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Результаты 1331-1340 из 4,241
Determination of radioactivity levels and heavy metal concentrations in seawater, sediment and anchovy (Engraulis encrasicolus) from the Black Sea in Rize, Turkey
2017
Baltas, Hasan | Kiris, Erkan | Sirin, Murat
Seawater, sediment and fish (anchovy) samples consumed in the Rize province of the Eastern Black Sea region of Turkey were collected from five different stations. The radioactivity levels (226Ra, 232Th, 40K and 137Cs) were determined in all the samples using a high-purity germanium detector. While 226Ra, 232Th and 40K radionuclides were detected in all samples, the radionuclide concentration of 137Cs, except for the sediment samples (mean activity is 9±1.4Bqkg−1), was not detected for the seawater and fish samples. The total annual effective dose rates from the ingestion of these radionuclides for fish were calculated using the measured activity concentrations in radionuclides and their ingested dose conversion factor. Also, the concentrations of some heavy metals in all the samples were determined. The activity and heavy metal concentration values that were determined for the seawater, sediment and fish samples were compared among the locations themselves and with literature values.
Показать больше [+] Меньше [-]Immunotoxic effects of single and combined pharmaceuticals exposure on a harbor seal (Phoca vitulina) B lymphoma cell line
2017
Kleinert, Christine | Lacaze, Emilie | Mounier, Méryl | De Guise, Sylvain | Fournier, Michel
The potential risk of pharmaceuticals in the environment to top-predators is still largely unknown. In this study, we assessed the immunotoxic effects of ten pharmaceuticals individually and as mixtures on a harbor seal (Phoca vitulina) B lymphoma cell line. A significant reduction in lymphocyte transformation was observed following an exposure to 12,500μg/L 17α-ethinyl estradiol and 25,000μg/L naproxen. Exposure to 12,500μg/L 17α-ethinyl estradiol decreased the percentage of cell in the G0/G1 phase of the cell cycle while increasing the percentage of cells in the S phase. Carbamazepine exposure increased the amount of cells in the G2/M phase. Binary mixtures showed synergistic effects in lymphocyte transformation, cell cycle and apoptosis assays. Concentrations inducing toxic effects in the cell line were similar to those affecting fish in previous studies. A reduction of functional activities of the immune system may lead to altered host resistance to pathogens in free-ranging pinnipeds.
Показать больше [+] Меньше [-]Distribution and source analysis of heavy metals in soils and sediments of Yueqing Bay basin, East China Sea
2017
Yang, Xiaohui | Wu, Pengbao | Yin, Aijing | Zhang, Huan | Zhang, Ming | Gao, Chao
Concentrations of heavy metals in coastal soils, stream sediments and intertidal sediments of Yueqing Bay basin were analyzed to study their distribution and trace the possible sources. According to various single- and multi-index methods, heavy metal enrichment, especially for Cu, Zn, Cr and Ni in stream sediments, should draw environmental concern. Controlling factors such as inorganic scavengers, organic matter, sample grain size and hydrodynamic conditions were identified to influence the transportation and distribution of metals within coastal soils and sediments. Principal component analysis indicated that most metals in soils and stream sediments originate primarily from natural and anthropogenic sources, respectively. Most metals in intertidal sediments, originating both from natural processes and human activities, tend to be concentrated in fine particles. The exchange of water and sediment between the bay and open waters is strong enough to keep the metals in the tidal flats from rising to very high levels.
