Refine search
Results 1281-1290 of 4,042
Temporal scales for nearshore hits of current-driven pollution in the Gulf of Finland Full text
2016
Lagrangian trajectories of water parcels reconstructed using the TRACMASS model from three-dimensional velocity fields by the RCO model for 1965–2004 are used to analyse the temporal scales and the probability for the hits to the nearshore by pollution originating from a major fairway in the Gulf of Finland and transported by surface currents. Increasing the simulation length from 10 to 20days induces a linear increase in particle age, but the pattern of nearshore hits remains the same. A reasonable benefit can be reached by relatively small shifts of certain parts of the present fairway in a few locations. The overall probabilities do not reveal any trend for 1965–2004. The largest changes in the nearshore hits are revealed for the proportion of hits to the opposite nearshore areas. This feature probably reflects an abrupt turn of the geostrophic air-flow over the southern Baltic Sea by ~40° since 1987.
Show more [+] Less [-]Spatial distribution and enrichment assessment of heavy metals in surface sediments from Baixada Santista, Southeastern Brazil Full text
2016
Kim, Bianca Sung Mi | Salaroli, Alexandre Barbosa | Ferreira, Paulo Alves de Lima | Sartoretto, Juliê Rosemberg | Mahiques, Michel Michaelovich de | Figueira, Rubens Cesar Lopes
The Baixada Santista, besides being an important estuarine system, is responsible for most of the international trade and economic development in the region because of the Santos Port and the Cubatão Industrial Complex. The aim of this study is to assess heavy metal contamination of the Santos São Vicente Estuary using enrichment factors (EFs) and sediment quality guidelines (SQGs). Thus, superficial sediment samples were subjected to acid digestion and analyzed (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sc, V, and Zn) by inductively coupled plasma optical emission spectrometry (ICP-OES). The results indicated an absence of contamination, with the EFs indicating moderate enrichment. As and Pb presented higher enrichment probably due to the natural processes of weathering and sedimentation, and the influence of human activity. This conjoint analysis showed that potentially polluting activities are of concern as the highest values converge near the Cubatão Industrial Complex, which correspond to intense urbanization and industrial activity.
Show more [+] Less [-]Photochemical changes in water accommodated fractions of MC252 and surrogate oil created during solar exposure as determined by FT-ICR MS Full text
2016
Vaughan, Pamela P. | Wilson, Tashiema | Kamerman, Rebecca | Hagy, Melissa E. | McKenna, Amy | Chen, Huan | Jeffrey, Wade H.
To determine effects of photochemical weathering of petroleum, surrogate and Macondo (MC252) crude oils were exposed to solar radiation during the formation of Water Accommodated Fractions (WAFs) in sterile seawater. Samples were incubated in either unfiltered sunlight, with ultraviolet radiation blocked (Photosynthetically Active Radiation [PAR] only), or in darkness. WAFs were collected at two time points over the course of a week. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) analyses of water soluble species formed during exposure to sunlight were compared for the different treatments. Photochemical alterations resulted in differences in compound class distributions. In general, surrogate oil was photo-oxidized across a wider carbon number range compared to MC252. While photochemical differences were observed between MC252 and surrogate oils, microbial production in seawater responded similarly to both WAFs from both types of oils with the majority of the inhibition resulting from oil exposure to visible light.
Show more [+] Less [-]Evaluation of an urban modelling system against three measurement campaigns in London and Birmingham Full text
2016
Srimath, Srinivas T.G. | Sokhi, Ranjeet | Karppinen, Ari | Singh, Vikas | Kukkonen, Jaakko
The results of three measurement campaigns are presented in this study. The campaigns have been undertaken at an urban roadside site in London, for more than a year and three months in 2003–2004 and for a year in 2008, and at an urban background site in Birmingham, U.K, for about four months in 2002. The concentrations of PM2.5, PM10, NOx and NO2 were predicted using the roadside dispersion model CAR-FMI, combined with a national U.K. emission model, a meteorological pre-processor, and measured values at urban background stations. The agreement of the predicted and measured hourly and daily time-series has been assessed statistically for all of the campaigns and pollutants. For instance, the Indices of Agreement (IA) in all the campaigns ranged from 0.68 to 0.78, 0.87, from 0.70 to 0.80, and from 0.61 to 0.83 for PM2.5, PM10, NOx and NO2, respectively. However, in case of the campaigns in London, both the PM fractions and the nitrogen oxide concentrations were under-predicted. The model performance in terms of atmospheric stability, wind speeds and other factors was analysed, and reasons for the disagreement of predictions and measurements have been discussed. It is useful to consider the model performance statistics for several measurement campaigns simultaneously, as some of the results were found to be specific only to one or two campaigns. The spatial concentration distribution of NOx in London for 2008 has also been presented.
