A decade of e-cigarettes: Limited research & unresolved safety concerns

Abstract

It is well known that tobacco consumption is a leading cause of preventable deaths worldwide and has been linked to major diseases ranging from cancer to chronic obstructive pulmonary disease, atherosclerosis, stroke and a host of neurological/neurodegenerative disorders. In the past decade a number of alternative vaping products have hit the market, rapidly gaining consumers especially among the younger population. Electronic nicotine delivery systems or e-cigarettes have become the sought-after product due to the belief that they are much safer than traditional cigarettes. However, inadequate research and lack of regulatory guidelines for both the manufacturing process and the content of the vaping solution of the e-cigarette has become a major concern. Highly debated and unresolved questions such as whether e-cigarettes may help smokers quit and whether e-cigarettes will promote the use of nicotine among non-smokers add to the confusion of the safety of e-cigarettes. In this review article, we summarize the current understanding (and lack thereof) of the potential health impacts of e-cigarettes. We will also highlight the most recent studies (in vivo/in vitro) which seem to conflict with the broad safety claims put forward by the manufacturers. Finally, we provide potential solutions to overcome the research gap of the short and long-term health impact of e-cigarettes.

Keywords: Alternatives; Brain; Electronic cigarettes; Inflammation; Research; Teen smoking; Teen vaping; Toxicology; e-Liquids.

Figure 1. e-Cigarette schematic illustration

This device is primarily a battery operated product designed to turn nicotine and other chemicals (including solvents and flavoring agents) into a vapor; an atomizer heats the e-liquid producing the vapor inhaled by the user. A rechargeable battery (w/wo LED indicator) of different sizes and output powers to the atomizer. Note that the battery output and the resistance of the heating coils in the atomizer determine the vaping capacity of the e-cigarette.

Figure 2

Rise in e-Cigarette use among U.S. adults (2010–2014); Sample size >3000 each year (15 A.D.; McMillen et al., 2014).