| Autor: |
Edwards KC; Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States., Kapur S; Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States., Fang T; Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States.; Sustainable Energy and Environment Thrust, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou, Guangdong 511400, China., Cesler-Maloney M; Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, Fairbanks, Alaska 99775, United States., Yang Y; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States., Holen AL; Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States., Wu J; Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States., Robinson ES; Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, Maryland 21212, United States., DeCarlo PF; Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, Maryland 21212, United States., Pratt KA; Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.; Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States., Weber RJ; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States., Simpson WR; Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, Fairbanks, Alaska 99775, United States., Shiraiwa M; Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States. |
| Abstrakt: |
Environmentally persistent free radicals (EPFRs) play an important role in aerosol effects on air quality and public health, but their atmospheric abundance and sources are poorly understood. We measured EPFRs contained in PM 2.5 collected in Fairbanks, Alaska, in winter 2022. We find that EPFR concentrations were enhanced during surface-based inversion and correlate strongly with incomplete combustion markers, including carbon monoxide and elemental carbon ( R 2 > 0.75). EPFRs exhibit moderately good correlations with PAHs, biomass burning organic aerosols, and potassium ( R 2 > 0.4). We also observe strong correlations of EPFRs with hydrocarbon-like organic aerosols, Fe and Ti ( R 2 > 0.6), and single-particle mass spectrometry measurements reveal internal mixing of PAHs, with potassium and iron. These results suggest that residential wood burning and vehicle tailpipes are major sources of EPFRs and nontailpipe emissions, such as brake wear and road dust, may contribute to the stabilization of EPFRs. Exposure to the observed EPFR concentrations (18 ± 12 pmol m -3 ) would be equivalent to smoking ∼0.4-1 cigarette daily. Very strong correlations ( R 2 > 0.8) of EPFR with hydroxyl radical formation in surrogate lung fluid indicate that exposure to EPFRs may induce oxidative stress in the human respiratory tract. |
