Monday, August 3, 2009

PS 8-83: Heavy metals pollutants in the El Paso, TX Region: Results from a SEEDS Special Project

Elizabeth J. Walsh, The University of Texas at El Paso, David Borrok, University of Texas at El Paso, Israel Del Toro, University of Texas at El Paso, and Kevin W. Floyd, University of Texas at El Paso.

Background/Question/Methods .  Heavy   metal contaminants are known to negatively impact ecosystem function and structure.  Previous studies in the Northern Chihuahuan Desert have shown that the area has been subjected to considerable amounts of heavy metal contamination likely due to copper refining activities. UTEP SEEDS students gave on-campus and off-campus presentations on potential impacts of anthropogenic pollution in desert environments.  We also conducted a focused research project quantifying heavy metal distribution in relation to a copper smelting operation in El Paso, TX.  We sampled two aquatic sites and four terrestrial sites for As, Cd, Cu, Pb, and Zn.  The aquatic sites and one terrestrial site were located near the former smelter, while the other three terrestrial sites were located at increasing distances from the smelter.  At the aquatic sites we collected sediments, water samples, and soil from the shore.  Surface soil was collected at the terrestrial sites.  Total metals were extracted from the sediments and soils using microwave-assisted digestion with nitric acid.  Water samples were acid-fixed but not otherwise processed.  Metal concentrations were quantified using ICP-OES and ICP-MS.

Results/Conclusions .  Fifteen UTEP students participated in outreach and research during the year. Outreach consisted of five presentations on campus and six presentations to local K-12 public school students (~350 people) as well as the general public (~150 people). Key findings of the research component show that the terrestrial sites showed elevated levels of all five metals (5 to 400 times above the control) at the site closest to the smelter. Soil from the shores showed lower levels of contamination than the terrestrial site near the smelter, but higher than other terrestrial sites.  Aquatic sediments had lower levels of contamination, and the water samples were only slightly higher than background. We conclude that lotic environments reduce the accumulation of these heavy metals either by flushing and/or sedimentation. The SEEDS Special Project Grant provides an excellent opportunity for university student organizations to promote research experience for undergraduates and enhance community outreach and education efforts.