Refine search
Results 841-850 of 3,208
Polybrominated diphenyl ethers in thirteen shark species from offshore and coastal waters of Korea Full text
2015
Lee, Hyun Kyung | Kim, Sang-jo | Jeong, Yunsun | Lee, Sunggyu | Jeong, Woochang | Lee, Won-Chan | Choy, Eun-Jung | Kang, Chang-Keun | Moon, Hyo-Bang
Limited reports are available on polybrominated diphenyl ethers (PBDEs) in sharks. In this study, PBDEs were measured in dorsal muscles (n=105) from 13 shark species collected from offshore and coastal waters of Korea. The PBDE concentrations varied greatly not only among species but also within species of sharks. The major PBDE congeners detected in our samples were BDEs 47, 28, 99, 153, 100, and 154. Concentrations of PBDEs in sharks in this study were lower than those reported for previous studies. The high PBDE concentrations were found for aggressive shark species. Inter-species differences in the concentrations and accumulation profiles of PBDEs are explained by differences in feeding habits and sampling locations. Several contributing factors such as growth velocity, trophic level, and local contamination may affect the bioaccumulation of PBDEs in sharks. The present study provides baselines for the occurrence and accumulation status of PBDEs in various shark species.
Show more [+] Less [-]Seasonal variability and flux of particulate trace elements from the Yellow River: Impacts of the anthropogenic flood event Full text
2015
Hu, Bangqi | Li, Jun | Bi, Naishuang | Wang, Houjie | Yang, John | Wei, Helong | Zhao, Jingtao | Li, Guogang | Yin, Xuebo | Liu, Ming | Zou, Liang | Li, Song
In this study, the suspended particulate matter (SPM) of the Yellow River (Huanghe) was collected biweekly at the outlet and analyzed for particulate trace element contents. The seasonal variations of the trace elements were primarily controlled by hydrological processes, which determined different sources of the SPM. Moreover, As, Co, Cr, and Ni primarily originated from lithogenic sources, whereas Cd, Cu, Pb and Zn were influenced by anthropogenic activities. The Yellow River has suffered moderate to considerable ecological risk during the late stage of Water and Sediment Regulation (WSR). Using the discharge-weighted contents method, the annual trace element fluxes were estimated, with ca. 30% of the annual fluxes occurring within the short WSR period (6% of one year). More specifically, 75% of the Cd flux was from an anthropogenic source, which likely posed a significant threat to the estuary and the adjacent coastal ecosystems.
Show more [+] Less [-]Influence of atmospheric circulation patterns on urban air quality during the winter Full text
2015
Grundstrom, Maria | Tang, Lin | Hallquist, Mattias | Nguyen, Hung | Chen, Deliang | Pleijel, Håkan
Influence of atmospheric circulation patterns on urban air quality during the winter Full text
2015
Grundstrom, Maria | Tang, Lin | Hallquist, Mattias | Nguyen, Hung | Chen, Deliang | Pleijel, Håkan
Relationships between urban nitrogen dioxide (NO2) and atmospheric circulation at two spatial scales were studied for Southern Sweden. Lamb Weather Types (LWT) describe the circulation (scale: thousands of kilometers) including non–directional (cyclonic and anticyclonic) and directional types depending on the wind direction. LWTs with low wind speeds (anticyclonic, NW and N) were associated with strongly elevated [NO2], between 46–52% of the daily averages of NO2 exceeded the 60μg m−3 air quality standard (AQS) when occurring during these LWTs. The lowest fractions of exceedances of NO2 AQS were generally observed for LWTs E, S, SW and W. A larger scale circulation (several thousands of kilometers) was represented by the North Atlantic Oscillation (NAO) affecting meteorology over middle and high latitudes in the Northern Hemisphere. While a negative NAO index (NAOI) favors stagnant high pressure weather over Northern Europe, a positive NAOI is often associated with windy conditions. High [NO2] was found to be frequent under negative NAOI. Additionally, larger fractions of exceedances of NO2 AQS were observed for the majority of LWTs occurring at negative NAOI. It’s concluded that both LWTs and NAOI had partly independent effects on the urban air quality in a North European city. These circulation indices can be useful tools for air pollution risk assessment and forecasting.
