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Atmospheric hexachlorobenzene determined during the third China arctic research expedition: Sources and environmental fate Texte intégral
2014
Wu, Xiaoguo | Lam, James C.W. | Xia, Chonghuan | Kang, Hui | Xie, Zhouqing | Lam, Paul K.S.
In July to September 2008, air samples were collected aboard a research expedition icebreaker, Xuelong (Snow Dragon), under the support of the 2008 Chinese Arctic Research Expedition Program. All the air samples were analyzed for determination of the concentrations of Hexachlorobenzene (HCB). The levels of HCB ranged from 24 to 180pg m−3, with an average concentration of 88pg m−3. Generally, HCB were more uniform than other organchlorine pollutants in the North Pacific Ocean and the Arctic Ocean. Geographically, the average concentrations of HCB from high to low were in the following order: the Central Arctic Ocean (110±57pg m−3), the Chukchi and Beaufort Seas (93±29pg m−3), the East Asia (75±49pg m−3) and the North Pacific Ocean (69±38pg m−3). In the East Asia Sea and the North Pacific Ocean, both primary and secondary emissions of HCB from the nearby continents and/or oceans might contribute to the atmospheric HCB. In the Arctic, intense sea–ice melting in the summer of 2008 might result in the remobilization of HCB and enhance its atmospheric levels in this region.
Afficher plus [+] Moins [-]Shifting environmental baselines in the Red Sea Texte intégral
2014
Price, A.R.G. | Ghazi, S.J. | Tkaczynski, P.J. | Venkatachalam, A.J. | Santillan, A. | Pancho, T. | Metcalfe, R. | Saunders, J.
The Red Sea is among the world’s top marine biodiversity hotspots. We re-examined coastal ecosystems at sites surveyed during the 1980s using the same methodology. Coral cover increased significantly towards the north, mirroring the reverse pattern for mangroves and other sedimentary ecosystems. Latitudinal patterns are broadly consistent across both surveys and with results from independent studies. Coral cover showed greatest change, declining significantly from a median score of 4 (1000–9999m2) to 2 (10–99m2) per quadrat in 2010/11. This may partly reflect impact from coastal construction, which was evident at 40% of sites and has significantly increased in magnitude over 30years. Beach oil has significantly declined, but shore debris has increased significantly. Although substantial, levels are lower than at some remote ocean atolls. While earlier reports have suggested that the Red Sea is generally healthy, shifting environmental baselines are evident from the current study.
Afficher plus [+] Moins [-]Comparative study of 17 β-estradiol on endocrine disruption and biotransformation in fingerlings and juveniles of Japanese sea bass Lateolabrax japonicus Texte intégral
2014
Thilagam, Harikrishnan | Gopalakrishnan, Singaram | Bo, Jun | Wang, Ke-Jian
Estrogenic contaminants in the aquatic environment are associated with endocrine disruption and feminization in fish. The effects of endocrine disrupting chemicals (EDCs) on fish have been well documented. However, very few studies have focused on 17 β-estradiol (E2) and its effects on endocrine system and biotransformation in a single prolonged exposure. This study investigated changes in the levels of serotonin (5-hydroxytryptamine) and acetyl choline esterase (AchE) in brain, cortisol in plasma and Ethoxyresorufin-O-deethylase (EROD) activity in gill of two different size groups (fingerlings and juveniles) of Japanese sea bass (Lateolabrax japonicus) upon exposure to two sub-lethal concentrations (200 and 2000ngL−1) of E2 for 30d. The results indicate that cortisol level and EROD activity significantly increased in both groups, whereas serotonin level increased in juveniles and decreased in fingerlings due to E2 exposure. The correlation analysis revealed that E2 significantly affected the endocrine and biotransformation systems in both age groups.
Afficher plus [+] Moins [-]Plastic in the Thames: A river runs through it Texte intégral
2014
Morritt, David | Stefanoudis, Paris V. | Pearce, Dave | Crimmen, Oliver A. | Clark, Paul F.
