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Hazard Assessment (hazard + assessment)

Distribution by Scientific Domains

Chemistry	28%
Earth and Environmental Science	23%
Engineering	19%
Life Sciences	14%

Selected Abstracts

Controls on modern alluvial fan processes in the central Alps, northern Italy

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2004
Giovanni B. Crosta
Abstract Alluvial fan development in Alpine areas is often affected by catastrophic sedimentary processes associated with extreme ,oods events, causing serious risks for people living on the fans. Hazard assessment in these areas depends on proper identi,cation of the dominant sedimentary processes on the fans. Data from a set of 209 alluvial fans from the central Alps of Italy are presented in this paper and analysed with the help of various statistical techniques (linear regression, principal components analysis, cluster analysis, discriminant analysis and logistic regression). First, we used modern sedimentary facies and historical records (,ood events since 15th century), to distinguish between the two dominant sedimentary processes on alluvial fans: debris ,ows and stream,ows. Then, in order to analyse the main controls on past and present fan processes, 36 morphological, geological and land-use variables were analysed. As with observations for arid-environment fans, catchment morphology is the most in,uential factor in the study area, whereas geology and land use are minor controls. The role of climatic change and landsliding within the catchments also seems to be very important and is discussed. Statistical techniques also help in differentiating groups of alluvial fans by sets of controlling factors, including stage and type of evolution. Finally, by using discriminant analysis and logistic regression, we classi,ed alluvial fans according to the dominant sedimentary process, with a success rate ranging between 75 and 92 per cent. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Investigation of coupling between surface processes and induced flow in the lower continental crust as a cause of intraplate seismicity

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 12 2006
Rob Westaway
Abstract Many studies have highlighted the role of coupling between surface processes and flow in the lower continental crust in deforming the crust and creating topographic relief over Quaternary timescales. On the basis of the rheological knowledge gained, it is suggested that intraplate seismicity can also be caused by coupling between surface processes and flow in the lower continental crust. This view is shown to be a natural consequence of the modern idea that isostatic equilibrium is maintained by flow in the weak lower crust in response to erosion and sedimentation. It is supported by a general correlation between the vigour of surface processes and rates of intraplate seismicity, and by instances of seasonal seismicity that correlates with seasonal climate. Human interference in the environment can affect surface loading: for instance, deforestation for agriculture or urban development can cause increased erosion rates; global warming is expected to cause increased storminess (and thus increased erosion rates) and/or global sea-level rise. The possibility of increased rates of seismicity resulting from these processes should thus be considered in future hazard assessment. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Seismic microzonation of the greater Bangkok area using microtremor observations

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 2 2004
Rabin Tuladhar
Abstract Bangkok, the capital city of Thailand, is located at a remote distance from seismic sources. However, it has a substantial risk from these distant earthquakes due to the ability of the underlying soft clay to amplify ground motions. It is therefore imperative to conduct a detailed seismic hazard assessment of the area. Seismic microzonation of big cities, like Bangkok, provides a basis for site-specific hazard analysis, which can assist in systematic earthquake mitigation programs. In this study, a seismic microzonation map for the greater Bangkok area is constructed using microtremor observations. Microtremor observations were carried out at more than 150 sites in the greater Bangkok area. The predominant periods of the ground were determined from the horizontal-to-vertical (H/V) spectral ratio technique. A microzonation map was then developed for the greater Bangkok area based on the observations. Moreover, the transfer functions were calculated for the soil profile at eight sites, using the computer program SHAKE91, to validate the results from the microtremor analysis. The areas near the Gulf of Thailand, underlaid by a thick soft clay layer, were found to have long natural periods ranging from 0.8s to 1.2s. However, the areas outside the lower central plain have shorter predominant periods of less than 0.4s. The study shows that there is a great possibility of long-period ground vibration in Bangkok, especially in the areas near the Gulf of Thailand. This may have severe effects on long-period structures, such as high-rise buildings and long-span bridges. Copyright © 2003 John Wiley & Sons, Ltd. [source]

White pines, Ribes, and blister rust: integration and action

FOREST PATHOLOGY, Issue 3-4 2010
R. S. Hunt
Summary The preceding articles in this series review the history, biology and management of white pine blister rust in North America, Europe and eastern Asia. In this integration, we connect and discuss seven recurring themes important for understanding and managing epidemics of Cronartium ribicola in the white pines (five-needle pines in subgenus Strobus). Information and action priorities for research and management of the pathogen, telial and aecial hosts, and their interactions are listed in a detailed Appendix. Syntheses focused on genetics, plant disease, invasive species or forest management have provided alternative but knowledgeable lessons on the white pine blister rust pathosystem. Two critical issues for the conservation of white pines are to sustain ecosystems affected by blister rust and to maintain genetic diversity for adaptive traits such as disease resistance. Forest genetics includes tree improvement and molecular techniques for research; their application can increase rust resistance by artificial and natural selection. Silviculture augments genetics with methods to deploy and enhance resistance as well as to regenerate and tend white pine stands. Although cultivated or wild Ribes might serve as inoculum sources, silviculture and horticulture can reduce the risk of serious impacts from blister rust using genetics for breeding and epidemiology for hazard assessment and disease control. Climate change threatens to cause major alterations in temperature and precipitation regimes, resulting in maladapted conifers succumbing to various diseases and insect outbreaks. In contrast, many white pine species have broad ecological ranges and are tolerant of harsh environments,traits that permit successful establishment and growth over wide geographic and altitudinal zones. Given appropriate management, white pines could thrive as valuable commercial and ecologically important keystone species. In an uncertain environment, adaptive management provides a learning and participatory approach for sustaining resilient ecosystems. [source]

