Causes and consequences of decreasing atmospheric organic aerosol in the United States
Author(s)
Ridley, David Andrew
Heald, Colette L.
Ridley, K. J.
Kroll, Jesse
Date Issued
January 2018
Journal
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences (U.S.)
Citation
Ridley, D. A. et al. “Causes and Consequences of Decreasing Atmospheric Organic Aerosol in the United States.” Proceedings of the National Academy of Sciences 115, 2 (December 2017): 290–295 © 2018 National Academy of Sciences
Version
Final published version
Abstract
Exposure to atmospheric particulate matter (PM) exacerbates respiratory and cardiovascular conditions and is a leading source of premature mortality globally. Organic aerosol contributes a significant fraction of PM in the United States. Here, using surface observations between 1990 and 2012, we show that organic carbon has declined dramatically across the entire United States by 25–50%; accounting for more than 30% of the US-wide decline in PM. The decline is in contrast with the increasing organic aerosol due to wildfires and no clear trend in biogenic emissions. By developing a carbonaceous emissions database for the United States, we show that at least two-thirds of the decline in organic aerosol can be explained by changes in anthropogenic emissions, primarily from vehicle emissions and residential fuel burning. We estimate that the decrease in anthropogenic organic aerosol is responsible for averting 180,000 (117,000–389,000) premature deaths between 1990 and 2012. The unexpected decrease in organic aerosol, likely a consequence of the implementation of Clean Air Act Amendments, results in 84,000 (30,000–164,000) more lives saved than anticipated by the EPA between 2000 and 2010. Keywords: carbonaceous aerosol; organic aerosol; PM mortality; anthropogenic emissions; long-term trends
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
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Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1073/PNAS.1700387115
