Are U, Ni, and Hg an Environmental Risk within a RCRA/CERCLA Unit on the U.S. Department of Energy's Savannah River Site?

Abstract

The U.S. Department of Energy's Savannah River Site (SRS) is a former nuclear weapon production facility. From 1954From -1985, releases of Al, Cu, Cr, Hg, Ni, Pb, U, and Zn were discharged into the Tims Branch-Steed Pond water system. This study investigates whether metal concentrations in Tims Branch's sediment, biofilm and other biota exceed screening level risk calculations to determine if remedial actions should be pursued for the Contaminants of Potential Concern (U, Ni, Hg). Transfer factors (TFs) were calculated to determine metal concentration changes throughout lower trophic levels and results were compared with sediment benchmarks to create hazard quotients (HQs) to assess risk and a scientific-management decision point. Most TFs for Ni and U from lower to higher trophic level biota were < 1, suggesting no biomagnifications; however HQs > 1 and cumulative distributions showed the majority of the samples exceeded action levels. Elevated TFs and HQs > 1 in the upper trophic levels for Hg indicated a high degree of bioavailability and biomagnification. Monte Carlo resampling analyses supported these empirical results. This system should continue to be closely monitored to ensure that contamination does not move off the SRS.

WITHDRAWN: Assessment of Remediation Through Measuring Nuclear Respiratory Factor 1 (nrf1) Environmental Stressor Transcriptomic Gene Signatures

“…Machine driven in-silico models have shown that the combination of high throughput sequencing and bioinformatics improves the ability monitor changes associated to internal and external stimuli from exogenous exposures (Edwards et al, 2014). In addition, modeling has shown it can improve sampling patterns and can inform stakeholders of the contamination risks (Edwards et al, 2014).…”

Trace element accumulation in lotic dragonfly nymphs: Genus matters

“…The taxonomic level analyzed in studies of trace element accumulation in odonates varies extensively. Some studies analyzed organisms composited by order [ 77 , 78 ] or suborder [ 5 , 79 , 80 ]. Others have composited by family, sometimes with comparisons between families [ 81 ], but others with only a single anisopteran family [ 7 , 30 , 82 ].…”

“…Classification of dragonfly position based on stable isotope analysis (SIA) has been more varied. Some have classified dragonfly nymphs as predators [ 89 , 90 , 91 ], but others have considered nymphs likely feeding on both plant and animal material in some or all taxa [ 59 , 79 , 92 ]. In short, assimilation of plant material and the enrichment rate of 15 N in trophic transfers between dragonfly nymphs and lower trophic levels do not appear to have been confirmed.…”

Trace elements and radiocesium in game species near contaminated sites

“…In 1954, a drainage ditch that empties into Tim's Branch received direct environmental releases of large volumes of uranium (U), Al, and Ni and smaller quantities of Pb, copper (Cu), Cr, and Zn (Pickett et al 1987, Sowder et al 1996. Additionally, Hg contaminated groundwater was pumped into a tributary leading to Tim's Branch from -2007(Edwards et al 2014. Ecotoxicology studies have reported contamination in the aquatic, wetland, and terrestrial communities (Gaines et al 2005).…”

“…The contamination included Al, Zn, Mn, and sodium (Na), which resulted in adverse impacts on wetland vegetation (Greenwood et al 1990). Groundwater contaminated with Hg also entered this system (Edwards et al 2014).…”