WP041 (WAL-1117-805648) Seasonal variability in sources and distribution of organic contaminants in the Chesapeake Bay.
Start time: 8:00 AM
Walker, S¹, Boyd, T¹, ¹ Marine Biogeochemistry Section, US Naval Research Laboratory, Washington, DC, USA
Seasonal variations in sources of polycyclic aromatic hydrocarbons (PAHs) to the main stem and tributaries of the Chesapeake Bay were investigated during biannual sediment and water column sampling events. While previous investigations have determined general sources of PAHs to the sediments and water column of the mid and lower stem of Chesapeake Bay, seasonal variations have not been previously examined. The following hypotheses were proposed: during the early spring, surface water column PAH sources should be dominated by a combination of atmospheric deposition (combustion derived automotive sources) and runoff e.g. combustion and petrogenic sources, while bottom water will likely be dominated by combustion sources (coal from sediment resuspension and automotive from atmospheric deposition). In the late summer, surface water column PAH sources should be dominated by atmospheric automotive sources; bottom waters should also consist of an automotive atmospheric signal with potential contributions from a historic sediment signal. Based on previous investigations and given the integrative nature of sediments, coal sources should dominate sediment PAH signatures year-round. Sources of PAHs to the Chesapeake Bay will be examined through a combination of techniques, including isomer ratios and multivariate statistics (ie., principal component analysis). Preliminary results indicate that despite the increasing development of the Chesapeake Bay watershed, overall PAH concentrations in the Bay and the mouth of the tributaries are generally low relative to more impacted urban estuaries, ie., Baltimore Harbor, the Anacostia River, and the Elizabeth River. Additionally, biogenic PAHs, specifically perylene, consistently represent a significant component (15-∼50%) of the total resolved PAH concentrations in the main stem and the tributaries, irrespective of season.

WP042 (RUB-1117-811169) Development of a Sensitive Magnetic Particle Immunoassay for Polybrominated Diphenyl Ethers.
Start time: 8:00 AM
Rubio, F.¹, Parrotta, C.¹, Li, Q.², Barcelo, D.³, Lacorte, S.³, Shelver, W.⁴, ¹ Abraxis LLC, Warminster, PA, USA² University of Hawaii at Manoa, Honolulu, HI, USA³ IIQAB-CSIC, Barcelona, Spain⁴ USDA-ARS, Fargo, ND, USA
Polybrominated diphenyl ether (PBDE) mixtures are manufactured as flame retardant additives for electronic equipment, plastics and textiles. PBDEs are ubiquitous environmental contaminants, their bioaccumulation has led to the detection of PBDEs in many species of wildlife, human blood plasma and in milk. PBDEs are structurally similar to polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and thyroid hormones, and therefore may interfere with thyroid hormone homeostasis. Because of their potential health consequences it is desirable to have a rapid and high throughput assay to monitor PBDEs. Enzyme immunoassays (ELISAs), have proven to be rapid, sensitive, accurate, and cost-effective. Magnetic particle-based ELISAs have previously been described and widely applied to the detection of pesticides and other environmental contaminants in various sample matrices, including water, soil, produce, and fish tissue. The uniform dispersion of the particles throughout the reaction mixture allows for rapid reaction kinetics, precise addition of antibody and superior analytical sensitivity. This paper describes the development and assay performance of a magnetic particle-based ELISA for PBDEs in whole fish samples. The results showed that the magnetic particle based ELISA and GC-MS values are comparable with r2 = 0.872 at a measured range of 50 to 4800 ppt in 18 samples. Future plans include applying this assay method to soil, sediment and waste water samples and validating the results with GC-MS.

WP043 (MCE-1117-815002) Hydrocarbons as Molecular Markers in the Potomac River Watershed.
Start time: 8:00 AM
McEachern, P.¹, Foster, G. ¹, ¹ George Mason University Department of Chemistry and Biochemistry, Fairfax, Virginia, USA
Sediment particles act as vehicles for the transport of many classes of organic chemicals through riverine systems. These compounds are both of anthropogenic and natural origin, and partition into the organic matter bound to the sediment particles. These sediment particles are transported downstream in riverine systems through alternate cycles of accretion and erosion. As the sediment particles move downstream through areas of differential land use, patterns of chemical content and relative abundance change. Physical and chemical analysis of sediments taken from a longitudinal transect of the three major physiographic provinces (Allegheny Plateau, Piedmont, and Coastal Plain)of the Potomac River reveal these patterns, and are of importance in the determination of overall fate and transport of chemical in the riverine and estuarine environments. Further evidence was obtained by the examination of sediments from two control tributaries, one known to be heavily impacted by urbanization (the Anacostia River) and the other known to be lightly impacted (Chopawamsic Creek) Sediments were examined for grain size, moisture content, and organic carbon, hydrogen, and nitrogen. Sediments were chemically analyzed by Soxhlet extraction, fractionation, and Gas Chromatograph-Mass Spectrometry (GC-MS) for the presence and quantities of selected Alkanes and Polycyclic Aromatic Hydrocarbons (PAHs). As expected, grain size, moisture content and organic constituents were quite variable, and showed no clear trends. However, the content of alkanes and PAHs clearly showed interesting trends, particularly the PAHs, which markedly increase in value downstream from the confluence of the Potomac and the Anacostia, directly due to input from the Anacostia River.

