B.A., Grinnell College (2005) Ph.D., University of Wisconsin-Madison (2009)

Analytical Chemistry

Research in the Stone group focuses on the chemical composition solid/liquid particles in the atmosphere, called aerosols. Atmospheric aerosols are complex environmental mixtures that come from anthropogenic and natural sources. Primary sources emit aerosol directly to the atmosphere; such as motor vehicles, electric power utilities, biomass burning, plant detritus, and resuspended dust. Secondary aerosols form in the atmosphere, through chemical reactions and particle growth. The physical and chemical properties of aerosols determine their environmental and health impacts. Studies of ambient aerosol composition are used to understand its origin and gain insight to how aerosols transform in the environment. Several ongoing projects include (i) the characterization emissions from biomass burning, mobile source emissions, and secondary sources, (ii) the measurement and characterization of nitrogen and sulfur-containing organic molecules, and (iii) study of the spatial and temporal variation in ambient particulate matter and bioaerosols in Iowa. Our research is motivated by the need to understand how ambient air pollution impacts human and environmental health. Poor air quality is associated with asthma and cardio-vascular diseases, increased hospital visits, and mortality. Yet, the chemical drivers behind these health endpoints are not well understood. We also strive to better understand the role that aerosols play an important role in regulating climate, through direct and indirect radiative forcing. Our research incorporates field-based and laboratory experiments. We utilize a variety of quantitative analytical tools, including gas and liquid chromatography (GC and LC) to separate chemical species and enhance their detection and mass spectrometry (MS) for determination of marker species and quantitation. Aerosol measurements are used to evaluate temporal and spatial variations in aerosol concentrations and in source apportionment models. With an improved understanding aerosol composition and origins, the better equipped we are to manage air quality and protect human health.

Downard, J.; Singh, A.; Bullard, R.; Jayarathne, T.; Rathnayake, C. M.; Simmons, D. L.; Wels, B. R.; Spak, S. N.; Peters, T.; Beardsley, D.; Stanier, C. O.; Stone, E. A. "Uncontrolled combustion of shredded tires in a landfill - Part 1: Characterization of gaseous and particulate emissions" Atmospheric Environment, 2015, 104, 195-204. doi: 10.1016.j.atmosenv.2014.12.059 Singh, A.; Spak, S. N.; Stone, E. A.; Downard, J.; Bullard, R.; Pooley, M.; Kostle, P. A.; Mainprize, M. W.; Wichman, M. D.; Peters, T.; Beardsley, D.; Stanier, C. O. "Uncontrolled combustion of shredded tires in a landfill ‐ Part 2: Population Exposure, Public Health Response, and an Air Quality Index for Urban Fires" Atmospheric Environment, 2015, 104, 273-283. doi: 10.1016.j.atmosenv.2015.01.002 Washenfelder, R. A.; Attwood, A. R; Guo, J.; Weber, R. J.; Brock, C. A.; Brown, S. S.; Allen, H. M.; Ayres, B. R.; Baumann, K.; Cohen, R. C.; Draper, D. C.; Duffey, K. C.; Edgerton, E.; Fry, J. L.; Hu, W.; Jimenez, J. L.; Ng, N. L.; Palm, B.; Romer, R.; Stone, E. A.; Wooldridge, P. J.; Xu, L. "Biomass burning dominates brown carbon aerosol in the rural Southeastern United States" Geophysical Research Letters, 2015, in press. doi:10.1002/2014GL062444 Laskina, O.; Morris, H. S.; Grandquist, J. R.; Qin, Z.; Stone, E. A.; Tivanski, A. V.; Grassian, V. H. "Size Matters in the Water Uptake and Hygroscopic Growth of Atmospherically Relevant Multi-Component Aerosol Particles" Journal of Physical Chemistry A, 2015, in press. doi: 10.1021/jp510268p Jayarathne, T.; Stockwell, C. E.; Yokelson, R. J.; Nakao, S., Stone, E. A. "Emissions of fine particle fluoride from biomass burning" Environmental Science & Technology, 2014, 48 (21): 12636-12644. doi: 10.1021/es502933 Staudt, S.; Kundu, S.; He, X.; Lehmler, H.; Lin, Y.; Cui, T.; Kristensen, K.; Glasius, M.; Zhang, X.; Weber, R.J.; Surratt, J.D., Stone, E. A. "Aromatic organosulfates in atmospheric aerosols: synthesis, characterization, and abundance" Atmospheric Environment, 2014, 94, 366-373. doi:10.1016/j.atmosenv.2014.05.049 Kundu, S; Stone, E. A. "Composition and sources of fine particulate matter across urban and rural sites in the Midwestern United States" Environmental Science: Processes & Impacts, 2014, 16 (6), 1360 - 1370. doi: 10.1039/C3EM00719G Liu, Shang; Aiken, A. C.; Arata, C.; Dubey, M. K.; Stockwell, C. E.; Yokelson, R. J.; Stone, E. A.; Jayarathne, T.; Robinson, A.; DeMott, P. J.; Kreidenweis, S. M. "Aerosol single scattering albedo dependence on biomass combustion efficiency: Laboratory and field studies" Geophysical Research Letters. DOI: 10.1002/2013GL058392 Rutter, A.P.; Snyder, D. C.; Stone, E. A.; Shelton, B.; DeMinter, J.; Schauer, J. J. "Preliminary assessment of the anthropogenic and biogenic contributions to secondary organic aerosols at two industrial cities in the upper Midwest." Atmospheric Environment, 2014, 84: 307-313. Kundu, S.; Quraishi, T.; Yu, G.; Suarez, C.; Keutsch, F.; Stone, E. A. "Evidence and Quantitation of Aromatic Organosulfates in Ambient Aerosols in Lahore Pakistan" Atmospheric Chemistry and Physics, 2013, 13: 4865-4875. Stone, E. A; Nguyen, T.T.; Pradhan B. B.; Dangol, P. M., Assessment of biogenic secondary organic aerosol in the Himalayas. Environmental Chemistry, 2012, 9, 263-272, invited manuscript. Stone, E. A.; Yang, L.M.; Yu, L.E.; Rupakheti, M., Characterization of organosulfates in atmospheric aerosols at four Asian locations, Atmospheric Environment, 2012, 47, 323-329. Olson, C. O.; Galloway, M. M.; Yu, G.; Hedman, C. J.; Lockett, M. R.; Yoon, T.; Stone, E.A.; Keutsch, F. N., Hydroxycarboxylic acid-derived organosulfates: synthesis, stability, and quantification in ambient aerosol, Environmental Science & Technology, 2011, 45, 6468-6474. Stone, E. A.; Yoon, S.; Schauer, J. J., Composition of fine and coarse particulate matter in Gosan, Korea during the springtime dust season, Aerosol and Air Quality Research, 2011, 11, 1, 31-43.