T5 PM Emerging Pollutants|
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 321-323
340 (AAA-1122-049414) Veterinary Pharmaceuticals in Animal Wastes and their Effect on Water Resources.
Start time: 1:50 PM
Al-Savvagh, T1, Kassim, T2, 1 Kuwait Institute for Scientific Research (KISR), Kuwait2 Seattle University, Department of Civil and Environmental Engineering, Seattle, WA, USA
Research is documenting with increasing frequency that many organic chemicals that have not historically been considered as contaminants are present in the environment on a global scale. These "emerging contaminants" are commonly derived from municipal, agricultural, and industrial wastewater sources. The interest in veterinary pharmaceuticals as potential emerging contaminants has stemmed from the proliferation of large-scale animal feeding operations (AFOs) during the last decade. The large number of animals produced creates a proportionately large volume of animal waste and associated emerging contaminants (specifically veterinary antibiotics). Expansion and intensification of large-scale AFOs in the State of Kuwait has resulted in concern about environmental contamination and its potential public health impacts. The objective of this investigation was to obtain background data on a broad profile of antimicrobial residues in animal wastes, and surface and ground waters proximal to large-scale AFOs. The animal waste samples were measured for antimicrobial compounds and multiple classes of veterinary antibiotics at concentrations of >100 g/L were detected. In addition, several classes of antimicrobial compounds were detected in surface and ground water samples collected proximal to the animal farms. This study indicates that animal waste may serve as a source of antimicrobial residues for the aquatic environment of the State of Kuwait.
341 (KAS-1122-048373) Forensic Analysis, Source Partitioning and Genotoxic Evaluation of Different Size Fractions of Atmospheric Particulate Matter over the State of Kuwait.
Start time: 2:10 PM
Kassim, T1, Al-Sabbagh, T2, 1 Seattle University, Department of Civil and Environmental Engineering, Seattle, WA, USA2 Kuwait Institute for Scientific Research (KISR), Kuwait
During the last four decades oil exploration, development, and refining have been the major economic activities in the State of Kuwait, which have led to a major contamination of its atmospheric environment. Associations between atmospheric particulate matter (PM) concentrations and human health effects have been well researched; however the exact biological mechanisms underlying such effects are poorly understood. It is presumed that mutagens/carcinogens present in human lungs contribute to lung cancer. Most of these molecules are inhaled with PM through the respiratory tract and particles of different sizes reach defined regions of the pulmonary system. Airborne PM is not a single contaminant, but rather a mixture of contaminants with each one containing various chemical species. Atmospheric PM occurs as fine- and coarse-mode particles, which in addition to falling into different size fractions; differ in formation mechanisms, chemical composition, sources, and final effects in humans. For instance, the coarse fraction (i.e., particles >2.5 m) is dominated by natural sources (e.g., dust, pollen, bacteria, etc.), while the fine fraction (i.e., particles <2.5 m) is dominated by anthropogenic emissions. The objectives of the present study are to: (1) Conduct a comprehensive forensic analysis approach to characterize the natural vs. anthropogenic (specially emerging) organic chemical composition of airborne PMs (Total, PM10 and PM2.5) over the State of Kuwait; (2) Develop a PM source-partitioning model in order to group contaminants according to their original sources; and (3) evaluate the genotoxic effects of different PM sizes on various genetic targets using the Ames plate test, gene conversion and reversion, and the comet assay on human leukocytes.
342 (GAG-1115-728736) Occurrence and persistence of Bacillus thuringiensis Cry1Ab genes in the aquatic environment near a transgenic corn field.
