Superfund Research Program
Atmospheric Sources of PCB Congeners
Project Summary (2010-2015)
The long-term goal of Dr. Keri Hornbuckle’s research is to better understand the relationship between the observed concentrations in ambient air and specific sources of airborne PCBs in residential and industrial communities. The central hypothesis is that emissions of airborne PCBs are a function of measureable and quantifiable characteristics of the physical-chemical characteristics of the compounds and exposed environmental surfaces on which the PCBs reside. The Aims focus on identification, characterization and prediction of the magnitude and impact of sources of airborne PCBs:
Aim 1: To determine the sources and fate of airborne PCB congeners in the urban/industrial complex of Chicago. Dr. Hornbuckle hypothesizes that airborne PCBs in Chicago originate from contaminated surfaces throughout the city. The research group is testing their hypotheses by deploying air samplers throughout the City of Chicago and over seasons. Using the measurements, models, and geographic databases, they are determining the relative contribution of Chicago sources toward the annual mass of PCBs deposited in Lake Michigan, distinguishing long range versus local sources of airborne PCBs to the region, and determining neighborhoods of elevated risk for high exposure to airborne PCBs.
Aim 2: To characterize the sources and environmental exposure to airborne non- Aroclor PCBs. The researchers hypothesize that non-Aroclor PCBs have been released to the environment for decades and continue to be released due to their presence in commercial paint and other building materials. They will test this hypothesis by measuring non-Aroclor PCBs in archival and new samples and by measuring PCBs in commercial paint. Using sediment cores and archived sample extracts, they are determining the chronology of environmental exposure to these compounds and the magnitude of their current emissions.
Aim 3: To characterize the emission and fate of airborne PCBs in the Indiana Harbor and Ship Canal (IHSC).The researchers hypothesize that the sediment of the IHSC is a major source of airborne PCB congeners to the community of East Chicago, Indiana. To test their hypotheses, they are measuring PCBs in deep sediments of the IHSC. The research group is calculating the release of PCBs under no-dredging and dredging conditions, including partial removal that exposes deep sediments. They are monitoring the effect of dredging through local and regional air measurements. As a result of the work described here, Dr. Hornbuckle’s research promotes more scientifically sound and effective action to reduce human exposure to these potentially harmful compounds.