An electronic cigarette (e-cigarette or vape) is a device designed to deliver nicotine and other chemicals to the lungs in the form of an aerosol. First invented in 2003, it was initially promoted as a safer alternative to traditional cigarettes. However, research has shown that e-cigarettes pose significant health risks.
The main components of e-cigarette liquids include propylene glycol, vegetable glycerin, flavorings, and usually nicotine. Nicotine is a highly addictive substance that affects the central nervous system and has harmful effects on the brain, cardiovascular system, and mental health. Usage among adolescents and women is rapidly increasing, raising serious public health concerns.
E-cigarettes negatively affect the respiratory, cardiovascular, and digestive systems. They can cause lung inflammation, heart dysfunction, oral diseases, and gastrointestinal issues. Long-term use increases the risk of cancer and chronic diseases.
Several factors contribute to the widespread use of e-cigarettes, especially among youth. These include peer influence, lack of awareness about health risks, appealing flavors, and easy accessibility. Therefore, preventive education and targeted interventions for young people are urgently needed. It is need to study the e cigarette consumption among youth and produce evidence for urgent and clear policy making. In that reason we are introducing a literature review using more than 50 sources published in various countries.

Background: Electronic cigarettes were invented in 2003, and their use has increased rapidly worldwide, especially among adolescents. Research shows that young people are more vulnerable to nicotine addiction, and a significant proportion of users have never smoked traditional cigarettes, indicating that e-cigarettes attract new users.
Key factors contributing to the rise in e-cigarette use include a wide variety of flavors, pleasant aromas, the misconception that they are less harmful than conventional cigarettes, easy accessibility, peer influence, and curiosity. Studies also indicate that parental smoking and exposure to secondhand smoke influence adolescent use.
In Mongolia, adolescents make up 16.7% of the total population, suggesting a substantial number are at risk of e-cigarette use. Despite existing legal restrictions on sales to minors, usage among adolescents continues, highlighting the need for further research on this issue. Objective: To study the prevalence of e-cigarette use and identify influencing factors among adolescents in Songinokhairkhan District, Ulaanbaatar Materials and Methods: A descriptive cross-sectional study design was employed to assess the prevalence of e-cigarette use and its associated risk factors among adolescents in Songinokhairkhan District. The study population consisted of students aged 12–18 years enrolled in local secondary schools. Using simple random sampling, 679 students from 7 out of 24 schools in the district were selected to ensure a representative sample. Eligibility was determined according to predefined inclusion and exclusion criteria, and data were collected through a structured, self-administered questionnaire covering sociodemographic characteristics, behavioral factors, and exposure to e-cigarette-related information. Data entry and management were conducted using Microsoft Excel 2021, while IBM SPSS Statistics 26 was employed for data analysis. Descriptive statistics (frequencies, percentages, means, standard deviations) were used to summarize participant characteristics, and inferential statistics, including Pearson correlation analysis, were applied to examine relationships between e-cigarette use and potential influencing factors. Statistical significance was set at p < 0.05. Ethical approval was obtained from the Research Ethics Subcommittee of “Ach” Medical University (Resolution No. 5). All participants and their parents or guardians provided informed consent prior to participation, and the study was conducted in full compliance with ethical principles and relevant research guidelines. Results: A total of 679 adolescents participated in the study; 52% (n=356) were male, and 81% (n=547) were aged 15–19 years. Of the participants, 43% (n=293) reported using e-cigarettes.
Among e-cigarette users, the reasons for use included curiosity (56.5%, n=174), peer use (22%, n=68), and stress (15.9%, n=49). Regarding duration of use, 67.8% (n=137) had used e-cigarettes for 1–6 months, while 12.8% (n=26) had used them for 1-2 years.
Statistically significant differences were found between e-cigarette users and non-users in terms of gender, knowledge about nicotine content, awareness that e-cigarettes may be more harmful than regular cigarettes, presence of e-cigarette users among peers, and presence of e-cigarette users in the household (p=0.003; <0.001; 0.02; 0.008; 0.002).
Male adolescents were 1.3 times more likely to use e-cigarettes (p=0.003, O
=1.3). Adolescents aged 10-14 were 1.2 times more likely to use e-cigarettes (OR=1.2, p=0.236). Having a household member who uses e-cigarettes increased the likelihood of adolescent e-cigarette use by 1.7 times (OR=1.7; p<0.001). Conclusions E-cigarette use is common among adolescents in Songinokhairkhan District, and it is significantly influenced by sex, knowledge about e-cigarettes, and the use of e-cigarettes by family members and peers.