Size-resolved exposure risk of persistent free radicals (PFRs) in atmospheric aerosols and their potential sources

• Published in: Atmospheric chemistry and physics Vol. 20; no. 22; pp. 14407 - 14417
• Main Authors: Chen, Qingcai, Sun, Haoyao, Song, Wenhuai, Cao, Fang, Tian, Chongguo, Zhang, Yan-Lin
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 27-11-2020; Copernicus Publications
• Subjects: Aerosols; Algorithms; Alveoli; Atmospheric aerosols; Atmospheric particulate matter; Atmospheric particulates; Atmospheric physics; Atmospheric pollution deposition; Atoms & subatomic particles; Burning; Carbon; Cigarettes; Coal combustion; Combustion; Dust storms; Equivalence; Exposure; Free radicals; Hazardous substances; Health aspects; Health risk assessment; Health risks; Particle size; Particulate emissions; Particulate matter; Particulate matter sources; Particulates; Respiratory tract; Smoking; Summer; Suspended particulate matter; Winter; United States > US; China; Germany
• ISSN: 1680-7324; 1680-7316; 1680-7324
• DOI: 10.5194/acp-20-14407-2020

Environmentally persistent free radicals (EPFRs) are a
new type of substance with potential health risks. EPFRs are widely present
in atmospheric particulates, but there is a limited understanding of the
size-resolved health risks of these radicals. This study reports the
exposure risks and source of EPFRs in atmospheric particulate matter (PM) of
different particle sizes (<10 µm) in Linfen, a typical
coal-burning city in China. The type of EPFRs in fine particles (< 2.1 µm) is different from that in coarse particles (2.1–10 µm) in
both winter and summer. However, the EPFR concentration is higher in coarse
particles than in fine particles in summer, and the opposite trend is found
in winter. In both seasons, combustion sources are the main sources of EPFRs,
with coal combustion as the major contributor in winter, while other fuels
are the major source in summer. Dust contributes part of the EPFRs, and it is
mainly present in coarse particles in winter and the opposite in summer. The
upper respiratory tract was found to be the area with the highest risk of
exposure to EPFRs of the studied aerosols, with an exposure equivalent to
that of approximately 21 cigarettes per person per day. Alveolar exposure to
EPFRs is equivalent to 8 cigarettes per person per day, with combustion
sources contributing the most to EPFRs in the alveoli. This study helps us
to better understand the potential health risks of atmospheric PM with
different particle sizes.