69 research outputs found
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Comparison of MAGIC and Diatom paleolimnological model hindcasts of lakewater acidification in the Adirondack region of New York
Thirty-three lakes that had been statistically selected as part of the US Environmental Protection Agency's Eastern Lake Survey and Direct Delayed Response Project (DDRP) were used to compare the MAGIC (watershed) and Diatom (paleolimnological) models. The study lakes represented a well-defined group of Adirondack lakes, each larger than 4 ha in area and having acid-neutralizing capacity (ANC) <400 {mu}eq L{sup {minus}1}. The study first compared current and pre-industrial (before 1850) pH and ANC estimates from Diatom and MAGIC as they were calibrated in the preceding Paleocological Investigation of Recent Lake Acidification (PIRLA) and DDRP studies, respectively. Initially, the comparison of hindcasts of pre-industrial chemistry was confounded by seasonal and methodological differences in lake chemistry data used in calibration of the model. Although certain differences proved to be of little significance for comparison, MAGIC did predict significantly higher pre-industrial ANC and pH values than did Diatom, using calibrations in the preceding studies. Both models suggest acidification of low ANC Adirondack region lakes since preindustrial times, but differ primarily in that MAGIC inferred greater acidification and that acidification has occurred in all lakes in the comparison, whereas Diatom inferred that acidification has been restricted to low ANC lakes (<about 50 {mu}eq L{sup {minus}1}). 133 refs., 30 figs., 16 tabs
Post-blast explosive residue : a review of formation and dispersion theories and experimental research
The presence of undetonated explosive residues following high order detonations is not uncommon, however the mechanism of their formation, or survival, is unknown. The existence of these residues impacts on various scenarios, for example their detection at a bomb scene allows for the identification of the explosive charge used, whilst their persistence during industrial explosions can affect the safety and environmental remediation efforts at these sites. This review article outlines the theoretical constructs regarding the formation of explosive residues during detonation and their subsequent dispersal and deposition in the surrounding media. This includes the chemical and physical aspects of detonation and how they could allow for undetonated particles to remain. The experimental and computational research conducted to date is discussed and compared to the theory in order to provide a holistic review of the phenomeno
Childhood lead exposure in France: benefit estimation and partial cost-benefit analysis of lead hazard control
<p>Abstract</p> <p>Background</p> <p>Lead exposure remains a public health concern due to its serious adverse effects, such as cognitive and behavioral impairment: children younger than six years of age being the most vulnerable population. In Europe, the lead-related economic impacts have not been examined in detail. We estimate the annual costs in France due to childhood exposure and, through a cost benefit analysis (CBA), aim to assess the expected social and economic benefits of exposure abatement.</p> <p>Methods</p> <p>Monetary benefits were assessed in terms of avoided national costs. We used results from a 2008 survey on blood-lead (B-Pb) concentrations in French children aged one to six years old. Given the absence of a threshold concentration being established, we performed a sensitivity analysis assuming different hypothetical threshold values for toxicity above 15 μg/L, 24 μg/L and 100 μg/L. Adverse health outcomes of lead exposure were translated into social burden and economic costs based on literature data from literature. Direct health benefits, social benefits and intangible avoided costs were included. Costs of pollutant exposure control were partially estimated in regard to homes lead-based paint decontamination, investments aiming at reducing industrial lead emissions and removal of all lead drinking water pipes.</p> <p>Results</p> <p>The following overall annual benefits for the three hypothetical thresholds values in 2008 are: €22.72 billion, €10.72 billion and €0.44 billion, respectively. Costs from abatement ranged from €0.9 billion to 2.95 billion/year. Finally, from a partial CBA of lead control in soils and dust the estimates of total net benefits were € 3.78 billion, € 1.88 billion and €0.25 billion respectively for the three hypothesized B-Pb effect values.</p> <p>Conclusions</p> <p>Prevention of childhood lead exposure has a high social benefit, due to reduction of B-Pb concentrations to levels below 15 μg/L or 24 μg/L, respectively. Reducing only exposures above 100 μg/L B-Pb has little economic impact due to the small number of children who now exhibit such high exposure levels. Prudent public policies would help avoiding future medical interventions, limit the need for special education and increase future productivity, and hence lifetime income for children exposed to lead.</p
Global commitment towards sustainable energy
