The U.S. Environmental Protection Agency has developed regulations under the Hazardous and Solid Waste Amendments (HSWA) of 1984 to restrict the land disposal of hazardous wastes. As a result of the regulations, all hazardous wastes to be placed on the land must meet treatment standards based on the performance of the best demonstrated available technology (BDAT) identified for individual waste classifications. The Marathon Oil Company is currently evaluating innovative technologies for managing listed waste materials, with a focus on waste minimization and recycling. Remediation Technologies, Inc. (ReTeC) has conducted testing on wastewater treatment sludges from three Marathon refineries using a proprietary thermal desorption technology. The results from these tests have demonstrated that the technology has the ability to consistently meet BDAT treatment standards, while preferentially separating and condensing residual moisture and oils from the material. 相似文献
Natural biodegradation can contain groundwaters impacted by creosote and pentachlorophenol. Using natural biodegradation for such sites is attractive because groundwater restoration is often impracticable, but the dissolved plumes are biodegradable and exert relatively low oxygen demands. Three case studies of its successful use are presented, with emphasis on the types of evidence needed, the rates and extents of removal, and the strategies for incorporating natural biodegradation into a remediation approach. Natural biodegradation was proven at all three sites, using a combination of field geochemical measurements, laboratory simulations, and computer modeling. Contaminant plumes at these three sites were contained within 100 to 700 feet downgradient of the apparent sources, although the rates of biodegradation varied widely. Natural biodegradation should be considered as part of an overall remedial strategy for most sites contaminated by creosote and/or pentachlorophenol. 相似文献
Providing an accurate estimate of the dry component of N deposition to low N background, semi-natural habitats, such as bogs and upland moors dominated by Calluna vulgaris is difficult, but essential to relate nitrogen deposition to effects in these communities. To quantify the effects of NH3 inputs to moorland vegetation growing on a bog at a field scale, a field release NH3 fumigation system was established at Whim Moss (Scottish Borders) in 2002. Gaseous NH3 from a line source was released along of a 60 m transect, when meteorological conditions (wind speed >2.5 m s?1 and wind direction in the sector 180–215°) were met, thereby providing a profile of decreasing NH3 concentration with distance from the source. In a complementary study, using a NH3 flux chamber system, the relationships between NH3 concentrations and cuticular resistances were quantified for a range of NH3 concentrations and micrometeorological conditions for moorland vegetation. Cuticular resistances increased with NH3 concentration from 11 s m?1 at 3.0 μg m?3 to 30 s m?1 at 30 μg m?3. The NH3 concentration data and the concentration-dependent canopy resistance are used to calculate NH3 deposition taking into account leaf surface wetness. The implications of using an NH3 concentration-dependent cuticular resistance and the importance for refining critical loads are discussed. 相似文献
This study sought to identify the primary indicators for evaluating shelter assistance following natural disasters and then to develop a shelter evaluation instrument based on these indicators. Electronic databases and the ‘grey’ literature were scoured for publications with a relation to post‐disaster shelter assistance. Indicators for evaluating such assistance were extracted from these publications. In total, 1,525 indicators were extracted from 181 publications. A preliminary evaluation instrument was designed from these 1,525 indicators. Shelter experts checked the instrument for face and content validity, and it was revised subsequently based on their input. The revised instrument comprises a version for use by shelter agencies (48 questions that assess 23 indicators) and a version for use by beneficiaries (52 questions that assess 22 indicators). The instrument can serve as a standardised tool to enable groups to gauge whether or not the shelter assistance that they supply meets the needs of disaster‐affected populations. 相似文献
Most of the world's children live in resource-poor countries where people are at a relatively high risk of exposure to catastrophic situations arising from conflict and natural disasters.(6) Given the potential social, psychological and psychiatric consequences of exposure to disaster, mental health and psychosocial support programmes are increasingly part of humanitarian aid. A minimum standard on mental and social aspects of health is included in the recently revised Humanitarian Charter and Minimum Standards in Disaster Response (Sphere Handbook) (Sphere Project, 2004). Most recommendations for mental health and psychosocial interventions in guidance documents are based on expert opinion rather than research. Consequently, interventions are being implemented without full understanding of their potential benefit or harm. This paper offers a child-focused review of the evidence for each of the interventions described as indicators for the Sphere standard on mental and social aspects of health. It suggests some, but limited, support for each of them. However, the evidence base needs substantial strengthening. 相似文献
Global Positioning System (GPS) collars are increasingly used to study animal movement and habitat use. Measurement error
is defined as the difference between the observed and true value being measured. In GPS data measurement error is referred
to as location error and leads to misclassification of observed locations into habitat types. This is particularily true when
studying habitats of small spatial extent with large amounts of edge, such as linear features (e.g. roads and seismic lines).