Probabilities of activation of seismic faults in critical regions of the Aegean area

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2004
C. B. Papazachos
SUMMARY Properties of the accelerating seismic crustal deformation pattern and of the intermediate-term seismic quiescence pattern have been combined to identify faults in the Aegean area (34°N,43°N, 19°E,30°E) that have a considerable probability of generating strong earthquakes (M, 6.4) during the next 5-yr period. Eight groups of such faults have been identified, and the probability of each fault being activated during this time period has been estimated. Three of these groups are located in southern Greece (Hellenic Arc), two in central Greece (East Central Greece, Ionian Islands), two in northwestern Turkey and one in the area of the borders of Albania, Greece and the Former Yugoslav Republic of Macedonia. The importance of these results for intermediate-term seismic hazard assessment is discussed. [source]

Bioaccessibility studies of ferro-chromium alloy particles for a simulated inhalation scenario: A comparative study with the pure metals and stainless steel

INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 3 2010
Klara Midander
Abstract The European product safety legislation, REACH, requires that companies that manufacture, import, or use chemicals demonstrate safe use and high level of protection of their products placed on the market from a human health and environmental perspective. This process involves detailed assessment of potential hazards for various toxicity endpoints induced by the use of chemicals with a minimum use of animal testing. Such an assessment requires thorough understanding of relevant exposure scenarios including material characteristics and intrinsic properties and how, for instance, physical and chemical properties change from the manufacturing phase, throughout use, to final disposal. Temporary or permanent adverse health effects induced by particles depend either on their shape or physical characteristics, and/or on chemical interactions with the particle surface upon human exposure. Potential adverse effects caused by the exposure of metal particles through the gastrointestinal system, the pulmonary system, or the skin, and their subsequent potential for particle dissolution and metal release in contact with biological media, show significant gaps of knowledge. In vitro bioaccessibility testing at conditions of relevance for different exposure scenarios, combined with the generation of a detailed understanding of intrinsic material properties and surface characteristics, are in this context a useful approach to address aspects of relevance for accurate risk and hazard assessment of chemicals, including metals and alloys and to avoid the use of in vivo testing. Alloys are essential engineering materials in all kinds of applications in society, but their potential adverse effects on human health and the environment are very seldom assessed. Alloys are treated in REACH as mixtures of their constituent elements, an approach highly inappropriate because intrinsic properties of alloys generally are totally different compared with their pure metal components. A large research effort was therefore conducted to generate quantitative bioaccessibility data for particles of ferro-chromium alloys compared with particles of the pure metals and stainless steel exposed at in vitro conditions in synthetic biological media of relevance for particle inhalation and ingestion. All results are presented combining bioaccessibility data with aspects of particle characteristics, surface composition, and barrier properties of surface oxides. Iron and chromium were the main elements released from ferro-chromium alloys upon exposure in synthetic biological media. Both elements revealed time-dependent release processes. One week exposures resulted in very small released particle fractions being less than 0.3% of the particle mass at acidic conditions and less than 0.001% in near pH-neutral media. The extent of Fe released from ferro-chromium alloy particles was significantly lower compared with particles of pure Fe, whereas Cr was released to a very low and similar extent as from particles of pure Cr and stainless steel. Low release rates are a result of a surface oxide with passive properties predominantly composed of chromium(III)-rich oxides and silica and, to a lesser extent, of iron(II,III)oxides. Neither the relative bulk alloy composition nor the surface composition can be used to predict or assess the extent of metals released in different synthetic biological media. Ferro-chromium alloys cannot be assessed from the behavior of their pure metal constituents. Integr Environ Assess Manag 2010;6:441,455. © 2009 SETAC [source]

Relevance of the developmental toxicity of ethanol in the occupational setting: a review,

