Superfund Research Program
Toxic Metals in Airborne Particulate Matter Originating from Abandoned Uranium Mine (AUM) Sites
Project Leader: Melissa Gonzales
Co-Investigators: Adrian J. Brearley, Joseph Galewsky, Paul Robinson (Southwest Research and Information Center), Christopher L. Shuey (Southwest Research and Information Center)
Grant Number: P42ES025589
Funding Period: 2017-2022
- Project Summary
Project Summary (2017-2022)
Abandoned uranium mines (AUM) situated on the tribal lands of the Navajo Nation and Laguna Pueblo represent a major source of environmental contamination that threatens public health as a result of mobilization of toxic metals mixtures bearing uranium (U), vanadium (V), copper (Cu), and arsenic (As). The transport of toxic metal mixtures into the air, and the potential for inhalational exposures, has never been investigated in a rigorous manner.
Researchers from the University of New Mexico Metal Exposure and Toxicity Assessment on Tribal Lands in the Southwest Superfund Research Program Center (UNM METALS) are investigating the potential exposure hazards to toxic metals mixtures resulting from inhalation of particulate matter (PM) derived from an AUM site located on Laguna Pueblo tribal lands in New Mexico. The project is addressing two specific aims: 1) Defining the physical, chemical and mineralogic profile of metals mixtures in AUM-impacted soils and assessing vulnerability to transport by wind; and 2) Developing a computational model to predict the resuspension and transport of metal-bearing PM from one AUM site to estimate exposure risks for the nearby community. For the model, the researchers are ascertaining the particle size distributions and mineralogic characteristics of metal-bearing PM originating from an AUM site and the exposure potential to vulnerable populations living in the regional airshed under varied meteorological conditions.
This research is utilizing state-of-the-art monitoring, chemical analysis, micro- and nano-scale imaging, and atmospheric modeling techniques to provide a comprehensive dataset on the concentrations, speciation, valence, solubility, etc., of metals in different size fractions down to the nanoparticle scale that are essential to evaluate the potential toxicity and inhalation exposure risk for PM. The results will reduce uncertainty regarding the metal content, exposure concentrations, and sources of AUM-related PM exposures in risk reduction strategies.