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Reviews on Environmental Health

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Electronic cigarettes: a systematic review of available studies on health risk assessment

Aziemah Zulkifli
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
/ Emilia Zainal Abidin
  • Corresponding author
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia, Phone: +603 89472643, Fax: +603 89472395
  • Email:
/ Najihah Zainol Abidin
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
/ Amer Siddiq Amer Nordin
  • Faculty of Medicine, Department of Psychological Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
/ Sarva Mangala Praveena
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
/ Sharifah Norkhadijah Syed Ismail
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
/ Irniza Rasdi
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
/ Karmegam Karuppiah
  • Faculty of Medicine and Health Sciences, Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
/ Anita Abd Rahman
  • Faculty of Medicine and Health Sciences, Department of Community Health, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
Published Online: 2016-04-21 | DOI: https://doi.org/10.1515/reveh-2015-0075


Objective: This paper primarily aimed to review articles which specifically quantified the risk of electronic cigarette’s (e-cigarette) usage via the health risk assessment (HRA) approach.

Methods: Systematic literature searches were conducted using PubMed search engine databases. Search terms such as “electronic cigarette”, “e-cigarette”, “electronic nicotine delivery systems”, “electronic cigarette liquid”, “electronic cigarette vapors”, and “health risk assessment” were used to identify the relevant articles to be included in this review. To enable comparison, hazard quotient (HQ) and lifetime cancer risk (LCR) for the chemicals measured in the selected articles were calculated for three of the articles using the formula: [1] HQ=average daily dose (ADD)/reference dose (RfD) or exposure air concentration (EC)/reference concentration (RfC); [2] LCR=lifetime average daily dose (LADD) × cancer slope factor (CSF) or exposure air concentration (EC) × inhalation unit risk (IUR).

Results: Four articles pertaining to HRA of e-cigarettes were critically reviewed, three of the papers focused on specific chemicals namely nicotine, propylene glycol (PG), glycerol and 1,2-propanediol, while one article evaluated the health risks posed by heavy metals contained in e-cigarettes. The calculated HQs for the chemicals in this review had large variations. HQs of the six chemicals, i.e. nicotine, PG, glycerol, cadmium, ethylene glycol, nickel, aluminum and titanium, were found to have the potential to contribute to non-carcinogenic health risks. None of the LCR calculated had risks exceeding the acceptable limit.

Conclusion: There are limited HRA studies and the ones that were available provided inconsistent scientific evidences on the health risk characterization arising from the usage of e-cigarettes. As such, there is a need to perform more studies on HRA of e-cigarettes by using uniformed and comprehensive steps and similar reference threshold levels of exposures.

Keywords: electronic cigarettes (e-cigarettes); e-liquid; hazard quotient; health risk assessment (HRA); margin of exposure; risk characterization


  • 1.

    Dawkins L, Turner J, Roberts A, Soar K. “Vaping” profiles and preferences: an online survey of electronic cigarette users. Addiction 2013;108(6):1115–25.Web of ScienceGoogle Scholar

  • 2.

    Dockrell M, Morrison R, Bauld L, McNeill A. E-cigarettes: prevalence and attitudes in Great Britain. Nicotine Tob Res 2013;15(10):1737–44.Web of ScienceGoogle Scholar

  • 3.

    Adkison SE, O’Connor RJ, Bansal-Travers M, Hyland A, Borland R, et al. Electronic nicotine delivery systems: International Tobacco Control Four-Country Survey. Am J Prev Med 2013;44(3):207–15.Web of ScienceGoogle Scholar

  • 4.

    Basis S, Regulation TP, Report T, Group WHOS. WHO Study Group on Tobacco Product Regulation. Report on the scientific basis of tobacco product regulation: third report of a WHO Study Group. World Health Organ Tech Rep Ser 2009;(955):1–41.Google Scholar

  • 5.

    Regan K, Promoff G, Dube SR, Arrazola R. Electronic nicotine delivery systems: adult use and awareness of the “e-cigarette” in the USA. Tob Control 2011:19–23.Web of ScienceGoogle Scholar

  • 6.

    King BA, Patel R, Nguyen KH, Dube SR. Trends in awareness and use of electronic cigarettes among US adults, 2010–2013. Nicotine Tob Res 2015;17(2):219–27.Web of ScienceGoogle Scholar

  • 7.

