SREL Reprint #3815

Accumulation of trace elements in soil and fauna within a site historically contaminated with coal combustion residues

Kelly E. Holland1,2, Tracey D. Tuberville1, and James C. Beasley1,2

1Savannah River Ecology Lab, University of Georgia, Aiken, SC, United States
2Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, United States

Abstract: Legacy contaminants tied to energy production are a worldwide concern. Coal combustion residues (CCRs) contain high concentrations of potentially toxic trace elements such as arsenic (As), mercury (Hg), and selenium (Se), which can persist for decades after initial contamination. Coal combustion residue disposal methods, including aquatic settling basins and landfills, can facilitate environmental exposure through intentional and accidental releases. Wildlife exposed to CCRs can experience numerous deleterious effects, such as on development, reproduction, and survival. In the current study, we quantified and compared concentrations of As, Hg, Se, and strontium (Sr) within soils and target fauna (three vertebrate and three invertebrate taxa) from a CCR-contaminated site and a reference site within the U.S. Department of Energy’s Savannah River Site, South Carolina, United States. Our objectives were to (1) compare current concentrations of tested elements in soil and resident fauna to levels from our reference site, (2) assess natural attenuation of elements in soils by comparing current concentrations to historic levels, and (3) evaluate the biomagnification potential of the elements measured via body burden and trophic position correlations among fauna. Element concentrations were higher in contaminated soils than reference soils; however, concentrations in 2022 were unchanged from concentrations measured in 2003, suggesting no natural attenuation of tested elements. Additionally, target fauna had elevated As, Se, and Sr levels in comparison to reference samples. A positive correlation was observed in southern toads between Sr concentrations and trophic position, as assessed by nitrogen stable isotope ratios, suggesting potential for biomagnification of Sr within our study system. Collectively, our results demonstrate that legacy contaminants are still present and bioaccumulate in a diversity of taxa in a CCR-contaminated site that has not received effluents in more than 50years, suggesting monitoring programs in CCR-contaminated sites should be maintained long term in the absence of remediation.

Keywords: wildlife toxicology, bioaccumulation, coal fly ash, terrestrial biota, natural attenuation

SREL Reprint #3815

Holland, K. E., T. D. Tuberville, and J. C. Beasley. 2025. Accumulation of trace elements in soil and fauna within a site historically contaminated with coal combustion residues. Environmental Toxicology and Chemistry 44(4): 1039-1050.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).