Puffing style and human exposure minimally altered by switching to a carbon-filtered cigarette.

OBJECTIVE Potential Reduced Exposure tobacco Products (PREP) are intended to lower human exposure to toxic constituents of tobacco smoke, but rigorous clinical evaluations are required to assess such claims. The present study assessed human smoking behavior and short-term exposure to a new carbon-filtered PREP, Marlboro UltraSmooth (MUS). Two MUS prototypes with filter carbon loads of 120 and 180 mg were compared with low and ultralow-yield conventional cigarettes. METHODS After a 48-hour baseline period, 32 adult Marlboro Lights smokers were switched in a counterbalanced order, to MUS and Marlboro Ultra Lights for 48 hours each. Measures of smoking topography, subjective response, change in cardiac response, and carbon monoxide boost were obtained under supervised test conditions on separate days. After each test, topography measures were obtained via a 48-hour free smoking phase for each brand. Salivary cotinine was measured at the end of each 48-hour period. RESULTS Although MUS was generally smoked in a style similar to conventional cigarettes, compensatory smoking was observed with 1 MUS prototype (P = 0.003). Carbon monoxide boost was lower for MUS compared with Marlboro Lights, but salivary cotinine and cardiac function measures after smoking of MUS did not vary from conventional brands. CONCLUSIONS Smoking MUS produced few differences in smoking topography and exposure compared with conventional low and ultralow-yield cigarettes. Results suggest that the manner in which MUS is smoked by humans is unlikely in the short term to reduce exposure among smokers who switch from a conventional brand.