M5 PM Marine Environmental Chemistry of Organic Pollutants|
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 321-323
133 (DAC-1117-822237) Oceanic biogeochemical sequestration of atmospheric persistent organic pollutants revisited.
Start time: 1:50 PM
Dachs, J.1, Jurado, E.1, Simó, R.2, 1 Department of Environmental Chemistry, IIQAB-CSIC, Barcelona, Catalunya, Spain2 Institute of Marine sciences, CMIMA-CSIC, Barcelona, Catalunya, Spain
Sinking to the deep ocean and atmospheric degradation by OH attack are the two main permanent sinks of POPs such PCBs at the global scale. During the last decade several studies have focused in quantifying and understanding these two sinks. In the present work we have reviewed the oceanic and atmospheric sinks of PCB congeners using two complementary methodologies. The first involves the use of remote sensing data to quantify the spatial and temporal variability of environmental variables such aerosol load and size distribution, primary productivity, etc. This approach leads to an estimation of the global sink of PCBs of about 200 tn y-1. A second figure for global oceanic sink of POPs can be obtained by applying a recently developed global chemical tracer model for modeling the spatial and temporal distribution of pops. Both approaches will be compared and discussion will be presented on the role of water column cycling as a driver of atmospheric transport of POPs.
134 (DIC-1117-814874) Transport and Fate of Persistent Organic Pollutants (POPs) in Antarctic Coastal Seas.
Start time: 2:10 PM
Dickhut, R1, Cincinelli, A2, Cochran, M1, Geisz, H1, Ducklow, H1, 1 Virginia Institute of Marine Science, Gloucester Point, VA, USA2 University of Florence, Florence, Italy
The introduction of POPs into the Antarctic marine ecosystem is thought to be due to long-range atmospheric transport and deposition in the absence of point source pollution on the Antarctic continent. We collected high volume air samples, seawater, sea ice, snow and glacier ice along the Antarctic Peninsula during both the austral winter (Sept.-Oct., 2001) and summer (Jan.-March, 2002). An abundance of hexachlorobenzene (HCB) was observed in Antarctic air along with hexachlorocyclohexanes (HCHs), heptachlor, and heptachlor epoxide. BDE-47 was also detected in Antarctic air. For some POPs there was little spatial or temporal variability in atmospheric levels in the Antarctic over the past decade, and high levels of heptachlor in the Antarctic air samples were coincident with air masses traveling into the region from lower latitudes. HCHs, heptachlor, heptachlor epoxide, and brominated diphenyl ethers (BDEs) were also detected in snow, sea ice, and glacier ice samples, indicating current atmospheric deposition of these POPs to the Antarctic. However, whereas BDEs appear to concentrate in glacier and sea ice, HCHs and heptachlor do not, indicating differential cycling of these contaminants in Antarctic coastal ecosystems. In this paper we will explore the relative importance of glacier ice and sea ice as storage reservoirs for POPs, the cycling of POPs between air, snow, and ice in the Antarctic, and the transfer of POPs to Antarctic marine biota.
135 (LOH-1117-807374) POPs transport and partitioning on a transect from Northern Europe to the high Arctic.
