Electronic Nicotine Delivery Systems
Electronic vaping products (EVPs) 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 EVP 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 are disposable or 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 can contain flavoring chemicals.2-4 When a user takes a puff from an EVP, the e-liquid is heated by the heating element and forms particles and gases that the user inhales into their lungs. A portion of the aerosol and gases taken into the EVP user’s lung is exhaled, which might result in exposure to bystanders in proximity to the user.5,6
Use of EVPSs is rising among adults in the United States.7,8 As of 2019, e-cigarettes were used by approximately 4.5 to 5.5% of U.S. adults.7,8 While EVP aerosol can differ in some ways from tobacco smoke, users of EVPs and those around persons using EVPs are still exposed to many different types of chemical compounds (some of which are known carcinogens), very small particles, and numerous hazardous metals.9 Chemicals emitted by ENDS 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.9 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. 10,11 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. 12
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 Policies 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 EVPs 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.13
CDC Morbidity and Mortality Weekly Reports:
- Tobacco Product Use Among Adults – United States, 2019.
- 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
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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/
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Ranpara A, Stefaniak AB, Fernandez E, Lebouf RF. Effect of puffing behavior on particle size distributions and respiratory depositions from pod-style electronic cigarette, or vaping, products. Front. Public Health. 9: Article 750402 (2021).
Kianersi S, Zhang Y, Rosenberg M, Macy JT. Prevalence of e-cigarette use (2016 to 2018) and cigarette smoking (2012 to 2019) among U.S. adults by state: An interactive data visualization dashboard. Drug Alcohol Depend. 2021 Jan 1;218:108361.
MMWR Morb Mortal Wkly Rep. 2020 Nov 20;69(46):1736-1742. Tobacco Product Use Among Adults – United States, 2019. doi: 10.15585/mmwr.mm6946a4
Eshraghian EA, Al-Delaimy WK. A review of constituents identified in e-cigarette liquids and aerosols.Tob Prev Cessat. 2021 Feb 10;7:10.
Bitzer ZT, Goel R, Reilly SM, Elias RJ, Silakov A, Foulds J, Muscat J, Richie JP, Jr. Effect of flavoring chemicals on free radical formation in electronic cigarette aerosols. Free Rad Biol Med. 120:72-79 (2018).
Stefaniak AB, LeBouf RF, Ranpara AC, Leonard SS. Toxicology of flavoring-and cannabis-containing e-liquids used in electronic delivery systems. Pharmacol Ther. 2021 Aug;224:107838.b.
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
Breitbarth AK, Morgan J, Jones AL E-cigarettes – An unintended illicit drug delivery system. Drug Alcohol Depend. 192:98-111 (2018).