Environmental Toxin Center Gets Five More Years
Relatively small creatures – like zebrafish, killifish and fathead minnows – are yielding larger insights into whether or not a pollutant – even in tiny amounts -- can pose a threat to humans or the environment.
For the past ten years, scientists from Duke’s Pratt School of Engineering, Nicholas School of the Environment and the medical center have been using these and other tools as part of federally funded interdisciplinary research effort to assess the potential risks of chemicals or agents deemed toxic by the government’s Superfund program.
Based on the past successes of Duke’s research, as well as the promise of new technologies and additional scientists, the National Institute of Environmental Health Sciences (NIEHS) renewed Duke’s Superfund Research Center for another five years to the tune of $12.8 million.
While the team continues to build upon the successes of the past decade, several new facets of the program should give scientists new insights into the possible effects of even the tiniest trace amounts of potential pollutants in the environment and determine if nanoparticles used in the remediation of contaminated sites may be causing additional problems.
“In human and other vertebrates, embryonic development is not only a period of rapid growth and complex cellular differentiation, but it is also a time when the organism can be the most vulnerable to outside influences,” said environmental toxicologist Richard Di Giulio, DSRC director and member of both the Nicholas and Pratt faculties. “All the research efforts of this program will examine the heightened vulnerability of a developing organism to the effects of toxins.”
That’s where the little fish come in.
Di Giulio, DSRC director, has studied the three-inch long killifish and found that polycyclic aromatic hydrocarbons (PAH), a byproduct of fossil fuel combustion, had a negative impact on the development of its heart. Now, he is studying the fish in the native environment to determine why some appear to have developed a tolerance to the chemical.
In a new project, scientists will determine what effects different contaminants have on the development of the thyroid system of zebrafish. Lee Ferguson and Heather Stapleton, both also with joint appointments, will direct this project, as well as the state-of-the art chemical analysis unit that can not only detect minute amounts of a potential toxin, but likely identify possible new ones.
The other new focus is on whether various nanoparticles used in cleaning up contaminants in the sediments of surface and underground water are effective. In particular, the scientists want to find out how the nanoparticles interact with the surrounding microbes.
“We know that that some nanoparticles can influence the growth of microbes,” said Mark Wiesner, Pratt professor of civil and environmental engineering and director of the Center for the Environmental Impacts of Nanotechnology (CEINT). “We are interested in learning if interactions between nanoparticles introduced to clean up contaminants and microbes in the environment lead to byproducts that may be as toxic, or even more toxic, than the original problem.”
Theodore Slotkin, associate director of Duke SRC from the medical center’s Department of Pharmacology and Cancer Biology, will continue his studies of various toxins and how they impair the development of the mammalian nervous system. His earlier work in this area led to the ban of a popular household insecticide by the Environmental Protection Agency.