Human exposures to particulate matter in the atmosphere are among the leading causes of premature death worldwide. Particles in the air are also known to have large, but uncertain effects on the radiative balance of the earth. The health and climate effects of particulate matter depend on their chemical and physical properties, and reflect their sources and atmospheric processing. Research in the Stone Group combines analytical, environmental, and organic chemistry with the objective of advancing our understanding of the chemical composition and sources of atmospheric particulate matter.  We use chromatography and mass spectrometry to improve measurements of atmospheric pollutants and source apportionment techniques to link pollution to its sources.

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, and prevalent combustion sources in South and East Asia (e.g., cook stoves, brick kilns, and peat burning); (ii) the molecular characterization of sea spray aerosol under the influence of phytoplankton blooms within the Center for Aerosol Impacts on Climate and the Environment; (iii) quantification of organosulfates and sulfonates in background and urban locations, in order to examine anthropogenic influences on secondary organic aerosol formation, and (iv) the study of the spatial and temporal variation in ambient particulate matter and bioaerosols in Iowa.

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.