Superfund Research Program
Congratulations to the 2015 winners of the KC Donnelly Externship Award!
Kate Buckman, Ph.D., is a postdoctoral research associate at the Dartmouth College Superfund Research Program (SRP) Center under the guidance of Celia Chen, Ph.D. Buckman will conduct an externship at the U.S. Environmental Protection Agency (EPA) lab in Narragansett, Rhode Island, to evaluate ways to link mercury exposure to ecologically relevant outcomes using killifish.
Her current research involves examining the effects of temperature, salinity, and organic carbon on methylmercury bioaccumulation in estuarine organisms and conducting fieldwork across multiple estuarine and open water systems. For this externship, Buckman will enhance her skills in breeding, growing, and manipulating fish in the laboratory and use these skills to learn about the effects of maternal transfer of methylmercury to their eggs in killifish as a source of early-life methylmercury exposure. For example, she will measure later-life behavior effects in juvenile killifish that experienced early-life methylmercury exposure. Diane Nacci, Ph.D., from the Population Ecology Branch of the EPA's Atlantic Ecology Division, will serve as her mentor.
"Working with Dr. Nacci at the Narragansett EPA laboratory will allow me to both learn new techniques and skills as well as to establish a collaborative research project that will take advantage of the facilities, expertise, and support that are available within the Atlantic Ecology Division of the EPA," Buckman said. "Expanding my skill and knowledge base into behavioral studies of fish will also create additional professional opportunities for me to combine my interests in bioaccumulation with fish ecology."
Marvic Carmona De Jesus
Marvic Carmona De Jesus is a graduate student at the University of Puerto Rico in Mayagüez (part of the Northeastern University SRP Center) under the guidance of Ingrid Padilla, Ph.D. He will spend his externship at the Oregon State University (OSU) SRP Center, under the guidance of Kim Anderson, Ph.D.
His current research focuses on assessing and quantifying the fate and transport of dense non-aqueous phase liquids (DNAPLs) in karst groundwater systems. He also participates in a broader study aimed at determining the mobility, persistence, and spatio-temporal distributions of legacy and emerging contaminants in karst systems. During his externship, he will learn skills related to using passive sampling devices (PSD) to detect, monitor, and quantify these contaminants in water. These methods and technologies will then be applied in the karst region of northern Puerto Rico for sampling and monitoring of contaminants in water.
"The KC Donnelly externship will enable me to advance my knowledge and develop new skills that will advance our understanding of environmental health and engineering issues faced by the people of Puerto Rico, a population with a large burden of health disparities," said Carmona. "The externship will allow me to interact with superb mentors, develop personal skills and professional goals, and work in transdisciplinary and multicultural settings, where environmental health, science, and engineering intersect to bring solutions to real-world problems."
Lisandra Santiago Delgado
Lisandra Santiago Delgado is a graduate student at the OSU SRP Center under the guidance of Staci Simonich, Ph.D. For her externship at the EPA's Robert S. Kerr Environmental Research Laboratory, in Ada, Oklahoma, she will work with EPA hydrologist Eva Davis, Ph.D.
Her current research focuses on remediation of polycyclic aromatic hydrocarbons (PAHs). She will expand her knowledge of PAH remediation by using laboratory conditions comparable to real-world scenarios to identify potentially mutagenic and developmentally toxic compounds in Superfund soils. Her externship will involve thermally remediating Superfund soils contaminated with PAHs using steam injections and quantifying PAHs and toxicity in the soil before and after remediation.
"I am excited at the prospect of working with Dr. Davis, who is an expert in the field of thermal remediation, and with whom I share an interest in this area of research," Santiago Delgado said. "I believe that my previous and current research experiences have prepared me for this collaboration, and I am certain that this externship will provide me with an opportunity to enhance my capabilities as an independent researcher in environmental health sciences."
