Grantee Research Project Results
2003 Progress Report: The Fate and Potential Bioavailability of Airborne Urban Contaminants
EPA Grant Number: R828771C002Subproject: this is subproject number 002 , established and managed by the Center Director under grant R828771
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Reinventing Aging Infrastructure for Nutrient Management
Center Director: Mihelcic, James R.
Title: The Fate and Potential Bioavailability of Airborne Urban Contaminants
Investigators: Baker, Joel E. , Ondov, John M. , Mason, Robert P. , Crimmins, Bernard , Laurier, Fabien , Pancras, Patrick
Institution: University of Maryland - College Park
EPA Project Officer: Aja, Hayley
Project Period: October 1, 2001 through September 30, 2002
Project Period Covered by this Report: October 1, 2002 through September 30, 2003
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management
Objective:
The overall goal of this research project is to estimate the fate and bioavailability of atmospherically transported chemical contaminants in the urban environment. Parallel field and laboratory studies of trace metal, mercury, and organic contaminant speciation are underway. The specific objectives of this research project are to: (1) characterize the bioavailability of aerosol particle-associated metals and organic chemicals by leaching field-collected particles under well-controlled laboratory conditions; and (2) characterize the reactivity of atmospheric mercury and organic chemicals by measuring gaseous and particulate speciation in the ambient urban atmosphere. This project is part of a larger strategy encompassed within the Center for Hazardous Substances in Urban Environments (CHSUE) to quantify the sources and cycling of hazardous materials in the urban environment, and specifically, the exchange of contaminants between the land and the atmosphere. This research project quantifies the sources and cycling of airborne contaminants to better characterize the sources, pathways, and bioavailability of these contaminants.
Progress Summary:
Experiment 1: Bioavailability of Aerosol Particle-Associated Metals and Organic Chemicals by Leaching Field-Collected Particles Under Well-Controlled Laboratory Conditions
We have harvested approximately 10 g of coarse particulate matter (PM) (i.e., airborne particles with aerodynamic diameter > 2.5 µm) from the ultra-high-volume collector at Clifton Park about 2 km northeast of downtown Baltimore. The material was dried at 110°C and a 15-mg aliquot was analyzed for 18 elements by inductively coupled plasma-mass spectrometry (ICP-MS) after closed vessel acid digestion using the method adopted by us from National Institute of Standards and Technology for Standard Reference Material analyses. Data currently are being processed.
In January 2003, we conducted an intensive air sampling campaign to provide samples for metals analyses to reveal the atmospheric burdens and sources of cytokine-active and various metals (including Al, As, Se, Cu, Cr, Cd, Mn, Fe, Se, Pb, and Zn), either known to be toxic or useful as markers of high-temperature combustion sources and urban dust to complement Hg and organic measurements made by our colleagues. Between January 26, 2003, and February 12, 2003, more than 700 30-minute samples were collected with the University of Maryland's Semicontinuous Elements in Aerosol Sampler. Analyses of samples collected on February 4 and 8 (35 samples)—days for which discrete Hg-containing plumes were observed—have now been completed by ICP-MS. Elevated concentrations of Cd, Zn, Sb, and Pb (i.e., makers of municipal incinerator particle emissions) were observed between 10:30 and 11:30 a.m. Selenium and vanadium peaks also are evident. The relative abundances of these elements and wind directions suggest that these samples were influenced by the Baltimore municipal incinerator (station angle of 250°) and Gould Street power plant. The incinerator plume was more evident on February 8, when winds were more consistently from a westerly direction. Samples collected on February 10, 2003, during which time very large reactive gaseous mercury concentrations were observed, will be analyzed next. The results will be used to estimate Hg emissions from the likely sources of these plumes.
Experiment 2: Reactivity and Speciation of Atmospheric Mercury and Organic Chemicals in the Ambient Urban Atmosphere
The presence of nitro-substituted polycyclic aromatic hydrocarbons (nitro-PAHs) has been linked to the direct mutagenicity of these urban aerosols. Specific nitro-PAHs are formed by primary emissions (diesel exhaust) and through secondary gas-phase transformation reactions of parent PAHs via O3 or NO3 oxidation. The size distribution of nitro-PAHs from primary and secondary reactions provides valuable information on the potential mutagenicity of various particle sizes and populations. In conjunction with the Baltimore PM2.5 Supersite, 12- and 24-hour bulk- and size-resolved aerosol samples were collected using a modified Anderson Hi-Vol and Berner low-pressure impactor. The homologue distribution was used to estimate the size distribution of diesel-derived soot, and to further resolve primary and secondary sources of the various nitro-PAHs congeners in the Baltimore, MD, atmosphere. To our knowledge, this is the first size-resolved nitro-PAH data reported and explored as a potential diesel soot marker in the Eastern United States.
