Smokers' response to shortened cigarettes: dose reduction without dilution of tobacco smoke.

This study was designed to examine the response of smokers to shortening their usual brand of cigarettes. The shortening reduces the dose of smoke available from each cigarette without affecting concentration and therefore differs from dose reduction by dilution, which occurs when smokers switch to cigarettes with lower tar and nicotine deliveries. Measures of smoking behavior (e.g., cigarette consumption, puff rate), mouth-level nicotine intake (calculated from butt content), and intake to the lungs (plasma nicotine and COHb) were made in 10 smokers after 48 hr ad libitum smoking of full, three-quarter, and half-length cigarettes in a Latin square design. Mouth-level smoke intake was maintained on shortened cigarettes due to a combination of 2 types of compensatory maneuver: (1) by increasing the intensity of puffing and thereby extracting proportionately more of the smoke available from each cigarette and (2) by smoking more cigarettes. The amount of smoke inhaled, on the other hand, was only partially maintained (58% compensation). This was achieved by increase in cigarette consumption alone. There was achieved by increase in cigarette consumption alone. There was no evidence of any compensatory increase in the amount of smoke inhaled from each cigarette. Increase in consumption was thus the only maneuver that contributed to maintaining smoke intake at lung level; mouth-level intake was regulated by increasing intake per cigarette as well as consumption.