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

Abstract

Particle size distribution and number concentration measurements of mainstream cigarette smoke are reported for commercial cigarettes encompassing a broad range of design parameters. Measurements were made using a Cambustion DMS500 fast particulate spectrometer. Twenty-nine brand styles were evaluated using a 60-mL puff of 2-s duration taken once every 30 s. A subset of cigarettes was evaluated using additional smoking regimens to explore the influence of puff volume and filter ventilation blocking. The DMS500-derived particulate matter mass was compared with filter-collected mass to assess the reliability of the aerosol measurements. Under the 60-mL/2-s puffing condition, all puffs for all products were observed to exhibit count median diameters between 145 nm and 189 nm. Measured particle size was 12-22 nm smaller for a 60-mL puff relative to a 35-mL puff. Partial or complete filter ventilation blocking under the 60-mL/2-s puffing condition had a small effect on particle size. Some trends in particle size as a function of puff number and smoking regimen appear consistent with a tobacco-rod residence time/coagulation hypothesis; however, other observations suggest that smoke formation processes in addition to coagulation influence particle size. The DMS500 underestimates smoke particulate mass relative to gravimetric filter collection, indicating evaporation of cigarette smoke particulate matter within the instrument. Approximately 75% of the evaporated mass can be attributed to particulate phase water. Some data also suggest a possible underestimation of number concentration. This introduces a significant confounding bias in the measurements and limits the information on smoke formation that can be extracted.

Particle Size Distribution of E-Cigarette Aerosols and the Relationship to Cambridge Filter Pad Collection Efficiency

“…Conversely, spectral transmission measurements made in the undiluted state yielded particle count median diameters ranging from 210-390 nm and particle number concentrations were in the 10 9 particles/cm 3 range. These values are comparable to those of tobacco burning cigarette smoke (12,(15)(16)(17). Furthermore, aerosol mass calculated from these parameters was generally consistent with filtercollected gravimetric mass.…”

“…Aerosol dilution is also required to lower aerosol concentrations to within the operational range of some types of measurement instrumentation, e.g., electrical low pressure impactors and fast electric mobility analyzers. However, it has been established that significant amounts of particulate matter can evaporate under typical dilution levels, owing to the presence of volatile components in mainstream smoke (11)(12). The result is that the PSD measured is not reflective of the PSD exiting the cigarette.…”

Real-Time Measurement of Electronic Cigarette Aerosol Size Distribution and Metals Content Analysis

“…Freshly formed combustible tobacco smoke requires high dilution before measuring aerosol particle size because the high concentration of particles leads to coagulation and changes in the size distribution. 19 Particle concentration in e-cigarettes is smaller 20,21 than in combustible cigarette smoke, thus e-cigarette aerosol coagulates at a slower rate. Also, unlike combustible tobacco smoke particles, which consist mostly of semi-volatile and low-volatile compounds, e-cigarette aerosol at high dilution evaporates quickly.…”

Measurement of an electronic cigarette aerosol size distribution during a puff

“…The particle number concentration increased with increasing puff number. This phenomenon was observed in other studies as well [14,15] and it is probably caused by the actual length of the remaining smoldering cigarette. On the other hand, the size distributions were comparable between the puffs except for the first puff.…”