Show more [+] Less [-]The influence of atmospheric circulation and meteorology on urban air pollution and pollen exposure Full text
2015
Grundström, Maria
Urban air quality is a global health concern and is a growing problem due to large migration of people from rural areas to cities, a phenomenon occurring in many parts of the world. This means that more and more people can be expected to be exposed to high levels of air pollutants, many of which are associated with the urban environment. The exposure situation is characterised by different compounds emitted from different sources such as traffic, industry, wood burning and energy production. Air pollution levels tend to vary temporally both during the day and between seasons. Another important atmospheric constituent to consider is pollen which together with air pollutants can cause severe health effects in sensitive people. The climate and weather governs the atmospheric processes responsible for ventilation and stagnation of the air, which in turn also provides conditions for good or poor air quality. This thesis has investigated the urban air pollution levels of nitrogen oxides (NOx = NO + NO2), ozone (O3), particles (PM10 and PNC, particle number concentration) and birch pollen levels in relation to meteorology and atmospheric circulation. In this study circulation was represented by the large scale circulation pattern called the North Atlantic Oscillation (NAO) and by the synoptic circulation classification scheme Lamb Weather Types (LWT). The city of Gothenburg has been the main location but air quality and pollen in Malmö has also been investigated. It was shown that air pollution has a strong association to the variation in weather conditions represented by both NAO and LWTs. In winter calm and stagnant air masses were associated with high levels of NO and NO2, these conditions were more common NAO was in its so called negative mode (characterized e.g. by low wind speeds) and in LWTs associated with calm conditions and thus limited ventilation. Ultrafine particles (UFP), considered to be of large importance for health effects, are in many cases the dominating fraction in PNC. NOx was found to be a good proxy of PNC, e.g. situations with high NOx can be expected to have high PNC. Furthermore, the occurrence of high NO2, O3 and PM10 were co-varying very well with the occurrence of high birch pollen counts in Gothenburg. These situations were also associated with high sales of over-the-counter (OTC) antihistamines, indicating a combined effect on health symptoms represented by OTC sales, especially during calm and dry weather conditions. Finally, the usefulness of LWTs was illustrated by to their strong association with anomalies of inter-annual air pollution levels. By adjusting annual concentration/deposition trends of air pollutants for the yearly LWT variability, temporal trends were greatly improved, e.g. the relative importance of weather was quantified permitting more accurate evaluation of emission changes on air pollution levels. Furthermore, the strong association between urban air quality and atmospheric circulation shown in this thesis highlights the LWT classification as a good option to be integrated in a tool for risk assessment and information system for urban air quality including both air pollutants and pollen.
Show more [+] Less [-]Impact of spatial resolution on air quality simulation: A case study in a highly industrialized area in Shanghai, China Full text
2015
Tan, Jiani | Zhang, Yan | Ma, Weicun | Yu, Qi | Wang, Jian | Chen, Limin
The air pollution contribution from highly industrialized areas has been a prominent issue in regional air quality control. Particular emphasis on local industrial emissions is necessary to understand the complexity of air pollution over highly industrialized areas. Baoshan District, one of the most important industrialized areas in China and the most competitive steel and iron production base worldwide, was selected as the study area in this work. The WRF/CMAQ modeling system with local emission profile was applied to study the impact of spatial resolution on air quality modeling. The simulation results for SO2, NO, NO2, CO and PM10 at both 3–km and 1–km resolutions were verified by ground level observations. The results showed that the allocation of the emission inventory is improved by using finer resolution grids, which allow the consideration of detailed emission features. The influence of model resolution was more significant for air quality than for meteorology simulation. The relative errors using the finer resolution method ranged from –25% to 59%, an obvious improvement over the error value of 26%–245% obtained using the coarse resolution method. The changing tendencies of air pollutants in urban and rural areas were generally better modeled at finer than coarser resolution. However, the detailed variation in the most heavily polluted areas was still difficult to capture, and the model performance was not evidently improved by the use of a fine resolution. To improve the model performance over highly industrialized areas for future studies, combining the dynamic emission profile with detailed industrial activities and accurate local meteorological fields is suggested.
Show more [+] Less [-]Illegal discharges in Spanish waters. Analysis of the profile of the Alleged Offending Vessel Full text
2015
Martín Alonso, J.M. | Ortega Piris, Andrés | Pérez Labajos, Carlos
There is at present a growing concern, on an international level, over environmental offences caused by oil discharges into the sea from vessels. The objective of the Spanish Maritime Administration is to prevent the illegal discharges of polluting substances in Spanish maritime waters by vessels in transit. To combat such discharges, since 2007 Spain has reinforced its means of response with the use of aircrafts that provide services of maritime surveillance, identifying the Alleged Offending Vessels and acting as a deterrent.The objective of the present study is both to introduce the concept and to analyze certain aspects of the so-called “Alleged Offending Vessel” (AOV) that have been detected within Spanish Search and Rescue (SAR) jurisdiction waters in the period 2008–2012, in order to build a profile of such a vessel. For this purpose, an analysis methodology is formalized based on the GINI index and Lorenz curves, associated with certain aspects of vessels: type, flag and sailing area.
Show more [+] Less [-]The effects of flow rate and temperature on SPMD measurements of bioavailable PAHs in seawater Full text
2015
Chang, Wan-Ting | Lee, Chon-Lin | Brimblecombe, Peter | Fang, Meng-Der | Zhang, Guodong | Liu, James T.
