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Finite-time compressibility as an agent of frequent spontaneous patch formation in the surface layer: A case study for the Gulf of Finland, the Baltic Sea Full text
2014
Giudici, Andrea | Soomere, Tarmo
We explore the possibilities for spontaneous formation of surface patches with high concentrations of contaminants through time correlations of the convergence field and the Lagrangian transport. The test area is the Gulf of Finland, the Baltic Sea, where surface velocity fields show extensive convergence. The flow properties are extracted from 3D velocity fields simulated for 1987–1991 using the OAAS model with a resolution of 1mile. The focus is on the spatial distribution of the areas in which the values of finite-time flow compressibility of surface velocity fields exceed the threshold for clustering of floats. The distribution of such areas is asymmetric, with likely areas of patch formation located predominantly in the southern and eastern regions of the gulf. Out of nine areas of likely patch formation, six are located along the coast in regions of frequent downwelling, while three are identified in the central region of the gulf.
Show more [+] Less [-]Chemical characterization of roadside PM2.5 and black carbon in Macao during a summer campaign Full text
2014
Song, Shaojie | Wu, Ye | Zheng, Xuan | Wang, Zhishi | Yang, Liu | Li, Jiaqi | Hao, Jiming
Air pollution is the leading environmental concern in Macao. The temporal variations of particulate matter (PM) and black carbon (BC) mass concentrations and the size–resolved PM2.5 chemical compositions, including trace elements and carbonaceous species, were measured in Macao during a near–road summer campaign. The average concentrations for PM10, PM2.5 and BC at a roadside measurement site were 37.8μg m−3, 31.4μg m−3 and 5.6μg m−3, respectively. Results showed that local emissions contributed at least 35% to PM2.5 mass in Macao. Higher BC concentrations were observed in the daytime than at night, consistent with the diurnal variations of traffic flow. Factor analysis classified trace elements into three categories, representing crustal sources (Mg, Si, Al, Na, Fe, Ca and K), road traffic sources (Cu and Co) and secondary inorganic particle formation (S). Crustal elements and road traffic elements were enriched in the size ranges of >1.0μm and <0.2μm, respectively. The unimodal distribution pattern with a peak at <0.2μm for organic carbon (OC) was probably due to secondary organic aerosol formation, whereas about 70% of elemental carbon (EC) was in the size range of 0.2–1.0μm. Secondary organic aerosols were found to be a strong contributor to PM in the size ranges of <0.2μm and 1.0–2.5μm.
Show more [+] Less [-]Workplace personal exposure to respirable PM fraction: a study in sixteen indoor environments Full text
2014
Saraga, Dikaia E. | Volanis, Lefteris | Maggos, Thomas | Vasilakos, Christos | Bairachtari, Kyriaki | Helmis, Costas G.
The present paper focuses on respirable particulate matter (RPM) measurements conducted at the breathing zone of adult volunteers in sixteen different working environments: two offices, a house, a chemical laboratory, a non–smoking shop, a pharmacy store, a car garage, a hairdresser's store, a photocopy store, a taxi, a gym, a mall, a restaurant, a bar, a kiosk and a school. The sixteen different cases were categorized according to the location, the type of the activities taking place indoors, the number of occupants, the proximity to heavy traffic roads, the ventilation pattern etc. According to the results, the maximum particle concentration (in average 285μg m−3) was recorded at the hairdresser store while the minimum concentration was measured in the cases of the housewife and the employee in the non–smoking shop (in average 30μg m−3). The results indicated smoking as a factor which strongly influences the exposure levels of both smokers and passive smokers. Furthermore, it was found that the building ventilation pattern comprises an important factor influencing the exposure levels especially in cases of buildings with great number of visitors (resuspension) and smoking.
Show more [+] Less [-]Mandating responsible flagging practices as a strategy for reducing the risk of coastal oil spills Full text
2014
Miller, Dana D. | Hotte, Ngaio | Sumaila, U Rashid
As human civilization is becoming more aware of the negative impact our actions can inflict upon the natural world, the intensification of fossil fuel extraction and industrial development is being met with increasing opposition. In Western Canada, proposals that would increase the volume of petroleum transported by pipelines and by tankers through the coastal waters of British Columbia have engaged the province in debate. To ease public concern on the risk of a coastal oil spill, there are additional commitments that involved parties could make. There is evidence to show that the practice of registering vessels under foreign flags of states that have exhibited failure in compliance with international obligations is more common amongst petroleum tankers that have been involved in large-scale oil spills. To prove that they are committed to reducing the risk of oil spills, businesses need to stop registering their vessels under flags of foreign, non-compliant states.
Show more [+] Less [-]Spatial patterns of metals, PCDDs/Fs, PCBs, PBDEs and chemical status of sediments from a coastal lagoon (Pialassa Baiona, NW Adriatic, Italy) Full text
2014
Guerra, Roberta | Pasteris, Andrea | Lee, Seok-hyung | Park, No-jin | Ok, Gon
The European Water Framework Directive (WFD) establishes a framework for the protection and improvement of all water bodies including transitional waters; its final objective is to achieve at least ‘good status’ by 2015. In the present work, a hierarchical sampling design was applied to analyze the influence of anthropogenic inputs on the spatial distribution of metals, polychlorinated dibenzo-p-dioxins (PCDDs) dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in sediment at four areas in Pialassa Baiona coastal lagoon. In order to assess the chemical status, levels of priority substances and other pollutants were compared with the recently developed national Environmental Quality Standards (EQS) and site specific background levels for metals. Levels of mercury and PCBs were particularly high and exceeded their national EQS values at all sampled areas, thus not contributing to the achievement of a good chemical status of this transitional water body according to the WFD classification.
