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Mercury profiles in sediments of the Pearl River Estuary and the surrounding coastal area of South China
2010
Shi, Jian-bo | Ip, Carman C.M. | Zhang, Gan | Jiang, Gui-bin | Li, Xiang-Dong
The spatial and temporal variations of mercury (Hg) in sediments of the Pearl River Estuary (PRE) and the surrounding coastal area (South China Sea) were studied. In surface sediments, the concentrations of Hg ranged from 1.5 to 201 ng/g, with an average of 54.4 ng/g, displaying a decreasing trend with the distance from the estuary to the open sea. This pattern indicates that the anthropogenic emissions from the Pearl River Delta (PRD) region are probably the main sources of Hg in this coastal region. Using the 210Pb dating technique, the historical changes in the concentrations and influxes of Hg in the last 100 years were also investigated. The variations in Hg influxes in sediment cores obviously correlate with the economic development and urbanization that has occurred the PRD region, especially in the last three decades.
Mostrar más [+] Menos [-]Perfluorinated compounds in water, sediment, soil and biota from estuarine and coastal areas of Korea
2010
Naile, Jonathan E. | Khim, Jong Seong | Wang, Tieyu | Chen, Chunli | Luo, Wei | Kwon, Bong-Oh | Park, Jinsoon | Ko, Chʻŏr-hwan | Jones, Paul D. | Lü, Yonglong | Giesy, John P.
Soil, sediment, water, and biota collected from the western coast of Korea were analyzed to determine occurrence and sources of perfluorinated compounds (PFCs). PFCs were significantly concentrations of PFCs were measured in some water and biological samples, while concentrations of PFCs in soils and sediments were relatively low. The most widely detected compound was found to be perfluorooctanesulfonate (PFOS), with a maximum concentration in water of 450 ng/L and in fish of 612 ng/g, dw. PFOS concentrations in water and biota were both less than those thought to cause toxicity. However, in both cases concentrations were within a factor of 10 of the toxicity threshold concentration. Concentrations of PFCs were significantly greater downstream than those upstream on the same river, suggesting point sources. Overall, the detection of PFCs at relatively great concentrations in various environmental matrixes from this region of Korea suggests that further studies characterizing PFCs and their potential risk to both humans and wildlife are needed.
Mostrar más [+] Menos [-]Distribution of Several Heavy Metals in Tidal Flats Sediments within Bahía Blanca Estuary (Argentina)
2010
Botté, Sandra Elizabeth | Freije, Rubén Hugo | Marcovecchio, Jorge Eduardo
Sediment pollution by metals is of high interest considering that it can affect marine life. The estuaries' quality may be reflected by the environmental intertidal zone condition. Subsurface sediments collected at the nude tidal flats from three sampling stations in the Bahía Blanca Estuary were analyzed for total metals concentrations (Hg, Cd, Pb, and Cr), distribution, and geochemical partitioning. Most of the elements (Hg, Cd, and Cr) have shown highest concentration values in the industrial-influenced area. Maximum value of Pb was obtained where the main freshwater input discharges. Intertidal sediments have presented higher values of Cr than the subtidal ones. Cd and Pb contents near the industrial area were strongly higher in the subtidal zones. The distribution of Cd and Pb demonstrated the occurrence of a diffusion pattern from the land toward the sea, showing a dependence on both the metal itself and/or the source. Not all studied metals have shown the highest content in the fine fraction. The chemical partitioning in the fine fractions offered evidence that the tidal flats were an important source as well as sink of metals to the adjacent coastal area. The studies of intertidal sediments provide an integrative knowledge on the potential effects of different trace metals in the environment and they must be used in the contamination studies within coastal areas.
