Geology Reports⌕ Search
Home/Archive/USGS

USGS · 70282991

Influence of activated carbon on the bioaccumulation of methylmercury from sediment by the amphipod Leptocheirus plumulosus

Susan Kane Driscoll·Cynthia C. Gilmour·Steven S. Brown·Sara Nedrich·Guilherme R. Lotufo·Daniel Farrar·Jeffery A. Steevens·Grace Schwartz·James P. Sanders
View original source ↗Export metadata ↓

Abstract

We evaluated the potential for activated carbon (AC) amendments to reduce the bioavailability of methylmercury (MeHg) in field-collected sediments. To do so, we adapted a standard 28-day bioaccumulation bioassay with the benthic invertebrate Leptocheirus plumulosus to address challenges associated with assessing the dynamic nature of MeHg biogeochemistry and the difficulty of testing a heavily vegetated marsh sediment. After method development, we compared the bioavailability of MeHg in unamended sediment, sediment amended with powdered AC, and sediment amended with the commercial AC product SediMite. A subsequent study compared the bioavailability of MeHg in unamended sediment, sediment freshly amended with AC, and sediment amended with AC almost 2 years prior to the start of this study. Activated carbon amendments consistently reduced the bioavailability of MeHg to L. plumulosus , as indicated by a 2- to 4-fold decrease in the biota–sediment accumulation factor, which normalizes tissue concentrations to sediment concentrations. However, AC amendments increased sediment MeHg concentrations in five of seven studies, apparently by altering the balance between MeHg production and degradation. As a result, the net effect of AC amendment on absolute concentrations of MeHg in amphipods was mixed, with moderate reductions at some time points in some experiments but increasing concentrations or no effect in other cases. The AC amendments significantly decreased Hg and MeHg in porewater in all cases, however. A literature review of biota–sediment accumulation factors for other studies was also conducted. The mechanisms by which AC influences the physical and biogeochemical drivers of net methylation and concentrations of MeHg in sediment remain unclear. Any potential use of AC for Hg remediation should undergo site-specific testing before implementation.

Explore related subjects

Environmental Toxicology and ChemistryArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Susan Kane Driscoll, Cynthia C. Gilmour, Steven S. Brown, Sara Nedrich, Guilherme R. Lotufo, Daniel Farrar, Jeffery A. Steevens, Grace Schwartz, James P. Sanders. 2025-10-24. Influence of activated carbon on the bioaccumulation of methylmercury from sediment by the amphipod Leptocheirus plumulosus. https://doi.org/10.1093/etojnl%2Fvgaf259

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Acute toxicity and tissue concentrations of 6PPD-quinone in Arctic grayling (Thymallus arcticus, Thymallinae)

Studies of N -(1,3-dimethylbutyl)- N' -phenyl- p -phenylenediamine-quinone (6PPDQ) toxicity have identified sensitive and resistant species within the subfamily Salmoninae, but thus far fewer than 10 species, all in two genera ( Oncorhynchus and Salvelinus ), have shown sensitivity in experiments. The Arctic grayling ( Thymallus arcticus , Salmonidae, Thymallinae) was extirpated from its range in the Great Lakes region of the United States, but because of the importance of this species to the Native American tribes of Michigan, a reintroduction effort is underway. Because high 6PPDQ concentrations have been found in Great Lakes tributaries, it is important to understand if this species is at risk from 6PPDQ exposure. Using standard methods with flow-through exposures to provide stable 6PPDQ concentrations, we exposed Arctic grayling at 3 weeks after swim-up to a series of 6PPDQ concentrations for 96 hr, evaluating mortality and measuring tissue concentrations of 6PPDQ in surviving and dying fish. We observed that grayling were sensitive to 6PPDQ, with 24- and 96-hr median lethal concentrations of 5,136 and 3,137 ng/L, respectively. Tissue concentrations were much higher than those observed in other sensitive salmonines in previous studies. While this is only the third genus found to be sensitive to 6PPDQ leading to acute lethality and the first species outside of Salmoninae, the median lethal concentrations determined for the Arctic grayling exposed in this study are at 6PPDQ water concentrations unlikely to be encountered in situ.

Great Lakes↗
USGS2026

Polychlorinated biphenyl (PCB) exposure assessment of Carolina wren (Thryothorus ludovicianus) and barn swallow (Hirundo rustica) eggs and nestlings collected along Snow Creek and Choccolocco Creek watersheds near Anniston, Alabama, USA

Polychlorinated biphenyls (PCBs) persist for decades when released into the environment and bioaccumulate in aquatic and terrestrial environments, resulting in harmful concentrations of PCBs in fishes, birds, and humans. Approximately 310,000 metric tons of PCBs were produced at a facility in Anniston, Alabama from 1929–1971. Hundreds of metric tons of PCB-contaminated waste were suspected to have been released into local environments. This study was the first systematic exposure assessment of the degree and extent of PCBs and potential co-contaminants—polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, Pb, and Hg—in avian tissues downstream of the Anniston facility. We collected 122 egg and 36 nestling tissue samples from across four exposure areas downstream of the facility and a reference site. A total of seven bird species were collected, but samples were predominantly Carolina wren (resident, Thryothorus ludovicianus ) and barn swallow (migratory, Hirundo rustica ). Concentrations of Pb and Hg in bird tissues collected from the exposure areas were less than toxicity reference values, suggesting Pb or Hg exposures alone were unlikely to affect birds. Total PCB concentrations in avian eggs and nestlings collected from exposure areas were among the greatest ever recorded in birds collected in North America. The PCB congener profiles in this study, paired with results from previous soil and sediment sampling, suggest that PCB-contaminated sediment and soil were the likely source of elevated PCBs in the avian tissues. The PCB concentrations observed in birds downstream of the Anniston facility were at magnitudes that likely affect populations of both resident and migratory birds that utilize the area for foraging and reproduction.

Alabama↗
USGS2026

Using organic compounds and salt mixtures to investigate potential mechanisms of major ion toxicity to the mayfly Neocloeon triangulifer

Field assessments and laboratory studies have demonstrated that mayflies (Ephemeroptera) are relatively sensitive to increased concentrations of major geochemical ions (Na + , Ca 2+ , Mg 2+ , K + , Cl − , SO 4 2− , HCO 3 − /CO 3 2- ), but much remains to be learned about potential mechanisms of toxicity. In the present study, we sought to determine whether solution osmolarity is sufficient to predict the toxic effects of major ions to a mayfly, Neocloeon triangulifer . We further investigated whether binary mixtures of major ion salts with common cations or common anions provide evidence of concentration addition or independent action, potentially illuminating toxicity drivers for this species. Finally, we sought to determine if there are mechanisms for major ion toxicity to mayflies that are comparable to those for other species. The toxicity of single salts showed a Ca-dependent correlation with the total component concentration (the sum of individual ion concentrations, a close correlate of osmolarity), but the effect concentrations were well below those causing toxicity from mannitol (presumed to have only an osmotic effect), suggesting that a general osmotic effect is not responsible for major ion toxicity in this species. The mixture experiments consistently indicated additive toxicity and consistency with the relationship to total component concentration, which supports a single toxic mechanism and thus no evidence for ion-specific mechanisms, as reported for other species. Given the lack of evidence of ion-specific toxicity, the total component metric is likely useful for a broad range of ionic compositions.

Environmental Toxicology and Chemistry↗