Wirkstoff bzw. jede Substanzklasse individuell zu bewerten ist und somit Inhalator und Formulierung aufeinander abgestimmt werden müssen. Der Einsatz der e-Zigarette als Medizinprodukt zur Applikation von Arzneimitteln setzt stets Prüfungen nach Europäischem Arzneibuch voraus. Durch Modifizierungen könnte eine Dosierung gut kontrollierbar gemacht werden, aber auch die Partikelgrößenverteilung kann insoweit reguliert werden, dass die Wirkstoffe je nach Partikelgröße zu einem geeigneten Applikationsort wie Mund, Rachen oder Bronchien transportiert werden. Der Vergleich mit den Eigenschaften anderer medizinischer Inhalatoren führt zu dem Schluss, dass die Technologie der e-Zigarette durchaus eine gleichartige oder bessere Performance für thermisch stabile Wirkstoffe bieten könnte. Dieses fiktive Medizinprodukt könnte aus einer hersteller-unspezifisch produzierten, wieder aufladbaren Energiequelle mit Universalgewinde zum mehrfachen Gebrauch und einer hersteller- und wirkstoffspezifisch produzierten Einheit aus Verdampfer und Arzneimittel bestehen. Das Arzneimittel, ein medizinisches Liquid (Vehikel und Wirkstoff) kann in dem Tank des Verdampfers mit konstanten, nicht variablen Parametern patientenindividuell produziert werden. Inhalative Anwendungen werden perspektivisch wohl nicht zuletzt aufgrund der aktuellen COVID-19-Pandemie eine zunehmende Rolle spielen. Der Bedarf nach alternativen Therapieoptionen wird weiter ansteigen. Diese Arbeit liefert einen Beitrag zum Einsatz der Technologie der elektronischen Zigarette als electronic nicotin delivery system (ENDS) nach Modifizierung zu einem potentiellen pulmonalen Applikationssystem als electronic drug delivery system (EDDS) von inhalativen, thermisch stabilen Arzneimitteln in Form eines Medizinproduktes.
View
View
Die e-Zigarette als Ausstieg aus dem Rauchen
Chapter
  • Jan 2020
E-cigarettes and its use in smoking cessation and as harm reduction
View
Objective assessment of nasal resistance among electronic cigarette users
Article
  • Jun 2021
Background Electronic cigarettes have been a popular alternative to tobacco smoking. The effect of tobacco smoking on nasal airway resistance has been investigated before; however, the effect of the aerosol generated by electronic cigarettes is still unknown. This study aimed to evaluate the short-term effects of e-cigarettes on nasal airway resistance. Methods Sixty-one participants were recruited into a vapers group and a control group. The vapers group was instructed to smoke for 5 minutes, and their nasal resistance was measured pre-procedure and at 1 and 5 minutes post-procedure. The results were compared between both groups. Results Repeated measures analysis of variance demonstrated that vaping has no statistically significant effect on total nasal airway resistance. Conclusion Although the differences between both groups were not statistically significant overall, the vapers group showed a reduction in nasal airway resistance in the short term.
View
Dampfen statt Rauchen -ein Projekt der Suchthilfe Ost in Olten
Thesis
  • Jul 2020
The Suchthilfe Ost in Olten, Schweiz, analyzed its project "Mit der E-Zigarette zum Rauchstopp" after 18 months of duration. The Author Hélène Neuhaus gathered information about relevant details of this project and wrote her Bachelor Thesis about the current state of knowledge of e-cigarettes (ENDS).
View
Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms
Article
Full-text available
  • Mar 2015
The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro. Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study. All vehicles exhibited bactericidal activity at 100% concentration. Propylene glycol was effective against three organisms namely S. mutans E. faecalis and E. coli and its bactericidal activity was at 50%, 25% and 50% respectively. PEG 1000 was effective against S. mutans and E. coli at 25%. Hence propylene glycol was effective on more number of organisms of which E. faecalis is a known resistant species. PEG 1000 was bactericidal at a lower concentration but was effective on two organisms only.
