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Laboratory and field magnetic evaluation of the heavy metal contamination on Shilaoren Beach, China 全文
2017
Wang, Yonghong | Huang, Qinghui | Lemckert, Charles | Ma, Ying
This study uses magnetic measurements to evaluate the heavy metal contamination of the surface sediments on Shilaoren Beach. The values of the laboratory magnetic measurements have a positive relationship with the concentrations of Fe, Mn, Cr, Ni, As and Pb. The field magnetic parameter provides an effective and rapid method for evaluating the distribution and dispersal of heavy metal. Sediments with higher heavy metal contents generally accumulate near higher and lower tide lines on the beach, reflecting the control of waves and tides. The sewage and stormwater outlets are the primary sources of the heavy metal contamination. Variations in seasonal waves and winds affect the sediment transport and the heavy metal distribution patterns. Based on the Australian ISQG-Low sediment quality criteria, Fe, Mn and Cr generally exhibit intermediate accumulation levels, whereas Pb and Zn exhibit higher accumulation levels because of the socioeconomic status of the area surrounding the beach.
显示更多 [+] 显示较少 [-]Characterization of emissions and residues from simulations of the Deepwater Horizon surface oil burns 全文
2017
Gullett, Brian K. | Aurell, Johanna | Holder, Amara | Mitchell, William | Greenwell, Dale | Hays, Michael | Conmy, Robyn | Tabor, Dennis | Preston, William | George, Ingrid | Abrahamson, Joseph P. | Vander Wal, Randy | Holder, Edith
The surface oil burns conducted by the U.S. Coast Guard from April to July 2010 during the Deepwater Horizon disaster in the Gulf of Mexico were simulated by small scale burns to characterize the pollutants, determine emission factors, and gather particulate matter for subsequent toxicity testing. A representative crude oil was burned in ocean-salinity seawater, and emissions were collected from the plume by means of a crane-suspended sampling platform. Emissions included particulate matter, aromatic hydrocarbons, polychlorinated dibenzodioxins/dibenzofurans, elements, and others, the sum of which accounted for over 92% by mass of the combustion products. The unburned oil mass was 29% of the original crude oil mass, significantly higher than typically reported. Analysis of alkanes, elements, and PAHs in the floating residual oil and water accounted for over 51% of the gathered mass. These emission factors, along with toxicity data, will be important toward examining impacts of future spill burning operations.
显示更多 [+] 显示较少 [-]Distribution of heavy metals and environmental assessment of surface sediment of typical estuaries in eastern China 全文
2017
Bi, Shipu | Yang, Yuan | Xu, Chengfen | Zhang, Yong | Zhang, Xiaobo | Zhang, Xianrong
Estuary sediment is a major pollutant enrichment medium and is an important biological habitat. This sediment has attracted the attention of the marine environmental scientists because it is a more stable and effective medium than water for monitoring regional environmental quality conditions and trends. Based on a large amount of measurement data, we analyzed the concentrations, distribution, and sources of seven heavy metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) in the surface sediment of typical estuaries that empty into the sea in eastern China: the Liaohe River Estuary, Yellow River Estuary, Yangtze River Estuary, Minjiang River Estuary, and Pearl River Estuary. The heavy metal concentrations in the sediments vary considerably from one estuary to the next. The Liaohe River Estuary sediment contains elevated levels of Cd, Hg, and Zn. The Yellow River Estuary sediment contains elevated levels of As. The sediments in the Yangtze River and Minjiang River estuaries contain elevated levels of Cd and Cu and of Pb and Zn, respectively. The sediment in the Pearl River Estuary contains elevated levels of all seven heavy metals. We used the Nemerow index method to assess the environment quality. The heavy metal pollution in the Liaohe River and Pearl River estuaries is more severe than that in the other estuaries. Additional work indicates that the heavy metal pollution in the Liaohe River and Pearl River estuaries is caused mainly by human activity.
显示更多 [+] 显示较少 [-]Geophysical features influence the accumulation of beach debris on Caribbean islands 全文
2017
Schmuck, Alexandra M. | Lavers, Jennifer L. | Stuckenbrock, Silke | Sharp, Paul B. | Bond, Alexander L.
Anthropogenic beach debris was recorded during beach surveys of 24 Caribbean islands during April 2014–April 2016. Beach debris was classified according to material type (e.g., polystyrene) and item use (e.g., fishing). Geophysical features (substrate type, beach direction, and human accessibility) of sample sites were recorded in order to investigate their relationship with debris density. Results suggest the density of macro debris (items >5mm) is highest on uninhabited, sandy beaches facing a leeward direction. Higher debris quantities on inaccessible beaches may be due to less frequent beach clean ups. Frequently accessed beaches exhibited lower macro, but higher micro debris (items 1–5mm) densities, possibly due to removal of macro debris during frequent beach clean ups. This suggests that while geophysical features have some influence on anthropogenic debris densities, high debris densities are occurring on all islands within the Caribbean region regardless of substrate, beach direction, or human accessibility.
