CHAPEL HILL -- As part of the nation's Superfund research and clean-up efforts, the National Institute of Environmental Health Sciences, in cooperation with the Environmental Protection Agency, has awarded $16 million to scientists at the University of North Carolina at Chapel Hill.
The grant will enable the public health and engineering experts to continue work begun with NIEHS support in 1991 for another five years.
"We're trying to understand the human health and environmental risks associated with hazardous waste sites and to devise strategies for cleaning up such sites to minimize public health concerns," said Dr. James A. Swenberg, professor of environmental sciences and engineering at the UNC-CH School of Public Health and Superfund Basic Research project director. "We have created an interdisciplinary group of scientists leading eight research projects and five cores supporting studies of the health consequences of exposure to toxic substances. These dedicated people are examining the potential of neutralizing hazardous wastes and developing new strategies for cleaning up Superfund sites."
Swenberg's group, for example, is trying to determine how chemicals such as trichloroethylene and polychlorinated biphenyls found at Superfund sites damage health through a process known as oxidative stress. Oxidative stress occurs when electrically charged molecules called free radicals damage nucleic acids, proteins, fats and enzymes.
"We are developing new techniques to measure the level of oxidative stress in the body through use of biomarkers, which are biological indicators of damage or disease in the body," Swenberg said. "We're also developing a dose-response model, which predicts how levels of exposure to chemicals correspond to the amount of oxidative stress in the body. Another area of research is how genetic traits may make certain individuals more susceptible to oxidative stress."
Another study, led by Dr. Stephen M. Rappaport, seeks to explain how the body metabolizes the cancer-causing chemical benzene through analysis of blood and urine samples.
A project directed by Dr. Michael D. Aitken is examining microbial transformation of polycyclic aromatic hydrocarbons (PAHs), a group of more than 100 chemicals that are major, persistent contaminants of soil and groundwater and have been identified at about 600 of the 1,430 Superfund National Priorities List sites. Aitken's research is aimed at understanding breakdown of PAHs, particularly cancer-causing compounds, so that strategies can be developed to boost their degradation.
Drs. Frederic K. Pfaender and Russell F. Christman study hydrophobic organic contaminants such as PAHs that do not dissolve in water and may remain inaccessible to microorganisms that could degrade them. Their goals are to learn how the chemicals act and change over time in the environment and to improve both assessment of potential health risks and cleanup methods. Dr. Cass T. Miller, chair of environmental sciences and engineering, is developing new methods of removing dense industrial solvents such as trichloroethylene and tetrachloroethylene from groundwater using brine solutions. Those chemicals are found at more than half of the Superfund sites.
Dr. George Christakos is creating computerized systems to model how contaminants move through soil and water, how humans are exposed to them and what the health impacts could be. Dr. Leena Nylander-French is investigating methods to improve measurement of skin exposures to benzene and naphthalene, commonly found at contaminated sites. The methods she develops also will also be useful in determining skin exposures to other contaminants.
The program projects are supported by core facilities in chemistry, molecular epidemiology, mathematical modeling, outreach and student training. The chemistry core includes a synthesis laboratory and a mass spectrometry facility. The former provides custom synthesis of metabolic intermediates for dosing experiments, labeled compounds for spiking standards for microanalysis, products for structural verification and specialized reagents. The latter does both routine analysis and methods development using a variety of ionization sources and combining the ionization sources with chromatographic techniques.
The chemistry core also assists in interpreting spectroscopic data and collaborates with the various projects in applying chemical strategies. The molecular epidemiology core provides high-throughput genotyping to examine the effect of DNA repair and metabolism genes on susceptibility to diseases linked to toxic chemicals. The mathematical modeling core will assist all investigators with advanced modeling and statistical analysis.
"Over the past nine years, we've trained about 110 graduate students and 40 postdoctoral fellows to do specialized research that involves interdisciplinary interaction between health science and engineering," Swenberg said. "That's unusual but very much needed." The nation spends about $2 billion a year on Superfund issues alone, not including money spent on environmental issues by the defense and energy departments, he said.
The UNC-CH Superfund Basic Research Program, which has always disseminated its research findings to the professional community, now has a formal Community Outreach and Education Program, which serves the general public, school teachers and policymakers. That effort is being directed by Dr. Frances Lynn, with Kathleen Gray as the deputy director.
"Our ultimate goal for the COEP is to help all North Carolina citizens become aware of issues involved in the disposal of hazardous waste and to help policymakers benefit from the research taking place at UNC-Chapel Hill," Lynn said. "Whether you live near a Superfund site or not, these are important health and environmental issues for everyone. COEP staff have designed the program's new World Wide Web site, are producing a newsletter, the Superfund Scoop, conducting teacher training workshops and preparing a manual to help citizens participate in decision making at sites."
More information is available at the program's Web site: http://www.sph.unc.edu/sfcoep/research. "The site contains lay versions of each of our research projects and has links to EPA Superfund issues and all kinds of information for teachers, students and others," Swenberg said.
Note: Swenberg can be reached at (919) 966-6139.
School of Public Health contact: Lisa Katz, 966-7467. News Services contact: David Williamson, 962-8596.