Superfund Research Program
Polychlorinated Biphenyls (PCBs) - Remediation
- Archived Seminar (10/09/02)
- Introduction - Larry Reed, NIEHS
- James Tiedje, Ph.D., Michigan State University
- Richard Bopp, Ph.D., Rensselaer Polytechnic Institute
This seminar, sponsored by the National Institute of Environmental Health Sciences (NIEHS) and U.S. Environmental Protection Agency (EPA) Office of Emergency and Remedial Response, presented the latest advances in polychlorinated biphenyls (PCB) bioremediation research. This involved genome sequencing and other genomic tools to evaluate the consequences of pollutant exposure on the overall bacterial community genome. The health of this genome is critical for effective bioremediation of PCBs to a biologically acceptable endpoint. In addition, presenters examined the lessons learned from the PCBs found in dated sediment cores taken from the Hudson River in New York and New Jersey. Cores from depositional areas have been used to determine the history of PCB contamination, the progress of in situ dechlorination of PCBs, and the extent of influence of PCB inputs to the upper Hudson.
PCBs - Monitoring and Detection
This seminar, sponsored by the National Institute of Environmental Health Sciences (NIEHS) and U.S. EPA Office of Emergency and Remedial Response, discussed the limitations of Aroclor (commercial PCB mixture) analysis and why congener analysis provides for better decision-making with regards to human health and ecological risks of exposure to PCBs. Andy Beliveau, of the EPA's Office of Environmental Measurements and Evaluation, focused on how congener analysis can be used to detect total PCBs, dioxin-like congeners, as well as environmentally modified PCBs. The pros and cons of each type of congener analysis were discussed as well as the costs. The major uses of each type of analysis was put in a historical framework, and state-of-the-art current applications were presented. In addition to the discussion of congener analysis, Dr. Sylvia Daunert, of the University of Kentucky Superfund Research Program, presented her team's work on development of genetically engineered cell-based biosensing systems. Both PCBs and their breakdown products have been shown to have significant effects on human health. The researchers are developing optical sensing systems for the detection of PCBs and their breakdown products found in hazardous waste sites. The work included the development of biosensing systems for chlorocatechols, which are toxic intermediates often produced by the breakdown of PCBs.
PCBs - Health Effects
- Archived Seminar (12/4/02)
- Susan Korrick, M.D., Harvard University
- Rita Loch-Caruso, Ph.D., University of Michigan
This seminar, sponsored by the National Institute of Environmental Health Sciences (NIEHS) and U.S. EPA Office of Emergency and Remedial Response, was the last in a series of three seminars examining current research on PCBs sponsored by EPA and the National Institute of Environmental Health Sciences (NIEHS). Because of their once-popular commercial uses, improper disposal and environmental persistence, polychlorinated biphenyls (PCBs) are common environmental contaminants found in many designated Superfund sites. The event highlighted the cutting edge research being conducted by NIEHS scientists into the non-cancer endpoints of exposure to PCBs. Recognition of polychlorinated biphenyls (PCBs) and related compounds as potential human neurodevelopmental toxicants was largely a consequence of two mass poisonings in Japan (1968) and Taiwan (1979). Dr. Susan Korrick, of Harvard University, reviewed findings from the population-based epidemiologic studies for which prenatal PCB exposure measures are available. The particular emphasis was on findings related to growth and neurocognitive development in infancy and later childhood. Additionally, Dr. Rita Loch Caruso, of the University of Michigan, discussed her findings that acute in vitro exposures to commercial PCB mixtures and microbially dechlorinated commercial PCB mixtures increase the frequency of spontaneous contractions of uteri from pregnant rats. Increased uterine stimulation was observed with PCB mixtures containing increased abundance of lesser-chlorinated, ortho-substituted congeners. By showing that PCBs stimulate uterine contraction in vitro, these studies provided a biologically plausible mechanism by which PCB exposures could decrease gestation length.