Introduction and objective:
Since the introduction of electronic cigarettes (e-cigarettes), they have become popular in a short period of time, especially among youths. They are considered to be a healthier nicotine delivery system than cigarettes and supposed to be helpful in quitting smoking. However, studies have shown that they are a source of carcinogens such as, formaldehyde and acetaldehyde, polycyclic aromatic hydrocarbons, nitrosamines and heavy metals. The use of e-cigarettes can lead to the development of civilization diseases. The components of e-cigarette aerosol can also be harmful to people passively exposed to them.

Material and methods:
A questionnaire survey was conducted in 2022–2023 in a group of 79 medical students (47 women and 32 man) aged 19–37 at the Medical University of Silesia in Katowice, south-west Poland.

Results:
In the surveyed group of students, 28 reported smoking traditional cigarettes and 21 reported using e-cigarettes. Most e-cigarette smokers (52.4%) use less than 2ml of liquid per day. E-cigarettes are most often used at parties and in combination with alcohol. More than 90% of e-smokers smoke in rooms where non-smokers are present. Nearly 91% of respondents were passively exposed to e-cigarette vapour. When asked about toxic compounds formed during the process of liquid vaporization, nearly half of respondents (46.7%) answered ‘don’t know’. The second most common answer was ‘carcinogenic compounds’, and some mentioned heavy metals.

Conclusions:
The vast majority of respondents were exposed to passive smoking of e-cigarettes. Many respondents had no knowledge of the harmful substances contained in e-cigarette smoke or gave incorrect answers.