Previous or current diseases:

• People who have had or have respiratory, cardiovascular, allergic problems or diseases that can be aggravated by tobacco use are especially vulnerable.
• Pregnancy and lactation: Nicotine crosses the placental barrier that protects the fetus and also passes into breast milk.

In front of minors:

• Not only are they exposed to smoke, but they are taught an erroneous model of behavior for them.
• Small rooms and without good ventilation.

Adolescents:

• The age of onset is related to tobacco dependence and the difficulty in quitting.

NOT SMOKING IS ESPECIALLY IMPORTANT IN CASES IN WHICH THE DAMAGE TO YOUR OWN HEALTH OR THIRD PARTIES INCREASES.