ENVIRONMENTAL HEALTH & AQUATIC TOXICOLOGY

Anthropogenic impacts on the environment are ubiquitous...Within this broad context, my research is motivated by two overarching questions:

1. How does environmental degradation affect aquatic ecosystems?

2. How do ecosystem-specific features influence the magnitude or duration of these effects?


Current Research Projects

 Graphical abstract of research results from ES&T publication - Selenium ecotoxicology in freshwater lakes receiving coal combustion residual effluents: A North Carolina example

Graphical abstract of research results from ES&T publication - Selenium ecotoxicology in freshwater lakes receiving coal combustion residual effluents: A North Carolina example

Selenium ecotoxicology in freshwater lakes

Selenium is naturally occurring trace element that is enriched in coal and we find high concentrations of it in the by-products of coal combustion. These by-products (i.e. coal combustion residuals or CCRs) are collected in ponds at coal-fired power plants from where the top waters are released to freshwater rivers and lakes. In the past, elevated selenium concentrations have caused fish species extirpations and high rates of deformities in fish and aquatic birds. The CCR waste stream is now subject to federal and state-level regulation.

The overarching goal of this work was to document concentrations of selenium in the different compartments of CCR-receiving lakes to better understand the potential impacts that the waste streams have on aquatic ecosystems. This work also informs the ongoing discussions about coal ash and degraded ecosystem management.

Collaborators: Gary S. Dwyer, Emily S. Bernhardt, Richard Di Giulio, and the NC Wildlife Resources Commission.

This work was primarily funded by a grant from the UNC System's Water Resources Research Institute.

You can find our results here.


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Patterns and ecological influences on coal combustion residual (CCR) distribution in freshwater lakes

In this project, we consider the coal ash waste stream as a source of multivariate stress to freshwater lakes. Trace elements are bound together in coal but are subsequently liberated through excavation, combustion, and treatment processes. In this work, we ask how the elements making up the CCR mixture cycle through aquatic ecosystems? Which elements are sequestered by sediments and which move through aquatic food webs? We also consider how the retention time and size of a given ecosystem influences CCR distribution and how differential element distribution influences the mixture's potential toxicity to higher trophic level animals.

Collaborators: Marie Simonin, Emily S. Bernhardt, Richard Di Giulio, and the NC Wildlife Resources Commission.

This work was primarily funded by a grant from the UNC System's Water Resources Research Institute.


 Fish otolith showing LA-ICP-MS ablation line and age rings.

Fish otolith showing LA-ICP-MS ablation line and age rings.

Fish otoliths as metabolically stable contaminant RECORDS and TRACERS

Unlike fish tissues - which metabolize and eliminate contaminants over time - fish otoliths are metabolically stable and can serve as life-time records of fish exposure to inorganic elements. For decades, researchers have exploited this trait to understand the migratory patterns of fish that travel between freshwater and saltwater environments and fish exposure to environmental pollutants. 

In this work, we are studying the relationship between otolith concentrations of CCRs and the historic loading of CCRs from coal-fired power plants to the lakes from which fish were collected. We are comparing fish of different ages and different species with the broader goal of advancing the usefulness of these biological tracers for ecotoxicological research.


 

Related publications

Published

Brandt, J.E.; Bernhardt, E.S.; Dwyer, G.S.; and Di Giulio, R.T. 2017. Selenium ecotoxicology in freshwater lakes receiving coal combustion residual effluents: A North Carolina example. Environ Sci &Technol. 51 (4): 2418–2426, DOI: 10.1021/acs.est.6b05353

Yang, Y.; Chen, B.; Hower, J.; Schindler, M.; Winkler, C.; Brandt, J.; Di Giulio, R.; Liu, M.; Fu, Y.; Zhang, L.; Priya, S.; and Hochella, M. 2017. Discovery and ramifications of incidental Magneli phase generation and release from industrial coal burning. Nature Communications 8, DOI:10.1038/s41467-017-00276-2

In preparation

Brandt, J.E.; Simonin, M.; Di Giulio, R.T.; and Bernhardt, E.S. Characterizing the coal ash syndrome in lake ecosystems. In prep.

Brandt, J.E.; Humphreys, C.*; Trevisan, R.; Massarsky, A.; Kozal, J.S.; and Di Giulio, R.T. Multi-generational bioenergetic consequences of dietary selenium exposure in zebrafish (Danio rerio). In prep.

* denotes co-supervised undergraduate researcher


Research Press