Start time: 2:30 PM
Gagné, F.1, Douville, M.1, André, C.1, Blaise, C.1, 1 Environment Canada, Montréal, Québec, Canada
Genetically modified corn crops are being used to control pest infestations from insects of the Lepidoptera family. Cry1Ab endotoxin derived from Bacillus thuringiensis ssp. Kurstaki (Bt) have successfully inserted in corn crops. The aims of this study were to examine for the occurrence and persistence of Cry1Ab genes in aquatic environments in the vicinity of Bt-corn fields. First, an optimal DNA preparation and extraction method was developed to allow gene analysis by real time polymerase chain reaction from various environmental samples. Second, in vitro spiking experiments with Bt or Bt corn DNA to surface waters and sediments were examined to evaluate their relative persistence in the environment. Third, Soil, sediment and water samples were collected before seeding, 1-2 weeks after pollen release and after harvesting and composting for the presence of Cry1Ab gene and protein. The results showed that DNA was readily extracted and relatively pure i.e., high absorbance at 260 nm/absorbance at 230 nm ratio and absence of PCR inhibiting substances from soil, sediments and surface waters. Persistence experiments revealed that Cry1Ab in surface waters and sediments persisted for more than 21 and 40 days respectively. The removal of bacteria by filtration in surface waters did not increase significantly the t1/2 of the transgene but their levels were 5 fold more abundant than with unfiltered water at the end of exposure time. In sediments, Cry1Ab from either Bt and Bt-corn were still detected after 40 days in clay and sand rich sediments. Field surveys revealed that Cry1Ab transgene (corn) and from naturally-occurring Bt products were more prevalent in the sediment compartment than with surface waters. The Cry1Ab transgene was detected down to the Richelieu and St-.Lawrence rivers suggesting multiple sources of these genes and/or transport on large scale. Sediment associated Cry1Ab from Bt-corn tended to decreased downstream to the cultivation field and was significantly correlated with Cry1Ab in surface waters (R=0.82; p<0.01). The data indicate that released DNA from Bt-corn and Bt are fairly persistent in the aquatic environments and are detected in aquatic environments draining agricultural areas.
343 (GOE-1117-827535) Factors influencing air concentrations of polybrominated diphenyl ethers in rural Maryland and Delaware.
Start time: 2:50 PM
Goel, A.1, McConnell, L.2, Torrents, A.1, Scudlark, J.3, Simonich, S.4, 1 University of Maryland, College Park, MD, USA2 United States Department of Agriculture, Beltsville, MD, USA3 University of Delaware, Lewes, DE, USA4 Oregon State University, Corvallis, OR, USA
Polybrominated Diphenyl Ethers (PBDEs) are an emerging class of pollutants which have been detected in almost all environmental compartments, including human milk. Even so, data on their atmospheric presence is lacking. Aerial concentrations of penta BDEs, almost exclusively used in North America and the most toxic and bioaccumulable of the various congeners, were monitored at three sites on the predominantly rural Delmarva Peninsula. Two of the sites are close to the Atlantic coast in Delaware (Dover and Lewes) and the third is near the mouth of the Choptank River in Maryland (Horn Point). 24-h weekly air samples (n=240, 2001-2003) were collected using high volume air samplers. Overall, BDE congeners 47, 99 and 100 were detected most frequently at 58%, 60%, and 39%, respectively. However, the three sites differed in terms of PBDE occurrence and concentrations. The average concentrations at Horn Point and Dover (BDE 47: 13-19 pg/m3; BDE-99: 5.4-6.6 pg/m3) are comparable to that observed in rural Canada (BDE-47: 4.6 pg/m3; BDE-99: 4.3 pg/m3), suggesting that these sites reflect background levels. Lewes was different in that it had average concentrations that were up to 5-10 times higher than the other two sites. The spring-buffering effect of emerging foliage was weak at Lewes; the concentrations were high in the warmer months (PBDEmax= 910 pg/3) and showed significant correlation with temperature. The calculated heats of phase transition (53-21 kJ/mol) are much lower than the heats of vaporization of these compounds suggesting that vaporization from surfaces is not the controlling factor. Back trajectory analysis for the three sites suggests that the concentrations increase as the air mass travels over the Peninsula. Spray irrigation of treated municipal wastewater, a common practice for the counties on the Delmarva Peninsula, is suspected to be a source of PBDEs in the air at Lewes. Several spray irrigation facilities are located to the south and west of Lewes, the general wind direction during the spring and summer time when most of our samples were collected. The aerial concentrations at Lewes are also increasing at an exponential rate; the atmospheric doubling times for the different congeners range from 1.1-2.4 yrs.
Start time: 3:10 PM
344 (SEY-1117-824405) Uptake and quantification of low part-per-billion concentrations of perchlorate (ClO4-) in lettuce using IC-ESI-MS.
