Objective: To assess the status of current e cigarette perception and its influencing factors among adolescents in Shanghai, so as to provide reference for the refinement of the prevention and control measures of teenagers e cigarette use. Methods: From May to June 2021, a stratified random cluster sampling was used to investigate 7 456 junior high and high school students in Shanghai. Harm and benefit perception of e cigarette as well as its social environment benefits were collected. Results: The rate of adolescents ever and current e cigarette use was 3.19% and 1.09%, respectively. The top four risk factors for low harm perception of e cigarette were adolescent e cigarette use( OR=2.74, 95%CI =2.10-3.59), high school students ( OR=1.47, 95%CI = 1.32 - 1.64 ), family members ( OR=1.45, 95%CI =1.24-1.70) and friends ( OR=1.36, 95%CI =1.20-1.54) using e cigarette. Adolescent ecigarette use ( OR=2.77, 95%CI =1.97-3.89), high school students( OR=2.11, 95%CI =1.89-2.36), friends ( OR= 1.63, 95%CI =1.42-1.87) and family members using e cigarette( OR=1.39, 95%CI =1.18-1.65) were the top four associated factors for high benefit perception of e cigarette. And, adolescent e cigarette use ( OR=1.95, 95%CI =1.47-2.59), high school students ( OR= 1.73, 95%CI =1.55-1.93), friends ( OR=1.60, 95%CI =1.40-1.82) and pocket money≥200 yuan using e cigarette( OR= 1.29 , 95%CI =1.17-1.43) were the top four risk factors for high social environmental benefit perception of e cigarette. Moreover, perception of e cigarette harm, benefit and social environmental benefit were associated with the risk of future use of e cigarette( OR = 0.78,1.44,1.21, P <0.01). Conclusion Being high school students and using e cigarette by oneself, friends, and family members are the important influencing factors for adolescents e cigarette perception. Both low harm and high benefit perception of e cigarette elevate the risk of future e cigarette use among adolescents, so effective measures should be taken to promote control education about e cigarette and smoke free environment construction.

In recent years, with the vigorous marketing of e-cigarette manufacturers, e-cigarettes have become a popular tobacco product for adolescents. The problem of e-cigarette environmental exposure among adolescents is also getting worse and its associated adverse impacts cannot be ignored. However, domestic research on the environmental exposure to e-cigarettes among youth is insufficient, and experience on e-cigarette regulation is also limited. This review first briefly introduced the definition and sources of e-cigarette environment exposure, then focused on the differences of e-cigarette environmental exposure among adolescents with different characteristics to identify possible influencing factors, as well as the impacts of e-cigarette environmental exposure on adolescents, and finally summarized international countermeasures to prevent e-cigarette environmental exposure in adolescents, aiming to provide directional guidance for China to conduct e-cigarette control activities among adolescents.