Start time: 2:30 PM
Lohmann, R1, 2, Nizetto, L3, Caba, A4, Xie, Z4, Temme, C4, Gioia, R5, Jones, KC5, Schulz-Bull, D6, 1 University of Rhode Island2 University of Bremen3 University of Insumbria4 GKSS5 Lancaster University6 Institute for Baltic Sea Research
Air and water samples were collected on the FS Polarstern in the summer of 2004, from ca. 54 °N (Bremerhaven, Germany) to the high Arctic (ca. 85 °N). 30 Water samples were collected via a stainless steel inlet at 10 m depth, with volumes ranging from 750 to 1500 L. Particle-bound organic contaminants were captured on glass fiber filters (GFFs), and dissolved compounds on XAD columns. Air samples were taken with high-volume air samplers on the top deck of the ship with a combination of GFFs followed by polyurethane foam plugs. Air volumes ranged from 240 to 840 m3. Care was taken to minimize contamination during air sampling; air samples were only taken with the wind coming from the bow in a 70° angle each side, and with relative wind speeds exceeding 3.5 m/s. Additionally, passive air samplers were deployed at key locations across the FS Polarstern to assess the potential of the ship's emissions to contaminate the samples. Water samples were analyzed for PAHs, PCBs, organochlorine pesticides and dissolved organic carbon (DOC), while air samples were also analyzed for total suspended particulates (TSP), organic carbon (OC) and black carbon (BC) concentrations. Results of the passive air sample deployment on board showed some elevated concentrations of PCBs and PBDEs inside the ship, with the top deck being very clean. Water column concentrations displayed decreasing concentrations from South to North, especially for PAHs. Concentrations ranged from few ng/L near Europe to less than tens pg/L for selected PAHs. The concentration gradient was less pronounced for PCBs. Interestingly, a distince concentration gradient was apparent on an East-West axis, with relatively uniform concentrations both near Greenland and Norway, but lower concentrations in-between.
136 (SMI-1117-699181) Seasonality in the concentrations and partitioning of PCBs in Baltic Sea surface waters.
Start time: 2:50 PM
Smith, K.1, Czub, G.2, McLachlan, M.2, 1 Institut für Ostseeforschung, Warnemünde., Germany2 Laboratory for Analytical Environmental Chemistry, Department of Applied Environmental Science, Stockholm University, Stockholm., Sweden
In the marine environment the partitioning of PCBs between the dissolved and suspended matter phases in the water column plays a fundamental role in determining PCB fate e.g. air-water exchange or food-chain uptake. It was hypothesized that this partitioning could vary seasonally, particularly in temperate latitudes where biological, chemical, and physical conditions in the marine environment show a pronounced seasonality. Surface water samples from the western Baltic Sea were sampled regularly over an 18 month period between February 2003 and July 2004. The concentrations of seven PCB congeners were determined in the dissolved and suspended particulate matter (SPM) phases. A negative linear relationship was found between KPOC (i.e. the ratio between the particulate organic carbon (POC) normalized PCB concentration in SPM (pg/kg POC) and the dissolved concentration (pg/L)) and temperature. The decrease in the water temperature between summer and winter of 20°C resulted in approximately a factor of 5 increase in KPOC. POC normalized PCB concentrations in SPM were higher in winter than in summer by a factor of around 10. This was a reflection of the higher KPOC in winter and also somewhat greater PCB concentrations in the dissolved phase. The results demonstrate a clear seasonality in contaminant partitioning in the marine environment that should be accounted for when interpreting field data or modeling contaminant fate. Further research is needed to clarify whether the seasonality observed in the PCB levels associated with POC in the water column is also representative for those organisms occurring at the lower trophic levels such as phytoplankton and zooplankton, or whether the high concentrations in winter are largely associated with detritus.
(58120) COFFEE BREAK.
Start time: 3:10 PM
137 (LIE-1117-761150) Distribution and sources of PAHs in sediments and mussels from the western Baltic Sea.
Start time: 3:50 PM
Liehr, Gladys1, Witt, Gesine1, 1 Baltic Sea Research Institute (IOW), Rostock, Germany
During 2002 and 2004, sediment and mussels were sampled at 2 stations (dumping site, reference site) from the Mecklenburg Bight, western Baltic Sea. At each station the concentration, distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment and soft body tissue of Arctica islandica were investigated and analysed using Gas/Chromatography Mass spectrometry (GC/MS). Bioaccumulation factors (BAFs) of individual compounds from sediment were calculated and discussed according to the compound availability. The total PAH concentration (sum of 2- to 6-ring aromatic hydrocarbons) varied between 50 and 5500 ng/g dw. The highest concentration was measured in surface sediments from the dumping site. The contamination levels were higher by a factor of 80 to 200 as compared to the reference site. A ratio between Phenanthrene/Anthracene to Flouranthene/Pyrene and LMW/HMW (low molecular weight/high molecular weight) indicated that the PAHs in sediments are of pyrogenic origin. Total PAH concentrations in the soft tissue of A. islandica sampled at the dumping site were much higher (>1000 ng/g dw) compared to mussels from the reference site. These extremely high concentrations were just found in mussels which are directly sampled in harbours. Bioaccumulation factors for the PAHs were also higher in mussels from the dumping site. A. islandica was situated on the surface sediment. They were in direct contact with the sediment and were able to absorb particles from the resuspended sediment as well as the dissolved fraction of PAHs. Therefore the lower molecular PAHs (mainly 3-ring aromatics, which are water soluble) were more accumulated than the higher molecular weight, stronger sediment-bounded, compounds (4-6-ring aromatics) at both sites. A lower, decreasing abundance (1 Ind./m2) and a missing of recruits and adult mussels at the dumping site are further indices for unsuitable environmental conditions.