Start time: 3:50 PM
Seyfferth, A.1, Parker, D.1, 1 University of California, Riverside, CA, USA
Perchlorate (ClO4-) has caused widespread pollution in the United States, and many questions regarding potential human exposure from food crops remain unanswered. To date, there have been no controlled studies of plant uptake at environmentally relevant (low ppb) concentrations coupled with the accurate quantification of the resulting low levels of perchlorate in plants. The primary aims of this research are to develop an analytical method to quantify low levels of perchlorate in plants and to understand the factors controlling perchlorate uptake by several cultivars of winter lettuce. A sample clean-up method was developed to measure low ppb levels of perchlorate (ClO4-) in several varieties of lettuce using Ion Chromatography-Electrospray Ionization-Mass Spectrometry (IC-ESI-MS). Butterleaf lettuce was hydroponically grown, containing no perchlorate, and was spiked with 3.5 ppb perchlorate during the clean up procedure. Recoveries were between 91.4 – 94.3%. Similarly, hydroponically grown Romaine lettuce containing no perchlorate was spiked with 15.7 ppb perchlorate and recoveries were between 96.8 – 100%. This method was applied to 5 types of store-bought lettuce as part of a market survey. This method was also applied to Butterleaf, Redleaf, and Romaine lettuce grown hydroponically at concentrations of 1, 5 or 10 ppb perchlorate for 60 days. It has been suggested that perchlorate is likely taken up with the transpiration stream and thus should accumulate to a greater extent in large outer leaves as compared to smaller inner leaves. Factors such as these as well as variation amongst cultivars on perchlorate uptake will be addressed.
345 (AAA-1117-811960) Congener specific determination of PBDEs in four flame-retardant mixtures, DE-71, Bromkal 70-5DE, DE-79 and Bromkal 79-8DE.
Start time: 4:10 PM
La Guardia, M1, Hale, R1, Harvey, E1, 1 Virginia Institute of Marine Science, Gloucester Point, VA, USA
Decabromodiphenyl ether (BDE-209) has been under increased scrutiny due in part to its tendency to debrominate to lower brominated polybrominated diphenyl ethers (PBDEs) under laboratory conditions and possibly once released to the environment. Some of the less brominated congeners (e.g. BDE-47 and -99) are bioaccumulative endocrine disruptors. These have also become environmentally ubiquitous, akin to other persistent organic pollutants (POPs), such as PCBs. The full range of constituents of the technical mixtures must be understood in order to identify degradation products of -209, possible mixture contaminants and sources of accumulated PBDEs in biota. Previous studies have identified the major congeners within these formulations, but few have focused on their minor constituents. This has been exacerbated by the lack of commercially available standards and dependable analytical methods. Here we utilize some recent technical enhancements and the emergence of new analytical standards to develop a method capable of analyzing a larger suite of mono- through deca-BDEs. PBDEs were separated and detected by gas chromatograph selected-ion-monitoring mass spectrometry (GC-SIM) in electron-capture negative ionization (ECNI) mode, monitoring ions 79 and 81 m/z. Structural conformation based on the molecular ion and fragmentation patterns of the identified compounds was established by GC-MS using ECNI and electron ionization (EI) modes, scanning 50-1000 m/z. Four commercial PBDE formulations were examined: two Penta-BDE products (DE-71 and Bromkal 70-5DE) and two Octa-BDE products (DE-79 and Bromkal 79-8DE). In these products we identified and quantified 26 individual PBDE congeners, at concentrations > 0.02% by weight. (To our knowledge, this is the first time seven of these congeners have been identified in these commercial mixtures). These congeners are: BDE-75 and -77 detected in DE-71, -138, -140, -144, -184, and -201 in DE-79 and -144, -184 and -201 in Bromkal 79-8DE. There were also 11 additional congeners detected without corresponding analytical standards. These were tentatively assigned identifications based on molecular ion and fragmentation information.
346 (AAA-1117-677590) Assessment of PBDEs in spruce needles and air surrounding a sanitary landfill.
