خيارات البحث
النتائج 1811 - 1820 من 4,307
Characterization of emissions and residues from simulations of the Deepwater Horizon surface oil burns النص الكامل
2017
Gullett, Brian K. | Aurell, Johanna | Holder, Amara | Mitchell, William | Greenwell, Dale | Hays, Michael | Conmy, Robyn | Tabor, Dennis | Preston, William | George, Ingrid | Abrahamson, Joseph P. | Vander Wal, Randy | Holder, Edith
The surface oil burns conducted by the U.S. Coast Guard from April to July 2010 during the Deepwater Horizon disaster in the Gulf of Mexico were simulated by small scale burns to characterize the pollutants, determine emission factors, and gather particulate matter for subsequent toxicity testing. A representative crude oil was burned in ocean-salinity seawater, and emissions were collected from the plume by means of a crane-suspended sampling platform. Emissions included particulate matter, aromatic hydrocarbons, polychlorinated dibenzodioxins/dibenzofurans, elements, and others, the sum of which accounted for over 92% by mass of the combustion products. The unburned oil mass was 29% of the original crude oil mass, significantly higher than typically reported. Analysis of alkanes, elements, and PAHs in the floating residual oil and water accounted for over 51% of the gathered mass. These emission factors, along with toxicity data, will be important toward examining impacts of future spill burning operations.
اظهر المزيد [+] اقل [-]Impact of Middle Eastern Dust storms on human health النص الكامل
2017
Khaniabadi, Yusef Omidi | Daryanoosh, Seyed Mohammad | Amrane, Abdeltif | Polosa, Riccardo | Hopke, Philip K. | Goudarzi, Gholamreza | Mohammadi, Mohammad Javad | Sicard, Pierre | Armin, Houshang
Air pollution is emerging as a significant risk factor for human health in developing countries, particularly in Iran where air pollutant concentrations are elevated. Currently, knowledge of health effects of air pollution in developing countries is limited. The objective of this study was to estimate the excess number of hospitalizations for Chronic Obstructive Pulmonary Disease (COPD) and the number of excess cases of Respiratory Mortality (RM) associated with daily averages levels of particulate matter less than 10 μm in diameter (PM10) in Ilam (Iran) over 1-year period (2015–2016). The excess instances of COPD and RM were estimated based on relative risk (RR) and baseline incidence (BI). The numbers of excess cases for COPD and RM during normal, dusty and Middle Eastern Dust (MED) storm days were 60 and 5, 200 and 15, and 78 and 6 persons, respectively. The results also showed that about 4.9% (95% CI: 3.0–6.8%) of hospital visits for COPD and 7.3% (CI: 4.9–19.5%) of RM could be attributed to 10 μg/m3 increase in PM10 concentration, respectively. It was found that a higher number of people were admitted to hospital when PM10 concentrations exceed 200 μg/m3 related to the MED events. Significant exposure to air pollutants, particularly during MED event, led to an excess of hospital admissions for COPD and an excess of the respiratory mortality. Several immediate actions such as strategic management of water bodies or planting of tree species in suburbs particularly bare area around the city could be effective to mitigate the impact of desert dust on respiratory illness.
اظهر المزيد [+] اقل [-]Bi-species imposex monitoring in Galicia (NW Spain) shows contrasting achievement of the OSPAR Ecological Quality Objective for TBT النص الكامل
2017
Ruiz, J.M. | Carro, B. | Albaina, N. | Couceiro, L. | Míguez, A. | Quintela, M. | Barreiro, R.
Imposex is decreasing worldwide after the total ban on tributyltin (TBT) from antifouling paints. In order to assess improvement in the NE Atlantic, the OSPAR Convention designed an Ecological Quality Objective (EcoQO) based on the VDSI (vas deferens sequence index, an agreed measure of imposex) in the rock snail Nucella lapillus; wherever this is not available, the mud snail Nassarius reticulatus was proposed as a proxy. We determined VDSI in Galician populations of rock (n≥34) and mud (n≥18) snails at regular intervals from pre-ban times until 2009 and 2011, respectively. While imposex in the former started decreasing in 2006 and by 2009 the EcoQO had been met in the area, VDSI in the latter was not significantly reduced until 2011 and values contradict such an achievement. This suggests that the OSPAR imposex bi-species scheme may not be of direct application in the current post-ban scenario.
