R8 AM Contamination Source Identification and Apportionment|
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in 331-332
664 (MIN-1117-833741) Characterization of PAH composition patterns in diesel emissions.
Start time: 8:00 AM
Minegishi, T1, Crimmins, B1, Baker, J1, 1 University of Maryland Chesapeake Biological Laboratory, Solomons, MD, USA
Polycyclic Aromatic Hydrocarbons (PAHs) have been used to characterize the proportion of emission sources to ambient aerosol concentrations. Source apportionment using PAHs has separated coal, wood combustion, oil, and vehicle emissions. Positive Matrix Factorization (PMF) was the only multivariate method that could separate diesel and gasoline sources in ambient air samples from Baltimore, MD (Larsen, 2003). The purpose of this study was to characterize the PAH composition of diesel emissions in order to better distinguish between diesel and gasoline signals. Samples were collected adjacent to idling trucks at truck stops as well as field sites nearby interstate highways. Diesel emission was the dominant signal at the truck stop, and the field site consisted of a mixture of gasoline and diesel inputs. Preliminary results from Knoxville, TN showed that although the PAH concentration profiles were very similar, statistical analysis using Principal Component Analysis (PCA) separated the truck stop and highway samples. The variables contributing to the separation were dibenz[a,h+a,c]anthracene, benzo[a]pyrene, and chrysene+triphenylene for the truck stop, and 2-methyldibenzothiophene, 1-methylfluorene, and fluorene for the highway. There also appeared to be a separation between day and night samples. The variables contributing to this diurnal separation were benzo[a]fluorene, benzo[b]fluorene, and 3,6-dimethylnaphthalene for night (7am-7pm), and 1,5-Dimethylnapthalene, Napthacene, and Acenapthacene for day (7am-7pm). Diesel emissions collected from different locations under different conditions are being used to characterize a comprehensive PAH pattern for diesel emission.
665 (KAS-1118-433882) Molecular Marker Characterization and Source Partitioning of Processed Leaf Compost from the Northwest Region: An Environmental Forensics Approach.
Start time: 8:20 AM
KASSIM, Ph.D., T.1, SIMONEIT, Ph.D., B.R.T.2, 1 Seattle University, Department of Civil and Environmental Engineering, P.O. Box 222000, Seattle, WA 98122-1090, USA2 College of Oceanic and Atmospheric Sciences, Oregon State University, COAS Admin. Bldg. 104, Corvallis, OR 97331, USA
Composted deciduous leaves (CDLs) originating from various metropolitan cities in the Northwest region were collected and characterized in terms of their organic chemical contents, represented by their lipid molecular marker (MM) signatures. The distributions, chemical structures, and applicability of such lipid MMs in determining characteristic group(s) representative for CDL extracts are discussed in this paper using a multi-tracer environmental forensics MM approach. Several low molecular weight compounds were identified that represented a blend of diesel molecular markers. Traces of homologous long chain n-alkanes, CPI, unresolved complex mixture, and molecular markers such as pristane, phytane, tricyclic and tetracyclic terpanes, hopanes, steranes with a minor amounts of diasteranes were found to be the most suitable indicators to differentiate between petroleum hydrocarbon- from non petroleum hydrocarbon-containing CDL samples. On the other hand, high temperature thermogenic/pyrolytic derived compounds were indicated by a specific group of polycyclic aromatic hydrocarbons (PAHs). This group, ranging from phenanthrene to dibenzo(ae)pyrene with different alkyl-substituted PAH series, is considered to be combustion products from fossil fuel. Different terrestrial (i.e., natural) molecular markers were also characterized in all CDL samples, such as cholestane, stigmasterane, stigmast-4-en-3-one, stigmastan-3-one, stigmatan-7-one, cholesterol, and alpha and beta amyrane. Statistical analyses (extended Q-mode factor analysis and linear programming technique) were performed in order to examine the variations in the multi-tracer MM data set, group the data into specific groups, and find statistically significant associations (end members) in the data set to help assess and identify the different chemical sources and original compositions representing the Northwest CDL extracts.
