Background and objective:
The earlier a person reaches for nicotine, the longer they remain addicted to it. Use of tobacco products negatively affects the cardiorespiratory system. The study aimed to analyze factors associated with nicotine initiation among children and adolescents over a 3-year period.

Methods:
Data for analysis came from a questionnaire-based cross-sectional survey performed as part of the interdisciplinary SOPKARD-Junior program among the same cohort of students at elementary schools based in Sopot, Poland. Students and their parents participated in a prospective 3-year follow-up study. Responses were collected from children in 2018 at age of 10-11yo and again in 2021 at age 14-15yo. Each time, responses were also collected from the parent of the student research participant. The survey instrument was a set of forty-nine questions, based on the GYTS (The _Global Youth Tobacco Survey)_ questionnaire.

Results:
During the 3 year period, almost 4.5 times more children had already undergone nicotine initiation. An upward trend was observed in terms of teens noticing smoking people in mass-media - from 53% in 2018 to 68% in 2021. In 2018, children who underwent nicotine initiation declared using only one type of tobacco product. In 2021, already 53.8% of children after nicotine initiation had tried both traditional cigarettes and e-cigarettes. Teenagers were also two times more likely to declare using e-cigarettes than traditional cigarettes. There was a statistically significant correlation in both years indicating that non-smoking children who were frequently exposed to cigarette adverts in stores were more likely to initiate smoking after peer’s offer to smoke.

Conclusions:
In comparison to earlier elementary school grades, final grade students have a higher exposure to the concurrent use of electronic and traditional cigarettes and are more likely to initiate smoking. It is crucial to limit mass-media promotion of smoking and adolescents exposure to tobacco advertising.