Mostrar más [+] Menos [-]Imposex in Thais gradata as a Biomarker for TBT Contamination on the Southern Coast of Peninsular Malaysia
2010
Mohamat-Yusuff, Ferdaus | Zulkifli, Syaizwan Zahmir | Ismail, Ahmad | Harino, Hiroya | Yusoff, Mohd Kamil | Arai, Takaomi
Thais gradata samples were collected from six locations along the southern shores of Peninsular Malaysia and analyzed for imposex incidence and organotin (butyltins (BTs), including tributyltin, dibutyltin, and monobutyltin, and phenyltins (PTs), including triphenyltin, diphenyltin, and monophenyltin concentrations), in tissue burden. On average, the BT levels were found to be higher than the levels reported a year before for other biota. In contrast, the PT compounds were found to be lower than in the previous report. The present study also classified the morphological expressions of the imposex scheme for this species into seven stages (stage 0 to stage 6) by observing the development of vas deference sequence (VDS) and penis bulk. This latest imposex scheme clearly indicates the mechanism of VDS growth, the structural changes from penis bulk to a penis with flagellum, and from a normal vaginal opening to a swollen vaginal opening. The degree of imposex was assessed using the vas deference sequence index and the percentage of females possessing the imposex characteristics. It was found that locations possessing high imposex levels also tended to show high BT levels in the snail tissue samples. However, correlation analysis did not show a significant relationship among the two parameters. A better result could be obtained if more samples and sampling locations were added in order to prove the hypothesis. The nonsignificant correlation between the shell height and any of the organotin compounds, along with no significant differences between BT levels in female and lower imposex stage samples, suggests that the BT concentration detected was a recent contamination.
Mostrar más [+] Menos [-]A microbiological study of the self-cleaning potential of oily Arabian Gulf coasts
2010
Mahmoud, Huda | Al-Hasan, Redha | Khanafer, Majida | Raḍwān, Samīr Muḥammad
Background, aim, and scope Due to the active production and transport of crude oil in the Arabian Gulf region, the Arabian Gulf coasts are routinely polluted with oil. Therefore, such coasts have been subject of studies aiming at assessing the roles of indigenous microbial consortia in cleaning these environments. In the present study, epilithic microbial communities along Kuwait coasts were studied for their oil degradation potential. Materials and methods Gravel particles coated with deep green biofilms were collected from four coastal sites in autumn, winter, and spring. Phototrophs in these consortia were determined in terms of their chlorophyll a contents and identified by their morphological characteristics. Total bacteria were counted microscopically and cultivable bacteria by the dilution plating method on nutrient agar as well as on inorganic medium containing oil as a sole source of carbon and energy. The bacterial community structures were also characterized and compared by denaturing gradient gel electrophoresis (DGGE). Results Epilithic biomass samples from the four sites in the three seasons were rich in diatoms and picocyanobacteria as well as total bacteria. Direct counting gave bacterial numbers per square centimeter gravel surface of 2 to 6 × 10⁷ cells depending on the sampling site and season. Cultivable bacterial numbers on nutrient agar and crude oil as a sole source of carbon were 3 × 10³ to 8 × 10⁴ and 1 × 10³ to 7 × 10³ cells/cm² gravel surface, respectively. The DGGE profiles of epilithon biomass samples revealed major 16S rDNA bands that matched bands of pure oil-utilizing bacterial isolates. Discussion The microbial communities showed a degree of consistency in all sites and seasons. Conclusions The microbial consortia coating gravel particles are potentially suitable tools for self-cleaning of oily Gulf coasts. They are rich in oil-utilizing bacteria whose activities are probably enhanced by oxygen produced by the phototrophic partners in the consortia. Recommendations and perspectives The combination of conventional microbiological analysis with molecular approaches gives an enhanced idea about natural microbial communities especially those with environmental application potential.