    Palipudi KM, Morton J, Mbulo L, Bunnell R, Blutcher NG, et al. Awareness and current use of electronic cigarettes in Indonesia, Malaysia, Qatar, and Greece: findings from 2011–2013 Global Adult Tobacco Surveys. Nicotine Tob Res 2016;18(4):501–7.Google Scholar

  • 8.

    Global Adult Tobacco Survey Greece (GATS). 2013. Available at: http://www.who.int/tobacco/surveillance/survey/gats/grc_country_report.pdf [accessed on 9 February, 2016].

  • 9.

    Global Adult Tobacco Survey Malaysia (GATS). 2011. Available at: http://www.moh.gov.my/images/gallery/Report/GATS_Malaysia.pdf [accessed on 9 February, 2016].

  • 10.

    Global Adult Tobacco Survey Indonesia (GATS). 2011. Available at http://www.who.int/tobacco/surveillance/survey/gats/indonesia_report.pdf [accessed on 9 February, 2016].

  • 11.

    Siegel MB, Tanwar KL, Wood KS. Electronic cigarettes as a smoking-cessation: tool results from an online survey. Am J Prev Med 2011;40(4):472–5.Web of ScienceGoogle Scholar

  • 12.

    Pisinger C, Døssing M. A systematic review of health effects of electronic cigarettes. Prev Med (Baltim) 2014;69C:248–60.Web of ScienceGoogle Scholar

  • 13.

    Hutzler C, Paschke M, Kruschinski S, Henkler F, Hahn JR, et al. Chemical hazards present in liquids and vapors of electronic cigarettes. Arch Toxicol 2014;88(7):1295–308.Web of ScienceGoogle Scholar

  • 14.

    International Agency for Research on Cancer. IARC. 2010. Retrieved at http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/TobaccoProductsScientificAdvisoryCommittee/UCM215717.pdf [accessed on 9 February, 2016].

  • 15.

    Goniewicz ML, Kuma T, Gawron M, Knysak J, Kosmider L. Nicotine levels in electronic cigarettes. Nicotine Tob Res 2013;15(1):158–66.Google Scholar

  • 16.

    AEMSA. (2014). E-Liquid manufacturing standards (Version 1.8, pp. 1–10). Author.Google Scholar

  • 17.

    Laugesen M. Safety Report on the Ruyan® e-cigarette Cartridge and Inhaled Aerosol. Heal NZ 2008;(October 2008):1–23.Google Scholar

  • 18.

    Kim HJ, Shin HS. Determination of tobacco-specific nitrosamines in replacement liquids of electronic cigarettes by liquid chromatography-tandem mass spectrometry. J Chromatogr A 2013;1291:48–55.Google Scholar

  • 19.

    Goniewicz ML, Lingas EO, Hajek P. Patterns of electronic cigarette use and user beliefs about their safety and benefits: an Internet survey. Drug Alcohol Rev 2013;32(2):133–40.Google Scholar

  • 20.

    Westenberger BJ. Evaluation of e-cigarettes. St. Lous, MO: FDA. DPATR-FY-09-23, 2009.Google Scholar

  • 21.

    Stepanov I, Jensen J, Hatsukami D, Hecht SS. Tobacco-specific nitrosamines in new tobacco products. Nicotine Tob Res 2006;8(2):309–313.Google Scholar

  • 22.

    International Agency for Research on Cancer. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. v. 89. IARC; Lyon, FR: 2007. Smokeless tobacco and tobacco-specific nitrosamines; 421–583.Google Scholar

  • 23.

    Hecht SS. Biochemistry, biology, and carcinogenicity of tobacco-specific N- nitrosamines. Chem Res Toxicol 1998;11(6):559–603.Google Scholar

  • 24.

    Kienhuis AS, Soeteman-Hernandez LG, Bos PM, Cremers HW, Klerx WN, et al. Potential harmful health effects of inhaling nicotine-free shisha-pen vapor: a chemical risk assessment of the main components propylene glycol and glycerol. Tob Induc Dis 2015;13(1):15.Google Scholar

  • 25.

    Farsalinos K, Voudris V, Poulas K. Are metals emitted from electronic cigarettes a reason for health concern? a risk-assessment analysis of currently available literature. Int J Environ Res Public Health 2015;12(5):5215–32.Web of ScienceGoogle Scholar

  • 26.

