Research Project 1
| EPA Grant Number: | R828771-0-01 |
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Title: |
The Fate and Potential Bioavailability of Airborne Urban Contaminants |
| Investigators: | Drs. Robert P. Mason, Joel E. Baker and J. Ondov |
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Institutions:
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University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory (CBL) and the Chemistry Department, University of Maryland, College Park (UMCP), MD |
| Project Period: |
October 1, 2001 to September 30, 2004 |
| Description: |
| Numerous laboratory and epidemiological studies have suggested that urban particulate causes adverse health effects to humans, and can be an important source of contaminants to nearby waters. The physical or chemical properties of the ambient aerosol particles responsible for observed effects are poorly understood. This study will evaluate the importance of coarse particles entrained to the atmosphere from hazardous waste, brownfield and other urban sources as a source of contaminants to surrounding surface waters, and to humans via inhalation. We hypothesize that these coarse particles are not only an important source for contaminant cycling in the urban environment but also that the contaminants associated with these particles are readily available for desorption. The hypothesis will be tested through the coordination of our studies with those at the EPA-funded Baltimore PM supersite (http://www.chem.umd.edu/supersite/) which are focused on ascertaining the short term variability of physical and chemical properties of the ambient aerosol. We will collect aerosol samples at the Supersite, as an integrated urban site, to determine the characteristics of the coarse particle fraction and to measure the potential of the associated contaminants to be leached into water or to be taken up through the inhalation pathway. The changes in bioavailability between samples will be related to a full suite of chemical and physical characteristics of the particles and will be further compared to that of the potential source material from specific sites, such as those associated with hazardous waste sites, brownfields, and coal residues. |
| Approach: |
| Our approach will focus on using the new University of Maryland (UM) ultra high volume sampler to collect particle PM samples and additionally the new UM Semi-Continuous Aerosol Sampling System (SEAS) for the analysis of particulate collected at the supersite for metals. Short-term samples will be collected for metal and mercury (Hg) quantification. Organic chemicals, including PAHs, NPAHs, and tracer compounds, will also be analyzed. For organics, longer collection times may be needed, depending upon their particular concentrations. Additional ancillary measurements will quantify chemical and physical characteristics of the particles. Aerosol samples will be leached with distilled water and surface water from Baltimore Harbor to assess both the kinetics of dissolution as well as the potential steady state dissolution. From these results, the potential exposure from particulate to humans via inhalation will also be assessed. The first year of study will focus on this aspect of the transfer of urban contaminants at the land-air interface. |
| Expected Results: |
| From these studies we will derive a simple model to quantify the potential impact of this mode of transfer of contaminants from the land to nearby waters. Also, the studies will ascertain the potential for contaminants associated with particulate to exacerbate the respiratory impact of urban particulate on humans. |
| Supplemental Keywords: |
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aerosol, deposition, toxics |