Utilization of arrays as a monitoring tool for chromium exposure at a chromium contaminated Superfund site

Jonathan Adam Roling, University of Texas at El Paso

Abstract

The effects of chromium were analyzed on RNA expression as a biomarker in the sentinel species mummichog, Fundulus heteroclitus. Weights were measured to determine the no observable effect concentration (NOEC) and the lowest observable effect concentration (LOEC) in Fundulus at 1.5 (0.0288 mM) and 3 mg/L (0.0577 mM) for Cr(VI) and 32 (0.615 mM) and 64 mg/L (1.23 mM) for Cr(III), respectively. Mummichogs exposed to chromium demonstrated an exposure-dependent increase in body burden. In subsequent experiments, adults were exposed to Cr(VI) for 7-days at 0, 1.5 (NOEC), or 3 mg/L (LOEC), or Cr(III) at 0 or 32 mg/L (NOEC). A set of arrays were generated using sequences isolated by subtractive hybridization. The fingerprint of expression measured on the arrays in response to Cr(III) is significantly different than the fingerprint of expression caused by Cr(VI). The use of arrays as a biomonitoring tool was then assessed at a chromium-contaminated Superfund site. Chromium concentration in the sediment of Shipyard Creek significantly decreased from 1995 to 2005 due to remediation. The chromium body burden has also decreased from 2.52 μg/g in 2000, to 0.234 μg/g during remediation (2003). The number of genes differentially expressed and the magnitude of response on the array associate to the reduced body burden. Chromium body burden in concordance with gene expression increased in 2005 due to hydraulic dredging. In summary, our data supports the hypothesis that arrays can be used as multidimensional biomarkers to monitor site mitigation as the gene expression profile is associated with chromium bioavailability and body burden. ^

Subject Area

Biology, Molecular|Biology, Microbiology|Engineering, Environmental

Recommended Citation

Roling, Jonathan Adam, "Utilization of arrays as a monitoring tool for chromium exposure at a chromium contaminated Superfund site" (2006). ETD Collection for University of Texas, El Paso. AAI3214006.
http://digitalcommons.utep.edu/dissertations/AAI3214006

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