A comparative mercury speciation study was conducted between a coastal site, the Chesapeake Biological Laboratory (CBL), Solomons, MD, and an urban site, the PM Supersite in Baltimore, MD. Studies in Baltimore were coincident with studies by Baker and Ondov's groups. Atmospheric Hg0 and reactive gaseous Hg (RGHg) measurements were performed using the Tekran 1130 mercury speciation unit coupled to Tekran 2537A analyzer. Hg0 was determined using a vapor-phase mercury analyzer (Model 2537A). The speciation system was set up for a sampling time resolution of 5 minutes for Hg0 and 2-hours for RGHg. The particulate mercury was collected on a downstream quartz fiber filter and was not analyzed. At the Baltimore PM Supersite, no obvious diurnal cycle was observed. RGHg concentrations were up to four times the values reported at CBL. The temporal pattern likely is explained by local anthropogenic sources. It appears that there is a strong correlation between wind direction and concentration, which is expected if there are point sources in the vicinity. At CBL, RGHg concentration followed a diurnal pattern, suggesting RGHg formation by photochemical processes in the presence of sea-salt aerosol, leading to the oxidation of Hg0 by reactive halogen species. AT CBL, periods of low RGHg concentration and no diurnal cycle mostly corresponded to rain events (October 13-14, October 26-27, and October 30-31) and/or offshore winds. For Baltimore, yearly average flux estimates suggest that the RGHg flux is around 70 ng-2 d-1, about 2-3 times that of the rural sites, and that the RGHg flux is about 40-50 percent of the total wet plus dry deposition flux. Similarly, at CBL, RGHg deposition is an important part of the total flux. These results strongly indicate that RGHg deposition cannot be ignored in global, regional, or local estimates of Hg deposition.
Future Activities:
We will analyze the samples collected to reveal the atmospheric burdens and sources of cytokine-active and various metals (including Al, As, Se, Cu, Cr, Cd, Mn, Fe, Se, Pb, and Zn), and the results will be used to estimate Hg emissions from the likely sources of the plumes.
Journal Articles:
No journal articles submitted with this report: View all 3 publications for this subprojectSupplemental Keywords:
ultra-high-volume particle collection, urban particle solubility, reactive gaseous mercury, nitro-substituted polycyclic aromatic hydrocarbons, nitro-PAHs, size distributions, aerosol, deposition, toxics, particulate matter, PM, aerosol composition, aerosol particles, air pollution, air quality models, air sampling, air toxics, airborne aerosols, airborne particulate matter, airborne PM, airborne urban contaminants, ambient aerosol, ambient air quality, bioavailability, brownfield sites, contaminant cycling, contaminant dynamics, contaminant transport, environmental hazards, environmental health effects, epidemiology, hazardous substance contamination, human exposure, human health effects, human health risk, respiratory impact, risk assessment, technical outreach, technology transfer, urban air., RFA, Health, Scientific Discipline, Air, Waste, particulate matter, Health Risk Assessment, Risk Assessments, Brownfields, Hazardous Waste, Biochemistry, Ecology and Ecosystems, Hazardous, brownfield sites, environmental hazards, ambient aerosol, ambient air quality, urban air, contaminant transport, air toxics, epidemiology, contaminant dynamics, human health effects, risk assessment , air quality models, airborne particulate matter, contaminant cycling, bioavailability, air pollution, air sampling, environmental health effects, human exposure, aerosol composition, airborne aerosols, respiratory impact, PM, aersol particles, technology transfer, urban environment, airborne urban contaminants, human health risk, aerosols, technical outreachRelevant Websites:
http://www.chem.umd.edu/supersite Exit
http://www.jhu.edu/hsrc Exit
Progress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R828771 Center for Reinventing Aging Infrastructure for Nutrient Management Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828771C001 Co-Contaminant Effects on Risk Assessment and Remediation Activities Involving Urban Sediments and Soils: Phase II
R828771C002 The Fate and Potential Bioavailability of Airborne Urban
Contaminants
R828771C003 Geochemistry, Biochemistry, and Surface/Groundwater Interactions
for As, Cr, Ni, Zn, and Cd with Applications to Contaminated Waterfronts
R828771C004 Large Eddy Simulation of Dispersion in Urban Areas
R828771C005 Speciation of chromium in environmental media using capillary
electrophoresis with multiple wavlength UV/visible detection
R828771C006 Zero-Valent Metal Treatment of Halogenated Vapor-Phase Contaminants in SVE Offgas
R828771C007 The Center for Hazardous Substances in Urban Environments (CHSUE) Outreach Program
R828771C008 New Jersey Institute of Technology Outreach Program for EPA Region II
R828771C009 Urban Environmental Issues: Hartford Technology Transfer and Outreach
R828771C010 University of Maryland Outreach Component
R828771C011 Environmental Assessment and GIS System Development of Brownfield Sites in Baltimore
R828771C012 Solubilization of Particulate-Bound Ni(II) and Zn(II)
R828771C013 Seasonal Controls of Arsenic Transport Across the Groundwater-Surface Water Interface at a Closed Landfill Site
R828771C014 Research Needs in the EPA Regions Covered by the Center for Hazardous Substances in Urban Environments
R828771C015 Transport of Hazardous Substances Between Brownfields and the Surrounding Urban Atmosphere
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
Main Center: R828771
108 publications for this center
20 journal articles for this center