显示更多 [+] 显示较少 [-]The constitutively active estrogen receptor (ER) binds and activates the promoter of the vitellogenin (Vtg) gene in the Sydney rock oyster, Saccostrea glomerata 全文
2017
Trần, Thị Kim Anh | MacFarlane, Geoff R. | Kong, Richard Yuen Chong | O'Connor, Wayne A. | Yu, Richard Man Kit
Vitellogenin (Vtg) is a well-established biomarker of estrogenic exposure in aquatic animals. In vertebrates, Vtg gene transcription is controlled by the estrogen receptors (ERs). Although an ER ortholog is present in molluscs, its role as a transcriptional regulator remains elusive. Here, we tested the hypothesis that in the Sydney rock oyster, Saccostrea glomerata, the ER ortholog activates Vtg gene transcription through specific interaction with its promoter. Luciferase reporter assays indicated that sgER activated both a minimal promoter containing the consensus estrogen-responsive elements (EREs) and the sgVtg promoter in an estrogen-independent manner. The sgVtg promoter-luciferase activation was significantly reduced when any of three putative ERE half sites (½EREs) in the promoter were mutated. Electrophoretic mobility shift assay (EMSA) confirmed that sgER binds specifically to a 68-bp promoter sequence where these ½EREs reside. Overall, the results suggest that sgER is a constitutively active transcription factor that binds and activates the sgVtg promoter.
显示更多 [+] 显示较少 [-]Tissue concentrations of four Taiwanese toothed cetaceans indicating the silver and cadmium pollution in the western Pacific Ocean 全文
2017
Chen, Meng-Hsien | Zhuang, Ming-Feng | Zhou, Lianxiang | Liu, Jean-Yi | Shih, Chieh-Chih | Chen, Chiee-Young
Muscle, lung, kidney and liver tissues of 45 bycatch and stranded cetaceans, including 14 Grampus griseus (Gg), 7 Kogia simus (Ks), 10 Lagenodelphis hosei (Lh), and 14 Stenella attenuata (Sa), were collected in the waters off Taiwan from 1994 to 1995, and from 2001 to 2012. Baseline concentrations (in μgg−1 dry weight) of the cetaceans were lung (<0.05)=muscle (<0.05)<kidney (0.08±0.04)<liver (0.43±0.28) for Ag, and muscle (0.03±0.03)=lung (0.22±0.19)<liver (3.82±3.50)<kidney (16.22±18.81) for Cd. Unhealthy and critically dangerous Ag and Cd tissue concentrations in the toothed cetaceans are suggested. Marked high concentrations of Ag and Cd found in Gg and Lh are highly related to their squid-eating and deep diving habits. The highest ever recorded concentrations of liver-Ag and kidney-Cd were found in two Lh. These Taiwanese cetaceans indicate marked Ag and Cd pollution in the recent two decades in the western Pacific Ocean.
显示更多 [+] 显示较少 [-]Fractionation of heavy metals in sediments and assessment of their availability risk: A case study in the northwestern of Persian Gulf 全文
2017
Pejman, Amirhossein | Nabi Bidhendi, Gholamreza | Ardestani, Mojtaba | Saeedi, Mohsen | Baghvand, Akbar
Sequential extraction procedure was applied to determine the chemical forms of heavy metals in sediments in order to assess their mobility and availability in the aquatic environment. The mean concentrations of Cr, Ni, Pb, Cd, Cu and Zn in exchangeable and carbonate fractions were 14.9, 30.9, 17, 0.37, 4.4 and 14.4mg/kg, respectively. Based on the sediments quality guidelines (SQGs), the adverse biological effects caused by Ni, can occur frequently across the study area. Risk assessment code (RAC) suggested that the Cd has the highest level of environmental risk compared with other studied metals. Modified risk assessment code (mRAC) demonstrated a high potential adverse effect in the many of sampling sites. According to the fractionation results, the concentration of Ni in exchangeable and carbonate fractions was very considerable and more than other metals, hence, the potential risk of nickel release can be much more than other investigated metals.
显示更多 [+] 显示较少 [-]Characterization of air quality and fine particulate matter sources in the town of Hinton, Alberta 全文
2017
Bari, Md Aynul | Kindzierski, Warren B.
