Figure 2. Puffing and inhalation patterns showing interindividual variation during the interval between puffing and inhalation31.
Puffing begins during exhalation from points A to B. For some smokers, the smoke is immediately inhaled from the mouth into the pharynx and lungs and completed at point C (A); for others, there is a mouth holding period where point C marks the beginning of the inhalation and completed at D (B); for others, there is an immediate inhalation until point C then an exhalation followed by an larger inhalation at point D (C); others have an immediate exhalation followed by an inhalation from points C to D (D).