138 (DUN-1117-738102) Historical Anthropogenic Inputs of Black Carbon and Polycyclic Aromatic Hydrocarbons to the Chesapeake Bay Watershed.
Start time: 4:10 PM
Dunn, J1, Mitra, S2, 1 Binghamton University, Binghamton, NY, USA2 Binghamton University, Binghamton, NY, USA
Since colonization, the Chesapeake Bay (C. Bay) has been subjected to a suite of anthropogenic impacts. One of the processes, combustion, stands to detrimentally impact C. Bay water quality. A byproduct of combustion is black carbon (BC), the residue remaining after incomplete combustion of biomass or fossil fuels. BC is important in that it co-associates with many organic contaminants, such as polycyclic aromatic hydrocarbons (PAH's). This study focuses on recent and historical BC deposition into the C. Bay, an important coastal ecosystem, using two complementary approaches. In this study, we estimate historical atmospheric emission of BC via development of a BC emissions inventory for the states that comprise the C. Bay watershed. Our model utilizes historical consumption data and BC emission factors derived from literature, both of which are specific to BC fuel source. Results indicate a marked increase of BC influx from 1900 until 1945, followed by an equally marked decline until 2000. Additionally, BC was chemically extracted from sediments throughout a 66 cm box core and a 4.5 m piston core taken from an anoxic deep water site in the mainstem of the C. Bay. BC concentrations were quantified in sequential depth intervals and taken together with sediment mass accumulation rates in order to calculate historical BC depositional flux in the core. Results from the sediment core show BC concentrations ranging from 0.15-0.75 grams BC gdw-1. BC extracts were also analyzed for their stable carbon isotopic composition (13C). The range of 13C of the BC throughout the core is from -22.86 to -20.78 per mil, indicating historical variation in BC source. PAHs will be extracted from sediments at several depth intervals in order to delineate BC source.
139 (JOH-1117-665810) Polybrominated Diphenyl Ethers(PBDEs) and Polychlorinated Biphenyls(PCBs) in fish and dolphins from Florida Coast(USA).
Start time: 4:30 PM
Johnson-Restrepo, B.1, 2, Kannan, K.1, Addink, R.1, Adams, D.3, 1 Wadsworth Center, New York State Department of Health and State University of New York at Albany., Albany, New York, USA2 Environmental and Computational Chemistry Group, University of Cartagena, Cartagena, Colombia3 Florida Fish & Wildlife Conservation Commission, Fish & Wildlife Research Institute, Melbourne, Florida, USA
Polybrominated diphenyl ethers (PBDE) and polychlorinated diphenyls (PCBs) were measured in dorsal muscle tissues of seven marine fish including one species of shark and one species of stingray as well as in blubber tissues of bottlenose- and striped- dolphins collected along Florida coastal waters, USA. Concentrations of PBDE in muscle tissues of fish collected in 2004, on average, ranged from 7.7 ng/g, (lipid wt) in silver perch, to 273 ng/g, (lipid wt) in Atlantic sharpnose shark with an overall mean concentration of 75 ±91 ng/g, lipid wt. Mean concentrations of PBDEs in the blubber of bottlenose- and striped- dolphins collected in the early 1990s were 222 and 563 ng/g lipid wt, respectively. BDE-47 was the major congener detected in fish and dolphin samples, followed by BDE-99, BDE-153, BDE-100 and BDE-154. In contrast, BDE-209 was the most abundant congener in Atlantic sharpnose shark. Concentrations of PBDEs were, on average, 20- to 100-fold greater than those of PCBs in fish species analyzed. Nevertheless, dolphins collected in the early 1990s contained three orders of magnitude greater PCB concentrations than PBDEs. Occurrence of BDE-183, BDE-203, and BDE-209 in addition to other major congeners such as BDE-47, BDE-99 and BDE-100, suggests exposure to all technical PBDE formulations such as penta-, octa- and deca- BDE mixtures in marine fish. Biomagnification factors of PBDEs and PCBs were examined in this coastal marine food chain comprising fish, shark and dolphins.