However, no consistent framework exists to address the effect of measurement error on habitat classification of observed locations
and resulting biological inference. We developed a mechanistic, empirically-based method for buffering linear features that
minimizes the underestimation of animal use introduced by GPS measurement error. To do this we quantified the distribution
of measurement error and derived an explicit formula for buffer radius which incorporated the error distribution, the width
of the linear feature, and a predefined amount of acceptable type I error in location classification. In our empirical study
we found the GPS measurement error of the Lotek GPS_3300 collar followed a bivariate Laplace distribution with parameter ρ = 0.1123. When we applied our method to a simulated landscape, type I error was reduced by 57%. This study highlights the
need to address the effect of GPS measurement error in animal location classification, particularily for habitats of small
spatial extent. 相似文献
Groundwater, accessed using wells and municipal springs, represents the major source of potable water for the human population
outside of major urban areas in northwestern Romania, a region with a long history of metal mining and metallurgy. The magnitude
and spatial distribution of metal contamination in private-supply groundwater was investigated in four mining-affected river
catchments in Maramureş and Satu Mare Counties through the collection of 144 groundwater samples. Bedrock geology, pH and
Eh were found to be important controls on the solubility of metals in groundwater. Peak metal concentrations were found to
occur in the Lapuş catchment, where metal levels exceed Dutch target and intervention values in up to 49% and 14% of samples,
respectively. A 700 m wide corridor in the Lapuş catchment on either side of the main river channel was identified in which
peak Cd (31 μg l−1), Cu (50 μg l−1), Pb (50 μg l−1) and Zn (3,000 μg l−1) concentrations were found to occur. Given the generally similar bedrock geologies, lower metal levels in other catchments
are believed to reflect differences in the magnitude of metal loading to the local environment from both metal mining and
other industrial and municipal sources. Sampling of groundwater in northwestern Romania has indicated areas of potential concern
for human health, where heavy metal concentrations exceed accepted environmental quality guidelines. The presence of elevated
metal levels in groundwater also has implications for the implementation of the EU Water Framework Directive (WFD) and achieving
‘good’ status for groundwater in this part of the Danube River Basin District (RBD). 相似文献
Objective: The objective of this study was to determine the roadside prevalence of alcohol-impaired driving among drivers and riders in northern Ghana. The study also verifies motorists' perceptions of their own alcohol use and knowledge of the legal blood alcohol concentration (BAC) limit in Ghana.
Method: With the assistance of police, systematic random sampling was used to collect data at roadblocks using a cross-sectional study design. Breathalyzers were used to screen whether motorists had detectable alcohol in their breath and follow-up breath tests were conducted to measure the actual breath alcohol levels among positive participants.
Results: In all, 9.7% of the 789 participants had detectable alcohol, among whom 6% exceeded the legal BAC limit of 0.08%. The prevalence of alcohol-impaired driving/riding was highest among cyclists (10% of all cyclists breath-tested) followed by truck drivers (9%) and motorcyclists (7% of all motorcyclists breath-tested). The occurrence of a positive BAC among cyclists was about 8 times higher (odds ratio [OR] = 7.73; P < .001) and it was 2 times higher among motorcyclists (OR = 2.30; P = .039) compared to private car drivers. The likelihood for detecting a positive BAC among male motorists/riders was higher than that among females (OR = 1.67; P = .354). The odds for detecting a positive BAC among weekend motorists/riders was significantly higher than on weekdays (OR = 2.62; P = .001).
Conclusion: Alcohol-impaired driving/riding in Ghana is high by international standards. In order to attenuate the harmful effects of alcohol misuse such as alcohol-impaired driving/riding, there is the need to educate road users about how much alcohol they can consume and stay below the legal limit. The police should also initiate random breath testing to instill the deterrence of detection, certainty of apprehension and punishment, and severity and celerity of punishment among drink-driving motorists and riders. 相似文献