Energy is crucial to economic and social development and improves quality of life. However, fossil fuel energy produces greenhouse gases (GHGs) and cannot be sustained for a long time. It is essential to tackle these problems by moving towards renewable and sustainable energy. Some countries, including those in the Arabian Gulf region, are still in the appraisal stage of adopting different forms of renewable energy. This paper reviews the business potential and likely GHG reductions associated with adopting renewable energy in Oman. It is revealed that 1·9 Mt of annual carbon dioxide emissions could be cut by producing 10% of the country’s electricity from renewables. The paper further discusses the global sustainable energy commitment under the UN Framework Convention on Climate Change and reviews the 2030 targets of some countries that are high producers of GHGs. It is anticipated that if all these planned targets are achieved, the total sustainable energy contribution could grow by nearly 11 000 TWh by 2030. These plans provide guidance for those countries still preparing to submit their plans to the UN
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Radiological survey of the Mare Island Naval Shipyard, Alameda Naval Air Station, and Hunters Point Shipyard
Since 1963, the Eastern Environmental Radiation Facility (EERF), US Environmental Protection Agency (USEPA), in cooperation with the US Naval Sea Systems Command (NAVSEA) has surveyed facilities serving nuclear-powered warships on the Atlantic and Pacific coasts and the Gulf of Mexico. These surveys assess whether the operation of nuclear-powered warships, during construction, maintenance, overhaul, or refueling, have created elevated levels of radioactivity. The surveys emphasize sampling those areas and pathways that could expose the public. In 1984, NAVSEA requested that EPA survey all active facilities serving nuclear-powered warships over the next three years. This report contains the results of surveys conducted at Naval facilities located at Mare Island, Alameda, and Hunters Point in the San Francisco region. The locations of these facilities are shown. 3 refs., 4 figs., 3 tabs
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Partitioning between sediment and porewater of radiocesium from Chernobyl fallout
As part of a joint USA/USSR Environmental Agreement to determine the distribution and concentration of Chernobyl radioactivity in the northwest Black Sea area, the sediment from eight stations was collected and analyzed to assess the ability of sediment from the northwest Black Sea to adsorb radiocesium. Two methods were used to determine partitioning between liquid and solid phases; batch tests and porewater separation. In the batch test, Cs-137 tracer was added to mixtures of sediment and bottom water, with contact solutions ranging from 85 Bq/ml to 1760 Bq/ml. The distribution ratios (R{sub D}) for individual batch tests ranged from 390 to 1770 ml/g. Isotherms were linear for all cores and R{sub D} values calculated from the slopes of the isotherms ranged from 660 to 1660 ml/g. A second approach was used to determine the partitioning of Cs-137 between the porewater and the sediment under more natural conditions. The top 2 cm of two cores were sectioned and the sediment and the porewater were separated. In both samples the sediment contained significant amounts of Cs-137 and Cs-134 indicating the presence of fallout from the Chernobyl reactor accident. There was no cesium activity observed in the porewater at a minimum detectable level of 0,008 Bq/ml. 32 refs., 5 figs., 7 tabs
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Conventional combustion environmental assessment program
Fossil fuels have composed the largest segment of the nation's energy resources. This report discusses conventional methods of converting fossil fuels to usable forms of energy, associated with environmental penalties. The conventional combustion of fossil fuels has multimedia impacts which affect the air, land and water. 7 refs., 11 figs., 6 tabs
Analyzing the effect of Akoben programme on the environmental performance of mining in Ghana: A case study of a gold mining company
This study assessed the impact of Ghana's Environmental Protection Agency (EPA) Akoben programme, a rating and disclosure tool which seeks to promote better environmental performance in the mining and manufacturing industries in Ghana. Using a case study approach, the Akoben audit report card for a mining company was analyzed over a three-year period (2009–2011) based on 7-criteria – legal requirements, hazardous on-site waste management, toxic emissions management, environmental monitoring and reporting, best practice environmental management, complaint management, and corporate social responsibility. Key stakeholders' perceptions of the programme's suitability were solicited from the Ghana Chamber of Mines, EPA, and the mining company. Findings revealed that overall environmental performance over the three-year period under review was poor (2009 – 56.6%; 2010 – 65.6%; 2011 – 59.1%) with none of the years meeting the expected minimum limit, with the exception of legal requirements and corporate social responsibilities; the company failed in all other criteria. Specifically, both toxic and non-toxic waste emission discharges were major concerns as toxic parameters, such as for Arsenic, pH and Cyanide, were exceeded. Environmental monitoring and reporting was also a problem for the company. Stakeholders identified inadequate publicity, an absence of legal backing, and a lack of incentives for outstanding performances as the main weaknesses of the programme. Despite this, the stakeholders acknowledge the fact that the Akoben programme has improved the environmental performance of the mining companies because it puts their operations in check, although more can yet be achieved with regards environmental sustainability with this programme, if adequate measures including legal backing are put in place to ensure its continuity. Keywords: Akoben, Environmental, Ghana, Mining, Performance, Ratin
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