140 (FER-1117-830339) Cooperative effects between salinity and dissolved organic matter on the half-life of simvastatin.
Start time: 4:50 PM
He, L.1, Sima, L. 1, Chandler, G.2, Ferry, J.1, 1 Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, US2 Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, US
Naturally occurring dissolved organic carbon is known to experience significant aggregation across the salinity gradient encountered at the freshwater/marine interface. There is evidence that such aggregates present less-polar microenvironments that dissolved contaminants may associate with. This work addresses how the interaction between salinity, pH, and the loading of dissolved organic carbon affect the rate of hydrolysis of a lactone, the pharmaceutical simvastatin, to the corresponding hydroxy acid. A central composite experimental design was applied to examine the effects of these three variables over the pH range 5-9; a salinity range of 0-35 ppt, and a dissolved organic carbon load of 0-15 mg/L, evaluating their role as individual variables as well as possible interactions between any two of them. This design was selected as representative of the range of probable surface water conditions experienced during estuarine mixing. Over this range, it was observed that pH was by far the most important variable in predicting the hydrolysis rate of simvastatin. However, at a fixed pH (8.3) there was an apparent interaction between dissolved organic carbon and salinity (much smaller than the pH effect alone). The hydrolysis rate correlated positively with salinity or dissolved organic carbon alone, but negatively against the combined term. This is interpreted as evidence of aggregate formation at high carbon/salt loading with partitioning of simvastatin into a protected, non-polar environment either inside or on the surface of the aggregate. A quantitative model of hydrolysis rate and estimated half-live vs conditions is presented. Preliminary measurements of the gut pH of meiobenthic copepods suggest the statin will exist primarily in the closed form in the gut of the organism.
141 (WIT-1117-679614) Using Solid Phase Microextraction to evaluate the bioavailability of PAHs in sediments of the western Baltic Sea.
Start time: 5:10 PM
Witt, Gesine1, Liehr, Gladys1, Thiele, Rajko1, 1 Baltic Sea Research Institute, Seestrasse 15, D-18119 Rostock, Rostock, Germany
The risk of PAHs binding to sediment strongly depends on their mobility and consequently their bioavailability. In this study a partitioning based sampling technique was applied as tool to estimate the mobility of 9 PAHs in sediments of the western Baltic Sea focussing on a highly contaminated former dumping area. The freely dissolved PAH porewater concentration was measured using matrix solid-phase microextraction (SPME). It is shown that SPME is a very powerful method for the determination of truly dissolved PAHs. Only a minimum fraction of PAHs were presented as freely dissolved molecules in the porewater (9-192 ng/L). Based on these results it was possible to calculate the fraction of the total measured PAH sediment concentration that was available for equilibrium partitioning (0.01-25.8%). Furthermore elevated solid water distribution coefficients of the PAHs were calculated (log KOC between 4.5 and 9.2) and compared to data from the literature. The elevated partitioning coefficients of the sediment-porewater systems could be explained through the distribution model which included the soot-partitioning. Furthermore a comparison of the different sampling sites shows that no linear relationship exists between the sediment and freely dissolved porewater concentration. A particulate phase exists to which PAHs sorb more readily at the dumping site compared to the other stations in the western Baltic Sea. These findings indicate that soot carbon was not the primary sorption material for PAHs at the dumping site. The results are particularly important to predict the mobility and bioavailability of the PAHs in environmental samples of different origin.