Determining Size-Specific Emission Factors for Environmental Tobacco Smoke Particles

Abstract

Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides-in addition to estimates of the emissions size distribution and integrated emission factorsestimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1−2+ µm diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01−1+ µm diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange- S. Department of Energy (DOE) underContract DE-AC03-76SF0098. Additional support was provided by the TRDRP under grant 6RT-0118 to Stanford University. We would like to express our appreciation for the technical assistance of D. Sullivan. S. Baker assisted with filter preparation and experimental procedure. The graphics and much of the data analysis for this research were accomplished using the freely-available R system described by Ihaka and Gentleman (1996) and accessible on the World Wide Web at http://www.r-project.org.Address correspondence to Neil E. Klepeis, 16475 Tarpey Road, Watsonville, CA 95076-9015. E-mail: nklepeis@uclink.berkeley.edu rate 20 m 3 chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1-2 h after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle emission factors were fit with log-normal distributions, yielding an average mass median diameter of 0.2 µm and an average geometric standard deviation of 2.3 with no systematic differences between cigars and cigarettes. The equivalent total particle emission rate, obtained by integrating each size distribution, was 0.2-0.7 mg/min for cigars and 0.7-0.9 mg/min for cigarettes.

Personal exposure to ultrafine particles

“…Cigarette emissions Although many studies have calculated particle mass emissions from cigarettes, few have provided number emission rates (Klepeis et al, 2003). In one experiment, a single Marlboro cigarette was smoked in the kitchen of the Virginia town house on 24 December 1997.…”

“…Outdoor UFP concentrations were measured for 1-2 years in several US cities (U.S. EPA Supersites program; Solomon et al, 2008), and near roadways in California (Zhu et al, 2002) and also in Erfurt and Augsberg, Germany (Wichmann et al, 2000). Residential indoor concentrations have also been reported (Abt et al, 2000;Dennekamp et al, 2001;Long et al, 2001;Wallace and Howard-Reed, 2002;Klepeis et al, 2003;He et al, 2004;Wallace, 2000Wallace, , 2005Wallace, , 2006Wallace et al, 2004Wallace et al, , 2008Hoek et al, 2008). A number of studies of exposures while driving have been done (Westerdahl et al, 2005;Fruin et al, 2008;Zhu et al, 2008).…”

Modeling residential exposure to secondhand tobacco smoke

“…We did not differentiate by particle size or incorporate particle deposition in the lung. Gravimetrically determined values for total SHS particle emission factors reported in the literature for cigarettes are in the approximate range of 8−20 mg cig −1 (see Klepeis et al, 2003). We chose 10 mg cig −1 to represent typical SHS particle emissions from a cigarette and 50 mg cig −1 to represent typical cigarette CO emissions (Martin et al, 1997).…”

Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways—Results of a pilot study

“…A TSI 2.5-mm-size impactor was installed at the intake of each SidePak monitor, which can measure particles down to a diameter of 0.1 mm (TSI, 2013a). Although the size range of secondhand smoke particles is 0.02-2 mm, about 90% of the particle mass is between 0.1 and 0.5 mm (Klepeis et al, 2003). Jiang et al (2011) found a consistent relationship between the SidePak readings and known mass concentrations of tobacco smoke measured using a gravimetric, pump-driven sampler with filters weighted on a precision laboratory scale.…”