Download or read book Occurrence Transport and Fate of Polychlorinated Biphenyls in Selected Aquatic Systems in Kentucky written by William Allen Robison and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport and Fate of Polychlorinated Biphenyls in a Natural System written by Kenneth M. Kuhr and published by . This book was released on 1982 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Polychlorinated Biphenyls in the Upper Mississippi River written by Columbia National Fisheries Research Laboratory (U.S.) and published by . This book was released on 1978 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Sources Source Regions and Fate and Transport Processes on the Occurrence of Polychlorinated Naphthalenes and Coplanar Polychlorinated Biphenyls in Urban and Arctic Environments microform written by Paul Anthony Helm and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2002 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport and Fate of Polychlorinated Biphenyls in the Aquatic Environment with Special Emphasis on the Influence of Sediment Organic Matter written by and published by . This book was released on 2000 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Conceptual Models of the Occurrence Fate and Transport of Chlorinated Solvents in Karst Regions of Tennessee written by and published by . This book was released on 1997 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport Routes of Polychlorinated Biphenyls PCBs in Aquatic Ecosystems written by Per Larsson and published by . This book was released on 1983 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Polychlorinated Biphenyls in the Upper Mississippi River written by R. N. Dexter and published by . This book was released on 1978 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Polyethylene Passive Sampling to Assess Transport of Polychlorinated Biphenyls PCBs Between Contaminated Sediments Water and Biota written by Jennifer Nicole Apell and published by . This book was released on 2017 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polychlorinated biphenyls (PCBs), which were a widely used group of chemicals before their manufacture was banned in 1979 in the United States, still contaminate numerous aquatic systems. Although there are ongoing efforts to remediate these sites, our ability to implement effective remediation strategies has been hindered by a limited understanding of how PCBs are transported in the environment as well as how they bioaccumulate into aquatic animals. Investigations of contaminated sites often rely on sediment measurements since PCB concentrations are highest in the sediment phase. However, previous research has shown that sediment concentrations are a poor predictor of contaminant fate and effects, whereas freely dissolved water concentrations were able to predict the extent of bioaccumulation and the onset of toxicological effects more accurately. Additionally, the concentration gradient between the porewater (i.e., the interstitial water in sediment beds) and the overlying water is thought to be a major driver in PCB transport from the sediment bed. Passive samplers, which are made of polymers like polyethylene (PE), accumulate PCBs when they are deployed into environmental media, can be used to estimate freely dissolved water concentrations. When used in the laboratory by mixing with sediment samples, they provide a measure of the sediment-water equilibrium porewater concentration. When deployed in the field, they can provide measures of the in situ porewater and overlying water concentrations. In this work, PE samplers were deployed at two Superfund sites contaminated with PCBs to investigate if in situ porewater and sediments were at equilibrium with each other. In situ porewater concentrations were consistently found to be lower than equilibrium concentrations at both sites, an effect that was likely caused by water flow through the sediment bed. At one of the sites, measurements of a geochemical tracer also showed that the exchange of porewater with overlying water was occurring and that the transport of PCBs from sediments was affected by more than just the concentration gradient. Lastly, the sorptive disequilibria between environmental media and the spatial heterogeneity of contamination were shown to affect the extent of bioaccumulation in aquatic animals at one of the sites.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Incidence of Polychlorinated Biphenyls and Other Chlorinated Hydrocarbons in Raccoon Adipose Tissue and Selected Aquatic Organisms in the Central Wisconsin River Basin written by Michael Lee Knuth and published by . This book was released on 1979 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Sources Transport and Fate of Polychlorinated Biphenyls in Narragansett Bay written by James Stephen Latimer and published by . This book was released on 1989 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterizing Polychlorinated Biphenyl Exposure in Aquatic and Riparian Species of Campus Lake written by Megan Archer and published by . This book was released on 2015 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estimating the risk of polychlorinated biphenyls (PCBs) in aquatic systems requires evaluation of exposure, usually based on exhaustive chemical extraction of sediment and potentially exposed organisms and an assessment of toxicity. Remediation can then focus on areas where the exposure leads to the highest risk. Although effective, an approach that estimates exposure, which accounts for bioavailabilty, bioaccumulation, trophic transfer potential, and transport of materials within and out of the waterway, should serve as a more