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Growth effects of shading and sedimentation in two tropical seagrass species: Implications for port management and impact assessment Texto completo
2016
Benham, Claudia F. | Beavis, Sara G. | Hendry, Rebecca A. | Jackson, Emma L.
Seagrass meadows in many parts of the globe are threatened by a range of processes including port development, dredging and land clearing in coastal catchments, which can reduce water clarity and increase sedimentation pressure. As rates of seagrass loss increase, there is an urgent need to understand the potential impacts of development on these critical species. This research compares the effects of shading and burial by fine sand on two seagrass species Zostera muelleri and Halophila ovalis in Port Curtis Bay, an industrial harbour located on the continental margin adjacent to the Great Barrier Reef Heritage Area, Australia. The research finds that shading in combination with burial causes a significant decline in growth rates in both species, but that burial ≥10mm reduces growth rates to a greater extent than shading. The paper concludes by discussing the implications of these findings for port management and impact assessment.
Mostrar más [+] Menos [-]Chemometric techniques in oil classification from oil spill fingerprinting Texto completo
2016
Ismail, Azimah | Toriman, Mohd Ekhwan | Juahir, Hafizan | Kassim, Azlina Md | Zain, Sharifuddin Md | Ahmad, Wan Kamaruzaman Wan | Wong, Kok Fah | Retnam, Ananthy | Zali, Munirah Abdul | Mokhtar, Mazlin | Yusri, Mohd Ayub
Extended use of GC–FID and GC–MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC–FID and GC–MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.
Mostrar más [+] Menos [-]The exposure of pedestrians, drivers and road transport passengers to nitrogen dioxide Texto completo
2016
Żak, Magdalena | Melaniuk-Wolny, Edyta | Widziewicz, Kamila
People travelling by road transport are exposed to high levels of nitrogen oxides (NOx), that are considered to be one of the primary pollutants from motor vehicles. This study examines the exposure of drivers, passengers and pedestrians to NO2 during different trip scenarios: travelling by private or public means of transport, along the major commuter routes in one of the biggest Polish agglomerations - Silesia Agglomeration, and other important communication routes in Poland, as well as during walks in both city centers and residential areas. The NO2 samples were collected in cars, trucks and buses interiors, as well as in the ambient air by passive samplers and next NO2 concentrations were analyzed by means of the spectrophotometric technique. The obtained results indicate that travelling by cars through city centers is associated with the exposure to NO2 concentrations of about 15% higher than in the case of travelling suburban routes; 33% greater than travelling by bus in urban traffic; more than app. 60% higher than in the case of travelling by bus in suburban traffic or by foot in city centers and up to 80% higher than moving on foot near little-used roads. The exposure profile of six groups of road users exposed to NO2 was therefore determined in this study. The obtained results could be used by policy makers to minimize the exposure to transportation-related pollutants concentrations and for planning far-reaching changes in the field of urban road transport.
Mostrar más [+] Menos [-]Localised and limited impact of a dredging operation on coral cover in the northwestern lagoon of New Caledonia Texto completo
2016
Adjeroud, Mehdi | Gilbert, Antoine | Facon, Mathilde | Foglia, Marion | Moreton, Benjamin | Heintz, Tom
We report here an interannual survey (2006–2012) of coral cover in the northwestern lagoon of New Caledonia, to assess the impact of an important dredging operation (August 2008–February 2010) associated with the construction of the largest nickel mining site in the Pacific. A BACI (Before-After Control-Impact) analysis failed to detect any significant interaction between period (before, during, and after dredging) and the category of the stations (impact vs. control). Among the 31 stations surveyed, only seven showed decreasing coral cover during the study period, mainly due to a decline in Acroporidae. However, the relationship between the dredging and this decrease was highly plausible only for one station, situated 0.9km from the dredging site. High hydrodynamism in the study area, the abundance of resistant corals and efficient protective measures during the dredging operation might explain these localised and limited impacts.
Mostrar más [+] Menos [-]Green Marine: An environmental program to establish sustainability in marine transportation Texto completo
2016
Walker, Tony R.
European maritime companies have adopted programs to limit operational impacts on the environment. For maritime companies in North America, the Green Marine Environmental Program (GMEP) offers a framework to establish and reduce environmental footprints. Green Marine (GM) participants demonstrate annual improvements of specific environmental performance indicators (e.g., reductions in air pollution emissions) to maintain certification. Participants complete annual self-evaluations with results determining rankings for performance indicators on a 1-to-5 scale. Self-evaluations are independently verified every two years to ensure rigor and individual results are made publicly available annually to achieve transparency. GM benefits the marine industry across North America by encouraging sustainable development initiatives. GM's credibility is reflected through a diverse network of environmental groups and government agencies that endorse and help shape the program. Merits of this relatively new maritime certification (not previously described in the academic literature), are discussed.