View
Exposure to Electronic Cigarettes Impairs Pulmonary Anti-Bacterial and Anti-Viral Defenses in a Mouse Model
Article
Full-text available
Electronic cigarettes (E-cigs) have experienced sharp increases in popularity over the past five years due to many factors, including aggressive marketing, increased restrictions on conventional cigarettes, and a perception that E-cigs are healthy alternatives to cigarettes. Despite this perception, studies on health effects in humans are extremely limited and in vivo animal models have not been generated. Presently, we determined that E-cig vapor contains 7x1011 free radicals per puff. To determine whether E-cig exposure impacts pulmonary responses in mice, we developed an inhalation chamber for E-cig exposure. Mice that were exposed to E-cig vapor contained serum cotinine concentrations that are comparable to human E-cig users. E-cig exposure for 2 weeks produced a significant increase in oxidative stress and moderate macrophage-mediated inflammation. Since, COPD patients are susceptible to bacterial and viral infections, we tested effects of E-cigs on immune response. Mice that were exposed to E-cig vapor showed significantly impaired pulmonary bacterial clearance, compared to air-exposed mice, following an intranasal infection with Streptococcus pneumonia. This defective bacterial clearance was partially due to reduced phagocytosis by alveolar macrophages from E-cig exposed mice. In response to Influenza A virus infection, E-cig exposed mice displayed increased lung viral titers and enhanced virus-induced illness and mortality. In summary, this study reports a murine model of E-cig exposure and demonstrates that E-cig exposure elicits impaired pulmonary anti-microbial defenses. Hence, E-cig exposure as an alternative to cigarette smoking must be rigorously tested in users for their effects on immune response and susceptibility to bacterial and viral infections.
View
Electronic Cigarette Liquid Increases Inflammation and Virus Infection in Primary Human Airway Epithelial Cells
Article
Full-text available
Background/Objective The use of electronic cigarettes (e-cigarettes) is rapidly increasing in the United States, especially among young people since e-cigarettes have been perceived as a safer alternative to conventional tobacco cigarettes. However, the scientific evidence regarding the human health effects of e-cigarettes on the lung is extremely limited. The major goal of our current study is to determine if e-cigarette use alters human young subject airway epithelial functions such as inflammatory response and innate immune defense against respiratory viral (i.e., human rhinovirus, HRV) infection. Methodology/Main Results We examined the effects of e-cigarette liquid (e-liquid) on pro-inflammatory cytokine (e.g., IL-6) production, HRV infection and host defense molecules (e.g., short palate, lung, and nasal epithelium clone 1, SPLUNC1) in primary human airway epithelial cells from young healthy non-smokers. Additionally, we examined the role of SPLUNC1 in lung defense against HRV infection using a SPLUNC1 knockout mouse model. We found that nicotine-free e-liquid promoted IL-6 production and HRV infection. Addition of nicotine into e-liquid further amplified the effects of nicotine-free e-liquid. Moreover, SPLUNC1 deficiency in mice significantly increased lung HRV loads. E-liquid inhibited SPLUNC1 expression in primary human airway epithelial cells. These findings strongly suggest the deleterious health effects of e-cigarettes in the airways of young people. Our data will guide future studies to evaluate the impact of e-cigarettes on lung health in human populations, and help inform the public about potential health risks of e-cigarettes.
View
Effect of Smoking Abstinence and Reduction in Asthmatic Smokers Switching to Electronic Cigarettes: Evidence for Harm Reversal
Article
Full-text available
Electronic cigarettes (e-cigs) are marketed as safer alternatives to tobacco cigarettes and have shown to reduce their consumption. Here we report for the first time the effects of e-cigs on subjective and objective asthma parameters as well as tolerability in asthmatic smokers who quit or reduced their tobacco consumption by switching to these products. We retrospectively reviewed changes in spirometry data, airway hyper-responsiveness (AHR), asthma exacerbations and subjective asthma control in smoking asthmatics who switched to regular e-cig use. Measurements were taken prior to switching (baseline) and at two consecutive visits (Follow-up/1 at 6 (±1) and Follow-up/2 at 12 (±2) months). Eighteen smoking asthmatics (10 single users, eight dual users) were identified. Overall there were significant improvements in spirometry data, asthma control and AHR. These positive outcomes were noted in single and dual users. Reduction in exacerbation rates was reported, but was not significant. No severe adverse events were noted. This small retrospective study indicates that regular use of e-cigs to substitute smoking is associated with objective and subjective improvements in asthma outcomes. Considering that e-cig use is reportedly less harmful than conventional smoking and can lead to reduced cigarette consumption with subsequent improvements in asthma outcomes, this study shows that e-cigs can be a valid option for asthmatic patients who cannot quit smoking by other methods.
