Table 3. Exposure to environmental tobacco smoke (n = 427).

Items	Category	Frequency	Percentage
Is there any smoker in your family?	Yes	130	30.4
	No	297	69.6
Do you sit with family members while smoking?	Yes	75	17.6
	No	352	82.4
Regarding your friends, do you usually sit with smokers while smoking?	Yes	186	43.6
	No	241	56.4
If yes, how many times do you sit with friends(smokers) while smoking.	Daily	52	27.96
	3 to 4 days per week	27	14.5
	Weekends	37	19.9
	Occasionally	70	37.6