M8 AM Persistent Organic Pollutants|
Monday, 14 November 2005: 8:00 AM - 11:40 AM in 337-338
64 (BEG-1117-359021) Status of Persistence Toxic Substances in Arabian Gulf States.
Start time: 8:00 AM
Beg, M.1, Al-Ghadban, A.1, 1 Environmental Sciences Department, Kuwait Institute for Scientific Research, PO Box 24885, Safat-13109, Kuwait, Kuwait
This presentation will provide an insight in the problems of persistence toxic substances (PTS) in the region of Arabian Gulf States; identify the gaps in knowledge and an action plan. Available reports indicated that PTS analyzed in tissues or environmental samples rarely occurred as single compound. Most of the chlorinated compounds were detected n sediment and biota of Gulf waters. However, their concentration was found to be extremely low. Several organochlorine compounds were detected in fairly young mothers milk though not to an alarming levels but indicating the presence of unknown sources. Methyl mercury in the marine sediment was in the lower end of the range of values typical of uncontaminated near shore and offshore sediments. Of the fish analyzed twenty one percent exceeded the WHO limits. River discharges and industrial areas have the highest PAHs contamination. Khor Bubiyan in Kuwait and Abadan in Iran showed contamination with degraded and fresh oil. PAHs were also reported in sediment from Abadan and Qatar. Fish samples contained low levels of PAHs. Organotin compounds (butyl and phenyl-tin) in muscle and liver samples of fish were detected throughout Arabian Gulf but were less than in Tokyo Bay. Environmental monitoring of combustion products dioxins and furans has been initiated in many countries but data are not yet available. Regarding PTS sources inventories do not exists so far or not frequently accessible to get quantitative information of input in the environment. Oil hydrocarbons (PAHs) and combustion products are on the top of priority list in oil producing Gulf States.
65 (MAR-1117-845112) Bioaccumulation and biomagnification of POPs by bottlenose dolphins in coastal Georgia (USA).
Start time: 8:20 AM
Pulster, Erin1, Maruya, Keith2, 1 Skidaway Institute of Oceanography, Savannah, GA, USA2 Southern California Coastal Water Research Project, Westminster, CA, USA
In coastal ecosystems, top aquatic predators such as marine mammals are exposed to persistent organochlorine pollutants (POPs) via contaminated fish that serve as part or all of their diet. Inshore populations of bottlenose dolphins (Tursiops truncatus) in particular are thought to be at risk because they consume fish as their preferred prey, have limited POP biotransformation capacity, and exhibit long-term fidelity to specific tidal estuaries. The objective of this research was to generate and validate a predictive POP biomagnification model for T. truncatus in southeastern U.S. estuaries, including the heavily contaminated Turtle/Brunswick River (TBR) estuary in coastal Georgia (USA). Mean total PCB and toxaphene (TOX) concentrations were up to two orders of magnitude greater in TBR fish species preferred by inshore Tursiops (42 and 49 mg/kg lipid, respectively) than in other regional estuaries. Prey- and estuary-specific modeling suggests that inshore TBR dolphins would accumulate POPs (approx. 60 mg/kg lipid total PCB; approx. 20 mg/kg lipid total TOX) to levels that exceed thresholds associated with deleterious effects. Order of magnitude agreement between predicted and recently measured POP concentrations in T. truncatus blubber from strandings (n=6) and dart biopsy samples (n=7) was achieved, with better concordance for PCBs than toxaphene. This on-going study indicates that contaminated prey (fish in this case) serve as important vectors as well as predictive modeling elements for biomagnification of POPs in coastal aquatic systems.
66 (BAR-1117-828743) Hexachlorobenzene (HCB) in the global environment: emissions, levels, distribution, trends and processes.
Start time: 8:40 AM
Barber, J1, Sweetman, A1, van Wijk, D2, Jones, K, 1 Lancaster University, Lancaster, UK2 Euro Chlor, Brussels, Belgium
Hexachlorobenzene (HCB) will be considered as a model persistent organic pollutant. Data on its sources, emissions, environmental levels and distributions and trends have been compiled and will be used to assess its fate and behaviour in the global environment. Global production exceeded 100 000 tonnes and primary emissions to atmosphere probably peaked in the 1970s. There has been a consistent downward trend in the environment over the past 20 years. Consideration will be given as to the extent to which it has undergone repeated air-surface exchange or hopping to become globally dispersed, the balance between primary and secondary sources in maintaining ambient levels, and its ultimate sinks in the environment. Temporal trends of HCB in the environment vary, dependent on time period measured, media studied and study location, but the average half-life from all the studies is 8 years. Estimates made of the contemporary burden in the environment range between 10 000-26 000 tonnes, and are dominated by the loadings in treated and background soils, sediments and oceans. Estimates of the trends of HCB emissions from treated soils have been derived. At its peak, the amount of HCB emitted from soil to air may have been in the hundreds to thousands of tonnes per year, which would have made it a significant source of HCB to the environment. Whilst the amount of HCB being emitted from contemporary soil is much lower, only a small amount of re-emission of HCB from soil to air is required to maintain contemporary air concentrations under the current primary emission scenario.
