The importance of inhalation volume when measuring smoking behavior

Theoretical and technical considerations of measuring puff and inhalation volumes during cigarette smoking are reviewed. Measures of smoking behavior using a flowmeter and inductance plethysmography are described and demonstrated with seven subjects smoking over a 3-to 4-h period. Puff volume and duration, inhaled volume and duration, interpuff and intercigarette interval, and number of puffs varied for each individual over the session. The ratio of puff volume to inhaled volume changed with successive cigarettes. Smokers adjust the concentration of smoke by blending air with the smoke. Thus, to completely characterize smoking behavior, the volume of smoke and air inhaled into the lungs must be measured directly.