Submitted to: Proceedings of Environmental Protection Agency Dust Emissions
Publication Type: Proceedings
Publication Acceptance Date: 4/25/2001
Publication Date: 5/1/2001
Citation: Zobeck, T.M., and Amante-Orozco, A. 2001. Effect of dust source clay and carbonate content on fugitive dust emissions. Proceedings of the US-EPA 10th Annual Emission Inventory /conference. On CD at website: http://www.epa.gov/ttn/chief/conference/ei10/index.html#ses-12
Interpretive Summary: Wind erosion of soils, roads, and other bare land surfaces is a major source of airblown dust in the Southern High Plains of Texas. Little is known about how much and the characteristics of fine suspended dust from agricultural soils. This study describes the properties of suspended dust collected from eight soils of the Southern High Plains near Lubbock, Texas. .The soils included high and low amounts of clay and carbonate. A special dust generating device developed by the USDA-ARS was used to create and analyze the particle sizes of the dust from the soils. The dust concentration was also measured by several dust monitor devices which measured fine dust regulated by the USEPA called PM10, particulate matter 10 microns in diameter and smaller. We found the dust levels increased as the clay and carbonate level in the soil increased. Soil with high carbonate content tended to create more dust than soils with high clay content. The size of the dust particles tended to decrease as carbonate and clay content increased. We also found that dustiness of soils was highly variable. The amount of dust created from several sites within the same field were often quite variable. This study demonstrated that broad generalizations about the amount of dust generated from soils is not appropriate. The amount and characteristics of the dust will greatly vary within the same field and among soils with different chemical and physical properties.
Technical Abstract: Wind erosion of soils, roads, and other bare land surfaces is a major source of fugitive dust in the Southern High Plains of Texas. Little is known about the relationship of the characteristics of the source of this fugitive dust and PM2.5, and PM10 concentrations. A dust generation, analysis and sampling system has been developed in Lubbock (LDGASS) to relate the properties of sediments with PM2.5 and PM10. In this study, we evaluate the effect of sample clay and calcium carbonate content on PM2.5 and PM10 generated from the samples. Eight soils from three sites located on the Southern High Plains were selected for this study. Dust particle concentrations were measured with DataRam and MiniVol dust monitors and dust particle size distributions were measured with a laser particle sizer in LDGASS. Particulate matter concentrations increased with soil clay content for the PM10 data set from the MiniVol dust monitor, but did not significantly increase (P<0.05) for PM10 and PM2.5 as measured with DataRAMs. However, PM2.5 and PM10 emissions were significantly increased as carbonate content increased. PM2.5 was highly correlated with PM10 concentration (R=0.92) and composed about 27% of the total PM10. Dust particle size distributions also were significantly affected by soil clay and carbonate content. The median particle size decreased as clay and carbonate content increased. Significant variation in dust emissions also was found within the same farm field, mapped as the same soil unit.