View
Electronic cigarettes for smoking cessation and reduction (Protocol)
Article
  • Dec 2014
  • COCHRANE DB SYST REV
Background: Electronic cigarettes (ECs) are electronic devices that heat a liquid - usually comprising propylene glycol and glycerol, with or without nicotine and flavours, stored in disposable or refillable cartridges or a reservoir - into an aerosol for inhalation. Since ECs appeared on the market in 2006 there has been a steady growth in sales. Smokers report using ECs to reduce risks of smoking, but some healthcare organisations have been reluctant to encourage smokers to switch to ECs, citing lack of evidence of efficacy and safety. Smokers, healthcare providers and regulators are interested to know if these devices can reduce the harms associated with smoking. In particular, healthcare providers have an urgent need to know what advice they should give to smokers enquiring about ECs. Objectives: To examine the efficacy of ECs in helping people who smoke to achieve long-term abstinence; to examine the efficacy of ECs in helping people reduce cigarette consumption by at least 50% of baseline levels; and to assess the occurrence of adverse events associated with EC use. Search methods: We searched the Cochrane Tobacco Addiction Groups Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and two other databases for relevant records from 2004 to July 2014, together with reference checking and contact with study authors. Selection criteria: We included randomized controlled trials (RCTs) in which current smokers (motivated or unmotivated to quit) were randomized to EC or a control condition, and which measured abstinence rates or changes in cigarette consumption at six months or longer. As the field of EC research is new, we also included cohort follow-up studies with at least six months follow-up. We included randomized cross-over trials and cohort follow-up studies that included at least one week of EC use for assessment of adverse events. Data collection and analysis: One review author extracted data from the included studies and another checked them. Our main outcome measure was abstinence from smoking after at least six months follow-up, and we used the most rigorous definition available (continuous, biochemically validated, longest follow-up). For reduction we used a dichotomous approach (no change/reduction < 50% versus reduction by 50% or more of baseline cigarette consumption). We used a fixed-effect Mantel-Haenszel model to calculate the risk ratio (RR) with a 95% confidence interval (CI) for each study, and where appropriate we pooled data from these studies in meta-analyses. Main results: Our search identified almost 600 records, from which we include 29 representing 13 completed studies (two RCTs, 11 cohort). We identified nine ongoing trials. Two RCTs compared EC with placebo (non-nicotine) EC, with a combined sample size of 662 participants. One trial included minimal telephone support and one recruited smokers not intending to quit, and both used early EC models with low nicotine content. We judged the RCTs to be at low risk of bias, but under the GRADE system the overall quality of the evidence for our outcomes was rated 'low' or 'very low' because of imprecision due to the small number of trials. A 'low' grade means that further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. A 'very low' grade means we are very uncertain about the estimate. Participants using an EC were more likely to have abstained from smoking for at least six months compared with participants using placebo EC (RR 2.29, 95% CI 1.05 to 4.96; placebo 4% versus EC 9%; 2 studies; GRADE: low). The one study that compared EC to nicotine patch found no significant difference in six-month abstinence rates, but the confidence intervals do not rule out a clinically important difference (RR 1.26, 95% CI: 0.68 to 2.34; GRADE: very low). A higher number of people were able to reduce cigarette consumption by at least half with ECs compared with placebo ECs (RR 1.31, 95% CI 1.02 to 1.68, 2 studies; placebo: 27% versus EC: 36%; GRADE: low) and compared with patch (RR 1.41, 95% CI 1.20 to 1.67, 1 study; patch: 44% versus EC: 61%; GRADE: very low). Unlike smoking cessation outcomes, reduction results were not biochemically verified.None of the RCTs or cohort studies reported any serious adverse events (SAEs) that were considered to be plausibly related to EC use. One RCT provided data on the proportion of participants experiencing any adverse events. Although the proportion of participants in the study arms experiencing adverse events was similar, the confidence intervals are wide (ECs vs placebo EC RR 0.97, 95% CI 0.71 to 1.34; ECs vs patch RR 0.99, 95% CI 0.81 to 1.22). The other RCT reported no statistically significant difference in the frequency of AEs at three- or 12-month follow-up between the EC and placebo EC groups, and showed that in all groups the frequency of AEs (with the exception of throat irritation) decreased significantly over time. Authors' conclusions: There is evidence from two trials that ECs help smokers to stop smoking long-term compared with placebo ECs. However, the small number of trials, low event rates and wide confidence intervals around the estimates mean that our confidence in the result is rated 'low' by GRADE standards. The lack of difference between the effect of ECs compared with nicotine patches found in one trial is uncertain for similar reasons. ECs appear to help smokers unable to stop smoking altogether to reduce their cigarette consumption when compared with placebo ECs and nicotine patches, but the above limitations also affect certainty in this finding. In addition, lack of biochemical assessment of the actual reduction in smoke intake further limits this evidence. No evidence emerged that short-term EC use is associated with health risk.
