Grantee Research Project Results
2002 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: Mason, Robert P. , Baker, Joel E. , Ondov, John M. , Crimmins, Bernard , Laurier, Fabien , Pancras, Patrick
Current 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, 2001 through September 30, 2002
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 objective of this research project is to estimate the fate and bioavailability of atmospherically transported chemical contaminants in the urban environment. To achieve this objective, 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 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 that is encompassed within the Center for Hazardous Substances in Urban Environments to quantify and understand the sources and cycling of hazardous materials in the urban environment, and specifically, the exchange of contaminants between the land and the atmosphere. This project is aimed at better quantifying the sources and cycling of airborne contaminants as improvements in characterizing the sources, pathways, and bioavailability of these contaminants to determine whether exposure levels have been, or will be, high enough to cause adverse health effects.
Progress Summary:
Progress in Year 1 of this study has encompassed work on bulk sample collections using the University of Maryland Ultra-High Volume Aerosol Sampler. The system consists of an air inlet, a 1-meter cyclone separator (Dustex, ST-6, Dustex, Charlotte, SC), filter cassettes, and a positive displacement regenerative blower (Roots URAI 59, Dresser Industries, Pittsburgh, PA). A mesh screen over the inlet prevented very large particles (e.g., most insects greater than 0.2 cm) from being directly sampled. Coarse particles (>2.5 µm, aerodynamic diameter) are removed in the high volume 1-meter cyclone sampler, and fine particles are collected downstream on an array of Teflon membrane filters (Zefluor, 3 µm pore size, Gelman Sciences, Ann Arbor, MI), each measuring 20.3 cm by 25.4 cm. The blower is capable of sustaining flow rates from 5.7 to 12.0 m3/min-1, with a maximum pressure drop of 0.41 bar. The sampling flow rate is determined from a Pitot tube installed in the 10 cm duct in front of the cyclone. The system is installed in a trailer at Clifton Park, about 2 km northeast of downtown Baltimore, MD, to collect PM2.5 for use in standard reference materials. Course particles captured by the cyclone are to be used in the leaching studies. Constructed of stainless steel, the original cyclone was found to contaminate the collected particles. Therefore, we replaced the stainless steel cyclone with an aluminum cyclone. The new cyclone (ST10), sized to permit a doubling in sampling capacity, was installed and tested last fall using an aerosol generator and a Thermo Systems, Inc., Aerodynamic Particle Sizer (APS) to alternately measure the particle size distribution before and after the cyclone. Tests were done at two flow rates to determine the influence of velocity on the sharpness of the cyclone efficiency curve. Results of the efficiency measurements revealed a cutpoint of 2.8 µm at 440 CFM. However, the curve was quite broad, indicating that substantial amounts of particles as large as 10 mm would penetrate to the filter cassette. Therefore, we decided to replace the larger cyclone with an aluminum ST6 cyclone, which has not yet been delivered.
Our former system relied on frequent user intervention to manually maintain the flow rate through the cyclone. To provide for more precise operation and improved documentation, we developed and implemented a computer control program to maintain the proper flow rate and log the appropriate data. A high precision capacitance manometer was installed in parallel to the magnahelix to measure the Pitot tube pressure differential. Additionally, absolute pressure and temperature/relative humidity sensors were installed in the filter cassette to monitor these critical parameters. The control and data logging program was written in Visual Basic and logs average Pitot tube pressure, calculated volumetric flow rate, T, RH, and air pressure in the filter enclosure. An electronics control module was constructed to house an analog/digital IO converter board, sensor amplifiers, relays, etc. The system has been installed in the trailer and successfully tested.
Sampling equipment for size-segregated organic chemicals in ambient air was installed and operated at the Baltimore Supersite during the spring and summer of 2002, sampling intensives. Consecutive 12- and 24-hour integrated samples were collected using both the Berner low-pressure impactor and standard high-volume filter/polyurethane foam (PUF) samplers. These samples currently are being analyzed in the laboratory. During the summer 2002 sampling intensive at the Baltimore Supersite, mercury speciation measurements also were made. Results are pending.
Future Activities:
A new, all aluminum 1-meter cyclone will be installed in place of the stainless steel 1-meter cyclone. Once this is accomplished, we will begin collecting samples. Laboratory leaching studies will follow. Analysis of ambient air samples collected during the intensives continues, and a further sampling intensive is planned for the winter of 2002.
Journal Articles:
No journal articles submitted with this report: View all 3 publications for this subprojectSupplemental Keywords:
ultra-high-volume particle collection, dry deposition, elemental composition, urban particle solubility, reactive gaseous mercury, polycyclic aromatic hydrocarbon, PAH, gas/particle distribution., 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
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