666 (TEU-1117-748054) Identification of Bioaccumulated Halogenated Natural Products.
Start time: 8:40 AM
Teuten, E1, Reddy, C1, 1 Woods Hole Oceanographic Institution, Woods Hole, MA, USA
Over the last decade, at least 20 halogenated organic compounds (HOCs) of unknown origin have been observed bioaccumulated in animal tissues. Determining whether these compounds are industrially or naturally-derived is of great importance. If they are industrially synthesized, their source must be determined, whereas if they are produced naturally they could provide insight on the cycling and environmental fate of industrial HOCs. To address the origin of these compounds, we have analyzed their natural abundance radiocarbon content. Radiocarbon analysis provides a very effective means of distinguishing industrial HOCs, which are generally derived from petrochemicals and contain no radiocarbon, from the contemporary 14C content of natural HOCs. We have shown that two methoxylated polybrominated diphenyl ethers (MeO-PBDEs) found in a True's beaked whale are natural products and not metabolites of industrial PBDEs, which are used as flame retardants. Following analysis of the blubber from a selection of marine mammals from coastal New England, we have identified several previously unreported mixed halogenated bipyrroles. Four other similar bipyrroles have been found previously in animal tissue. It has been assumed that these compounds are natural products, although no natural sources are known. Studies are underway to isolate these compounds for radiocarbon analysis, and determine whether they have a natural or industrial source.
667 (BID-1117-839609) DDT/DDE Ratios as Indicators of "Old" and "New" Residues in the Atmosphere.
Start time: 9:00 AM
Bidleman, T.1, Wong, F.1, Alegria, H.2, 1 Meteorological Service of Canada, Egbert, ON, Canada2 California Lutheran University, Thousand Oaks, CA, USA
The proportion of p,p'-DDT/p,p'-DDE (DDT/DDE) has long been used as a rough indicator of the age of DDT residues in the environment, higher ratios suggesting relatively recent DDT application. However, there are no guidelines on "high" and "low" with respect to atmospheric samples. Recent work by ourselves and others in southern Mexico and Central America has revealed concentrations of airborne DDT residues that exceed ambient air levels in Canada. These measurements were made between 2000-2004, coincident and just after Mexico officially stopped using DDT for disease vector control. The availability of air data from a region where DDT has recently been used provides an opportunity for comparisons with the U.S. and Canada, where DDT has been banned for several decades. Ratios of DDT/DDE were compared in the following media: a) air samples from southern Mexico and Central America, b) literature reports for air and soil samples from the U.S. and Canada, c) experiments in which air samples were collected 40 cm above agricultural soils containing DDT residues. Mean DDT/DDE ratios in soils from 11 different regions of the U.S. and Canada ranged from 0.5 - 7.3, with a median of 1.3. The wide range reflects a high variability in degradation rates, as has been reported in many studies. DDT is less volatile than DDE, and vapour-phase emissions from soil reflect this fractionation. Soil-air exchange experiments at four sites indicated that the DDT/DDE ratios in overlying air could be accurately predicted from the DDT/DDE ratio in soil multiplied by the liquid-phase vapour pressures of DDT/DDE. Predicted DDT/DDE ratios in air emissions from the 11 soil survey sites ranged from 0.07 - 1.12 (median 0.20). Reported DDT/DDE ratios in regional ambient air from the southern U.S., eastern and western Canada, the Great Lakes and the Canadian Arctic ranged from 0.33 - 0.79 (median 0.45), while the range and median from 10 air sampling surveys in Mexico - Central America were 0.83 - 6.0 (1.8). Results suggest that the DDT residues in ambient air of the U.S. and Canada are largely due to emission of old residues in soils, whereas continued DDT usage and/or emission of undegraded residues plays a greater role in Mexico - Central America.
Start time: 9:20 AM
668 (SOW-1117-572296) Source contribution of bioavailable polycyclic aromatic hydrocarbons and the impact of seasonal and episodic events in the Willamette River, Oregon.
