Evaluation of Electronic Cigarette Use (Vaping) Topography and Estimation of Liquid Consumption: Implications for Research Protocol Standards Definition and for Public Health Authorities’ Regulation
Background: Although millions of people are using electronic cigarettes (ECs) and research on this topic has intensified in recent years, the pattern of EC use has not been systematically studied. Additionally, no comparative measure of exposure and nicotine delivery between EC and tobacco cigarette or nicotine replacement therapy (NRTs) has been established. This is important, especially in the context of the proposal for a new Tobacco Product Directive issued by the European Commission. Methods: A second generation EC device, consisting of a higher capacity battery and tank atomiser design compared to smaller cigarette-like batteries and cartomizers, and a 9 mg/mL nicotine-concentration liquid were used in this study. Eighty subjects were recruited; 45 experienced EC users and 35 smokers. EC users were video-recorded when using the device (ECIG group), while smokers were recorded when smoking (SM-S group) and when using the EC (SM-E group) in a randomized cross-over design. Puff, inhalation and exhalation duration were measured. Additionally, the amount of EC liquid consumed by experienced EC users was measured at 5 min (similar to the time needed to smoke one tobacco cigarette) and at 20 min (similar to the time needed for a nicotine inhaler to deliver 4 mg nicotine). Results: Puff duration was significantly higher in ECIG (4.2 ± 0.7 s) compared to SM-S (2.1 ± 0.4 s) and SM-E (2.3 ± 0.5 s), while inhalation time was lower (1.3 ± 0.4, 2.1 ± 0.4 and 2.1 ± 0.4 respectively). No difference was observed in exhalation duration. EC users took 13 puffs and consumed 62 ± 16 mg liquid in 5 min; they took 43 puffs and consumed 219 ± 56 mg liquid in 20 min. Nicotine delivery was estimated at 0.46 ± 0.12 mg after 5 min and 1.63 ± 0.41 mg after 20 min of use. Therefore, 20.8 mg/mL and 23.8 mg/mL nicotine-containing liquids would deliver 1 mg of nicotine in 5 min and 4 mg nicotine in 20 min, respectively. Since the ISO method significantly underestimates nicotine delivery by tobacco cigarettes, it seems that liquids with even higher than 24 mg/mL nicotine concentration would be comparable to one tobacco cigarette. Conclusions: EC use topography is significantly different compared to smoking. Four-second puffs with 20–30 s interpuff interval should be used when assessing EC effects in laboratory experiments, provided that the equipment used does not get overheated. Based on the characteristics of the device used in this study, a 20 mg/mL nicotine concentration liquid would be needed in order to deliver nicotine at amounts similar to the maximum allowable content of
References
[1]
Rigotti, N.A.; Pipe, A.L.; Benowitz, N.L.; Arteaga, C.; Garza, D.; Tonstad, S. Efficacy and safety of varenicline for smoking cessation in patients with cardiovascular disease: A randomized trial. Circulation 2010, 121, 221–229, doi:10.1161/CIRCULATIONAHA.109.869008.
[2]
Rodu, B.; Godshall, W.T. Tobacco harm reduction: An alternative cessation strategy for inveterate smokers. Harm Reduct. J. 2006, 3, 37, doi:10.1186/1477-7517-3-37.
[3]
Goniewicz, M.L.; Knysak, J.; Gawron, M.; Kosmider, L.; Sobczak, A.; Kurek, J.; Prokopowicz, A.; Jablonska-Czapla, M.; Rosik-Dulewska, C.; Havel, C.; et al. Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tob. Control 2013, doi:10.1136/tobaccocontrol 2012-050859.
[4]
ISO 3308: Routine Analytical Cigarette-Smoking Machine—Definitions and Standard Conditions; International Organization for Standardization (ISO): Geneva, Switzerland, 2000.
[5]
McQueen, A.; Tower, S.; Sumner, W. Interviews with “vapers”: Implications for future research with electronic cigarettes. Nicotine Tob. Res. 2011, 13, 860–867, doi:10.1093/ntr/ntr088.
[6]
Bullen, C.; Mc Robbie, H.; Thornley, S.; Glover, M.; Lin, R.; Laugesen, M. Effects of an electronic nicotine delivery device (ecigarette) on desire to smoke and withdrawal, user preferences and nicotine delivery: Randomised cross-over trial. Tob. Control 2010, 19, 98–103, doi:10.1136/tc.2009.031567.
[7]
Vansickel, A.R.; Cobb, C.C.; Weaver, M.F.; Eissenberg, T.E. A clinical laboratory model for evaluating the acute effects of electronic “cigarettes”: Nicotine delivery profile and cardiovascular subjective effects. Cancer Epidemiol. Biomark. Prev. 2010, 19, 1945–1953, doi:10.1158/1055-9965.EPI-10-0288.
[8]
Vansickel, A.R.; Eissenberg, T. Electronic cigarettes: Effective nicotine delivery after acute administration. Nicotine Tob. Res. 2013, 15, 267–270, doi:10.1093/ntr/ntr316.
[9]
European Commission. Proposal for a Directive of the European Parliament and of the Council on the Approximation of Laws, Regulations and Administrative Provisions of the Member States Concerning the Manufacture, Presentation and Sale of Tobacco and Related Products. Available online: http://ec.europa.eu/health/tobacco/docs/com_2012_ 788_en.pdf (accessed on 15 March 2013).