WP044 (MAL-1118-707219) Analysis of Pressures and Impacts on the Water Quality of the Senne River in Belgium.
Start time: 8:00 AM
Malpartida, Norka¹, Bauwens, W², ¹ The Institute of the Environment and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX, USA² Free Universitu of Brussels, Brussels, Belgium
The bad quality of water bodies has been a major concern of the European Community during the last decade. A new challenge of achieving good status of all waters by 2015 was introduced by the Water Framework Directive (WFD). As a result, the Common Strategy on the Implementation (CSI) of the WFD has established several working groups. In October 2001, the group called IMPRESS, was set up. After one year, IMPRESS came out with a guidance document for the analysis of pressures and impacts. Water pollution on the Senne River has become a problem due to continuous wastewater discharges from different sources, which determined in 2001 the announcement of the European Court of Justice indicating the failure on the implementation of the European rules for the treatment of household and wastewater in Brussels. Thus, Belgian authorities are striving hard to implement the goals of the WFD. This research applied the methodology proposed by IMPRESS, based on the Driver-Pressure-State-Impact-Response (DPSIR) model, in order to describe driving forces, identify significant pressures and analyse impacts from point and non-point source pollution on the water quality of the Senne River. An overall analysis of the present and future scenarios is also provided based on existing outcomes of the Extended Soil and Water Analysis Tool (ESWAT) model. The results indicate that the pressure from household discharges is greater in Brussels. Industrial activities have higher influence in Flanders and Wallonia, while major pressure from agricultural activities is present in Flanders. Impacts from these pressures are the current bad quality status of most of the physico-chemical parameters analyzed at downstream sites. The upstream river water is still under good water quality conditions. The analysis of the future scenario demonstrates the amelioration of COD, ammonium and oxygen concentrations. However, oxygen levels will require further improvement.

WP045 (KHI-1117-348887) Distribution and sources of trace organic contaminants in marine sediment.
Start time: 8:00 AM
Khim, JS¹, Villeneuve, DL², Kannan, K³, Giesy, JP^{4, 5}, Koh, CH¹, ¹ Seoul National University, Seoul, Korea² U.S. Environmental Protection Agency, Duluth, MN, USA³ State University of New York at Albany, Albany, NY, USA⁴ Michigan State University, East Lansing, MI, USA⁵ City University of Hong Kong, Kowloon, China
Concentrations of several classes of trace organic contaminants were measured in 26 marine sediments collected from Yeongil Bay, Korea, in order to characterize their spatial distribution and sources. PCBs were detected mainly in the inner bay locations and detectable at concentrations ranging from 2.85 to 26.5 ng/g, dry wt. Among different organochlorine pesticides analyzed, concentrations of HCHs were the greatest (mean: 1.16 ng/g, dry wt) followed by DDTs, CHLs, and HCB with mean concentrations of 0.58, 0.16, and 0.05 ng/g, dry wt, respectively. The sedimentary PAH concentrations ranged from <10.0 to 1870 (mean: 309) ng/g, dry wt, which were predominated by 3 and 4 ring aromatic hydrocarbons. Isomer ratios of selected PAHs associated with sediment indicated that primary sources of PAHs were pyrolytic. Alkylphenols (nonylphenol, octylphenol, and butylphenol) were next in predominance to PAHs and their mean concentrations were 89.1, 4.61, and 11.0, ng/g dry wt. respectively. While nonylphenol was detected from nearly all of the locations in Yeongil Bay, bisphenol A was detected in only one location (# 1), nearby an inland point source, at a concentration of 191 ng/g, dry wt. Concentrations of alkylphenols and bisphenol A were greater at inner locations proximal to municipal wastewater discharges into the Hyeongsan River, whereas those of PCBs and PAHs were great near shipyards and industrial complexes. Vertical profiles of PAHs and alkylphenols indicated that they have been associated with sediments since the 1950s. Although the mean concentration of PCBs and PAHs in Yeongil Bay sediments was less than the suggested sediment quality guidelines, their concentrations in some locations were close to or above the guidelines.

