Project Summary (2010-2015)

The overall goal of Dr. Schnoor’s work is to provide engineering research (non-biomedical) for the remediation of sites containing airborne PCB congeners which may expose humans. Specifically, it is to determine whether plants can provide in situ phytoremediation of PCB congeners from the air and other airborne sources like dredged sediments at the planned Confined Disposal Facility (CDF) in East Chicago, Indiana, near two schools. Thus the Project focuses on PCB congeners of higher volatility which are present in Chicago air and which display significant mass, toxicity or persistence in the environment. Plants can uptake PCB congeners from soil and soil-water, intercept semi-volatile congeners from the air onto the waxy cuticle of leaves and bark, and metabolize contaminants directly. In addition, plants stimulate rhizosphere bioremediaton of PCBs by providing the habitat, redox potential, and substrate necessary for degradation. The significance of this project is that, by studying further the genomic, proteomic, and metabolomic basis of PCB phytoremediation, it provides the scientific basis for the development and application of land management strategies for intervention at contaminated waste sites, and to break the continuous cycling of PCBs in the atmosphere and subsequent exposure to humans. Four specific aims comprise this project:

• Identify plant metabolites of selected PCB congeners (PCB-3, 11, 15, 28, 52, 77, 153) and the
• uptake/resolution/metabolism of chiral compounds (PCB-95, 136) using GC/MS and LC/MS/MS
• Mineralize PCB mixtures (in mesocosms and site plots) by varying redox conditions which microbially dechlorinates PCBs under anoxic conditions and oxidizes the biphenyl ring under aerobic conditions
• Analyze the proteomic response and toxicity to pure cultures of selected aerobic PCB degraders and identified anaerobic degraders exposed to PCBs and PCB metabolites
• Characterize PCB-induced changes on the soil microbial community at CDF sites and sediments using T-RFLP analysis and proteomic analysis

The leading themes of this research are to identify more completely the PCB metabolites, the biotransformation proteins involved, and to demonstrate complete mineralization of PCB congeners in the root zone of plants by using the latest techniques of metabolomics and proteomics.