Mostrar más [+] Menos [-]Elemental composition, distribution and control of biogenic silica in the anthropogenically disturbed and pristine zone inter-tidal sediments of Indian Sundarbans mangrove-estuarine complex Texto completo
2016
Dhame, Shreya | Kumar, Alok | Ramanathan, AL. | Chaudhari, Punarbasu
Spatial distribution and interrelationship among organic nutrients – silica and carbon – and various lithogenic elements were investigated in the surficial sediments of Matla estuary and Core Zone of Indian Sundarbans Reserve Forest using spatial analysis and multivariate statistics. Biogenic silica (BSi), an important parameter for coastal biogeochemisry, was measured using Si-time alkaline leaching method. BSi concentration ranged from 0.01% to 0.85% with higher concentrations in upstream region of Matla estuary and attenuated values towards the bay, seemingly due to changes in hydrodynamics and land use conditions. Spatial distribution of BSi did not exhibit significant correlation with sediment parameters of organic carbon (OC), elemental composition and clay content. However, it showed significant contrasting trends with total phosphorus (TP) and total silica of human influenced Matla estuary sediments as well as the dissolved silica (DSi) of its surface waters. Anthropogenic influence on sediment geochemistry is discernable with the presence of higher concentrations of organic and inorganic elements in Matla estuary than in Core Zone sediments. Spatial variation trends are often challenging to interpret due to multiple sources of input, varying energy and salinity conditions and constant physical, chemical and biological alterations occurring in the environment. Nonetheless, it is certain that anthropogenic activities have a substantial influence on biogeochemical processes of Sundarbans mangrove-estuarine complex and potentially the coastal ocean.
Mostrar más [+] Menos [-]Assessment of pollutant mean concentrations in the Yangtze estuary based on MSN theory Texto completo
2016
Ren, Jing | Gao, Bing-Bo | Fan, Hai-Mei | Zhang, Zhi-Hong | Zhang, Yao | Wang, Jin-Feng
Reliable assessment of water quality is a critical issue for estuaries. Nutrient concentrations show significant spatial distinctions between areas under the influence of fresh-sea water interaction and anthropogenic effects. For this situation, given the limitations of general mean estimation approaches, a new method for surfaces with non-homogeneity (MSN) was applied to obtain optimized linear unbiased estimations of the mean nutrient concentrations in the study area in the Yangtze estuary from 2011 to 2013. Other mean estimation methods, including block Kriging (BK), simple random sampling (SS) and stratified sampling (ST) inference, were applied simultaneously for comparison. Their performance was evaluated by estimation error. The results show that MSN had the highest accuracy, while SS had the highest estimation error. ST and BK were intermediate in terms of their performance. Thus, MSN is an appropriate method that can be adopted to reduce the uncertainty of mean pollutant estimation in estuaries.
Mostrar más [+] Menos [-]Rare Earth Elements in the Soil Environment Texto completo
2016
Ramos, Silvio J. | Dinali, Guilherme S. | Oliveira, Cynthia | Martins, Gabriel C. | Moreira, Cristiano G. | Siqueira, José O. | Guilherme, Luiz R. G.
Rare Earth Elements in the Soil Environment Texto completo
2016
Ramos, Silvio J. | Dinali, Guilherme S. | Oliveira, Cynthia | Martins, Gabriel C. | Moreira, Cristiano G. | Siqueira, José O. | Guilherme, Luiz R. G.
Rare earth elements (REE) are a homogenous group of 17 chemical elements in the periodic table that are key to many modern industries including chemicals, consumer electronics, clean energy, transportation, health care, aviation, and defense. Moreover, in recent years, they have been used in agriculture. One of the consequences of their worldwide use is the possible increase of their levels in various environmental compartments. This review addresses major topics concerning the study of REE in the soil environment, with special attention to the latest research findings. The main sources of REE to soils, the contents of REE in soils worldwide, and relevant information on the effects of REE to plants were explored. Ecological and human health risk issues related to the presence of REE in soils were also discussed. Although several findings reported positive effects of REE on plant growth, many questions about their biological role remain unanswered. Therefore, studies concerning the actual mechanism of action of these elements on cellular and physiological processes should be further refined. Even more urgent is to unveil their chemical behavior in soils and the ecological and human health risks that might be associated with the widespread use of REE in our modern society.
Mostrar más [+] Menos [-]Rare earth elements in the soil environment Texto completo
2016
Ramos, Silvio J. | Dinali, Guilherme S. | Oliveira, Cynthia | Martins, Gabriel C. | Moreira, Cristiano G. | Siqueira, José O. | Guilherme, Luiz R. G.