67 (SET-1117-822824) STP Model: Calibration and testing on a full-scale sewage treatment plant.
Start time: 9:00 AM
Seth, R1, Wang, J1, Drouillard, K1, 1 University of Windsor, Windsor, Ontario, Canada
Sewage treatment plants (STPs) can be a significant source of exposure to humans and the environment for a variety of chemicals of historical and emerging concern. Most countries require that such chemicals and especially those which are new to commerce be assessed for their treatability in sewage treatment plants using a screening level model. The STP model has been used widely for such assessments in Canada, the U.S. and elsewhere. For chemicals with biodegradation as a significant loss process, the greatest uncertainty in model predictions is in its loss by the process. This is mainly due to the uncertainty surrounding the proper selection or derivation of biodegradation rate constants for application to the various stages of the sewage treatment process. Samples were collected under dry-weather conditions at six different locations at the Little River STP in Windsor, Ontario, Canada in this study, and analyzed for a suite of 31 chemicals of historical concern, including PAHs, chlorobenzenes, and organochlorine pesticides. A dataset comprising of ten PAHs, which were detected at all stages of the treatment process, was compiled and used for the calibration and testing of the STP model. The results suggest that the biodegradation rate constant for use in the STP model could be derived from those reported in surface waters, by applying a factor. A range for such a factor is suggested. The results using the factor show excellent agreement between the observed and modeled chemical trends during the treatment process for all the ten PAHs.
Start time: 9:20 AM
68 (AAA-1117-815905) The mechanism of interaction between polycyclic aromatic hydrocarbons and natural organic matter.
Start time: 10:00 AM
He, M1, 1 State Key Labortary of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China
The mechanism of interaction between polycyclic aromatic hydrocarbons and natural organic matter from sediment of different regions is studied. The sediments were collected from different regions of China. The humic acid was extracted from these sediments, and the element analysis, FT-IR spectrum and solid-state CP/MAS 13C NMR were used to obtain the structure and compositional information of humic acids. The sorption of polycyclic aromatic hydrocarbons by humic acids were examined in batch sorption experiments. There were big differences on the contents of C, H, N, and O among humic acid that extracted from those 9 kinds of river or lake sediments. Although the humic acid from different sediments showed very similar FT-IR spectrum character, detailed analysis showed that there were some differences among them. By using CP/MAS 13C NMR to analyze the spectra characteristics of humic acid, along with the comparison of the humic acid absorption experimental results, it was found that for non polar organic pollutants, there was a positive correlation between absorption capacity of humic acid and its aliphaticity, but showed negative correlation with its aromaticity.
69 (SWA-1117-653695) Development of a microwave assisted extraction method for organohalogen contaminant analysis in blood.
Start time: 10:20 AM
Swarthout Jr, R1, 2, Keller, J1, Davis, W1, Kucklick, J1, 1 National Institute of Standards and Technology, Charleston, SC, USA2 College of Charleston, Charleston, SC
Application of scientific microwave technology has recently experienced rapid growth in the scientific community. Originally developed from conventional microwave ovens, the technology has been refined for greater control of temperature and power. Development of open-focused microwave systems has lead to extremely reproducible oven conditions and increased potential for performing extractions. Microwave technology has routinely been applied in the field of environmental chemistry mainly for matrix digestion in inorganic contaminant analysis and to a lesser extent for extraction of organic contaminants from solid matrices such as sediment and ash. We investigated the potential of a microwave assisted extraction (MAE) method for the extraction of polychlorinated biphenyls (PCBs), organochlorine pesticides, polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) from blood using an open-focused microwave system. The extraction parameters, time and temperature, were optimized by extracting aliquots of NIST Standard Reference Material (SRM) 1589a (PCBs, Pesticides, and Dioxins/Furans in Human Serum) spiked with 10 mass-labeled surrogate compounds. Recovery of the surrogate compounds was determined by gas chromatography with mass spectrometric detection (GC/MS). The optimal extraction temperature and time were found to be three extraction cycles of 90 °C and 3 min, respectively. Recoveries of individual surrogate compounds ranged from 65% to 120% which were equal to or greater than recoveries from a liquid-liquid extraction (LLE) method and a solid phase extraction (SPE) method applied to SRM 1589a. Contaminant concentrations calculated using MAE were similar to those calculated using LLE and SPE. The automated MAE method resulted in total extraction times of approximately 45 min per sample which was less than half the run time of the SPE method. The MAE method was less labor intensive than the LLE method but was not as automated as the SPE method. MAE provides a valid relatively high throughput alternative to conventional LLE and SPE.