Erika Fritsch, Ph.D., a postdoctoral fellow at the University of California (UC), Davis SRP Center, studies the effects of polychlorinated biphenyls (PCBs) on the ryanodine receptor (RyR) in killifish. This receptor is essential to neuron signaling and health and may play a role in the neurotoxic mechanism associated with PCBs. Fritsch will travel to the Woods Hole Oceanographic Institution (WHOI) in Massachusetts to work with John Stegeman, Ph.D., who is part of the Boston University SRP Center.
During her externship, Fritsch will gain bioinformatics expertise through training and research that will help to establish fish as models for RyR toxic endpoints. She will assess the genetic differences between fish that may affect RyR-related toxicity to help draw conclusions from fish studies that may be pertinent to other animals, including humans. These new applications of phylogenetics and bioinformatics will enhance her ongoing molecular research at the UC Davis SRP Center under the guidance of Isaac Pessah, Ph.D.
"The KC Donnelly Externship will not only help me foster further collaborative relationships with Dr. Stegeman and other members at WHOI, but it will also provide me with the opportunity to learn and apply cutting-edge techniques in the increasingly important field of bioinformatics," Fritsch said. "Together, the tools developed will allow me to capitalize upon the impending age of big data to better define genetic and molecular determinants for sensitivity to toxicants."
Zhilin Guo is a graduate student under the mentorship of Mark Brusseau, Ph.D., at the University of Arizona SRP Center. She will conduct an externship at the UC Davis SRP Center under the guidance of Graham Fogg, Ph.D.
Guo is currently exploring factors that affect groundwater remediation of hazardous waste sites contaminated with chlorinated solvents. For her externship, she will work on developing a more efficient way to solve the current research problems examining various factors that impact plume persistence, which has been observed in many field sites. She will also investigate the significance of each factor by using the advanced random walk particle method (RWHET) along with Modflow and MT3D. This advancement will enhance site characterization and site management for contaminant sites with large groundwater plumes.
"The supplement provides an opportunity for me to learn an advanced numerical flow and transport program, which will enrich my current research and improve my understanding of how media impacts contaminant transport behavior," said Guo. "The experience will also give me the opportunity to build professional networks with Dr. Fogg's group and offer a chance to expand my research vision."
Miao Li, a graduate student at the University of Iowa SRP Center, is currently investigating the mechanism of toxicity of airborne PCBs by the formation of protein adducts. He will expand his current research under the mentorship of Gabriele Ludewig, Ph.D., through an externship at the University of California, Berkeley Center with Daniel Nomura, Ph.D.
Li will learn methods to identify protein targets for PCB metabolites. Identifying these targeted proteins could help reveal the mechanisms involved in the toxicity of airborne PCBs. During the externship, Li will receive assistance in profiling the target proteins of PCB metabolites, and provide an opportunity to collaborate with the experts who created the method of interest.
"The University of California, Berkeley provides an ideal environment for the externship with cutting edge techniques and state-of-the-art instruments," said Li. "As a future toxicologist in an industrial or government position, the chance to work with experts aiming at translating cutting edge methods into the real world applications will be a distinct opportunity."
Lauren Redfern, a graduate student in the Duke University SRP Center under the guidance of Claudia Gunsch, Ph.D., focuses on microbial communities and their potential for bioremediation at Superfund sites. She will travel to the UC Berkeley SRP Center to evaluate microbial interactions under the mentorship of Lisa Alvarez-Cohen, Ph.D.
In microbial communities, bacterial strains often exchange genetic information that provides a selective advantage. If strains are exchanging genes that encode proteins capable of degrading site contaminants and scientists could favor this interaction, they could quickly and naturally degrade site contaminants. During her externship, Redfern will determine which biogeochemical influences enhance gene transfer between bacterial species and result in increased degradation rates. These results will expand our understanding of horizontal gene transfer as a bioremediation technique.
"In addition to completing my project that focuses on gene transfer, I will gain a greater understanding of dechlorinating communities and methods of monitoring intercellular interactions," said Redfern. "I believe collaborations and new perspectives will help develop my research and improve my personal scientific skills."