Electronic Nicotine Delivery Systems
Electronic nicotine delivery systems (ENDS) such as e-cigarettes, e-hookahs, e-pipes and e-cigars are devices that deliver aerosolized nicotine, flavorings, and/or other chemicals into the lungs of users. Use of ENDS is sometimes referred to as “vaping.” A typical ENDS device contains three main components: a battery, a heating element, and a cartridge or tank that holds the e-liquid.1 Some of the newer devices look like USB sticks and have a disposable pod containing the e-liquid. The e-liquid is a solution that typically contains a mixture of nicotine, propylene glycol and glycerin. Additionally, e-liquid may also contain flavoring chemicals.2-4 When an ENDS user takes a puff from a device, the e-liquid is heated by the heating element and forms an aerosol and gases that the user inhales into their lungs. A portion of the aerosol and gases taken into the ENDS user’s lung is exhaled, which may result in exposure to bystanders in proximity to the user.5-6 A portion of the aerosol taken into the ENDS user’s lung is exhaled, which may result in exposure to bystanders in proximity to the user.
Use of ENDS is rising among never-tobacco smokers and former or current tobacco smokers.6-9 In 2017, e-cigarettes were used by approximately 2.8% (6.9 million) of U.S. adults.10 While ENDS aerosol may differ in some ways from tobacco smoke, users of ENDS and those around persons using ENDS are still exposed to many different types of chemical compounds (some of which are known carcinogens), very small particles, and numerous hazardous metals.11-13 Chemicals emitted in ENDS aerosols can include carcinogens such as formaldehyde, polyaromatic hydrocarbons, and other chemicals, as well as various organic compounds that are irritating to the lung, and flavoring compounds.14,16-18 Among flavoring compounds emitted in some ENDS aerosol are 2,3-pentanedione and diacetyl, which NIOSH has linked to causing obliterative bronchiolitis, a devastating lung disease in workers.4 Other flavoring chemicals can generate free radicals, which cause oxidative stress and are thought to influence the development of many tobacco-related diseases, such as cardiovascular disease, chronic obstructive pulmonary disease (COPD), and cancer.19 In addition to concerns about chemicals emitted from ENDS, there is also a risk of burns following spontaneous combustion of the lithium battery in the device.16
The potential health risks to users or bystanders exposed to secondhand smoke from ENDS is still under investigation. NIOSH issued a Current Intelligence Bulletin 67: Promoting Health and Preventing Disease and Injury Through Workplace Tobacco Policiespdf icon, that recommends employers establish “smoke-free workplaces that protect those in workplaces from involuntary, secondhand exposures to tobacco smoke and airborne emissions from e-cigarettes and other electronic nicotine delivery systems.” This recommendation covers all varieties of ENDS including e-hookahs, e-pipes, e-cigars, e-cigarettes and advanced modular ENDS. Some e-cigarettes are used to deliver aerosolized illicit drugs such as cannabis, methamphetamines, and cocaine to the user. By adding the illicit drug to the e-liquid, it may alter the characteristic of the drug (such as smell), making it difficult to know if a person is using an illicit drug.20
CDC Morbidity and Mortality Weekly Reports:
- E-cigarette Use Among Middle and High School Students – United States, 2020
- E-cigarette Unit Sales, by Product and Flavor Type – United States, 2014-2020
- Characteristics of E-cigarette, or Vaping, Products Used by Patients with Associated Lung Injury and Products Seized by Law Enforcement — Minnesota, 2018 and 2019
- Update: Interim Guidance for Health Care Providers for Managing Patients with Suspected E-cigarette, or Vaping, Product Use–Associated Lung Injury — United States, November 2019
- Characteristics of Hospitalized and Nonhospitalized Patients in a Nationwide Outbreak of E-cigarette, or Vaping, Product Use–Associated Lung Injury — United States, November 2019
- Risk Factors for E-Cigarette, or Vaping, Product Use–Associated Lung Injury (EVALI) Among Adults Who Use E-Cigarette, or Vaping, Products — Illinois, July–October 2019
Grana R, Ling P, Neal B, Glantz S . Electronic Cigarettes. Circulation; 129: 1972-1986.