70 (HUD-1118-067126) Tribal assessment of PBT contaminant concentrations across size ranges of commonly harvested Lake Superior fish.
Start time: 10:40 AM
Hudson, M1, 1 Great Lakes Indian Fish & Wildlife Commission, Odanah, WI, United States
Wisconsin and Michigan Chippewa tribes harvested 1,400,000 lbs of whitefish (Coregonus clupeaformis) 264,000 lbs of lake trout (Salvelinus namaycush namaycush), and 11,000 lbs of siscowet trout (Salvelinus namaycush siscowet,) from Lake Superior in 2003. This fishery constitutes both a source of subsistence food and commercial income. The objective of the current study was to analyze composites of Lake Superior whitefish, lake trout, and siscowet trout, across the size range of commonly harvested fish (whitefish, 43-61 cm, lake trout, 43-72.5 cm, siscowet trout, 43-65 cm) for 37 persistent, bioaccumulative, and toxic (PBT) contaminants. Each species of fish were composited within these size ranges based on length, age, and tissue type (skin, fat, muscle) within four size groups. PBT contaminant concentrations were measured in the muscle tissue and estimated in skin and fatty tissue using percent lipid in those tissues and lipid normalized muscle concentrations. The relationship between concentration and length and/or age, regression analysis, and comparison of fillet data to current health advisory trigger levels are evaluated and discussed.
71 (AAA-1117-652527) Assessing the influence of black carbon and sorbate planarity on sorption of PCBs by Lake Hartwell sediment.
Start time: 11:00 AM
Im, J1, Lee, C1, Coates, J1, 1 Clemson University, Anderson, SC, USA
The objective of this study is to develop a better understanding of complicated environmental sorption of PCBs in natural sediment systems including the role of black carbon of different types, humic acid, and sorbate planarity. Sorption of three PCB congeners [tri-CB (IUPAC 35), and tetra-CB (IUPAC 54 and 77)] by sediment from a reservoir contaminated with PCBs but relatively free of black carbon (BC) and by sediment amended with two well-characterized black carbon materials or humic acid will be reported. The sorbents are sediment collected from Lake Hartwell located on the border between South Carolina and Georgia; black carbon reference material (BCRM), which was developed by the Black Carbon Steering Committee of the AGU; and NIST standard reference material (SRM 2975), which consists of diesel particulate matter. Elliot Soil Humic Acid was obtained from International Humic Substances Society. For both Lake Hartwell sediment suspension (less than 53 um) and kaolinite (a major component of the reservoir sediment), isotherms for the tri-CB indicated much less sorption compared to BCRM or SRM 2975. Isotherm results from the reservoir sediment with various levels of BC (0.0 %, 1.0 %, 2.0 %, 4.0 %, and 8.0 % of the Lake Hartwell sediment weight) added will be reported for the congeners. Results for the black carbon reference material (BCRM) sorbent indicated a greater affinity for the planar tri-CB (IUPAC 35) than the nonplanar tetra-CB (IUPAC 54). The PCB congeners have similar hydrophobicity, however, the planarity of two compounds are very different due to the number of chlorine attached to the ortho positions of biphenyl. For tri-CB, sorption by BCRM was greater than SRM 2975.
72 (MAY-1117-720737) Diffusive mass transfer of 11 PAHs through different exposure media.
Start time: 11:20 AM
Mayer, P1, Christensen, P1, 2, Karlson, U1, Reichenberg, F1, Forbes, V2, 1 National Environmental Research Institute, Roskilde, Denmark2 Roskilde University, Roskilde, Denmark
The biological uptake of hydrophobic organic compounds is often limited by the diffusive transport through a thin boundary layer. Therefore, a micro-scale technique was developed that quantifies mass transfer through a 100 micrometer thick layer of different exposure media. This technique has been applied to determine the diffusive mass transfer of 11 PAHs through water, air, digestive fluid of a deposit-feeding worm, aqueous soil extracts and solutions of surfactants. The diffusive flux of PAHs increases in the presence of, for instance, surfactants and digestive fluids. The enhancement factor increased with increasing molecular size of the PAHs, and the diffusive flux of benzo(a)pyrene was enhanced 71 times through gut fluid of a deposit-feeding worm when compared to water. The working principle of the new method will be presented along with the experimental results that have implications for (bio)availability and for comparing different exposure routes.