Start time: 4:30 PM
St-Amand, A1, Mayer, P1, Blais, J2, 1 Department of Chemistry, University of Ottawa, Ottawa, ON, CANADA2 Department of Biology, University of Ottawa, Ottawa, ON, CANADA
Polybrominated diphenyl ethers (PBDEs) are flame retardants used during the manufacturing process of a variety of electronic devices, plastics and fabrics in order to increase their fire resistance. Several studies have shown that PBDEs are present in areas as far away as the arctic, and that their concentration is increasing rapidly. The objectives of this study are to assess PBDEs concentrations in spruce needles and air (volatile and particulate-bound) near the Trail Waste Facility in Ottawa, Canada and evaluate surface (needles)-air exchange for more than a year (two spring episodes). Spruce needle samples collected from February to November 2004 showed an average total PBDE concentration of 0.56ng/g dry weight (0.050ng/g-2.6ng/g) or 42ng/g lipid (2.1ng/g-160ng/g). A general decrease of total PBDE concentration in needles was seen following the arrival of spring (snow melt) which was followed by an increase throughout the summer. Air samples collected in the same time period generally had a total volatile PBDE concentration of less than 2pg/m3, but was usually higher than 2pg/m3 total for particulate-bound PBDE. Total PBDE concentration in air samples were more dynamic and were largely influenced by the weather at time of sampling. Wind speed and direction were noted as the primary influence. Illustrative plots demonstrated that particle-bound deposition was the primary process for plant uptake. In general, the congener profiles were very similar between samples showing that presence of PBDEs at the Trail Waste Facility is due to commercial formulations.
347 (HUN-1118-444495) Brines as an Emerging Contaminant Transport Mechanism in the Subsurface.
Start time: 4:50 PM
Hunt, J1, 1 University of California, Berkeley, CA, USA
Concentrated salt solutions can become source terms for a number of environmental contaminants released into subsurface. These brines arise from industrial processes such as solid rocket fuel production, landfill leachates, and nuclear fuel reprocessing. In addition, dense and viscous fluids such as lactate and hydrogen peroxide are being introduced into the subsurface for remediation purposes without fully appreciating transport pathways. Brine transport processes are quantified from the considerable literature available combined with recent experimental data that quantify the importance of density and viscosity contrasts. Since brines tend to sink to less accessible locations in the subsurface, contaminant release from brine pools will be mass transfer limited. For contaminants soluble in water but with very low acceptable concentrations such as radioactive wastes, chromate, and perchlorate, models predict that groundwater quality will be degraded for decades. Two examples from field sites illustrate the possible importance of brines as source terms. One site is where cooling water containing chromate was discharged over 40 years ago, but chromate still continues to contaminant an aquifer. Another field site examines a persistent perchlorate plume decades after the releases. For conventional and non-conventional pollutants present within dense brines, source recognition and control remain illusive goals.
348 (BEG-1118-211734) Polybrominated Diphenyls in the Kuwaiti Environment.
Start time: 5:10 PM
Gevao, B.1, Beg, M.1, Helaleh, M.1, Zafar, J.1, 1 Environmental Sciences Department, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat-13109, Kuwait
Polybrominated diphenyl ether (PBDE) concentrations were measured in surficial sediments from coastal sediments receiving industrial and municipal effluents in Kuwait. The PBDE concentrations varied by two orders of magnitude ranging from 80 to 3800 pg g-1 dw. The congener distribution was dominated by BDE-183, with minor contributions from BDE-154, and BDE-153. This contrasted sharply with the congener distribution in ambient air in Kuwait, with congeners 47, 99, 100, 153, and 154 being the congeners routinely detected (in order of decreasing concentrations). The profile in air was remarkably similar to that in Bromkal 50-7DE, the technical penta mixture whereas the sediment profile is indicative of the octa technical mixture. The absence of BDEs 47, 99, and 100, in sediments, which together constitute ca 90% of the PBDE concentration in ambient air in Kuwait, suggests either a selective deposition/retention of the high molecular weight, more hydropbhobic congeners, or direct inputs of a different technical mixture possibly via wastewater discharges to the sea. A combination of low annual precipitation rates and high annual ambient temperatures supports the first scenario, because these factors will favour the selective deposition of high molecular weight congeners (e.g. BDE-153, -154, -183) which will predominantly be associated with aerosol as opposed to the more volatile congeners (e.g. BDE-47, -99, -100) that will predominantly be in the gas phase. However, the observed gradient in concentration distribution, with high PBDE concentrations near the shore and an exponential decrease seaward, indicates that the second scenario is more likely and suggests that atmospheric deposition may not an important delivery mechanism of these contaminants to the sediment.