One of the main differences between e-cigarettes and tobacco lies in their safety of use. How are e-cigarettes a safer alternative to smoking? Their safety is demonstrated firstly in their inhibition and reduction of combustion, which studies have proven to be one of the leading causes of tobacco-related morbidity and mortality [21,22], and secondly in their reduction of the environmental nuisance caused by second- or third-hand smoke. As e-cigarettes produce less toxic vapor than smoke from combustible cigarettes [21], some scholars consider them as being relatively less harmful to health than tobacco [23].

Another difference is that e-cigarettes function as an alternative to tobacco during smoking cessation. The relatively low risk of e-cigarettes makes them an essential aid in quitting smoking. They are the most popular method of quitting in the United Kingdom and the United States [24]. The health concerns of tobacco (nicotine) addiction are of great concern [25] and can lead to physiological and psychological problems. Physiologically, nicotine increases dopamine, produces adrenaline and blood glucose, and for a short time, brings pleasure, increases concentration, reduces appetite, and increases energy, but this good state does not last; a bad mood returns, followed by a greater craving for pleasure, which leads to the vicious cycle of tobacco addiction [26]. When an addictive substance is used repeatedly, tolerance to the substance gradually develops, which leads to demand for higher quantities of the substance in order to achieve the same effect [27]. Regarding the multidimensional and complex self-control of tobacco addiction, prevention, treatment, and cessation are of great concern [28,29]. Compared to other ways of quitting, e-cigarettes offer a pleasant alternative to smoking that can meet the needs of smokers by replacing the physical, psychological, social, cultural, and identity-related aspects of addiction [30,31].

However, the alternative effects of e-cigarettes are still worthy of deeper investigation. Studies have found secondary effects, such as smoking relapse, dual use, and priming effects in e-cigarette users [31,32]. Meanwhile, opponents argue that e-cigarettes and traditional cigarettes do not have a causal relationship, and that the temporary, linear channel between them is interfered with by other factors. Further, they argue that e-cigarette and traditional cigarette use behaviors are understood as sequential connections, and that these behaviors are part of a complex holistic process that also includes risk behaviors, consumption, and a variety of social complexities (gender, race, class) that cannot be reduced to individual components [33].

As a new tobacco and recreational product, e-cigarettes have revolutionized traditional smoking behavior with their unlit, portable, and flavorful features. The use of e-cigarettes is rich in connotations, both as a form of smoking cessation and as a new form of smoking behavior, which stems from the cross-cutting attribute of e-cigarettes’ being understood as both “cigarettes” and different from “traditional tobacco.” As the number of e-cigarette users increases globally, the social implications of e-cigarette use must be taken into account. From an e-cigarette user’s perspective, how are e-cigarettes viewed, and do they have alternative uses, dual uses, and introductory effects? How do e-cigarette users understand e-cigarette behavior in their daily lives? 

As individuals enter adolescence, along with experiencing the awakening and strengthening of self-awareness, they can become susceptible to the influence of peers, popular culture, and fashion discourse, and can develop health-hazardous behaviors, such as e-cigarette use [34]. A total of 3.6 million young Americans used e-cigarettes in 2018, and this figure rose to 5 million in 2019 [21]. In 2022, the Annual National Youth Tobacco Survey, which focused on middle and high school students, found that more than 2.5 million U.S. students currently used e-cigarettes. Meanwhile, recent data from the Chinese Center for Disease Control and Prevention reported that young people had an e-cigarette usage rate of 1.5% in 2018 in China. By 2021, young people’s usage rate had reached 2.5%, which was higher than that of 1.6% among adults, a finding which has also been supported in recent empirical studies [20,35].

Research on youth e-cigarette use behavior has first focused on the causal factors leading to e-cigarette use, specifically the peer effect [2,20], social attributes, and curiosity drive. The peer effect refers to e-cigarette use that is influenced by friends, classmates, and family members [21]; following and imitating are the main behavioral factors of e-cigarette use in the context of peer relationships. Closely related to peer influence, the social uses of e-cigarettes relate to their use in a broader sense, with e-cigarette features such as their providing freedom from smoke-free environments and transmission sharing [36,37,38] reinforcing connections among young users in specific settings. The curiosity-driven psychological factor relates to the value of e-cigarettes as a fashionable entertainment and lifestyle exhibition tool, providing a subcultural lifestyle that satisfies young people [2]. However, this kind of psychological motivation is vulnerable to the manipulation of e-cigarette suppliers, and supply advertising can enhance the e-cigarette acceptance of young people through the use of attractive photos, videos, and text on online platforms where youth gather [21,36].

Second, the influences of the technology, taste and decorative features of e-cigarettes can be explained from a developmental and objective perspective. E-cigarette technology has evolved through four generations to achieve more powerful features and to feature adaptive flavors. The current fourth generation of e-cigarettes, the pod-style e-cigarette (pod system), has gained new highs in the number of young users due to, among other factors, its portability due to its low weight, improved oil leakage, and lower manufacturing costs and prices (USD 43−46 in the Chinese market) [39]. The adaptability of e-cigarette flavors avoids the olfactory irritation and tarry taste of smoking traditional cigarettes and is dedicated to a pleasant sensory experience for users while suppressing the aversive effects of nicotine [40]. Worryingly, the presence of flavor, while masking the irritation of traditional cigarette use, can likewise reduce the body’s immediate perception of harm. For instance, Pepper [41] and other scholars found that American adolescents preferred to try menthol-, fruit-, and candy-flavored e-cigarettes, a preference that led to almost six times the interest in trying fruit flavored e-cigarettes compared to tobacco-flavored e-cigarettes, which fuelled e-cigarette use (this preference was discovered also in Jongenelis’ study [42]). Finally, the decorative features of e-cigarettes also appeal to young people. Featuring shapes full of design elements that support personalized design, such as protective cases and decorations, e-cigarette devices reinforce their users’ desire to purchase e-cigarette products [21,43,44].

Therefore, researchers have grown concerned that e-cigarettes can trigger more complex negative effects than traditional cigarettes. First, adolescents and young adults do not have a clear understanding of the hazards of e-cigarettes and only perceive them to be less harmful than traditional cigarettes [40], which could lead to physical dangers for users. Second, people who have tried e-cigarettes are more likely to use traditional cigarettes, given the “introductory effect” of e-cigarettes [45]. A meta-analysis of 91,051 adolescent subjects showed that the risk of adolescents using e-cigarettes and then using traditional cigarettes was 2.21 times higher than the risk of “never using e-cigarettes” [46]. Therefore, it is likely that e-cigarette addiction will occur before a user quits traditional cigarettes [47]. Based on this perception, some regions and countries have controlled the sale and use of e-cigarettes by improving state laws, regulating sales, and publishing the hazards of e-cigarette ingredients [48,49,50].