Показать больше [+] Меньше [-]Near-port air quality assessment utilizing a mobile measurement approach
2017
Steffens, Jonathan | Kimbrough, Sue | Baldauf, Richard | Isakov, Vlad | Brown, Ryan | Powell, Alan | Deshmukh, Parikshit
Mobile monitoring is a strategy to characterize spatially and temporally variable air pollution in areas near sources. EPA's Geospatial Measurement of Air Pollution (GMAP) vehicle – an all-electric vehicle is outfitted with a number of measurement devices to record real-time concentrations of particulate matter and gaseous pollutants – was used to map air pollution levels near the Port of Charleston in South Carolina. High-resolution monitoring was performed along driving routes near several port terminals and rail yard facilities, recording geospatial coordinates and concentrations of pollutants including black carbon, size-resolved particle count ranging from ultrafine to coarse (6 nm–20 μm), carbon monoxide, and nitrogen dioxide. Additionally, a portable meteorological station was used to characterize local conditions. The primary objective of this work was to characterize the impact of port facilities on local scale air quality. The study determined that elevated concentration measurements of black carbon and PM correlated to periods of increased port activity and a significant elevation in concentration was observed downwind of ports. However, limitations in study design prevented a more complete analysis of the port effect.
Показать больше [+] Меньше [-]The impact of seismic air gun exposure on the haemolymph physiology and nutritional condition of spiny lobster, Jasus edwardsii
2017
Fitzgibbon, Quinn P. | Day, Ryan D. | McCauley, Robert D. | Simon, Cedric J. | Semmens, Jayson M.
There is a critical knowledge gap regarding the impacts of seismic air gun signals on the physiology of adult crustaceans. We conducted four controlled field experiments to examine the impact of seismic acoustic signals on spiny lobster, Jasus edwardsii. Seismic air gun exposure suppressed total haemocyte count (THC) for up to 120days post-exposure, suggesting a chronic negative impact of immune competency. THC levels after 365days post-exposure, were elevated two fold, potentially indicating an immune response to infection. Haemolymph refractive index was reduced after 120days post exposure in one experiment, suggesting a chronic impairment of nutritional condition. There was no effect of air gun exposure on 24 haemolymph biochemical parameters, hepatopancreas index or survival. Collectively these results indicate that the biochemical haematological homeostasis of J. edwardsii is reasonably resilient to seismic acoustic signals, however, air gun exposure may negatively influence the lobster's nutritional condition and immunological capacity.
Показать больше [+] Меньше [-]Delayed fluorescence as an indicator of the influence of the herbicides Irgarol 1051 and Diuron on hard coral Acropora digitifera
2017
Katsumata, Masakazu | Takeuchi, Ichirō
We examined the effect of two herbicides (Irgarol 1051 and Diuron) on symbiotic dinoflagellates in the hard coral Acropora digitifera using delayed fluorescence (DF), specifically assessing changes in molecular membrane transport, i.e. inflow and outflow rates, and the binding of the herbicides to target proteins in photosystem II. The DF approach is rapid (e.g. measurement time, 60 s) and non-invasive, and can provide data on the extent of a photosynthetic system and the activity of its electron carriers. The DF of A. digitifera is inhibited 2 h after exposure to 1 μg/L of either Irgarol or Diuron. Analysis of DF inhibition over time by a compartment model suggests that Irgarol exposure results in a relatively higher inflow rate and lower outflow rate than does Diuron exposure. This suggests that Irgarol exposure more strongly inhibits photosynthesis and that the coral symbiotic dinoflagellates recover less from inhibition.
Показать больше [+] Меньше [-]Distribution profiles of per- and poly fluoroalkyl substances (PFASs) and their re-regulation by ocean currents in the East and South China Sea
2017
Zheng, Hongyuan | Wang, Feng | Zhao, Zhen | Ma, Yuxin | Yang, Haizhen | Lu, Zhibo | Cai, Minggang | Cai, Minghong
We investigated the distribution of 17 individual per- and polyfluoroalkyl substances (PFASs) in 42 surface water samples collected from the East and South China Seas (7.0–36.0°N, 110.0°N–123.0°E). Concentrations of 7 individual PFASs, including perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluoropentanoic acid (PFPA), perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonamide (FOSA), were quantified in the East China Sea, but only concentrations of PFOA and FOSA were quantified in the South China Sea. The total concentrations of the 17 PFASs ranged from 181 to 2658pg/L in the East China Sea and from 62 to 494pg/L in the South China Sea. We also show that river fluxes and ocean currents had a strong influence on the distribution of PFASs in the East China Sea. Using ArcGIS 10.1, we show how ocean currents control the spatial distribution of PFOA in the central South China Sea.