    Hahn J, Monakhova YB, Hengen J, Kohl-Himmelseher M, SchÜssler J, et al. Electronic cigarettes: overview of chemical composition and exposure estimation. Tob Induc Dis 2014;12(23). Doi: 10.1186/s12971-014-0023-6.CrossrefWeb of ScienceGoogle Scholar

  • 27.

    Exponent. NJOY e-cigarette health risk assessment. 2009. Available at: http://truthaboutecigs.com/science/5.php [accessed on 15 October, 2015].

  • 28.

    Zhu S-H, Sun JY, Bonnevie E, Cummins SE, Gamst A, et al. Four hundred and sixty brands of e-cigarettes and counting: implications for product regulation. Tob Control 2014;23 (suppl 3):iii3–9.Web of ScienceGoogle Scholar

  • 29.

    United States Environment al Protection Agency. 2015. Available at: http://www2.epa.gov/risk/human-health-risk-assessment [accessed on 9 February, 2016].

  • 30.

    EPA (United States Environmental Protection Agency). Methodology for deriving ambient water quality criteria for the protection of human health. Washington, DC: EPA. EPA822-B-00-004, 2000.Google Scholar

  • 31.

    Etter J-F. Electronic cigarettes: a survey of users. BMC Public Health 2010;10(1):231.Web of ScienceGoogle Scholar

  • 32.

    Farsalinos KE, Polosa R. Safety evaluation and risk assessment of electronic cigarettes as tobacco cigarette substitutes: a systematic review. Ther Adv drug Saf 2014;5(2):67–86.Google Scholar

  • 33.

    Orr MS. Electronic cigarettes in the USA: a summary of available toxicology data and suggestions for the future. Tob Control 2014;23(Suppl 2):ii18–22.Web of ScienceGoogle Scholar

  • 34.

    Trehy ML, Ye W, Hadwiger ME, Moore TW, Allgire JF, et al. Analysis of electronic cigarette cartridges, refill solutions, and smoke for nicotine and nicotine related impurities. J Liq Chromatogr Relat Technol 2011;34(14):1442–58.Web of ScienceGoogle Scholar

  • 35.

    Goniewicz ML, Knysak J, Gawron M, Kosmider L, Sobczak A, et al. Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tob Control 2014;23(2):133–9.Web of ScienceGoogle Scholar

  • 36.

    Watanabe KH, Djordjevic MV, Stellman SD, Toccalino PL, Austin DF, et al. Incremental lifetime cancer risks computed for benzo [a] pyrene and two tobacco-specific N-nitrosamines in mainstream cigarette smoke compared with lung cancer risks derived from epidemiologic data. Regul Toxicol Pharm 2009;55(2):123–33.Web of ScienceGoogle Scholar

  • 37.

    Pankow JF, Watanabe KH, Toccalino PL, Luo W, Austin DF. Calculated cancer risks for conventional and “potentially reduced exposure product” cigarettes. Cancer Epidemiol Biomarkers Prev 2007;16(3):584–92.Web of ScienceGoogle Scholar

  • 38.

    Xie J, Marano KM, Wilson CL, Liu H, Gan H, et al. A probabilistic risk assessment approach used to prioritize chemical constituents in mainstream smoke of cigarettes sold in China. Regul Toxicol Pharm 2012;62(2):355–62.Web of ScienceGoogle Scholar

  • 39.

    Fowles J, Dybing E. Application of toxicological risk assessment principles to the chemical constituents of cigarette smoke. Tob Control 2003;12(4):424–30.Google Scholar

  • 40.

    US EPA. HH: Risk characterization. 2015. Available at http://www.epa.gov/region8/hh-risk-characterization [accessed on 1 December, 2015].

  • 41.

    ILSI Risk Science Institute. The relevance of the rat lung response to particle overload for human risk assessment: a workshop consensus report. Inhal Toxicol 2000;12:1–17.Google Scholar

About the article

Received: 2015-12-10

Accepted: 2016-02-09

Published Online: 2016-04-21

Citation Information: Reviews on Environmental Health, ISSN (Online) 2191-0308, ISSN (Print) 0048-7554, DOI: https://doi.org/10.1515/reveh-2015-0075.

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