Inhalable cigarette-burning particles: Size-resolved chemical composition and mixing state

Area of Science:

• Environmental Chemistry
• Atmospheric Science
• Aerosol Science

Background:

• Cigarette-burning particles (CBPs) are a significant source of indoor and outdoor air pollution.
• Understanding the chemical composition and size distribution of CBPs is crucial for assessing health risks associated with smoking.
• Previous studies have often lacked detailed, size-resolved chemical characterization of CBPs.

Purpose of the Study:

• To analyze the size-resolved chemical compositions of cigarette-burning particles (CBPs).
• To identify specific chemical components and their distribution across different particle sizes.
• To classify different types of CBPs based on their chemical signatures.

Main Methods:

• Utilized a single particle mass spectrometer (SPAMS) to characterize CBPs in the size range of 0.2-2.0 μm.
• Analyzed the presence and mixing ratios of various chemical compounds including polycyclic aromatic hydrocarbons (PAHs), organonitrate, metals, and biomass burning markers.
• Determined particle size distributions and classified particle types based on chemical composition.

Main Results:

• CBPs contain a complex mixture of PAHs, organonitrate, vinylpyridine, indene, guaiacol, methylindane, and metals (Fe, Cr, Mn, Cu).
• Fresh CBPs exhibit a modal size distribution peaking at 0.40 μm, with larger particles (>0.5 μm) favoring nicotine uptake.
• Biomass burning markers, sulfate, naphthalene, and methylindane were more abundant in larger CBPs (0.5-1.0 μm) compared to smaller ones (0.2-0.5 μm).
• Four main particle types were identified: CB-BB (50.3%), CB-BB-Metals (49.3%), CB-Nicotine (0.3%), and CB-Aged (0.1%).

Conclusions:

• The study provides a detailed chemical profile of CBPs, highlighting the importance of size-resolved analysis.
• Findings enhance scientific understanding of CBP formation, aging, and atmospheric behavior.
• Results offer valuable data for exposure assessment studies, particularly concerning secondhand smoke and its health impacts.