Show more [+] Less [-]Seasonal hypoxia regulates macrobenthic function and structure in the Mississippi Bight Full text
2016
Rakocinski, Chet F. | Menke, Daneen P.
Hypoxic conditions are escalating to the east of the Mississippi River within the Mississippi Bight. The objective of this study was to examine changes in macrobenthic function and structure relative to seasonal hypoxia over a 3.5year period at the 10m (Site 6) and 20m (Site 8) isobaths within the Mississippi Bight. Seasonal hypoxia acted as a regular periodic disturbance during the study period, although the magnitude and duration of hypoxia varied inter-annually. Macrobenthic metrics revealed seasonal hypoxia effects on secondary production potential and community maturity, which agrees with previous studies. In addition, metrics were notably higher at the 20m isobath during the latter half of the study period, following the Deepwater Horizon (DwH) oil spill. This study confirms hypoxia as a major driver affecting the function and structure of soft-bottom macrobenthos in the Mississippi Bight.
Show more [+] Less [-]The effect of sewage pollution on the feeding behaviour and diet of Hediste (Nereis diversicolor (O.F. Müller, 1776)) in three estuaries in south-east England, with implications for saltmarsh erosion Full text
2016
Aberson, M.J.R. | Bolam, S.G. | Hughes, R.G.
Stable isotope analyses of the abundant infaunal polychaete Hediste diversicolor, recognised as an indicator of sewage pollution, support the hypothesis that nutrient enrichment promotes surface deposit feeding, over suspension feeding and predation. At sewage-polluted sites in three estuaries in SE England Hediste mainly consumed microphytobenthos, sediment organic matter and filamentous macroalgae Ulva spp. At cleaner sites Hediste relied more on suspension feeding and consumption of Spartina anglica. There were no consistent differences in Hediste densities between the polluted and cleaner sites, probably because of increased densities at the cleaner sites too, facilitated by the planting of Spartina and nitrogen enrichment there too, including from agricultural run-off. Increased nutrient enrichment and the artificial availability of Spartina have probably increased densities of, and deposit-feeding by, Hediste in the past half-century and contributed indirectly to saltmarsh losses, since deposit-feeding by Hediste has been implicated in recent saltmarsh erosion in SE England.
Show more [+] Less [-]Potential biodegradation of crude petroleum oil by newly isolated halotolerant microbial strains from polluted Red Sea area Full text
2016
Shetaia, Yousseria M.H. | El khalik, Wafaa A.A. | Mohamed, Tarek M. | Farahat, Laila A. | ElMekawy, Ahmed
Two microbial isolates from oil polluted Red Sea water in Egypt, designated as RS-Y1 and RS-F3, were found capable of degrading Belayim mix (BX) crude oil. Strains RS-Y1 and RS-F3 were assigned to the genera Lipomyces tetrasporus and Paecilomyces variotii based on their morphological and physiological characteristics. Both isolates were compared for the biodegradation of crude petroleum-oil hydrocarbons in basal salt medium supplemented with 5% (w/v) of BX-crude oil. Gas chromatography profile showed that the biodegradation of total petroleum hydrocarbons (TPHs) inoculated with L. tetrasporus (68.3%) and P. variotii (58.15%) along with their consortium (66%) significantly reduced TPHs levels as compared to the control after 30days. L. tetrasporus (44.5%) was more effective than P. variotii strain (32.89%) in reducing the unresolved complex mixtures (UCM) content from the medium. Both isolates exhibited a strong growth over a wide range of salinity (5–45g/L NaCl).