Barrington-Trimis J, Samet J, McConnell R . Flavorings in electronic cigarettes an unrecognized respiratory health hazard? J Am Med Assoc; 312: 2493-2494.
Brown J, Luo W, Isabelle L, Pankow J . Candy flavorings in tobacco. Brown et al. N Eng J Med; 370:2250-2252.
Allen J, Flanigan S, LeBlanc M, Vallarino J, MacNaughton P, Stewart J, Christiani D . Flavoring chemicals in e-cigarettes: Diacetyl, 2,3-Pentanedione, and Acetoin in a sample of 51 products, including fruit, candy, and cocktail-flavored e-cigarettes. Environ Health Perspect. E-printhttp://ehp.niehs.nih.gov/15-10185/
Czogala J, Goniewicz M, Fidelus B, Zielinska-Danch W, Travers M, Sobczak A, . Secondhand exposure to vapors from electronic cigarettes. Nic Tobac Res; 16:655–662.
Johnson et al. Int J Hyg Environ Health. E-print (2019)
Singh T, Arrazola R, Corey C, Husten C, Neff L, Homa D, King B . Tobacco use among middle and high school students – United States, 2011-2015. MMWR Morb Mortal Wkly Rep; 65:361–367.
Pearson J, Richardson A, Niaura R, Vallone D, Abrams D . E-Cigarette awareness, use, and harm perceptions in US Adults. Am J Public Health; 102:1758– 1766.
Grana R, Benowitz N, Glantz S . E-Cigarettes, A scientific review. Circulation; 129:1972-1986.
King B, Patel R, Nguyen K, Dube S . Trends in awareness and use of electronic cigarettes among US adults, 2010-2013. Nicotine Tob Res; 17:219–227.
Wang, T. W. e. a. (2018). Tobacco Product Use Among Adults — United States, 2017. https://www.cdc.gov/mmwr/volumes/67/wr/mm6744a2.htm?s_cid=mm6744a2_w
Williams M, Villarreal A, Bozhilov K, Lin S, Talbot P . Metal and silicate particles including nanoparticles are present in electronic cigarette cartomizer fluid and aerosol. PLoS ONE; 8(3) e57987.
Bekki K, Uchiyama S, Ohta K, Inaba Y, Nakagome H, Kunugita N . Carbonyl compounds generated from electronic cigarettes. Int J Environ Res Publ Health; 11: 11192-11200.
Geiss O, Bianchi I, Barahona F, Barrero-Moreno J . Characterisation of mainstream and passive vapours emitted by selected electronic cigarettes. Int J Hyg Environ Health; 218:169-180.
Kim H, Shin H . Determination of tobacco-specific nitrosamines in replacement liquids of electronic cigarettes by liquid chromatography-tandem mass spectrometry. J Chromatog A; 1291: 48– 55.
Farsalinos K, Gillman I, Melvin M, Paolantonio A, Gardow W, Humphries K, Brown S, Poulas K, Voudris V . Nicotine levels and presence of selected tobacco-derived toxins in tobacco flavoured electronic cigarette refill liquids. Int J Environ Res Public Health; 12: 3439-3452.
Geiss O, Bianchi I, Barrero-Moreno J . Correlation of volatile carbonyl yields emitted by e-cigarettes with the temperature of the heating coil and the perceived sensorial quality of the generated vapours. Int J Hyg Environ Health; 219: 268-277.
Walsh K, Sheikh Z, Johal K, Khwaja N . Case Report: Rare case of accidental fire and burns caused by e-cigarette batteries. BMJ Case Rep; doi:10.1136/ bcr-2015-212868.
Bitzer et al. Free Rad Biol Med. 120 pg72-79 (2018)
Breitbarth et al. Drug Alcohol Depend. 192 pg98-111 (2018)