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Environmental Threats (environmental + threat)
Selected AbstractsReview: Biodegradation of tributyltins (organotins) by marine bacteriaAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 1 2003S. K. Dubey Abstract Many marine bacterial strains have an inherent capability to degrade toxic organotin compounds, especially tributyltins (TBTs), that enter into the environment in the form of insecticides, fungicides and antifouling paints as a result of anthropogenic and industrial activities. Significant degradation of these compounds in the ambient environment may take several years, and it is necessary to consider methods or strategies that can accelerate the degradation process. There have been few demonstrations of biological degradation of these organotin biocides exclusively in laboratory-scale experiments. Compared with the few bench-scale degradation processes, there are no reports of field-scale processes for TBT bioremediation, in spite of its serious environmental threat to non-target organisms in the aquatic environment. Implementation of field-scale biodegradation of TBT requires inputs from biology, hydrology, geology, chemistry and civil engineering. A framework is emerging that can be adapted to develop new processes for bioremediation of toxic environmental wastes. In the case of TBT bioremediation, this framework incorporates screening and identification of natural bacterial strains, determination of optimal conditions for growth of isolates and TBT degradation, establishment of new metabolic pathways involved in TBT degradation, identification, localization and cloning of genes involved in degradation and in TBT resistance, development of suitable microbial strains using genetic manipulation techniques for practical applications and optimization of practical engineering processes for bioremediation of organotin-contaminated sites. The present review mainly addresses the aspect of TBT biodegradation with special reference to environmental sources of TBT, chemical structure and biological activity, resistant and degrading bacterial strains, possible mechanisms of resistance and degradation and the genetic and biochemical basis of TBT degradation and resistance. It also evaluates the feasibility and potential of natural and genetically modified TBT-degrading bacterial strains in field-scale experiments to bioremediate TBT-contaminated marine sites, and makes recommendations for more intensive and focused research in the area of TBT bioremediation mediated by marine bacterial strains. Copyright © 2002 John Wiley & Sons, Ltd. [source] Human Vulnerability, Dislocation and Resettlement: Adaptation Processes of River-bank Erosion-induced Displacees in BangladeshDISASTERS, Issue 1 2004David Mutton The purpose of this research was to identify and analyse patterns of economic and social adaptation among river-bank erosion-induced displacees in Bangladesh. It was hypothesised that the role of social demographic and socio-economic variables in determining the coping ability and recovery of the river-bank erosion-induced displacees is quite significant. The findings of the research reveal that displacees experience substantial socio-economic impoverishment and marginalisation as a consequence of involuntary migration. This in part is a socially constructed process, reflecting inequitable access to land and other resources. Vulnerability to disasters is further heightened by a number of identifiable social and demographic factors including gender, education and age, although extreme poverty and marginalisation create complexity to isolate the relative influence of these variables. The need to integrate hazard analysis and mitigation with the broader economic and social context is discussed. It is argued that the capacity of people to respond to environmental threats is a function of not only the physical forces which affect them, but also of underlying economic and social relationships which increase human vulnerability to risk. Hazard analysis and mitigation can be more effective when it takes into account such social and demographic and socio-economic dimensions of disasters. [source] Greenhouse gas emission policies in the UK and Germany: influences and responsesENVIRONMENTAL POLICY AND GOVERNANCE, Issue 3 2002Bettina Schrader Climate change is considered to be one of the greatest environmental threats. In response to this threat, developed countries agreed in Kyoto to legally binding targets, which will reduce their atmospheric emissions. In April 1999 Germany introduced an environmental tax. At the same time the UK announced the introduction of a levy on energy consumption, from April 2001. This paper investigates the proposals from both governments and the influences upon them of a variety of institutions (NGOs, industry and business organizations). The similarities and differences between the consultation experiences, and the resulting policies, will be discussed for the two countries. Lessons are drawn applicable to the wider context of EU environmental legislation. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment [source] DNAPL Characterization Methods and Approaches, Part 2: Cost ComparisonsGROUND WATER MONITORING & REMEDIATION, Issue 1 2002Mark L. Kram Contamination from the use of chlorinated solvents, often classified as dense nonaqueous phase liquids (DNAPLs) when in an undissolved state, pose environmental threats to ground water resources worldwide. DNAPL site characterization method performance comparisons are presented in a companion paper (Kram et al. 2001). This study compares the costs for implementing various characterization approaches using synthetic unit model scenarios (UMSs), each with particular physical characteristics. Unit costs and assumptions related to labor, equipment, and consumables are applied to determine costs associated with each approach for various UMSs. In general, the direct-push sensor systems provide cost-effective characterization information in soils that are penetrable with relatively shallow (less than 10 to 15 m) water tables. For sites with impenetrable lithology using direct-push techniques, the Ribbon NAPL Sampler Flexible Liner Underground Technologies Everting (FLUTe) membrane appears to be the most cost-effective approach. For all scenarios studied, partitioning interwell tracer tests (PITTs) are the most expensive approach due to the extensive pre-and post-PITT requirements. However, the PITT is capable of providing useful additional information, such as approximate DNAPL saturation, which is not generally available from any of the other approaches included in this comparison. [source] Human resources planning on terrorism and crises in the Asia Pacific region: Cross-national challenge, reconsideration, and proposition from western experiencesHUMAN RESOURCE MANAGEMENT, Issue 1 2008Dian-Yan Liou Since the 9/11 attacks in the United States (2001) and the two bombing events in Bali (2002, 2005), there has been renewed interest in emergency prevention policies in many organizations around the world. Functional terrorism preparedness requires changes in organizational thinking about external environmental threats. This shift in organizational thinking could be led by human resource departments. In order to achieve this goal, HR departments must redefine their role in terms of crisis management, and then four key planning measures for insuring postemergency operations should be observed. Using system dynamics (SD) methodology, this article examines the causes of states in which organizations operate after terrorist attacks. Based on the qualitative analytic approach of causal loops, this article explores the major challenges for HR development prompted by terrorism. Specifically, we focus on changes both to organizational communication and to workforce planning and succession. These activities are a tremendous challenge immediately following a disaster. A functional HR plan must include elements for proactive alertness, the ability to dispatch inventory, evacuation plans, and record preservation coupled with dissemination to employees and explicit employee training and cross-cultural management. © 2008 Wiley Periodicals, Inc. [source] Environmental dew point and skin and lip weatheringJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2010C Devillers Abstract Xerosis represents a physiological response of the stratum corneum (SC) to environmental threats. The influence of the environmental dew point (DP) is not fully understood. This parameter is the air temperature at which the relative humidity is maximum. This study aimed to assess the relationship between the environmental DP and the water-holding capacity of the skin and lower lip vermilion. For comparison, SC property was evaluated after occlusive application of cooled and uncooled hydrogel pads. Electrometric measurements using a dermal phase meter (DPM) device were performed on the back of the hands, the cheeks and the lower lip of 40 healthy menopausal women. Assessments were performed in the outdoor conditions during winter and spring. The same measurements were recorded after hydrogel pads, at room temperature or cooled to 4 °C, were placed for 15 min on the test sites. The environmental DP was recorded at each evaluation time. The SC water-holding capacity was discretely influenced by the DP. In the open-air environmental conditions, a positive linear relationship was found on the cheeks between the DP and DPM values. The relationship was weaker on the lips. Conversely, a consistent increase in DPM values was recorded immediately after removal of the cooled and uncooled hydrogel pads. The observations made in the open-air testing conditions are consistent with the predicted events following the Arrhenius law. By contrast, the combination of cooling and occlusion by the hydrogel pads is responsible for the reverse effect on the SC. [source] Seabed Morphology and Pollution Along the Bagnoli Coast (Naples, Italy): a Hypothesis for Environmental RestorationMARINE ECOLOGY, Issue 2002Tommaso De Pippo Abstract. The interaction of coastal and submarine morphology with the hydrodynamic regimes exerts a control on coastal dynamic processes, conditioning the dispersion of sediments and potential pollutants existing in the area. Thus, the study of such parameters is useful in order to define environmental threats. Within the submerged sector of the Bagnoli coast and particularly in the southern part of the investigated area, there are sediment groups composed of very fine sands located in low-energy zones due to wave refraction and diffraction; they can also be found on the sea bottom and on the man-made structures typical of this zone. These areas show high pollutant levels of N, P, Cu, Fe, Mn, Ni, Pb, Zn, Cd, polyaromatic hydrocarbons (PAHs) and polychlorinated bi-phenyls (PCBs). The northern area, a place of high-energy hydrodynamic processes, also shows high concentration levels of pollutants due to the presence of secondary cell circulation. Morphological research and analysis of textural characteristics of bottom sediments along the Bagnoli coast allowed the actual processes and their evolution in space and time to be defined. It has also been possible to correlate such processes to the seabed morphology system, the wave formations which affect the coast, the