Mostrar más [+] Menos [-]Gas phase reactions of unsaturated esters with Cl atoms
2010
Martín Porrero, María Pilar | Gallego-Iniesta García, Maria Paz | Espinosa Ruiz, Jose Luis | Tapia Valle, Araceli | Cabañas Galán, Beatriz | Salgado Muñoz, Maria Sagrario
Background, aim, and scope Acrylate and methacrylate esters are α,β-unsaturated esters that contain vinyl groups directly attached to the carbonyl carbon (CH₂=CHCOO- and CH₂=CCH₃COO-, respectively) and are widely used in the polymer plastic and resin production. Rate coefficients for Cl reactions for most of the unsaturated esters have not been previously determined, and a good understanding is needed of all the atmospheric oxidation processes of these compounds in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of photo-oxidants and therefore on health and environment. Materials and methods The relative rate technique has been used to obtain rate coefficients for the reactions between the Cl atom and a series of unsaturated esters. The experiments have been carried out in a static Teflon reactor at room temperature and atmospheric pressure (N₂ as bath gas) using gas chromatography with flame ionization detection as detection system. Results The following rate coefficients are obtained (in cubic meter per molecule per second): methyl acrylate + Cl = 1.71 ± 0.13 × 10⁻¹⁰; methyl methacrylate + Cl = 2.30 ± 0.18 × 10⁻¹⁰; ethyl acrylate + Cl = 1.82 ± 0.13 × 10⁻¹⁰; ethyl methacrylate + Cl = 2.71 ± 0.21 × 10⁻¹⁰; butyl acrylate + Cl = 2.94 ± 0.23 × 10⁻¹⁰; butyl methacrylate + Cl = 3.83 ± 0.30 × 10⁻¹⁰; methyl 3-methyl acrylate + Cl = 2.21 ± 0.17 × 10⁻¹⁰; and methyl 3,3-dimethyl acrylate + Cl = 3.58 ± 0.28 × 10⁻¹⁰. Discussion Rate coefficients calculated for Cl reactions are around one order of magnitude higher than OH ones. The effect in the reactivity of increased substitution at the carbon-carbon double bond is analyzed and also the effect of the identity of the alkyl group R in the -C(O)OR. Atmospheric lifetimes of the compounds against the attack by the major oxidants are estimated and the atmospheric implications are discussed. Conclusions The dominant atmospheric loss process for acrylate esters is clearly their daytime reaction with the hydroxyl radical. However, in coastal areas and in the marine boundary layer and in some industrial zones, Cl-atom-initiated degradation of the unsaturated esters considered here can be a significant if not dominant homogeneous loss process. Recommendations and perspectives Product analysis should be necessary in order to evaluate the real environmental impact of these reactions. OH and ozone reactions of most of the considered compounds have already been studied and products determined, but kinetic and products information for NO₃ radical reactions is especially scarce.
Mostrar más [+] Menos [-]Submarine wastewater discharges: dispersion modelling in the Northern Adriatic Sea
2010
Background, aim and scope Opposite interests must coexist in coastal areas: the presence of significant cities and urban centres, of touristic and recreational areas, and of extensive shellfish farming. To avoid local pollution caused by treated wastewaters along the Northern Adriatic coast (Friuli Venezia-Giulia and Veneto regions), marine outfall systems have been constructed. In this study, the application of a numerical dispersion model is used to support the traditional monitoring methods in order to link information concerning the hydrodynamic circulation and the microbiological features, to evaluate possible health risks associated with recreational and coastal shellfish farming activities. The study is a preliminary analysis of the environmental impact of wastewater treatment plants (WWTPs) with submarine discharge outfalls. It also could be useful for the water profile definition according to the Directive 2006/7/EC on the quality of bathing water and for the integrated areal analysis (Ostoich et al. 2006), to define the area of influence of each submarine discharge point. Materials and methods Historical data on discharges of the considered WWTPs were recovered and evaluated. Data on discharges' control for Veneto region (WWTPs of Lido and Cavallino) were produced by the WWTPs' manager Veritas Laboratory service, while data for the WWTPs of Friuli Venezia-Giulia region were produced by the regional environmental protection agency in the institutional control activity following official methods. The hydrodynamic model used in this work is the three-dimensional version of the finite element model SHYFEM, developed