Although contamination of the marine ecosystems by plastics is becoming recognised as a serious pollution problem, there are few studies that demonstrate the contribution made by freshwater catchments. Over a three month period from September to December 2012, at seven localities in the upper Thames estuary, 8490 submerged plastic items were intercepted in eel fyke nets anchored to the river bed. Whilst there were significant differences in the numbers of items at these locations, the majority were some type of plastic. Additionally in excess of 20% of the litter items were components of sanitary products. The most contaminated sites were in the vicinity of sewage treatment works. While floating litter is visible, this study also demonstrates that a large unseen volume of submerged plastic is flowing into the marine environment. It is therefore important that this sub-surface component is considered when assessing plastic pollution input into the sea.
Afficher plus [+] Moins [-]Characterization of urban pollution in two cities of the Puglia region in Southern Italy using field measurements and air quality (AQ) model approach Texte intégral
2014
Estellano, Victor H. | Pozo, Karla | Silibello, Camillo | Mulder, Marie D. | Efstathiou, Christos | Tomasino, Maria P. | Funaro, Fulvia | Donadio, Ivana | Focardi, S. (Silvano)
Passive air sampling (PAS) consisting of polyurethane foam (PUF) disks were deployed simultaneously over four periods of 2–5 months at four locations in urban and sub–urban sites of Bari and San Vito Taranto in Southern Italy. The purpose of the study was to characterize the urban pollution for two groups of semi volatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), by using two different approaches consisting of PAS–PUF and air quality models (Flexible Air quality Regional Model, FARM). The concentrations in the air ranged from 20 to 200pg m−3 for PCBs and from 5 to 48ng m−3 for PAHs with the highest concentrations being detected at Bari center. PCB composition was dominated by the 3–Cl congeners (periods 1 and 2) and by 5–Cl (periods 3 and 4). PCB–28 and –37 were the most abundant congeners during the four periods. The PAHs profile was dominated by the 3–ring (70±6)%, with phenanthrene alone accounting for (49±2)%. On a seasonal basis opposite patterns were observed for PCBs and PAHs showing high PCB concentrations during the warm periods, period 3: summer and 2: spring, while PAHs were found during cool periods, period 4: autumn, and 1: winter. The results obtained from the application of the FARM model, during 2010, and limited to period 4 in this study, showed similar estimated levels for PCBs indicating a good performance for PCB modeled concentrations whilst for benzo[b]fluoranthene (B[b]F) the results showed a less better agreement. This study represents one of the few efforts at characterizing PCBs and PAHs compositions in ambient air in southern Italy and also represents one of the preliminary attempts at using PAS–PUF to give more insight into a modeling prediction in Italy. These results also provide useful information for the future development of the FARM model.
Afficher plus [+] Moins [-]Occurrence of contaminants of emerging concern along the California coast (2009–10) using passive sampling devices Texte intégral
2014
Alvarez, David A. | Maruya, Keith A. | Dodder, Nathan G. | Lao, Wenjian | Furlong, Edward T. | Smalling, Kelly L.
Three passive sampling devices (PSDs), polar organic chemical integrative samplers (POCIS), polyethylene devices (PEDs), and solid-phase microextraction (SPME) samplers were used to sample a diverse set of chemicals in the coastal waters of San Francisco Bay and the Southern California Bight. Seventy one chemicals (including fragrances, phosphate flame retardants, pharmaceuticals, PAHs, PCBs, PBDEs, and pesticides) were measured in at least 50% of the sites. The chemical profile from the San Francisco Bay sites was distinct from profiles from the sites in the Southern California Bight. This distinction was not due to a single compound or class, but by the relative abundances/concentrations of the chemicals. Comparing the PSDs to mussel (Mytilus spp.) tissues, a positive correlation exists for the 25 and 26 chemicals in common for the PEDs and SPME, respectively. Diphenhydramine was the only common chemical out of 40 analyzed in both POCIS and tissues detected at a common site.
Afficher plus [+] Moins [-]Refocusing Mussel Watch on contaminants of emerging concern (CECs): The California pilot study (2009–10) Texte intégral
2014
Maruya, Keith A. | Dodder, Nathan G. | Schaffner, Rebecca A. | Weisberg, Stephen B. | Gregorio, Dominic | Klosterhaus, Susan | Alvarez, David A. | Furlong, Edward T. | Kimbrough, Kimani L. | Lauenstein, Gunnar G. | Christensen, John D.