Show more [+] Less [-]Macrobenthic succession and characteristics of a man-made intertidal sandflat constructed in the diversion channel of the Ohta River Estuary Full text
2014
Nishijima, Wataru | Nakano, Yoichi | Nakai, Satoshi | Okuda, Tetsuji | Imai, Tsuyoshi | Okada, Mitsumasa
We compared succession and characteristics of the macrobenthic community in a small-scale experimental intertidal sandflat constructed in the artificial diversion channel of the Ohta River Estuary with those of three natural intertidal sandflats at lower elevation in the same channel. The macrobenthic population density in the man-made intertidal sandflat increased significantly between 3 and 9months after construction. Simplisetia erythraeensis was dominant (98% of individuals) after 9months, but its proportion gradually declined with the increase in biodiversity until 26months, indicating that succession of the macrobenthic community was nearly complete by 26months. The macrobenthic community in the man-made intertidal sandflat differed from those of the three natural intertidal sandflats, and its population density was about double that at the natural sites, with smaller temporal fluctuation. The different structures of the macrobenthic communities in the man-made and natural intertidal sandflats were likely caused by differences in elevation.
Show more [+] Less [-]De novo transcriptomic profile in the gonadal tissues of the intertidal whelk Reishia clavigera Full text
2014
Ho, Kevin K.Y. | Leung, Priscilla T.Y. | Ip, Jack C.H. | Qiu, J.W. | Leung, Kenneth M.Y.
The intertidal whelk Reishia clavigera (formerly named as Thais clavigera) is one of the most sensitive species to organotin-associated imposex. However, the limited information on mRNA transcriptome of the species has restricted the molecular investigation on such endocrine disruption. By means of Illumina sequencing, we obtained a global de novo transcriptome from the gonadal tissues of both male and female R. clavigera, with 197,324 assembled transcripts and 151,684 condensed non-redundant transcripts. Blast hit results from the NCBI’s non-redundant molluscan database showed that 28,948 transcripts were successfully annotated with significant matches at an e-value of ⩽1e−6. Among them, 1108 transcripts were assigned a well-defined gene ontology term. As the first transcriptomic study on the gonadal tissues of R. clavigera, this study has enhanced the information of mRNA transcriptome on this species and will thus facilitate mechanistic studies of chemical contaminants (e.g., organotins) on this common biomonitor species.
Show more [+] Less [-]Multiple stressors threatening the future of the Baltic Sea–Kattegat marine ecosystem: Implications for policy and management actions Full text
2014
Jutterström, S. | Andersson, H.C. | Omstedt, A. | Malmaeus, J.M.
The paper discusses the combined effects of ocean acidification, eutrophication and climate change on the Baltic Sea and the implications for current management strategies. The scientific basis is built on results gathered in the BONUS+ projects Baltic-C and ECOSUPPORT. Model results indicate that the Baltic Sea is likely to be warmer, more hypoxic and more acidic in the future. At present management strategies are not taking into account temporal trends and potential ecosystem change due to warming and/or acidification, and therefore fulfilling the obligations specified within the Marine Strategy Framework Directive, OSPAR and HELCOM conventions and national environmental objectives may become significantly more difficult. The paper aims to provide a basis for a discussion on the effectiveness of current policy instruments and possible strategies for setting practical environmental objectives in a changing climate and with multiple stressors.
Show more [+] Less [-]Fish biological effect monitoring of chemical stressors using a generalized linear model in South Sea, Korea Full text
2014
Jung, Jee-Hyun | Choi, Seung Bae | Hong, Sang Hee | Chae, Young Sun | Kim, Hana | Yim, Un Hyuk | Ha, Sung Yong | Han, Gi Myung | Kim, Dae Jung | Shim, Won Joon
To evaluate the health status at six different study areas, we used the generalized linear model approach with selected biochemical markers in resident fish from uncontaminated and contaminated sites. We also confirmed the independence between the biochemical indices and the morphometric indices including the hepato-somatic index (HSI), gonado-somatic index (GSI), and condition factor (CF) in fish from the sampling areas. The effect of area on the presence of biotransformation markers (ethoxyresorufin-O-deethylase activity; EROD) was significantly high in Masan Bay. The area with the greatest effect on acetylcholinesterase (AChE) activity was Jindong Bay, while there was no significant effect of GSI, HSI, CF, and sex in the EROD model and HSI, CF and sex in the AChE model. These results clarify that fish from Masan, Gwangyang and Jindong Bay were affected by pollutant stress, and the analysis of sensitive biochemical responses allowed for an improved interpretation of the results.
Show more [+] Less [-]Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of the Hormuz strait, Persian Gulf Full text
2014
Rahmanpoor, Shirin | Ghafourian, Hosein | Hashtroudi, Seyed Mehri | Bastami, Kazem Darvish
The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the sediment from the Hormuz strait, Persian Gulf. The sum of 16 PAHs (ΣPAH) concentrations varied from 72.17 to 277.77ngg−1 dry weight, with an average value of 131.20±59.29ngg−1 dry weight. An ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene and acenaphthylene occasionally may take place in the sediment of Hormuz strait. PAH source identification showed that the PAHs in the sediments come from pyrogenic and mixed origin. Based on classification of pollution levels, sediments from Hormuz strait could be considered as low to moderately polluted with PAHs.
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