es0c00483_si_001.pdf (1.69 MB)
Fine Particle Iron in Soils and Road Dust Is Modulated by Coal-Fired Power Plant Sulfur
journal contribution
posted on 2020-05-22, 16:05 authored by Jenny
P. S. Wong, Yuhan Yang, Ting Fang, James A. Mulholland, Armistead G. Russell, Stefanie Ebelt, Athanasios Nenes, Rodney J. WeberTransition metal ions,
such as water-soluble iron (WS-Fe), are toxic components of fine particles
(PM2.5). In Atlanta, from 1998 to 2013, a previous study
found that WS-Fe was the PM2.5 species most associated
with adverse cardiovascular outcomes. We examined this data set to
investigate the sources of WS-Fe and the effects of air quality regulations
on ambient levels of WS-Fe. We find that insoluble forms of iron in
mineral and road dust combined with sulfate from coal-fired electrical
generating units were converted into soluble forms by sulfate-driven
acid dissolution. Sulfate produced both the highly acidic aerosol
(summer pH 1.5–2) and liquid water required for the aqueous
phase acid dissolution, but variability in WS-Fe was mainly driven
by particle liquid water. These processes were more pronounced in
summer when particles were most acidic, whereas in winter the relative
importance of WS-Fe from combustion emissions increased. Although
WS-Fe constituted a minute fraction of PM2.5 mass (0.15%),
the WS-Fe-PM2.5 mass correlation was high (r = 0.67) and may be explained by these formation routes, which, in
part, could account for observed associations between PM2.5 mass and adverse health seen in past studies. Similar processes
are expected in many regions, implying that these unexpected benefits
from coal-burning reduction may be widespread.
History
Usage metrics
Categories
Keywords
ambient levelssulfate-driven acid dissolutioncombustion emissionsroad dustPM 2.5 massformation routesPM 2.5 speciesminute fractionCoal-Fired Power Plant Sulfur Transition metal ionsSimilar processesRoad Dustcoal-burning reductionPM 2.5WS-Fe-PM 2.5 mass correlationacidic aerosolphase acid dissolutionair quality regulationsFine Particle Iron
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC