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Chemical Characterization of Coarse Particulate Matter in the Desert Southwest - Pinal County Arizona, USA
Citation:
Clements, A., M. Fraser, N. Upadhyay, P. Herckes, M. Sundblom, J. Lantz, AND P. Solomon. Chemical Characterization of Coarse Particulate Matter in the Desert Southwest - Pinal County Arizona, USA. Atmospheric Pollution Research. Turkish National Committee for Air Pollution Research and Control, Izmir, Turkey, 5(1):52-61, (2014).
Impact/Purpose:
The National Exposure Research Laboratory′s (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA′s mission to protect human health and the environment. HEASD′s research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA′s strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
Description:
The Desert Southwest Coarse Particulate Matter Study was undertaken 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 (NAAQA) 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 material representing 15%. Fine particles still contain a significant crustal fraction (30%) but organic material dominantes at 37% of the particle mass.
URLs/Downloads:
FINAL FINAL PMCCHEMCHAR_APRREVISIONPLAIN WITH SUPPLEMENTAL.PDF (PDF, NA pp, 1099.862 KB, about PDF)APR-14-005-SM SUPPLEMENTAL.PDF (PDF, NA pp, 2401.99 KB, about PDF)
Atmospheric Pollution Research