This work investigates the dependence of the sampling rate (Rs) of semi-permeable membrane devices (SPMDs) on flow rate and temperature. The in situ Rs values were obtained using performance reference compounds (PRCs) with weighted polynomial regression and used to estimate the bioavailable polycyclic aromatic hydrocarbon (PAH) concentrations in seawater. The in situ Rs values did not vary with flow rate and temperature. The empirical equation of the Rs value from the SPMDs was established. This infers that PRCs could be avoided by using an established empirical equation under similar field conditions. The sum of the bioavailable PAHs ranged from 0.281 to 0.611ngL−1 on the eastern side of the Taiwan Strait and from 0.438 to 1.10ngL−1 on the western side. Distinct sources and toxicity of these bioavailable PAHs were observed and mainly resulted from different types of energy consumption.
Show more [+] Less [-]Relationship between the lability of sediment-bound Cd and its bioaccumulation in edible oyster Full text
2015
Chakraborty, Parthasarathi | Ramteke, Darwin | Chakraborty, Sucharita | Chennuri, Kartheek | Bardhan, Pratirupa
A linkage between Cd speciation in sediments and its bioaccumulation in edible oyster (Crassostrea sp.) from a tropical estuarine system was established. Bioaccumulation of Cd in edible oyster increased with the increasing lability and dissociation rate constants of Cd-sediment complexes in the bottom sediments. Total Cd concentration in sediment was not a good indicator of Cd-bioavailability. Increasing trace metal competition in sediments increased lability and bioavailability of Cd in the tropical estuarine sediment. Low thermodynamic stability and high bioavailability of Cd in the estuarine sediment were responsible for high bioaccumulation of Cd in edible oysters (3.2–12.2mgkg−1) even though the total concentration of Cd in the bottom sediment was low (0.17–0.49mgkg−1).
Show more [+] Less [-]Pollution risk assessment of oil spill accidents in Garorim Bay of Korea Full text
2015
Lee, Moonjin | Jung, Jung-Yeul
This study presents a model to assess the oil spill risk in Garorim Bay in Korea, where large-scale oil spill accidents frequently occur. The oil spill risk assessment is carried out by using two factors: 1) The impact probability of the oil spill, and 2) the first impact time of the oil that has been spilt. The risk assessment is conducted for environmentally sensitive areas, such as the coastline and aquaculture farms in the Garorim Bay area. Finally, Garorim Bay is divided into six subareas, and the risks of each subarea are compared with one another to identify the subarea that is most vulnerable to an oil spill accident. These results represent an objective and comprehensive oil spill risk level for a specific region. The prediction of the oil spill spread is based on real-time sea conditions and can be improved by integrating our results, especially when sea conditions are rapidly changing.
Show more [+] Less [-]An assessment of PCB and PBDE contamination in two tropical dolphin species from the Southeastern Brazilian coast Full text
2015
Lavandier, Ricardo | Arêas, Jennifer | Dias, Patrick S. | Taniguchi, Satie | Montone, Rosalinda | de Moura, Jailson Fulgencio | Quinete, Natalia | Siciliano, Salvatore | Moreira, Isabel
PCBs and PBDEs were determined in two dolphin species, Sotalia guianensis and Steno bredanensis, from an upwelling system off the Central-northern coast of Rio de Janeiro, Brazil. PCB levels varied from 0.040 to 0.75μgg−1lw in muscles and from 0.022 to 1.32μgg−1lw in liver samples from S. guianensis. In S. bredanensis, values varied from 0.085 to 11.3μgg−1lw in muscles and from 0.024 to 18.6μgg−1lw in livers. PCB-138, -153 and -180 were the major PCB congeners detected in both species, while BDE-47 was the predominant PBDE congener found in both species. Higher concentrations in S. bredanensis were possibly related to the different feeding habits for both delphinid species. These results contribute to extend the database on organic contamination in cetaceans from the southern hemisphere, understanding their distribution and environmental fate in Southeastern Brazil.
Show more [+] Less [-]Environmental epigenetics: A promising venue for developing next-generation pollution biomonitoring tools in marine invertebrates Full text
2015
Suarez-Ulloa, Victoria | Gonzalez-Romero, Rodrigo | Eirín López, José M.
Environmental epigenetics investigates the cause-effect relationships between specific environmental factors and the subsequent epigenetic modifications triggering adaptive responses in the cell. Given the dynamic and potentially reversible nature of the different types of epigenetic marks, environmental epigenetics constitutes a promising venue for developing fast and sensible biomonitoring programs. Indeed, several epigenetic biomarkers have been successfully developed and applied in traditional model organisms (e.g., human and mouse). Nevertheless, the lack of epigenetic knowledge in other ecologically and environmentally relevant organisms has hampered the application of these tools in a broader range of ecosystems, most notably in the marine environment. Fortunately, that scenario is now changing thanks to the growing availability of complete reference genome sequences along with the development of high-throughput DNA sequencing and bioinformatic methods. Altogether, these resources make the epigenetic study of marine organisms (and more specifically marine invertebrates) a reality. By building on this knowledge, the present work provides a timely perspective highlighting the extraordinary potential of environmental epigenetic analyses as a promising source of rapid and sensible tools for pollution biomonitoring, using marine invertebrates as sentinel organisms. This strategy represents an innovative, groundbreaking approach, improving the conservation and management of natural resources in the oceans.
Show more [+] Less [-]