Start time: 10:00 AM
Sower, G1, Sethajintanin, D1, Grove, R1, 2, Anderson, K1, 1 Oregon State University, Corvallis, Oregon2 USGS Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon
Concentrations of biologically available EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) along 18 miles of the lower Willamette River were determined by sampling water with passive sampling devices and analyzed using HPLC with diode array and fluorescence detectors. The study area includes the Portland Harbor (approx. river mile (RM) 3.5 – 9.5) and McCormick and Baxter (RM 7) superfund sites. Designated as a superfund site in 2000, Portland Harbor is a heavily industrialized stretch of the Willamette contaminated with heavy metals, polychlorinated biphenyls (PCBs), dioxin/furans, pesticides, and PAHs. Within Portland Harbor lies the former wood treating site of McCormick and Baxter which was designated a superfund site in 1994 and is characterized by soil, sediment and water contamination by PAHs, penta-chlorophenol, and heavy metals. Additional potential sources of PAHs include urban runoff, fires and spills. Fluoranthene to pyrene and phenanthrene to anthracene ratios were used to help identify sources. These ratios varied spatially and temporally at almost all sampling sites suggesting that the major sources of PAH contamination vary depending on several factors including, but not limited to, precipitation and river flow levels.
669 (PEN-1117-852559) PAH Source Identification and Apportionment using SPME-GC-IRMS: Isotope Fractionation during Extraction and Analysis.
Start time: 10:20 AM
Peng, J1, Maruya, K1, Zeng, E2, 1 Southern California Coastal Water Research Project, Westminster, CA, USA2 Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong, China
Gas chromatography-isotope ratio mass spectrometry (GC-IRMS) is a potentially useful tool for identifying sources of trace organic contaminants. The use of solid phase microextraction (SPME) not only simplifies sample collection, its selectivity eliminates the need for costly and time-consuming cleanup steps whereas its design enables direct injection of environmental samples sorbed to SPME fibers into the GC-IRMS. The potential for isotopic fractionation during different stages of SPME extraction as well as during GC-IRMS analysis needs to be assessed, however, before this technique can be effectively used in source identification. In this study, isotope fractionation of SPME-sorbed PAHs during thermal desorption inside the GC injector was measured in a time series experiment. Second, isotope fractionation was measured for several PAHs extracted sequentially and exhaustively by multiple batches of SPME fibers under non-equilibrium conditions (1-day extraction). A third experiment involved batch SPME extraction of PAHs under equilibrium conditions (2-week extraction)until exhaustion. We observed clear fractionation during thermal desorption inside the GC injector, with isotope ratios of remaining PAHs becoming heavier (averaging +1.75 per mil) after 5 seconds of thermal desorption when over 90 percent PAHs were desorbed. There were no significant shifts in isotope ratios during sequential SPME extractions under non-equilibrium conditions. However, a clear enrichment of 13C during the equilibrium SPME extractions was observed, with the second batch about 1.5 per mil heavier than the first batch after 75 percent depletion of PAHs in the spiked solution. Comparatively, the isotope ratios obtained by equilibrium SPME extractions were more consistent with the true values than those obtained under non-equilibrium conditions, suggesting that equilibrium extraction is a prerequisite for SPME-GC-IRMS for source tracking. Our preliminary results suggest that equilibrium SPME-GC-IRMS analysis can be a potentially useful tool for HOC source identification and apportionment.
670 (TOT-1117-646586) Attempts to Identify Atmospheric PCB sources in the Philadelphia Metro Area.
Start time: 10:40 AM
Du, S1, Totten, L1, 1 Rutgers University, New Brunswick, NJ, USA
The concentrations of polychlorinated biphenyls (PCBs) in the atmosphere in the Philadelphia metropolitan area (specifically at Camden, NJ and Swarthmore, PA), as measured by the New Jersey Atmospheric Deposition Network (NJADN), are elevated by as much as 20 times over regional background, averaging more than 3,000 pg per cubic meter. Because of these high levels, the loading of PCBs to the tidal Delaware River via via wet, dry, and gaseous atmospheric deposition exceeds the entire Total Maximum Daily Load (TMDL) recently established for PCBs. Identification of the sources of these atmospheric PCBs is therefore crucial to the implementation of the TMDL. Two models were used to identify atmospheric PCB sources in the region: A probabilistic model called the Potential Source Contribution Function (PSCF) which aims to identify source regions, and Positive Matrix Factorization (PMF), which identifies co-varying congener patterns. By itself, the PSCF model indicated that the major sources of PCBs to Camden lie to the west and south. Furthermore, the PSCF plots show high probabilities in the area within 50 km of the sampling site, indicating a strong local influence from Philadelphia metropolitan area. PMF analysis of the PCB concentration data yielded 4 co-varying congener patterns, which were tentatively identified based on the similarity of the congener pattern to known PCB sources. Combination of the two models indicated that the PMF factors may arise from different geographical regions around the Philadelphia metropolitan area.