[10]
Benowitz, N.L.; Jacob, P.; Savanapridi, C. Determinants of nicotine intake while chewing nicotine polacrilex gum. Clin. Pharmacol. Ther. 1987, 41, 467–473, doi:10.1038/clpt.1987.58.
[11]
Schneider, N.G.; Olmstead, R.E.; Franzon, M.A.; Lunell, E. The nicotine inhaler: Clinical pharmacokinetics and comparison with other nicotine treatments. Clin. Pharmacokinet. 2001, 40, 661–684, doi:10.2165/00003088-200140090-00003.
[12]
Dawkins, L.; Turner, J.; Roberts, A.; Soar, K. “Vaping” profiles and preferences: An online survey of electronic cigarette users. Addiction 2013, 108, 1115–1125, doi:10.1111/add.12150.
[13]
Blank, M.D.; Dispharoon, S.; Eissenberg, T. Comparison of methods for measurement of smoking behaviour: Mouthpiece-based computerized devices versus direct observation. Nicotine Tob. Res. 2009, 11, 896–903.
[14]
Breland, A.B.; Kleykamp, B.A.; Eissenberg, T. Clinical laboratory evaluation of potential reduced exposure products for smokers. Nicotine Tob. Res. 2006, 8, 727–738, doi:10.1080/14622200600789585.
[15]
Pfizer. Nicotrol Inhaler Prescribing Information. Available online: http://www.pfizer.com/files/ products/uspi_nicotrol_inhaler.pdf (accessed on 24 May 2013).
[16]
European Commision. Directive 2001/37/EC of the European Parliament and of the Council of 5 June 2001 on the Approximation of the Laws, Regulations and Administrative Provisions of the Member States Concerning the Manufacture, Presentation and Sale of Tobacco Products. Available online: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:2001 L0037: 20090807:EN:PDF (accessed on 25 May 2013).
[17]
Purkis, S.W.; Troude, V.; Hill, C.A. Effect of puffing intensity on cigarette smoke yields. Regul. Toxicol. Pharmacol. 2013, 66, 72–82, doi:10.1016/j.yrtph.2013.03.006.
[18]
Djordjevic, M.V.; Fan, J.; Ferguson, S.; Hoffmann, D. Self-regulation of smoking intensity. Smoke yields of the low-nicotine, low-“tar” cigarettes. Carcinogenesis 1995, 16, 2015–2021.
[19]
Eberhardt, H.J.; Scherer, G. Human smoking behavior in comparison with machine smoking methods: A summary of the five papers presented at the 1995 meeting of the CORESTA Smoke and Technology Groups in Vienna. Beitr. Tab. Intl. 1995, 16, 131–140.
[20]
Rodu, B. The scientific foundation for tobacco harm reduction, 2006–2011. Harm Reduct. J. 2011, 8, 19, doi:10.1186/1477-7517-8-19.
[21]
Antal, M.J.; Mok, W.S.L.; Roy, J.C.; T-Raissi, A. Pyrolytic sources of hydrocarbons from biomass. J. Anal. Appl. Pyrolysis 1985, 8, 291–303.
[22]
Stein, Y.S.; Antal, M.J.; Jones, M.J. A study of the gas-phase pyrolysis of glycerol. J. Anal. Appl. Pyrolysis 1983, 4, 283–296, doi:10.1016/0165-2370(83)80003-5.
[23]
Etter, J.F.; Bullen, C. Electronic cigarette: Users profile, utilization, satisfaction and perceived efficacy. Addiction 2011, 106, 2017–2028, doi:10.1111/j.1360-0443.2011.03505.x.
[24]
Cahn, Z.; Siegel, M. Electronic cigarettes as a harm reduction strategy for tobacco control: A step forward or a repeat of past mistakes? J. Public Health Policy 2011, 32, 16–31.
[25]
McNeill, A.; Munafò, M.R. Reducing harm from tobacco use. J. Psychopharmacol. 2013, 27, 13–18.
[26]
Farsalinos, K.; Tsiapras, D.; Kyrzopoulos, S.; Voudris, V. Acute and chronic effects of smoking on myocardial function in healthy heavy smokers: A study of Doppler flow, Doppler tissue velocity and two-dimensional speckle tracking echocardiography. Echocardiography 2013, 30, 285–292, doi:10.1111/echo.12052.
[27]
Bolliger, C.T.; Zellweger, J.P.; Danielsson, T.; van Biljon, X.; Robidou, A.; Westin, A.; Perruchoud, A.P.; Sawe, U. Influence of long-term smoking reduction on health risk markers and quality of life. Nicotine Tob. Res. 2002, 4, 433–439, doi:10.1080/1462220021000018380.
[28]
Hatsukami, D.K.; Kotlyar, M.; Allen, S.; Jensen, J.; Li, S.; Le, C.; Murphy, S. Effects of cigarette reduction on cardiovascular risk factors and subjective measures. Chest 2005, 128, 2528–2537, doi:10.1378/chest.128.4.2528.
[29]
Godtfredsen, N.S.; Prescott, E.; Osler, M. Effect of smoking reduction on lung cancer risk. JAMA 2005, 294, 1505–1510, doi:10.1001/jama.294.12.1505.
[30]
Djordjevic, M; Stellman, S.D.; Zang, E. Doses of nicotine and lung carcinogens delivered to cigarette smokers. J. Natl. Cancer Inst. 2000, 92, 106–111.
[31]
Benowitz, N.L.; Hukkanen, J.; Jacob, P. Nicotine chemistry, metabolism, kinetics and biomarkers. Handb. Exp. Pharmacol. 2009, 192, 29–60.
