6,004 research outputs found
Chelation: Harnessing and Enhancing Heavy Metal Detoxification—A Review
Toxic metals such as arsenic, cadmium, lead, and mercury are ubiquitous, have no beneficial role in human homeostasis, and contribute to noncommunicable chronic diseases. While novel drug targets for chronic disease are eagerly sought, potentially helpful agents that aid in detoxification of toxic elements, chelators, have largely been restricted to overt acute poisoning. Chelation, that is multiple coordination bonds between organic molecules and metals, is very common in the body and at the heart of enzymes with a metal cofactor such as copper or zinc. Peptides glutathione and metallothionein chelate both essential and toxic elements as they are sequestered, transported, and excreted. Enhancing natural chelation detoxification pathways, as well as use of pharmaceutical chelators against heavy metals are reviewed. Historical adverse outcomes with chelators, lessons learned in the art of using them, and successes using chelation to ameliorate renal, cardiovascular, and neurological conditions highlight the need for renewed attention to simple, safe, inexpensive interventions that offer potential to stem the tide of debilitating, expensive chronic disease
Hydrologic Response and Erosion Modeling of Geomorphic Landform Reclamation in Mountainous Terrain
Surface mining and valley-fill practices often lead to environmental impacts including headwater stream loss, increased flooding risk, and degraded downstream water quality. Geomorphic landform design (GLD) is an innovative reclamation technique proposed to lessen the impacts associated with surface mining and valley-fill activities. GLD incorporates mature landform shapes and created stream channels on site, imitating the function of the undisturbed landscape. The purpose of this research was to model GLDs in mountainous terrain and evaluate the hydrologic response and erosion potential of GLD in surface mining application. Computer modeling of valley-fill designs using geomorphic landform principles of a study site in southern West Virginia was performed. Four enhanced GLDs were created for application on new and previously constructed valley fills: 1) regional data GLD for new valley fill, 2) retrofit GLD for existing conventional valley fill, 3) regional data GLD enhanced with bench pond retention structures, and 4) regional data GLD enhanced with valley pond retention structures. Soil erosion was evaluated using the Revised Universal Soil Loss Equation (RUSLE) for the regional data GLD, conventional valley fill, and the undisturbed site during different stages of the reclamation process. Soil loss rates were highest (conventional: 123.2 t ha-1 yr-1; GLD: 204.3 t ha-1 yr-1) during the post-mining, pre-vegetation condition along the stream channels and steep slopes (slope \u3e50%). Erosion rates were lowest for the post-reclamation, long term condition (conventional: 35.6 t ha-1 yr-1 ; GLD: 41.8 t ha-1 yr-1) along the ridges. Model predictions of soil erosion rates and spatial distributions illustrated areas of increased erosion potential for future minimization and reclamation method/management practices improvement. Hydrologic response modeling was performed for a watershed in southern West Virginia disturbed by surface mining and valley-fill activities to predict impacts on stream flows at the landscape scale. Incorporation of GLD reclamation methods did not result in substantial changes in current (2011-2020) or future (36500-2050) stream flowrates (≤3.3% difference) or stormflow volumes (≤2.1% difference). The differences in flows and volumes could be used for mitigation plans in watersheds disturbed by surface mining and valley-fill activities
The Integration of Geomorphic Design into West Virginia Surface Mine Reclamation
Approximately 40% of operating mines in West Virginia are surface mines, producing around 50 million tons of coal each year. Federal regulations that have been designed to control environmental impacts associated with surface mining are becoming increasingly stringent. The West Virginia Department of Environmental Protection (WVDEP) Division of Mining and Reclamation and the United States Environmental Protection Agency (EPA) recently have delayed or temporarily suspended surface mining permits because of the implementation of more rigorous standards relating to reclamation and post-mining land use. As the demand for energy continues to increase, there is a need to find an alternative to the typical surface mine reclamation techniques used today in Appalachia.;The short-term outcome of this research was to assess the feasibility of coal companies to implement geomorphic design into surface mine reclamation in Appalachia. Many other considerations were studied throughout the duration of this project. Laws and regulations were also evaluated to determine where geomorphic design may be applied in Appalachian surface mining. With regulations becoming more stringent and changing frequently, implementing geomorphic ideas into the steep terrain of Appalachia while adhering to current regulations is a challenge. However, this is the first step in creating a successful geomorphic