Wildfire particulate matter as a source of environmentally persistent free radicals and reactive oxygen species

Abstract

Wildfires, which have been occurring increasingly in the era of climate change, emit massive amounts of particulate matter (PM) into the atmosphere, strongly affecting air quality and public health. Biomass...

Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment

“…87 The measured ROS concentration (ROS V ) sampled in outdoor PM was 1.1 ± 1.0 pmol m −3 , which is ∼9 times lower than those reported near highway sites in California 86 but is comparable to ROS V measured in wildfire PM in Irvine, CA. 87 The average OP DTT per sampled outdoor air was 254 (± 103) pmol min −1 m −3 , which is lower than previous measurements in studies conducted in Irvine, 86 but similar to measurements in Atlanta 116 and the central California basin. 117 Georgia Tech focused on measurements of OP DTT for both the outdoor and indoor environments to assess health-relevant PM properties and how indoor air was affected by infiltration of outdoor air and by indoor sources.…”

“…As a baseline for indoor experiments and to understand health-relevant measures of outdoor air, we measured outdoor concentrations of EPFRs per volume of air (EPFR v ) outside the house to be 18 (± 12) pmol m –3 , which is 1.3 times higher than previous measurements at an urban site in Irvine, CA, but 2 times lower than near highway sites in California, and lower than highly urban polluted cities in China, such as Linfen and Beijing. , The average EPFR concentration per particle mass (EPFR m ) was 1.4 (± 0.4) pmol μg –1 , which is higher than ambient EPFR m in Mainz, and highway and urban samples for PM 1 . The measured ROS concentration (ROS V ) sampled in outdoor PM was 1.1 ± 1.0 pmol m –3 , which is ∼9 times lower than those reported near highway sites in California but is comparable to ROS V measured in wildfire PM in Irvine, CA . The average OP DTT per sampled outdoor air was 254 (± 103) pmol min –1 m –3 , which is lower than previous measurements in studies conducted in Irvine, but similar to measurements in Atlanta and the central California basin …”

“…The neighborhood surrounding the house had different sources from the more urban downtown site; therefore, the contrast between measurements of outdoor air at the house and downtown contributes to improving understanding of sources and chemical processing (C2, C4, C5, H5). Measurements of health-relevant properties, such as the oxidative potential (OP), − of PM both indoors and outdoors were used to address goals H1 and H2. Infiltration and changes to particles upon warming (H3, H4) were investigated by alternately sampling indoor and outdoor air with these real-time instruments and comparing gas and particle composition, including analysis by a semivolatile gas/particle (SV-TAG) instrument. , The SV-TAG, the single-particle aerosol time of flight mass spectrometer (ATOFMS), and the high-resolution aerosol mass spectrometer (HR-AMS) can detect chemical species such as polycyclic aromatic hydrocarbons (PAHs) and quinones that are known to affect OP, so the combination of these measurements should improve understanding of molecular species involved in outdoor and indoor health-related properties such as OP.…”

“…The neighborhood surrounding the house had different sources from the more urban downtown site; therefore, the contrast between measurements of outdoor air at the house and downtown contributes to improving understanding of sources and chemical processing (C2, C4, C5, H5). Measurements of health-relevant properties, such as the oxidative potential (OP), 84 − 87 of PM both indoors and outdoors were used to address goals H1 and H2. Infiltration and changes to particles upon warming (H3, H4) were investigated by alternately sampling indoor and outdoor air with these real-time instruments and comparing gas and particle composition, including analysis by a semivolatile gas/particle (SV-TAG) instrument.…”

Light Exposure of Wood Smoke Aerosol: Connecting Optical Properties, Oxidation, Radical Formation, and Chemical Composition

“…This analysis is not feasible with the aqueous extracts because their analyte abundance is too low to produce an EPR signal. In particular, it is known that wood smoke contains radical species. − Thermal processes, such as combustion, can induce persistent free radical formation through decomposition of molecular precursors containing the phenol moiety, such as catechol and hydroquinone . The radical products, such as semiquinone radicals, derive their stability through resonance as well as association with solid particle surfaces.…”