Chemical characterization of coarse particulate matter in the Desert Southwest - Pinal County Arizona, USA

Andrea L. Clements, Matthew Fraser, Nabin Upadhyay, Pierre Herckes, Michael Sundblom, Jeffrey Lantz, Paul A. Solomon

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


The Desert Southwest Coarse Particulate Matter Study was undertaken to further our understanding of ambient concentrations and the composition of fine and coarse particles in rural, arid environments. Sampling was conducted in Pinal County, Arizona between February 2009 and February 2010. The goals of this study were to: (1) chemically characterize the coarse and fine fraction of the ambient particulate matter in terms of mass, ions, elements, bulk organic and elemental carbon; (2) examine the temporal and spatial variability of particles within the area using a series of three sampling locations and use this information to determine the contribution of local vs. regional sources; (3) collect, re-suspend, and chemically characterize various crustal sources within the area to identify differences which may isolate them (crustal sources) as independent sources, and; (4) use a receptor based modeling approach to identify particle sources and the relative impact of each on ambient PM concentrations. This work reviews the study objectives, design, site descriptions, and measurement techniques relevant to this research effort and presents the general characteristics of PM during the study period. This unique dataset will support efforts to reduce PM10 and PM2.5 concentrations in the area to below the National Ambient Air Quality Standards (NAAQS) for these pollutants. Coarse particle concentrations are, on average, approximately 5 times fine particle mass concentrations within the region. Coarse particle concentrations in Pinal County are highest during spring and fall seasons, consistent with the tilling and harvesting seasons while fine particles concentrations are highest during fall. Crustal material is the dominant component of coarse particle composition, representing 50% of the mass on average followed closely by organic matter representing 15%. Fine particles still contain a significant crustal fraction (30%) but organic matter dominates at 37% of the particle mass.

Original languageEnglish (US)
Pages (from-to)52-61
Number of pages10
JournalAtmospheric Pollution Research
Issue number1
StatePublished - Jan 2014


  • Chemical composition
  • Coarse particles
  • Desert aerosols
  • Fine particles

ASJC Scopus subject areas

  • Waste Management and Disposal
  • Pollution
  • Atmospheric Science


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