complex system of sediment transport, as well as to the man-made interventions in the area. The results of recent chemical analyses of beach sediments and bottom sediments off the Bagnoli coast were also incorporated. They prove the presence of heavy metals, PAHs and PCBs in high and sometimes very high concentrations. Finally, based on the results of research and analyses, a hypothesis for an intervention for environmental restoration has been formulated in order to renaturalise the coast through dredging and treatment of the sand, both on the seabed and on the emerged beach. [source] Assessing in situ rates of anaerobic hydrocarbon bioremediationMICROBIAL BIOTECHNOLOGY, Issue 2 2009Lisa M. Gieg Summary Identifying metabolites associated with anaerobic hydrocarbon biodegradation is a reliable way to garner evidence for the intrinsic bioremediation of problem contaminants. While such metabolites have been detected at numerous sites, the in situ rates of anaerobic hydrocarbon decay remain largely unknown. Yet, realistic rate information is critical for predicting how long individual contaminants will persist and remain environmental threats. Here, single-well push,pull tests were conducted at two fuel-contaminated aquifers to determine the in situ biotransformation rates of a suite of hydrocarbons added as deuterated surrogates, including toluene- d8, o -xylene- d10, m -xylene- d10, ethylbenzene- d5 (or - d10), 1, 2, 4-trimethylbenzene- d12, 1, 3, 5-trimethylbenzene- d12, methylcyclohexane- d14 and n -hexane- d14. The formation of deuterated fumarate addition and downstream metabolites was quantified and found to be somewhat variable among wells in each aquifer, but generally within an order of magnitude. Deuterated metabolites formed in one aquifer at rates that ranged from 3 to 50 µg l,1 day,1, while the comparable rates at another aquifer were slower and ranged from 0.03 to 15 µg l,1 day,1. An important observation was that the deuterated hydrocarbon surrogates were metabolized in situ within hours or days at both sites, in contrast to many laboratory findings suggesting that long lag periods of weeks to months before the onset of anaerobic biodegradation are typical. It seems clear that highly reduced conditions are not detrimental to the intrinsic bioremediation of fuel-contaminated aquifers. [source] Lake habitat suitability for the rare European macrophyte Najas flexilis (Willd.) Rostk.AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2005& Schmidt Abstract 1.Najas flexilis (Willd.) Rostk. & Schmidt is a submerged annual macrophyte, rare in Europe, which is protected under the EC Habitats Directive. 2.N. flexilis grows in deep, often coloured or turbid water in mesotrophic lakes. Because of this habitat preference it is difficult to locate and assess the ecological state of populations of the species for conservation monitoring purposes. 3.A method is described based on plant community information that can be used to determine the baseline probability that conditions in a lake are suitable for supporting N. flexilis growth. This can be applied to conservation management decisions, such as whether a detailed underwater survey is justified for monitoring the integrity of existing populations of N. flexilis, or whether the lake may be a suitable site for introduction, or reintroduction, of populations of the plant. 4.Two methods of plant community description are compared: a quantitative micro-habitat scale approach and a whole-lake-scale qualitative approach. Plant community data collected using each method were grouped using TWINSPAN, and environmental descriptors of the sites comprising each plant community group were compared statistically. 5.Micro-habitat-scale community groups differed significantly only in the light extinction coefficient, indicating the zone within the lake in which N. flexilis occurred. 6.The whole-lake-scale community groups differed in a number of environmental variables indicative of eutrophication and acidification, two major environmental threats to N. flexilis survival. 7.This study suggests that a lake-scale qualitative plant community description would be a better indicator of site suitability for N. flexilis growth than a quantitative micro-habitat plant community description. This is because the whole-lake-scale approach could detect a difference in the environmental factors that affect N. flexilis growth, which the micro-habitat scale approach could not. Copyright © 2005 John Wiley & Sons, Ltd. [source] Comment: A biological guide for electromagnetic safety: the stress responseBIOELECTROMAGNETICS, Issue 8 2004Martin Blank Abstract Questions of safety of electromagnetic (EM) fields should be based on relevant biological properties, i.e., specific cellular reactions to potentially harmful stimuli. The stress response is a well documented protective reaction of plant and animal cells to a variety of environmental threats, and it is stimulated by both extremely low frequency (ELF) and radio frequency (RF) EM fields. It involves activation of DNA to initiate synthesis of stress proteins. Thermal and non-thermal stimuli affect different segments of DNA and utilize different biochemical pathways. However, both ELF and RF stimulate the same non-thermal pathway. Since the same biochemical reactions are stimulated in different frequency ranges with very different specific absorption rates (SARs), SAR level is not a valid basis for safety standards. Studies of EM field interactions with DNA and with model systems provide insight into a plausible mechanism that can be effective in ELF and RF ranges. Bioelectromagnetics 25:642,646, 2004. © 2004 Wiley-Liss, Inc. [source] | |||||||||||||