To expand the utility of the Mussel Watch Program, local, regional and state agencies in California partnered with NOAA to design a pilot study that targeted contaminants of emerging concern (CECs). Native mussels (Mytilus spp.) from 68 stations, stratified by land use and discharge scenario, were collected in 2009–10 and analyzed for 167 individual pharmaceuticals, industrial and commercial chemicals and current use pesticides. Passive sampling devices (PSDs) and caged Mytilus were co-deployed to expand the list of CECs, and to assess the ability of PSDs to mimic bioaccumulation by Mytilus. A performance-based quality assurance/quality control (QA/QC) approach was developed to ensure a high degree of data quality, consistency and comparability. Data management and analysis were streamlined and standardized using automated software tools. This pioneering study will help shape future monitoring efforts in California’s coastal ecosystems, while serving as a model for monitoring CECs within the region and across the nation.
Afficher plus [+] Moins [-]Impact of rainfall on the hygienic quality of blue mussels and water in urban areas in the Inner Oslofjord, Norway Texte intégral
2014
Tryland, Ingun | Myrmel, Mette | Østensvik, Øyvin | Wennberg, Aina C. | Robertson, Lucy J.
The effects of precipitation on the hygienic quality of water and blue mussels collected from five different localities in the urban areas in the Inner Oslofjord were investigated, with samples analysed for Escherichia coli, Salmonella spp., pathogenic Vibrio spp., Norovirus, Sapovirus, Cryptosporidium spp. and Giardia duodenalis. The sampling sites were located at varying distances from the outlet of combined sewer overflows (CSO)-impacted rivers/streams. In general, 1–3 log10 increases in fecal indicator bacteria and human pathogens were observed after heavy rainfalls. Blue mussels appeared to be a useful indicator of the impact of sewage at these sites, and generally a good correlation was identified between concentrations of E. coli and other human pathogens in the mussels. Provision of general advice to the public of avoiding areas near the outlets of CSO-impacted rivers after heavy rainfall may reduce the risk of gastroenteritis by bathers and others that may swallow water during recreational activities.
Afficher plus [+] Moins [-]Radioactivity levels in mussels and sediments of the Golden Horn by the Bosphorus Strait, Marmara Sea Texte intégral
2014
Kılıç, Önder | Belivermiş, Murat | Gözel, Furkan | Carvalho, Fernando P.
The Golden Horn is an estuary located in the center of İstanbul receiving freshwater discharges from two creeks and connecting to the Bosphorus Strait. Activity concentrations of natural and artificial radionuclides were determined in mussels (Mytilus galloprovincialis) and sediments from the Golden Horn sampled in February 2012. Mean activity concentrations of 137Cs, 40K, 226Ra, 228Ra, 210Po and 210Pb in the mussels were determined at 1.03±0.23, 389±41.6, 2.61±1.23, not detected (ND), 91.96±37.88 and 11.48±4.85Bqkg−1, respectively. In sediments, it was observed that 137Cs, 40K, 226Ra, 228Ra, 210Po and 210Pb activity concentrations in<63μm particle fraction of sediment were generally higher than those determined in mussels. Po-210 and 210Po/210Pb ratios in mussels from the Golden Horn were much lower than in mussels from other coastal regions and this was related to low plankton productivity and eutrophication of the Golden Horn.
Afficher plus [+] Moins [-]Chronic light reduction reduces overall resilience to additional shading stress in the seagrass Halophila ovalis Texte intégral
2014
Yaakub, Siti M. | Chen, Eugene | Bouma, Tjeerd J. | Erftemeijer, Paul L.A. | Todd, Peter A.
Seagrasses have substantial capacity to survive long periods of light reduction, but how acclimation to chronic low light environments may influence their ability to cope with additional stress is poorly understood. This study examines the effect of temporal light reduction by adding two levels of shading to Halophila ovalis plants in two meadows with different light histories, one characterized by a low light (turbid) environment and the other by a relatively high light (clear) environment. Additional shading resulted in complete mortality for both shading treatments at the turbid site while the clear site showed a pattern of decreased shoot density and increased photochemical efficiency (Fv/Fm) with increased shading. These contrasting results for the same species in two different locations indicate that acclimation to chronic low light regimes can affect seagrass resilience and highlights the importance of light history in determining the outcome of exposure to further (short-term) stress.
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