at ISMAR-CNR (Marine Science Institute of the Italian National Research Council) in Venice (Umgiesser et al. J Mar Syst 51:123-145, 2008). Results and discussion Numerical simulations have been carried out with the 3D version of the finite element model SHYFEM for 3 months during autumn 2007 to evaluate the bacterial pollution dispersion along the coasts of Veneto and Friuli Venezia-Giulia regions, prescribing meteo-marine forcings and concentration values at the points corresponding to the positions of the submarine outfalls. Model results show that during autumn 2007 the discharges of the submarine outfalls of the Venice province seem to have no impact on the surface water quality, while there are some visible effects in the Gulf of Trieste. This reflects the behaviour of the experimental data collected by ARPAV and ARPA FVG and monitoring campaigns both on water and shellfish quality. Further results have been elaborated to identify the area of influence of each discharge point; scenarios were developed with imposed concentrations. The results seem to highlight that the two discharges of the Veneto region are not noticeable, while the discharges of the Gulf of Trieste (in particular the Servola and Barcola ones) are perceptible. Conclusions This study represents a new step towards the study of the microbiological pollution dispersion and impact due to the discharges of the submarine outfalls of the Veneto and Friuli Venezia-Giulia regions (nine considered discharge points). With the 3D version of the finite element model SHYFEM, the information obtained from the hydrodynamic circulation has been linked to the classical methods of analysis, to assess possible risks connected to the microbiological parameter Escherichia coli. Recommendations and perspectives In future studies the time scale for microbiological parameters' decay could be linked to various environmental parameters such as light climate, temperature, and salinity. Interesting information would come from the study of new scenarios with different configurations of the discharge of the pipelines and/or the treatment plants and in particular from the improvements of the 3D version of the SHYFEM model, to take the stratification process into account which occurs during spring-summer, since the Northern Adriatic Sea is a very complex ecosystem, both as physical and ecological processes.
Mostrar más [+] Menos [-]Pollution in coastal fog at Alto Patache, Northern Chile
2010
Sträter, Ellen | Westbeld, Anna | Klemm, Otto
Background The Atacama Desert in Northern Chile is one of the most arid places on earth. However, fog occurs regularly at the coastal mountain range and can be collected at different sites in Chile to supply settlements at the coast with freshwater. This is also planned in the fog oasis Alto Patache (20°49′S, 70°09′W). For this pilot study, we collected fog water samples in July and August 2008 for chemical analysis to find indications for its suitability for domestic use. Methods Fog water samples were taken with a cylindrical scientific fog collector and from the net and the storage tank of a Large Fog Collector (LFC). Results The pHs of advective fog, originating from the stratus cloud deck over the Eastern Pacific, varied between 2.9 and 3.5. Orographic fog, which was formed locally, exhibited a pH of 2.5. About 50% of the total ionic concentration was due to sea salt. High percentages of sulfate and very high enrichment factors (versus sea salt) of heavy metals were found. Both backward trajectories and the enrichment factors indicate that the high concentrations of ions and heavy metals in fog were influenced by anthropogenic activities along the Chilean Pacific Coast such as power plants, mining, and steel industry. Conclusions We found no direct indication for the importance of other sources such as the emission of dimethyl sulfide from the ocean and subsequent atmospheric oxidation for acidity and sulfate or soil erosion for heavy metal concentrations. When fog water was collected by the LFC, it apparently picked up large amounts of dry deposition which accumulated on the nets during fog-free periods. This material is rinsed off the collector shortly after the onset of a fog event with the water collected first. During the first flush, some concentrations of acidity, nitrate, As, and Se, largely exceeded the Chilean drinking water limits. Before any use of fog water for domestic purpose, its quality should be checked on a regular basis. Strategies to mitigate fog water pollution are given.