Rare earth elements (REE) are a homogenous group of 17 chemical elements in the periodic table that are key to many modern industries including chemicals, consumer electronics, clean energy, transportation, health care, aviation, and defense. Moreover, in recent years, they have been used in agriculture. One of the consequences of their worldwide use is the possible increase of their levels in various environmental compartments. This review addresses major topics concerning the study of REE in the soil environment, with special attention to the latest research findings. The main sources of REE to soils, the contents of REE in soils worldwide, and relevant information on the effects of REE to plants were explored. Ecological and human health risk issues related to the presence of REE in soils were also discussed. Although several findings reported positive effects of REE on plant growth, many questions about their biological role remain unanswered. Therefore, studies concerning the actual mechanism of action of these elements on cellular and physiological processes should be further refined. Even more urgent is to unveil their chemical behavior in soils and the ecological and human health risks that might be associated with the widespread use of REE in our modern society.
Mostrar más [+] Menos [-]Natural Arsenic in Global Groundwaters: Distribution and Geochemical Triggers for Mobilization Texto completo
2016
Herath, Indika | Vithanage, Meththika | Bundschuh, Jochen | Maity, Jyoti Prakash | Bhattacharya, Prosun
The elevated concentration of arsenic (As) in the groundwaters of many countries worldwide has received much attention during recent decades. This article presents an overview of the natural geochemical processes that mobilize As from aquifer sediments into groundwater and provides a concise description of the distribution of As in different global groundwater systems, with an emphasis on the highly vulnerable regions of Southeast Asia, the USA, Latin America, and Europe. Natural biogeochemical processes and anthropogenic activities may lead to the contamination of groundwaters by increased As concentrations. The primary source of As in groundwater is predominantly natural (geogenic) and mobilized through complex biogeochemical interactions within various aquifer solids and water. Sulfide minerals such as arsenopyrite and As-substituted pyrite, as well as other sulfide minerals, are susceptible to oxidation in the near-surface environment and quantitatively release significant quantities of As in the sediments. The geochemistry of As generally is a function of its multiple oxidation states, speciation, and redox transformation. The reductive dissolution of As-bearing Fe(III) oxides and sulfide oxidation are the most common and significant geochemical triggers that release As from aquifer sediments into groundwaters. The mobilization of As in groundwater is controlled by adsorption onto metal oxyhydroxides and clay minerals. According to recent estimates, more than 130 million people worldwide potentially are exposed to As in drinking water at levels above the World Health Organization’s (WHO's) guideline value of 10 μg/L. Hence, community education to strengthen public awareness, the involvement and capacity building of local stakeholders in targeting As-safe aquifers, and direct action and implementation of best practices in identifying safe groundwater sources for the installation of safe drinking water wells through action and enforcement by local governments and international water sector professionals are urgent necessities for sustainable As mitigation on a global scale.
Mostrar más [+] Menos [-]Investigation on VOC Emissions from Automobile Sources by Means of Online Mass Spectrometry Texto completo
2016
Inomata, Satoshi | Yamada, Hiroyuki | Tanimoto, Hiroshi
This study reviews recent research on volatile organic compound (VOC) emissions from motorized vehicle sources by means of online mass spectrometry. Chemical ionization is a powerful tool that usually permits soft ionization of chemical species and it allows the time-resolved measurement of multiple VOCs, even in complex samples where many kinds of VOCs coexist. The vehicular exhaust gasses are investigated using H₃O⁺, NO⁺, Hg⁺, and CH₃C(O)O⁻ as a reagent ion in online chemical ionization mass spectrometry. The proton transfer using H₃O⁺ as a reagent ion was used for the detection of nitro-organic compounds such as nitromethane and nitrophenol. The time-resolved measurement of the nitro-organic compounds in the laboratory experiments with a chassis dynamometer system revealed their emission properties, such as the dependence of the emissions as a function of vehicular velocity and acceleration/deceleration, as well as the effect of various types of exhaust gas treatment. The data regarding the nitromethane and nitrophenol emissions obtained in the field measurements were consistent with the results of the laboratory experiments done with a chassis dynamometer system. In the experiments involving evaporative emissions from gasoline-powered cars, NO⁺ was used as a reagent ion. Online measurements showed that the adsorption of hydrocarbons in a sealed housing evaporative determination unit could result in emissions being underestimated, if the concentrations are monitored only before and after a diurnal breathing loss test. The composition analysis gave an estimated ozone formation potential (OFP) approximately 20 % higher for breakthrough emissions and refueling emissions than for the gasoline that was tested, but the OFP for the permeation emissions was almost the same as the OFP for the test fuel.
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