reclamation design.;The long-term outcome of this research was to incorporate Carlson RTM\u27s Natural RegradeRTM with GeoFluv(TM) software to create a geomorphic design for a sample surface mine in southern West Virginia. While this innovative reclamation design approach has been used with success in semi-arid regions of the United States, as well as throughout the world, the approach has not been utilized in West Virginia. One main purpose of this project was to analyze the effectiveness of geomorphic reclamation on surface mines in West Virginia as well as a comparison of the features of the completed geomorphic valley-fill design contrasted to an approximate original contour variance valley-fill design. By creating a geomorphic reclamation design for a site in West Virginia, data could be collected and compared directly to traditional designs in order to determine and assess advantages and disadvantages of implementing this innovative surface reclamation technique in Appalachia.;A safety analysis was also performed to compare both a traditional valley-fill design and the completed geomorphic valley-fill design so that any significant safety benefits or disadvantages could be assessed. Stream analysis, including the length of original streams, length of created streams, stream classification, and stream type, was performed to identify complete drainage systems. All of the numerous aspects that were analyzed between the traditional and geomorphic valley-fill designs, in return, yielded an accurate analysis of the benefits and/or disadvantages of the nontraditional reclamation approach as well as the ability to implement this geomorphic reclamation design method in West Virginia. Following the comparison, it was found that the Approximate Original Contour (AOC) variance valley-fill design was intended to ensure slope stability, control drainage, complement the drainage pattern of the surrounding terrain, and prevent stream sedimentation. The design consisted of:;• slope shapes exhibiting uniform benches.;• planar slopes having unvarying contours.;• drainage ditches located along the perimeter and/or center of the fill.;However, the traditional, planar reclamation method can be improved to appear more natural and decrease the drawbacks associated with it.;Features of the resulting Natural RegradeRTM design include:;• long-term stability due to dynamic equilibrium.;• suggested reduction in maintenance due to stability.;• projected reduced cost due to strategic placement of fill material.;• more aesthetically pleasing valley fill due to a diverse natural habitat with ridges and valleys.;These landform designs add variability and aid in establishing a site with a long-term hydrologic balance. The geomorphic landform reclamation approach has potential to extend beyond current industry practices and will improve environmental impacts, flood control, water quality, and human safety
National Transonic Facility: A review of the operational plan
The proposed National Transonic Facility (NTF) operational plan is reviewed. The NTF will provide an aerodynamic test capability significantly exceeding that of other transonic regime wind tunnels now available. A limited number of academic research program that might use the NTF are suggested. It is concluded that the NTF operational plan is useful for management, technical, instrumentation, and model building techniques available in the specialized field of aerodynamic analysis and simulation. It is also suggested that NASA hold an annual conference to discuss wind tunnel research results and to report on developments that will further improve the utilization and cost effectiveness of the NTF and other wind tunnels
Environmental Determinants of Chronic Disease and Medical Approaches: Recognition, Avoidance, Supportive Therapy, and Detoxification
The World Health Organization warns that chronic, noncommunicable diseases are rapidly becoming epidemic worldwide.
Escalating rates of neurocognitive, metabolic, autoimmune and cardiovascular diseases cannot be ascribed only to genetics, lifestyle, and nutrition; early life and ongoing exposures, and bioaccumulated toxicants may also cause chronic disease. Contributors to ill health are summarized from
multiple perspectives—biological effects of classes of toxicants, mechanisms of toxicity, and a synthesis of toxic contributors to major diseases.
Healthcare practitioners have wide-ranging roles in addressing environmental factors in policy and public health and clinical practice.
Public health initiatives include risk recognition and chemical assessment then exposure reduction, remediation, monitoring, and avoidance.
The complex web of disease and environmental contributors is amenable to some straightforward clinical approaches addressing multiple toxicants.
Widely applicable strategies include nutrition and supplements to counter toxic effects and to support metabolism; as well as exercise and sweating,
and possibly medication to enhance excretion. Addressing environmental health and contributors to chronic disease has broad implications for society,
with large potential benefits from improved health and productivity
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