Mostrar más [+] Menos [-]Partitioning of endocrine disrupting compounds in inland waters and wastewaters discharged into the coastal area of Thessaloniki, Northern Greece
2010
Arditsoglou, Anastasia | Voutsa, Dimitra
Background, aim, and scope In the Water Framework Directive 2000/60/EC, environmental objectives for the proper quality of inland, surface, transitional, coastal, and ground waters have been set. Member states are required to identify chemical pollutants of significance in the water bodies, to establish emission control measures, and to achieve quality standards. A specific category of pollutants are the compounds that may possess endocrine-related functions known as endocrine disrupting compounds (EDCs). This means that member states have the obligation to take action in order to prevent human exposure to these compounds via aquatic environment. The objective of this research was to study the occurrence and distribution of phenolic and steroid EDCs in inland waters and wastewaters discharged in the area of Thermaikos Gulf, Thessaloniki, Northern Greece. Materials and methods Samples were collected from three rivers, four streams, and four municipal and industrial wastewaters from the area of Thessaloniki, Northern Greece, during the period 2005-2006. The samples were analyzed for 14 EDCs (nonylphenol, octylphenol, their mono- and di-ethoxylate oligomers, bisphenol A, estrone, 17α-estradiol, 17β-estradiol, estriol, mestranol, and 17α-ethynylestradiol). The compounds were recovered by solid phase extraction and ultrasonic extraction from the dissolved phase and particulate phase, respectively, and determined by employing gas chromatography-mass spectrometry. Results Results revealed the presence of phenolic EDCs (NP, NP1EO, NP2EO, tOP, OP1EO, OP2EO, and BPA) in all water and wastewater samples. Steroid EDCs were not found at detectable concentrations. The relationships between field partition coefficients of EDCs and concentration of total suspended solids, dissolved, and particulate organic carbon were investigated. Discussion Rivers exhibited concentrations of EDCs similar to minimally impacted surface waters worldwide. The concentrations of NP and OP occasionally exceeded the environmental quality criteria proposed for inland waters. The concentrations of EDCs in streams exhibited wide variations due to low flow rate in these systems and the impact of wastewaters from various pollution sources. Wastewater from tannery activities showed extremely high concentrations of NP, whereas relatively high concentrations of EDCs were determined in effluents from the industrial wastewater treatment plant. Field partition coefficients of EDCs are negatively correlated with concentrations of total suspended solids and dissolved organic carbon and positively correlated with particulate organic carbon. Conclusions The examined rivers (Aliakmon, Axios, and Loudias) exhibited concentrations of EDCs similar to minimally impacted surface waters worldwide. However, special attention should be paid to these systems since the concentrations for NP and OP occasionally were above the proposed quality standards, revealing the impact of urban, industrial, and agricultural activities. High concentrations of EDCs were determined in streams, urban, and industrial wastewater posing significant risk to the aquatic environment they discharged. Recommendations and perspectives The occurrence of EDCs in inland waters and wastewaters discharged to Thermaikos Gulf results in an increased risk to the marine environment. Thus, these systems should be regularly monitored, especially for NP, OP, and BPA that are considered as priority hazardous compounds in the Water Framework Directive.
Mostrar más [+] Menos [-]Brominated phenols, anisoles, and dioxins present in blue mussels from the Swedish coastline
2010
Löfstrand, Karin | Malmvärn, Anna | Haglund, Peter | Bignert, Anders | Bergman, Åke | Asplund, L. (Lillemor)
INTRODUCTION: Naturally occurring hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methoxylated counterparts (MeO-PBDEs), and polybrominated dibenzo-p-dioxins (PBDDs), together with their potential precursors polybrominated phenols (PBPs) and polybrominated anisoles (PBAs), were analyzed in blue mussels (Mytilus edulis) gathered along the east coast (bordering the Baltic Sea) and west coast of Sweden (bordering the North Sea). Brown algae (Dictyosiphon foenicolaceus) and cyanobacteria (Nodularia spumigena) from the Baltic Sea, considered to be among the primary producers of these compounds, were also analyzed for comparison. MATERIALS AND METHODS: The samples were liquid–liquid extracted, separated into a phenolic and a neutral fraction, and subsequently analyzed by gas chromatography–mass spectrometry (GS-MS). RESULTS AND DISCUSSION: The levels of OH-PBDEs, MeO-PBDEs and PBDDs were significantly higher in Baltic Sea mussels than in those from the west coast, whereas the levels of PBPs and PBAs displayed the opposite pattern. The blue mussels from the Baltic Sea contained high levels of all analyzed substances, much higher than the levels of, e.g., polybrominated diphenyl ethers. In addition, the GC-MS chromatogram of the phenolic fraction of the west coast samples was dominated by four unknown peak clusters, three of which were tentatively identified as dihydroxy-PBDEs and the other as a hydroxylated-methyl-tetraBDE. CONCLUSIONS: Clearly, all of the compounds analyzed are natural products, both in the Baltic and the North Sea. However, the geographical differences in composition may indicate different origin, e.g., due to differences in the occurrence and/or abundance of various algae species along these two coasts or possibly a more extensive dilution on the west coast.
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