671 (BAR-1117-816531) Arsenic in the Wallkill River and its tributaries, northwestern New Jersey.
Start time: 11:00 AM
Barringer, J1, Bonin, J1, 1 United States Geological Survey, West Trenton, NJ, USA
Arsenic concentrations in water samples from the Wallkill River in mostly rural Sussex County, New Jersey, in 2004 ranged from 0.5 to 21 micrograms per liter, exceeding the New Jersey Surface Water Quality Standard of 0.017 micrograms per liter. The arsenic sources could be geologic, anthropogenic (pesticides, wastewater), and (or) a combination (mining wastes). The New Jersey Department of Environmental Protection needs to know the types and locations of those sources in order to develop a total maximum daily load for arsenic for the watershed. The river flows north through glacial deposits in a valley that follows faulted carbonate rocks—dolomite at the headwaters and at a far downstream segment, and the Franklin Marble, host to formerly mined zinc ores (and arsenic minerals), in the middle segment. Tributaries draining gneiss and granite highlands to the east and shale lowlands to the west contribute little arsenic to the river. Arsenic concentrations in filtered samples were highest in water emanating from man-made Lake Mohawk, at the river's headwaters, decreased downstream to the Franklin Marble outcrop, and then increased slightly. Zinc concentrations at and downstream from the marble outcrop increased to three to six times those farther upstream. Sediments at the outlet of Lake Mohawk contain high concentrations of leachable arsenic. Concentrations of boron, chloride, and sodium in the river water that exceeded background levels by about 20% accompanied the high arsenic levels there, indicating possible anthropogenic inputs (such as wastewater) to the river's headwaters. The high arsenic and zinc content of sediments at and downstream from the Franklin Marble outcrop, together with bed-sediment mineralogy, indicates that weathered materials and wastes from past mining activities likely contribute to arsenic concentrations in water from the middle river segment.
672 (FUC-1117-819651) Post-fire surface water quality: Comparison of fire retardant versus wildfire-related effects.
Start time: 11:20 AM
Crouch, R1, Timmenga, H2, Barber, T3, Fuchsman, P3, 1 Analytical Laboratory Services Inc., Phoenix, AZ, USA2 Timmenga & Associates Inc., Vancouver, BC, Canada3 ENVIRON International Corp., Cleveland, OH, USA
An understanding of the environmental effects of the use of wildland fire retardant is needed to provide informed decision-making regarding forest management. We compiled data from all post-fire surface water monitoring programs where the fire retardant constituents ammonia, phosphorus, and cyanide were measured, and data were available in the public domain. For streams near four major wildfires, we evaluated whether these chemicals originated primarily from fire or from retardant use. We compared measured concentrations in streams where chemical wildland fire retardant was applied with concentrations in streams draining areas where retardant was not used. Correlations with calcium provided an additional line of evidence, because calcium concentrations in ash are much higher than in retardant. Ammonia, phosphorus, and total cyanide were found in streams in burned areas where retardant was not used, at concentrations similar to those found in areas where retardant was applied. Concentrations of weak acid dissociable cyanide were generally non-detected or very low, whether or not wildland fire retardant was used in the watershed. These results indicate that the application of wildland fire retardant had minimal effects on proximate surface water quality. Cyanide concentrations in post-fire stormwater runoff were not affected by the presence of ferrocyanide in the retardant formulas and were due to pyrogenic sources.