Background:
Hainaut province has a low socioeconomic background and poor health indicators. Tobacco smoking is higher than national average. Since 1997, the Observatoire de la Santé du Hainaut has monitored the health of teenagers of its province.

Objectives:
Monitor health behaviours and health status of teenagers (10 to 17 years) and particularly smoking habits.

Methods:
Three samples of 500 pupils from 6th primary, 2nd and 4th secondary classes in Hainaut are drawn through a stratified cluster random sampling method. Students fill a self-questionnaire; weight, height, waist circumference and arterial pressure are measured during school medical examination. The survey includes specific indicators of tobacco/ e-cigarettes consumption: age at first consumption, frequency and habits, entourage influence, socioeconomic status indicators...

Results:
Smoking decreased from 30% in 1997 to 11% in 2017 among young people aged 15 to 17. Relatives have an influence: 16-year-olds whose parents and siblings are non-smokers have a limited risk of smoking (around 8%). However, the frequency of smoking (daily or non daily) increases to 17% if the father smokes, to 19% if the mother smokes and reaches 25% if a brother or a sister smokes. There is a smoking ban in all schools in Belgium. However, at 11 years old, 35% of the pupils declared that they saw a teacher smoking at school. This proportion increases to 54% for 16 year olds. Smoking habits are linked to family type and number of working parents. In 2017, 19% of 13-year-olds and 29% of 16-year-olds has experienced E-cigarette.

Conclusions:
Though smoking decreased in a twenty years period, it remains a public health challenge in groups where adults around keep on smoking and in disadvantaged social groups. E-cigarette is an emerging problem. Given the popularity of e-cigarette among teenagers, the risk that smoking increases again among the young adults is real.