Coagulation of Mainstream Cigarette Smoke in the Mouth During Puffing and Inhalation

Abstract

The effect of Brownian coagulation on the particle size distribution of mainstream cigarette smoke subjected to conditions encountered in the mouth during human smoking has been examined experimentally and simulated with a numerical coagulation model. Smoke puffed into an artificial mouth was subjected to variable aging times and exhausted to a fast electrical mobility analyzer for particle size distribution measurement. The experimental results agreed well with the predictions of a sectional-based model of Brownian coagulation that allowed for the modeling of various continuous feed and fixed volume coagulation environments. Due to the steady input of fresh, smaller particles, particle growth during the filling of the mouth with smoke, a process intrinsic to the puffing maneuver, was significant but slower than that during fixed volume, static aging. Mouth hold times and initial smoke mass concentration were found to be strong determinants of the average particle size of smoke exiting the mouth into the respiratory tract during inhalation. The results also suggest that the smallest particles present in fresh smoke, those less than 0.1 µm diameter, are greatly reduced in number during the unavoidable mouth coagulation during puffing and virtually eliminated after 1 s of mouth hold.

Aerosol deposition doses in the human respiratory tree of electronic cigarette smokers

“…Moreover, the following parameters for a Caucasian adult male with a sitting awake level of activity were obtained from the ICRP report (1994): i) a Functional Residual Capacity (FRC) of 3300 mL, ii) an Upper Respiratory Tract (URT) volume equal to 50 mL, iii) a 12 min À1 breathing frequency, iv) and an air volume inhaled during a single breath (tidal volume, V T ) of 0.75 L. During smoking, the cigarette puff is mixed with a volume of ambient air. This is equal to the average lung tidal volume that delivers the smoke to the lungs (Ingebrethsen et al, 2011;Sahu et al, 2013). This volume mixes with and dilutes the puff smoke as it travels into the respiratory tract.…”

Characterization of Mainstream Cigarette Smoke Particle Size Distributions from Commercial Cigarettes Using a DMS500 Fast Particulate Spectrometer and Smoking Cycle Simulator

“…This broad market survey employing multiple smoking conditions and direct comparison of the aerosol mass measurements to gravimetric values provides information not previously available. However, it is important to recognize that machine-smoked aerosol measurements do not provide the best input for dosimetry models unless the effects of mouth aging during puffing have been replicated or taken into account theoretically (Higenbottam et al 1980;Tobin and Sackner 1982;Robinson and Yu 1999;Bernstein 2004;Ingebrethsen and Alderman, 2011). Symonds et al (2007) have described the DMS500 and thus only a brief summary of its function is given here.…”

Polonium in size fractionated mainstream cigarette smoke, predicted deposition and associated internal radiation dose

“…In this study MultiplePath Particle Dosimetry (MPPD V2.11) model is used for deposition fraction calculations, which in developed jointly by the Hamner Institutes for Health Sciences and the Dutch National Institute for Public Health and the Environment has been used for calculation of deposition fractions in different compartments of the human respiratory tract. During smoking, the cigarette puff is mixed with a volume of ambient air equal to the average lung tidal volume (500 mL) that delivers the smoke to the lungs (Ingebrethsen et al, 2011). This tidal volume mixes with the puff smoke and dilutes, as it travels into the respiratory tract.…”