Project 8 : Characterization of wind-blown dust from tailings and other mining operations in the southwest

Project Leader(s):

Eric Betterton, PhD
Eduardo Saez, PhD

Background

In semiarid environments such as the Southwestern US, mining operations, including crushing, grinding, smelting, refining, and tailings management, are an important source of airborne metal and metalloid contaminants. Spent ore from mining operations is accumulated in mine tailing deposits, which are typically open to the atmosphere and thus susceptible to wind erosion. Dust particles emitted from mine tailings mobilize trace metals, which can then accumulate in soils, natural waters and vegetation. Furthermore, smelting operations release metals in the form of fume and fine particulate matter that disperses more readily than coarser soil dusts. Ancillary smelting activities and wastes may also contaminate local soils, which can then be dispersed by wind erosion. Human exposure to the dust can occur through inhalation and, especially in the case of children, incidental dust ingestion. Characterization of airborne dust in regions influenced by mining activity can provide information about sources, fate and transport, and the potential for human exposures.

At the University of Arizona, Drs. Betterton and Sáez are performing size-resolved chemical characterization of atmospheric aerosols near mining sites in Arizona. By determining the chemical components of mine tailings dust as a function of particle diameter, their research will generate source apportionment data, improve fate and transport models of airborne particulates, and better assess potential health impacts of contaminated dust.


Annual averaged lead and arsenic concentrations from  observations at an active mining and smelting site. Data represent average concentrations over thirty six 96-hour sampling periods.
 

Significance

Warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, with potential deleterious effects on human health and ecology. These studies will provide insights into the source and fate and transport of metal-contaminated airborne particulates, with implications for human exposure.


Objectives

1. To assess the role of atmospheric dust in the transport of metal contaminants from mine operations.
2. To provide evidence for contaminant source identification and improved remediation.
3. To assess the role of vegetation cover in contaminant transport by atmospheric dust (in conjunction with Project 9).
4. To validate an atmospheric model to predict dust contaminant transport from mine operations and assess human exposure by inhalation.


Click here to watch a video of Dr. Eric Betterton describing his work on dust, as featured at the University of Arizona Innovation Day 2012.

Click here to watch a video profile of Dr. Eduaro Saez, who was honored as a University of Arizona Distinguised Professor, 2011.


Click here for near-real time updates of conditions measured at the Iron King Mine Humboldt Smelter Superfund site via two dust/weather monitoring stations.

 


Project 8 publications resulting from research conducted under the Superfund Research Program during the grant funding period of 2010 to present.

 


NIEHS Research Briefs resulting from research conducted under the Superfund Research Program:
Research Brief 202: Size-resolved Chemical Characterization of Atmospheric Aerosols


Contact
 
Eric Betterton
Eduardo Saez
(520) 621-6831 or 621-6832
(520) 621-5369
 
 
 

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