With concern in recent years about dust issues and fine particulate matter (PM2.5) levels approaching a new Canadian Ambient Air Quality Standards (CAAQS), an investigation of air quality characteristics and potential sources influencing PM2.5 concentrations was undertaken in the community of Hinton, Alberta. The study was conducted for the period November 2013 to February 2016 using hourly concentrations of criteria air pollutants. Comparatively higher concentrations of PM2.5 were observed in summer (mean: 12.5 μg/m3, median: 8.0 μg/m3) than in winter (mean: 7.5 μg/m3, median: 6.0 μg/m3).The 3-year averages of annual average PM2.5 concentrations (8.1–8.9 μg/m3) were below the 2015 annual CAAQS value of 10 μg/m3. Exceedances of a 1 h Alberta Ambient Air Quality objective (58 times > 80 μg/m3) and a 24 h CAAQS (16 times > 28 μg/m3) were observed at Hinton for the study period and occurred during summer months primarily due to occurrence of forest fire episodes. A multivariate model positive matrix factorization (PMF) revealed five sources. Background dust and secondary aerosol was identified as the largest source contributing 68% to PM2.5 mass. Other sources included traffic (13.4%), an O3-rich source (12.7%), industry (3.1%) and a mixed source (3.1%). These findings offer preliminary information about contributions of different sources to PM2.5 at Hinton; and this information can support policy makers in developing appropriate management initiatives for reducing dust and secondary particulate matter pollution.
显示更多 [+] 显示较少 [-]Preliminary evaluation of heavy metal contamination in the Zarrin-Gol River sediments, Iran 全文
2017
Malvandi, Hassan
The major objectives of the study were to test the hypothesis of the Zarrin-Gol River as a reference site for ecotoxicological studies and to assess the contamination degree of heavy metals and metalloids in the river using four contamination indices. For these purposes, eleven heavy metal and metalloid concentrations were analyzed. The average concentrations (mgkg−1) in the sediments were: 37.67 (chromium) 286.28 (manganese), 13,751.04 (iron), 8.79 (cobalt), 12.39 (nickel), 32.68 (zinc), 21.91 (arsenic), 40.59 (selenium), 2923.86 (aluminum), ND (silver) and 785.96 (magnesium). Contamination factor, enrichment factor, pollution load index, and geoaccumulation index were calculated to evaluate the contamination degree and influence of human activities on heavy metal levels. The contamination indices of the sediment samples showed that arsenic and selenium were the highest pollutants. The results indicated that the Zarrin-Gol River could not be used as a reference site at least for arsenic and selenium.
显示更多 [+] 显示较少 [-]Combined effects of temperature and copper and S-metolachlor on embryo-larval development of the Pacific oyster, Crassostrea gigas 全文
2017
Gamain, Perrine | Gonzalez, Patrice | Cachot, Jérôme | Clérandeau, Christelle | Mazzella, Nicolas | Gourves, Pierre Yves | Morin, Bénédicte
Combined effects of temperature and copper and S-metolachlor on embryo-larval development of the Pacific oyster, Crassostrea gigas 全文
2017
Gamain, Perrine | Gonzalez, Patrice | Cachot, Jérôme | Clérandeau, Christelle | Mazzella, Nicolas | Gourves, Pierre Yves | Morin, Bénédicte
This study evaluates the combined effects of two contaminants (copper and a herbicide S-metolachlor) and temperature on the early life stages of the Pacific oyster Crasssotrea gigas, which is native to Arcachon Bay (southwest France). The responses of D-larvae, obtained from wild and cultivated oysters, were investigated for one year during the oyster breeding period at different sampling sites and compared with the response of D-larvae from a commercial hatchery. Embryotoxicity was measured by considering the percentage of abnormal D-shaped larvae. Normal development of embryos occurred only from 22°C to 26°C. There were synergistic effects of copper at low and high temperatures. Native oysters appear particularly sensitive to an increase in water temperature, suggesting a future increase in the percentage of larval abnormalities as a result of global climate change. Hatchery oysters represent a good alternative model for studying the effects of both pollutants and climate change stressors.
显示更多 [+] 显示较少 [-]Combined effects of temperature and copper and S-metolachlor on embryo-larval development of the Pacific oyster, Crassostrea gigas 全文
2017
Gamain, Perrine | Gonzalez, Patrice | Cachot, Jérôme | Clérandeau, Christelle | Mazzella, Nicolas | Gourves, Pierre Yves | Morin, Bénédicte | Environnements et Paléoenvironnements OCéaniques (EPOC) ; École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) | Ecosystèmes aquatiques et changements globaux (UR EABX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | International audience | This study evaluates the combined effects of two contaminants (copper and a herbicide S-metolachlor) and temperature on the early life stages of the Pacific oyster Crasssotrea gigas,which is native to Arcachon Bay (southwest France). The responses of D-larvae, obtained fromwild and cultivated oysters,were investigated for one year during the oyster breeding period at different sampling sites and compared with the response of D-larvae from a commercial hatchery. Embryotoxicity was measured by considering the percentage of abnormal D-shaped larvae. Normal development of embryos occurred only from 22 °C to 26 °C. There were synergistic effects of copper at low and high temperatures. Native oysters appear particularly sensitive to an increase in water temperature, suggesting a future increase in the percentage of larval abnormalities as a result of global climate change. Hatchery oysters represent a good alternative model for studying the effects of both pollutants and climate change stressors.
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