Показать больше [+] Меньше [-]Polycyclic aromatic hydrocarbons (PAHs) in traditionally harvested bivalves in northern British Columbia, Canada
2017
Thompson, Kim-Ly | Picard, Chris R. | Chan, Hing Man
Butter clams, blue mussels, and Nuttall's cockle are important traditional food of the Gitga'at First Nation in Canada. Samples were collected and analyzed for polycyclic aromatic hydrocarbon (PAH) from the Gitga'at harvest sites from 2006 to 2015 to: 1) establish baseline conditions; 2) determine the likely source; 3) understand species specific response to spills; and 4) evaluate health risk associated with consumption. Baseline lipid normalized-total PAH in mussels was 2.36 (±2.86, 95%CI) μg/g in mussels, 3.26(±4.14) μg/g in clams and 3.98 (±4.98) μg/g in cockles. PAHs varied according to proximity to point sources and became less petrogenic through time. Concentrations of PAHs were elevated in all three species following diesel spills but returned to baseline levels within 5months. However, Gitga'at harvesters avoided bivalves from spill-affected habitats for several years because of their detection of reduced quality and palatability, highlighting the importance of incorporating local knowledge into future monitoring programs.
Показать больше [+] Меньше [-]Boat anchoring pressure on coastal seabed: Quantification and bias estimation using AIS data
2017
Deter, Julie | Lozupone, Xavier | Inacio, Adrien | Boissery, Pierre | Holon, Florian
Global shipping is economically important, but has many adverse environmental effects. Anchoring contributes greatly to this adverse impact, as it is responsible for mechanical disturbance of highly sensitive marine habitats. Recovery of these ecosystems is limited by slow regrowth. Anchoring pressure on coastal seabed habitats was estimated using AIS (Automatic Identification System) data along 1800km of Mediterranean coastline between 2010 and 2015. A comparison with field observations showed that these results were most consistent for large boats (>50m). An analysis of AIS data coupled with a seabed map showed that around 30% of the habitats between 0 and −80m exhibited anchoring pressure. Posidonia oceanica seagrass beds were the most impacted habitat in terms of duration. This methodology efficiently estimates spatial and temporal anchoring pressure principally due to large boats and should interest managers of marine protected areas as much as coastline managers.
Показать больше [+] Меньше [-]Cross-reactivities of mammalian MAPKs antibodies in rotifer and copepod: Application in mechanistic studies in aquatic ecotoxicology
2017
Kang, Hye-Min | Jeong, Chang-Bum | Lee, Young-Hwan | Cui, Yan-Hong | Kim, Duck-Hyun | Lee, Min-Chul | Kim, Hŭi-su | Han, Jeonghoon | Hwang, Dae-Sik | Lee, Su-Jae | Lee, Jae-seong
The mitogen-activated protein kinases (MAPKs) family is known to mediate various biological processes in response to diverse environmental pollutants. Although MAPKs are well characterized and studied in vertebrates, in invertebrates the cross-reactivities of MAPKs antibodies were not clearly known in response to environmental pollutants due to limited information of antibody epitopes with material resources for invertebrates. In this paper, we performed phylogenetic analysis of MAPKs genes in the marine rotifer Brachionus koreanus and the copepods Paracyclopina nana and Tigriopus japonicus. Also in rotifer and copepods, several studies of Western blot of MAPK signaling pathways were shown in response to environmental pollutants, including multi-walled carbon nanotubes (MWCNTs), water-accommodated fractions (WAFs) of crude oil, and microplastics. This paper will provide a better understanding of the underlying mechanistic scenario in terms of cross-reactivities of mammalian antibodies in rotifer and copepod.
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