We are studying the effect of emerging contaminants on the microbial ecology in natural and engineered systems as well as their environmental and human health toxicological effects. In our research, we are focusing on two classes of emerging contaminants, namely pharmaceutically active compounds (PhACs), nanomaterials as well as the polybrominated diethyl ether (PBDEs) brominated flame retardants. These compounds are being introduced into the environment via community and on-site wastewater treatment facilities, through the overflow or leakages of storage facilities and land application of untreated animal wastes, and through manufacturing residues.
Many PhACs can undergo hydrolysis in the environment and become active again or simply accumulate leading to adverse human and environmental health effects. PBDEs, on the other hand, are extremely stable and tend to accumulate in wastewater treatment biosolids. The extent and magnitude of the risks posed by the presence of PhACs and PBDEs is not yet known due to a lack of research data. However, there are many concerns that PhACs may threaten the physiological and reproductive processes of micro and macro aquatic organisms and that they may have adverse human health effects. In addition, there is also the potential that disease causing microbes may develop resistance to PhACs, ultimately leading to an increase risk of human diseases. To date, in our research with PhACs, we have focused at studying the microbial inhibition resulting from their presence in environmental samples, whereas we have looked at the toxicological response initiated by PBDEs.
The PBDE portion of this project is funded through NIEHS's Center for Comparative Biology of Vulnerable Populations and is being performed in collaboration with Dr. Heather Stapleton.
The nanomaterial portion of this project is funded through CEINT.
Publications and Presentations:
S. Wang, R. Holzem and C.K. Gunsch, “Effects of Pharmaceutically Active Compounds on a Mixed Microbial Community Originating from a Municipal Wastewater Treatment Plant”, Environmental Science and Technology, 2008, 42(4):1091-1095. S. Wang* and C.K. Gunsch, “Effects of pharmaceutically active compounds on a mixed microbial community under different organic loadings”, Abstracts from the 108th General Meeting of the American Society for Microbiology, Boston, MA (June 1-5, 2008).
R. Pei* and C.K. Gunsch, “Effects of Pharmaceutically Active Compounds on Activated Sludge Microorganisms”. Accepted for presentation at the 107th General Meeting of the American Society for Microbiology, Toronto, Canada (May 21-26, 2007).
S. Wang* and C.K. Gunsch, “Inhibitory Effect of Four Pharmaceutical Compounds on Microbial Growth”. Presented at the 106th General Meeting of the American Society for Microbiology, Orlando, Florida (May 21-25, 2006).