comprehensive environmental assessment. The current study examined exposure of PCBs in several different trophic levels within the Campus Lake ecosystem, Carbondale, Illinois. The source of contamination and the distribution of PCBs among ecosystem components demonstrated contamination within the aquatic portion of Campus Lake and transport out of the aquatic environment to the riparian area. Several media were collected including sediment, emergent insects, spiders, and three species of fish. Sediment extractions demonstrated that PCBs were localized to one small cove and this area served as the source for transfer of PCBs to both aquatic and terrestrial organisms. Single-point 24-h Tenax extractions formed the basis for evaluating the bioavailable component of the sediment-associated PCBs with strong correlations to laboratory-based bioaccumulation assays for oligochaetes and chironomid larvae. Stable isotope data suggested that the source of carbon to the food web was relatively constant. Food web samples of emerging insects, fish, and spiders revealed that the PCBs in Campus Lake were bioavailable and the pattern of the PCB signature among food web components followed typical food web processes. The PCB congener pattern was consistent between emergent midges and spiders demonstrating the transfer of PCBs from aquatic to terrestrial species. The PCB concentrations detected in emerging insects from the contaminated area were on average 25 times greater than those detected in emerging insects from reference sites outside the area of greatest sediment contamination. High PCB concentrations found in several species of fish suggested that despite the localized sediment contamination, fish throughout the lake were exposed. These levels also exceeded the fish consumption advisory criteria. The PCB pattern comparisons suggested that the contaminated sediment was the source of exposure throughout the food web. This approach identified the scope of exposure to organisms, demonstrated bioavailability, and provided a basis for future PCB remediation and subsequent monitoring of Campus Lake. In comparison to studies focused solely on limited sampling of fish for consumption advisory purposes, this approach demonstrated the importance of more comprehensive studies to examine the range of ecosystem exposure even from very limited contamination sources.
Download or read book Fate and Transport of Polychlorinated Biphenyls in the Air Water and Sewers of the Delaware River Basin written by Jia Guo and published by . This book was released on 2013 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Passive air samplers were deployed at 45 sites across the Delaware River Basin to evaluate the spatial distribution of atmospheric polychlorinated biphenyls (PCBs). This study revealed strong spatial gradients in [Sigma]PCB concentrations, a significant urban fractionation effect, and a distinct congener pattern arising from the area around Swarthmore, PA. Five factors were resolved by positive matrix factorization (PMF) analysis with three of them being interpreted as volatilized or weathered Aroclors. The other two factors were strongly correlated to the congener profiles observed at the Swarthmore site on a building roof and an urban site near rail yards, respectively. These findings suggest that volatilization of Aroclors from building materials and spray on rail yards could represent significant sources of ambient atmospheric PCB concentrations. In the passive air sampling, the concentrations of a non-Aroclor congener, PCB 11, were detected with small spatial variation in the airshed of the Delaware River Basin. PCB 11 was measured from non-detect to 79 ng g-1 in consumer products containing pigments and dyes. The leaching potential of PCB 11 from these materials was confirmed by experimental tests. The inputs of PCB 11 to the Delaware River Basin were estimated between 0.025 and 42 kg y-1, while the outflows were between 8.4 and 260 kg y-1. These mass flows indicate that PCB 11 is present in pigments at levels close to or even exceeding the federal limits and/or that the degradation of these pigments releases PCB 11 into the basin. Reductive dechlorination of PCBs was investigated in anaerobic microcosms of sewer sediments amended with Aroclor 1260 under methanogenic conditions. Spatial heterogeneity of the sediments resulted in differences in the extent of dechlorination activity. The most active microcosm showed dechlorination evidence after 35 days of incubation with significant accumulation of documented dechlorination products and molar dechlorination product ratio (MDPR). Total chlorines per biphenyl decreased by up to 10% with short or no lag time. This suggests that rapid dechlorination is at least possible to account for the dechlorination products comprising 10~30% of the total PCBs, which were found in many of the sewer systems in the Delaware River Basin.
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PCBs written by Larry W. Robertson and published by University Press of Kentucky. This book was released on 2015-01-13 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: In April 2000 researchers from around the world met in Lexington, Kentucky to bring together the very latest information on the chemistry and biological effects of the environmental pollutants known as Polychlorinated Biphenyls (PCBs). The result is a comprehensive and extensive treatment of the very latest findings on all significant subjects relating to PCBs and their health risks. The thorough introduction and sixty-two scientific papers presented here represent the most up-to-date research by scientists in government, private industry, and academia.