اظهر المزيد [+] اقل [-]Impacts of Regional Transport on Particulate Matter Pollution in China: a Review of Methods and Results النص الكامل
2017
Sun, Jinjin | Huang, Lin | Liao, Hong | Li, Jingyi | Hu, Jianlin
China has been suffering serious particulate matter (PM) pollution in recent decades. Local emission and regional transport both contribute to PM pollution. Determining the contributions of local emissions vs. regional transport to PM concentrations is crucial in making effective PM control policies. This paper reviews the recent research on the contributions of regional transport to PM pollution in four regions in China, i.e., the northern China, eastern China, southern China, and the western China, respectively. The major findings include (1) HYSPLIT is the most popular methods in studies in all regions and often is used in combination with the CA, PSCF, and CWT techniques to investigate the transport pathways and source origins; (2) during the relatively polluted period, transport contributes over 50% of the PM concentrations in Beijing, Shanghai, Hangzhou, Guangzhou, Hong Kong, and Chengdu. Regional transport is important for PM pollution in major cities of China; and (3) regional transport exhibits clear seasonal variations and long term trends. The findings have important implication for emission control programs in these regions.
اظهر المزيد [+] اقل [-]Observations of aerosol color ratio and depolarization ratio over Wuhan النص الكامل
2017
Liu, Boming | Ma, Yingying | Gong, Wei | Zhang, Ming
The aerosol color ratio, depolarization ratio and aerosol optical depth (AOD) were measured by a two-wavelength-depolarization lidar at Wuhan, China during the period from May 2015–July 2016. The annual average AOD at Wuhan was about 0.33 during the period 2015–2016. The seasonal average AOD is small (0.26 ± 0.25) during the winter (December–February) season and large (0.4 ± 0.1) during the summer (June–August) season. The monthly average color ratio is small (0.23 ± 0.09) in January and large (0.76 ± 0.21) in August with an annual average value 0.54. The maximum monthly mean depolarization ratio (0.2 ± 0.07) occurred in the month of October, while the minimum (0.06 ± 0.02) occurred in the month of September, and the annual mean depolarization ratio was about 0.17. An analysis of temporal variations of color ratio and depolarization ratio suggests the presence of coarse and non-spherical particles during the autumn. The aerosol color ratio between 0.3 and 2.0 km was large (0.65), suggesting a large number of coarse particles in this range. The vertical distribution of the depolarization ratio is uniform. Finally, the spatial aerosol distribution under different weather conditions and its relationship with the color ratio is investigated in detail. The color ratio value of 0.74 could be used as a threshold for distinguishing polluted weather from clean weather. The aerosol optical and physical properties are investigated to provide a comprehensive understanding of aerosol radiative forcing and environmental problems in this region.
اظهر المزيد [+] اقل [-]Evaluation of environmental quality of sandy beaches in southeastern Brazil النص الكامل
2017
Suciu, Marjorie C. | Tavares, Davi C. | Costa, Leonardo L. | Silva, Marianna C.L. | Zalmon, Ilana R.
The effect of urbanization on the environmental quality of two sandy beaches was evaluated using metrics such as pH, dissolved oxygen, coliforms and solid waste. Urbanization effects on physicochemical metrics (pH and dissolved oxygen) were not significant. The coliforms concentration was below the established limit for primary contact, but it was significantly higher on beaches with highest recreational potential. Similarly, the abundance of solid waste was significantly higher in urbanized areas (~4.5 items/m2), and it was higher than what was found for 106 beaches worldwide. Plastic represented 84% of the total number of items and recreational activities were the main sources of debris (80%). Therefore, a balance between recreation and conservation actions, based on short-term (e.g. fines) and long-term measures (e.g. educational policies) is recommended. We demonstrate that the use of multiple metrics provides more robust estimates of the environmental quality of sandy beaches than a single impact metric.
