The beginning of ENDS (electronic nicotine delivery systems): origins, trends, and regulatory considerations.

Electronic nicotine delivery systems (ENDS), commonly known as e-cigarettes, are battery-operated devices that produce aerosols by vaporizing e-liquids, which typically contain propylene glycol and/or vegetable glycerin, nicotine, and flavorings. Since their launch in the U.S. in 2007, ENDS have evolved significantly to meet consumer demands, prompting federal regulation in 2016 under the Family Smoking Prevention and Tobacco Control Act. The first ENDS resembled conventional tobacco cigarettes and were initially marketed as smoking cessation tools. While their smoking cessation efficacy under advantageous conditions has been supported by randomized clinical trials, observational cohort studies have raised doubt about their utility for smoking cessation under more typical real-world use conditions. In 2018, the U.S. Surgeon General declared youth vaping a national epidemic as prevalence of current ENDS use rose to 27.5% among high school. The youth vaping trend alongside injury reports and deaths related to e-cigarette or vaping product use-associated lung injury (EVALI) raised public health alarms in 2019. Although youth vaping has since declined, over 1.6 million high school students and 410, 000 middle school students reported ENDS usage in 2024. Thus, the ongoing challenges surrounding vaping including adolescent usage and smoking cessation efficacy continue to attract public health concern and debate. Within this section of the Special Issue "Science Education and Research on Vaping and Interventions for Community Engagement", an overview of the history of the vaping epidemic, current formats and ENDS generations, usage statistics across various demographics along with market trends and regulatory guidelines will be discussed.