View
Cigarette Smoking and Mechanisms of Susceptibility to Infections of the Respiratory Tract and Other Organ Systems.
Article
  • May 2013
The predisposition of cigarette smokers for development of oral and respiratory infections caused by both microbial and viral pathogens is well recognised, with those infected with the human immunodeficiency virus (HIV) at particularly high risk. The current review consists of three major sections. The first of these is focused on the suppressive effects of smoking on the protective functions of airway epithelium, alveolar macrophages, dendritic cells, natural killer (NK) cells and adaptive immune mechanisms, as well as chronic systemic activation of neutrophils. This is followed by a consideration of the effects of cigarette smoke on microbial pathogens, specifically promotion of microbial virulence and antibiotic resistance. In addition to interactions between smoking and HIV infection, the final section covers specific infections/clinical syndromes associated with cigarette smoking, including those of the upper and lower respiratory tract, gastrointestinal tract, central nervous and other organ systems, as well as the benefits of smoking cessation.
View
The bactericidal action of propylene glycol vapor on microorganisms suspended in air
Article
  • Jun 1942
It has been found that propylene glycol vapor dispersed into the air of an enclosed space produces a marked and rapid bactericidal effect on microorganisms introduced into such an atmosphere in droplet form. Concentrations of 1 gm. of propylene glycol vapor in two to four million cc. of air produced immediate and complete sterilization of air into which pneumococci, streptococci, staphylococci, H. influenzae, and other microorganisms as well as influenza virus had been sprayed. With lesser concentrations of propylene glycol, rapid and marked reduction in the number of air-borne bacteria occurred, but complete sterilization of the air required a certain interval of time. Pronounced effects on both pneumococci and hemolytic streptococci were observed when concentrations as low as 1 gm. of glycol to fifty million cc. of air were employed. Numerous control tests showed that failure of the glycol-treated microorganisms to grow on the agar plates was due to actual death of the bacteria. The means by which propylene glycol vapor produces its effect on droplet-borne bacteria is discussed and data relating the bactericidal properties of propylene glycol in vitro to the lethal action of its vapor is presented. Atmospheres containing propylene glycol vapor are invisible, odorless, and non-irritating. This glycol is essentially non-toxic when given orally and intravenously. Tests on possible deleterious effects of breathing propylene glycol containing atmospheres over long periods of time are being carried out.
View
Ecigarettes: An evidence update. A report commissioned by Public Health England
  • Jan 2015
  • A Mcneill
  • Ls Brose
  • R Calder
  • Sc Hitchman
  • P Hajek
McNeill A, Brose LS, Calder R, Hitchman SC, Hajek P, et al. (2015) Ecigarettes: An evidence update. A report commissioned by Public Health England. PHE, London, UK.
Changes in the Frequency of Airway Infections in Smokers Who Switched To Vaping: Results of an Online Survey
  • Jan 2015
  • 290
  • A Mcneill
  • L S Brose
  • R Calder
  • S C Hitchman
  • P Hajek
McNeill A, Brose LS, Calder R, Hitchman SC, Hajek P, et al. (2015) Ecigarettes: An evidence update. A report commissioned by Public Health England. PHE, London, UK. Citation: Miler JA, Mayer BM, Hajek P (2016) Changes in the Frequency of Airway Infections in Smokers Who Switched To Vaping: Results of an Online Survey. J Addict Res Ther 7: 290. doi:10.4172/2155-6105.1000290