WP046 (KHI-1117-349648) Dioxin-like and estrogenic compounds and activities associated with marine sediment from Yeongil Bay, Korea.
Start time: 8:00 AM
Khim, JS¹, Villeneuve, DL², Kannan, K³, Giesy, JP^{4, 5}, Koh, CH¹, ¹ Seoul National University, Seoul, Korea² U.S. Environmental Protection Agency, Duluth, MN, USA³ State University of New York at Albany, Albany, NY, USA⁴ Michigan State University, East Lansing, MI, USA⁵ City University of Hong Kong, Kowloon, China
As part of a series of studies aimed at characterizing organic chemical contamination in Korean coastal areas, this study employed mechanism-specific in vitro bioassays to help characterize the occurrence and distribution of dioxin-like and estrogenic contaminants in sediment from Yeongil Bay, Korea. Approximately 85% of the sediments (total of 26 samples) tested induced significant dioxin-like activity in the H4IIE-luc bioassay, while approximately 50% induced significant estrogenic activity in the MVLN bioassay. Bioassay-derived estimates of 2,3,7,8-tetrachorodibenzo-p-dioxin equivalents (TCDD-EQs) and 17-estradiol equivalents (E2-EQs) were compared to instrumentally derived estimates (TEQs and EEQs, respectively) generated by multiplying congener specific chemical concentrations by previously published assay-specific relative potencies. Although some samples contained sufficient TEQs or EEQs to elicit a significant response in the bioassays, instrumentally-derived estimates tended to underestimate the magnitude of response, suggesting that compounds detected by chemical analysis did not account for all the activity associated with Yeongil Bay sediments, or that non-additive interactions were occurring. Profiles of responses observed for Florisil fractions of both surficial sediment and sediment core extracts showed a pattern that was consistent with previous studies of Korean coastal sediment contamination, with the greatest dioxin-like and estrogenic activity associated with the mid-polarity fractions (F2) expected to contain PAHs as well as chlorinated dioxins and furans. More polar fractions (F3) generated more modest responses both in terms of magnitude and the number of samples responding. Results suggest that more elaborate characterization of compounds associated with F2 should improve future understanding and monitoring of dioxin-like and estrogenic contamination associated with Korean coastal sediment.

WP047 (AAA-1117-776499) Atmospheric TGM (Total Gaseous Mercury) Concentrations and Source Identification using Hybrid Receptor Modeling in Seoul, Korea.
Start time: 8:00 AM
Yi, S.M.¹, Kim, S.H.¹, Huh, J.B.¹, Zoh, K.D.¹, Han, Y.J.², ¹ Seoul National University, Seoul, Korea² Kangwon National University, Chunchon, Korea
The objectives of this study were to measure ambient TGM concentrations in Seoul Korea, to determine the temporal variation of TGM, and to identify of TGM source areas using back-trajectory and back-dispersion based hybrid receptor modeling. Ambient TGM concentrations were measured at the roof of Graduate School of Public Health building in Seoul, Korea for a period of January to October 2004 and analyzed using CVAFS (Cold Vapor Atomic Fluorescence Spectrometry). Average TGM concentration was 3.43 ± 1.17 ng/m³. There was a significant positive correlation between TGM and PM2.5, indicating that reduction of Hg²⁺ to Hg⁰ occurred in liquid water contained in smog. The temporal variations of TGM were not statistically significant. Also, the strong correlation between TGM and SO₂ concentrations indicated that the source of TGM was from fossil fuel combustions including coal combustion. Hybrid receptor modeling incorporating backward trajectories including potential source contribution function (PSCF) and residence time weighted concentration (RTWC) and PSCF incorporating back-dispersion was performed to identify source areas of TGM. Using these models, central and eastern Chinese industrial areas and the west coast of Korea were determined as important source areas. Additionally, PSCF incorporating back-dispersion indicated that the major industrial areas of Russia including Vladivostik and Khabarovosk and some industrial areas of Japan including Hiroshima were significant sources.

WP048b (SMI-1127-856060) Investigating Triploid Chinese Grass Carp (Ctenopharyngodon Idella) As A Potential Vector Of Avian Vacuolar Myelinopathy.
Start time: 8:00 AM
Smith, R¹, Bowerman, W¹, Wilde, S², Habrun, S², Hope, C³, Murphy, T³, Hains, J⁴, McCord, R⁵, Morrison, J⁵, Grizzle, J⁶, ¹ Department of Forestry and Natural Resources, Institute of Environmental Toxicology, Clemson University, Pendleton, South Caroli² Belle Baruch Institute, University of South Carolina and Marine Resources Division, South Carolina Department of Natural Resourc³ South Carolina Department of Natural Resources, Green Pond, South Carolina⁴ United States Army Corp of Engineers, Calhoun Falls, South Carolina⁵ Environmental Services, Santee Cooper Power, Monks Corner, South Carolina⁶ Department of Fish Health and Disease, Auburn University, Auburn
Avian Vacuolar Myelinopathy (AVM) is a lethal disease of birds causing lesions in brain and spinal cord tissues. These lesions were first observed in bald eagles (Haliaeetus leucocephalus) and coots (Fulica americana) in western Arkansas in 1994. Since then, AVM has been diagnosed in several avian species that frequent surface water impoundments in the southeastern United States. Previous investigations have found no association with likely neurotoxins, infectious agents, pesticides, herbicides, or heavy metals. Feeding studies performed at Clemson University established a link between lake vegetation and AVM. Our working hypothesis is that an epiphytic toxin-producing Stigonematalen cyanobacteria, growing primarily on Hydrilla verticillata, is the etiologic agent. 2004-2005 research trials investigated the susceptibility of triploid Chinese grass carp (Ctenopharyngodon idella) to AVM, and if carp fed AVM-causing vegetation can act as a potential disease vector. Preliminary results indicated lesion formation in the treatment grass carp similar to symptomatic waterfowl. Our current research will seek to document sublethal effects on grass carp caused by exposure to the suspect cyanobacterium.