Show more [+] Less [-]Antifouling paint booster biocides (Irgarol 1051 and diuron) in marinas and ports of Bushehr, Persian Gulf Full text
2016
Saleh, Abolfazl | Molaei, Saeideh | Sheijooni Fumani, Neda | Abedi, Ehsan
In the present study, antifouling paint booster biocides, Irgarol 1051 and diuron were measured in ports and marinas of Bushehr, Iran. Results showed that in seawater samples taken from ports and marinas, Irgarol was found at the range of less than LOD to 63.4ngL−1 and diuron was found to be at the range of less than LOD to 29.1ngL−1 (in Jalali marina). 3,4-dichloroaniline (3,4-DCA), as a degradation product of diuron, was also analyzed and its maximum concentration was 390ngL−1. Results for analysis of Irgarol 1051 in sediments showed a maximum concentration of 35.4ngg−1 dry weight in Bandargah marina. A comparison between the results of this study and those of other published works showed that Irgarol and diuron pollutions in ports and marinas of Bushehr located in the Persian Gulf were less than the average of reports from other parts of the world.
Show more [+] Less [-]Quantifying the influence of meteorological variables on particle-bound PAHs in urban environments Full text
2016
Amarillo, Ana C. | Carreras, Hebe
Quantifying the influence of meteorological variables on particle-bound PAHs in urban environments Full text
2016
Amarillo, Ana C. | Carreras, Hebe
Seasonal trend of polycyclic aromatic hydrocarbons (PAHs) associated with PM10 particles was assessed in an urban area in Cordoba, Argentina, during 2011–2013. In addition, we quantified the contribution of temperature, relative humidity, rainfall, atmospheric pressure and wind speed on total and individual PAH concentrations. Mean PAH concentrations were higher during autumn and winter. Temperature was the meteorological parameter that affected the most total and individual PAHs. Its influence was stronger in lightweight than in heavy PAHs, since they are more easily partitioned in the vapor phase. We found also that temperature has a lagged effect on PAHs concentration with the strongest association observed with 2-day lag temperature. Wind speed and relative humidity were also significant predictors for both light and heavy PAHs. Despite the fact that we observed a decreasing trend in the concentration levels of PAHs, they are still high enough to pose a risk to human health due to chronic exposure.
Show more [+] Less [-]Quantifying the influence of meteorological variables on particle-bound PAHs in urban environments Full text
2016
Amarillo, Ana Carolina | Carreras, Hebe Alejandra
Seasonal trend of polycyclic aromatic hydrocarbons (PAHs) associated with PM10 particles was assessed in an urban area in Cordoba, Argentina, during 2011-2013. In addition, we quantified the contribution of temperature, relative humidity, rainfall, atmospheric pressure and wind speed on total and individual PAH concentrations. Mean PAH concentrations were higher during autumn and winter. Temperature was the meteorological parameter that affected the most total and individual PAHs. Its influence was stronger in lightweight than in heavy PAHs, since they are more easily partitioned in the vapor phase. We found also that temperature has a lagged effect on PAHs concentration with the strongest association observed with 2-day lag temperature. Wind speed and relative humidity were also significant predictors for both light and heavy PAHs. Despite the fact that we observed a decreasing trend in the concentration levels of PAHs, they are still high enough to pose a risk to human health due to chronic exposure. | Fil: Amarillo, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina | Fil: Carreras, Hebe Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina
Show more [+] Less [-]Assessing sewage impact in a South-West Atlantic rocky shore intertidal algal community Full text
2016
Becherucci, Maria Eugenia | Santiago, Lucerito | Benavides, Hugo Rodolfo | Vallarino, Eduardo Alberto
The spatial and seasonal variation of the specific composition and community parameters (abundance, diversity, richness and evenness) of the intertidal algal assemblages was studied at four coastal sampling sites, distributed along an environmental gradient from the sewage water outfall of Mar del Plata, Buenos Aires, Argentina. Two of them were located close to the sewage outfall (<800m) (impacted area) and the two other were 8 and 9km distant (non-impacted area). The algal abundance was monthly analyzed from October 2008 to May 2009. The algal assemblages varied according to the pollution gradient in spring, summer and autumn, being autumn the season when the highest difference was observed. Ceramium uruguayense was recognized as an indicator species for the non-impacted areas, while Berkeleya sp. represented an indicator species for the sewage outfall impact. Ulva spp. did not reflect the typical pattern observed for other sewage pollution areas.
Show more [+] Less [-]