اظهر المزيد [+] اقل [-]Distribution and enrichment of trace metals in surface marine sediments in the Gulf of Pozzuoli and off the coast of the brownfield metallurgical site of Ilva of Bagnoli (Campania, Italy) النص الكامل
2017
Trifuoggi, Marco | Donadio, Carlo | Mangoni, Olga | Ferrara, Luciano | Bolinesi, Francesco | Nastro, Rosa Anna | Stanislao, Corrado | Toscanesi, Maria | Di Natale, Gabriella | Arienzo, Michele
The distribution of metals in surface sediments of Gulf of Pozzuoli (GoP), embedding the former second Italian largest integrated steelworks of Bagnoli, was studied based on sediment dispersal, quality guidelines (SQGs) and quantitative pollution indices of the respective metals. As, Cd, Hg, Pb, Zn largely exceeded the limits. Hg had a mean of 5.8mg/kg, twentyfold higher the rule, accumulating primarily near Bagnoli site. The mean effective range quotient, m-ERM-Q, revealed a high potential for negative biological effects especially in the area nearby the Bagnoli site. The enrichment factor (EF) values were outstandingly high, >1.5 with values which were often ≥100. The geoaccumulation index, Igeo, was very critical for Cr, Cu, Hg and Ni, showing an Igeo in the range of strongly polluted (4<Igeo <5) and very strongly polluted (Igeo>5). The principal component analysis (PCA) and Pearson's correlation matrix (CM), excluded significant contribution from weathering products.
اظهر المزيد [+] اقل [-]Variations in the concentrations of heavy metals through enforcement of a rest-year system and dredged sediment capping at the Yellow Sea-Byung dumping site, Korea النص الكامل
2017
Chung, Chang-Soo | Song, Ki-Hoon | Choi, Ki-Young | Kim, Young-Il | Kim, Hye-Eun | Jung, Jun-Mo | Kim, Chang-Joon
In 2014, the concentrations of 13 heavy metals in surface sediments from 14 sampling stations were analyzed and compared to samples from previous years to evaluate the remediation effectiveness of the “rest-year” (RY) system and capping with dredged material at the Yellow Sea-Byung dumping site offshore Korea. Since the 2006 introduction of the RY system, annual variations in metal concentrations at stations within the RY zone have gradually decreased over time. Heavy metal concentrations at most stations were lower than sediment quality guidelines, indicating the success of the RY system. Additionally, the effects of capping the contaminated sediment with dredged materials were investigated. The results indicate that dredged materials successfully capped the contaminated sediment within the dredged material dumping area, as the concentrations of Cr and total organic carbon were significantly reduced. We conclude that dredged materials may be used as capping materials for the remediation of contaminated sediments.
اظهر المزيد [+] اقل [-]Ocean acidification narrows the acute thermal and salinity tolerance of the Sydney rock oyster Saccostrea glomerata النص الكامل
2017
Parker, Laura M. | Scanes, Elliot | O'Connor, Wayne A. | Coleman, Ross A. | Byrne, Maria | Pörtner, Hans-O | Ross, Pauline M.
Coastal and estuarine environments are characterised by acute changes in temperature and salinity. Organisms living within these environments are adapted to withstand such changes, yet near-future ocean acidification (OA) may challenge their physiological capacity to respond. We tested the impact of CO2-induced OA on the acute thermal and salinity tolerance, energy metabolism and acid-base regulation capacity of the oyster Saccostrea glomerata. Adult S. glomerata were acclimated to three CO2 levels (ambient 380μatm, moderate 856μatm, high 1500μatm) for 5weeks (24°C, salinity 34.6) before being exposed to a series of acute temperature (15–33°C) and salinity (34.2–20) treatments. Oysters acclimated to elevated CO2 showed a significant metabolic depression and extracellular acidosis with acute exposure to elevated temperature and reduced salinity, especially at the highest CO2 of 1500μatm. Our results suggest that the acute thermal and salinity tolerance of S. glomerata and thus its distribution will reduce as OA continues to worsen.
اظهر المزيد [+] اقل [-]Italy introduces pre and post operation monitoring phases for offshore seismic exploration activities النص الكامل
2017
Fossati, C. | Mussi, B. | Tizzi, R. | Pavan, G. | Pace, D.S.
Concern is growing that marine fauna can be affected by noise such as naval sonar, pile driving or geophysical surveys, among others. Literature reports a variety of animal reactions to human noise (from apparently null or negligible to strong). However, conclusive results on its effects on marine mammals at individual and population level are still lacking. In 2015, the Italian Environmental Impact Assessment Commission mandated seismic operators apply a standard scientific protocol comparing marine mammal presence before, during, and after offshore seismic survey. For 60days before and after the survey, marine mammals are monitored using visual and acoustic methods. One or more acoustic autonomous recorders, depending on area size, must also be deployed throughout the three phases for continuous monitoring. Consistent data gathered from many surveys will enable robust statistical analysis of results. Diffusion of this monitoring method internationally would improve the study of far-reaching, intense, low frequency noise.
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