JOURNAL OF APPLIED TOXICOLOGY, Issue 5 2003
Lorraine F. H. Irvine
Abstract Numerous studies have been conducted investigating the reproductive toxicology of ethanol, the overwhelming majority concerning the adverse effects of consuming alcohol in beverages during pregnancy. Because many of the in vivo studies were designed to model alcoholism, they used comparatively high doses and assessed relatively few endpoints. Outcomes may have been affected by disturbances of metabolism at such high exposures, giving rise to secondary effects on development. The available data on ethanol from ,conventional' developmental toxicity study test methods of the type used for regulatory hazard assessment of chemicals are limited. It is in this context, however, i.e. the use of ethanol as an industrial chemical rather than as a component of beverages, that this review is based. Using the usual criteria applied for the purpose of hazard assessment of industrial chemicals, it is concluded that there is no evidence that industrial exposure to ethanol is a developmental toxicity hazard. Developmental toxicity may result from drinking alcoholic beverages, the threshold level for all aspects of which has yet to be de,ned. This is not, however, considered relevant to the low blood alcohol concentrations resulting from any conceivable inhalation or dermal exposure in the workplace or through the directed use of any consumer product containing ethanol. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Methods for the identi,cation of chemical respiratory allergens in rodents: comparisons of cytokine pro,ling with induced changes in serum IgE

JOURNAL OF APPLIED TOXICOLOGY, Issue 4 2003
R. J. Dearman
Abstract No validated or widely recognized test methods are currently available for the prospective identi,cation of chemicals with the potential to cause respiratory allergy. The cellular and molecular mechanisms that result in the induction of chemical sensitization of the respiratory tract are unclear, although there is evidence for the selective development of T helper 2 (Th2)-type responses and, in some cases, the production of IgE antibody. We have therefore examined the utility of cytokine pro,ling using BALB/c mice, together with the measurement of induced increases in the total serum concentration of IgE in the Brown Norway (BN) rat, as markers for the prospective identi,cation of chemical respiratory allergens. Responses provoked by the reference respiratory allergen trimellitic anhydride (TMA) have been compared with those stimulated by the respiratory sensitizing diisocyanates toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI) and by the acid anhydride hexahydrophthalic anhydride (HHPA). Topical exposure of BN rats to TMA, TDI and HHPA each provoked marked immune activation (increases in lymph node cellularity and proliferation). However, only treatment with TMA stimulated vigorous increases in the total serum concentration of IgE. In contrast, exposure to HHPA, TDI or HDI failed to provoke signi,cant changes in serum IgE concentration or induced only transient and relatively weak increases in serum IgE levels. In parallel experiments using BALB/c strain mice, however, topical application of all four chemical respiratory allergens provoked a marked Th2-type cytokine secretion pro,le in draining lymph node cells. These data suggest that the measurement of induced changes in serum IgE is not suf,ciently sensitive for the robust identi,cation of chemical respiratory allergens. Furthermore, irrespective of the reasons for variations in TMA-induced IgE production among BN rats, doubts remain regarding the utility of these animals for the characterization of immune responses to chemical allergens. Cytokine pro,ling using the BALB/c strain mouse apparently provides a more robust method for the hazard assessment of chemical respiratory allergens. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Allergy assessment of foods or ingredients derived from biotechnology, gene-modified organisms, or novel foods

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2004
Lars K. Poulsen
Abstract The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein and a risk of sensitizing susceptible individuals. No single predictive test exists to perform a hazard assessment in relation to allergenic properties of newly expressed proteins in gene-modified organisms (GMOs). Instead, performance of a weighted risk analysis based on the decision tree approach has been suggested. The individual steps of this analysis comprise sequence homology to known allergens, specific or targeted serum screens for immunoglobulin E (IgE) cross-reactions to known allergens, digestability studies of the proteins in simulated gastric and/or intestinal fluids, and animal studies. These steps are discussed and five examples of risk evaluation of GMOs or novel foods are presented. These include ice-structuring protein derived from fish, microbial transglutaminase, GMO-soybeans, amylase and the Nangai nut. [source]

Remote sensing of permafrost-related problems and hazards

PERMAFROST AND PERIGLACIAL PROCESSES, Issue 2 2008
Andreas Kääb
Abstract Modern remote sensing techniques can help in the assessment of permafrost hazards in high latitudes and cold mountains. Hazard development in these areas is affected by process interactions and chain reactions, the ongoing shift of cryospheric hazard zones due to atmospheric warming, the large spatial scales involved and the remoteness of many permafrost-related threats. This paper reviews ground-based, airborne and spaceborne remote sensing methods suitable for permafrost hazard assessment and management. A wide range of image classification and change detection techniques support permafrost hazard studies. Digital terrain models (DTMs) derived from optical stereo, synthetic aperture radar (SAR) or laser scanning data are some of the most important data sets for investigating permafrost-related mass movements, thaw and heave processes, and hydrological hazards. Multi-temporal optical or SAR data are used to derive surface displacements on creeping and unstable frozen slopes. Combining DTMs with results from spectral image classification, and with multi-temporal data from change detection and displacement measurements significantly improves the detection of hazard potential. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Permafrost monitoring in the high mountains of Europe: the PACE Project in its global context

PERMAFROST AND PERIGLACIAL PROCESSES, Issue 1 2001
Charles Harris
Abstract This paper introduces the structure and organization of permafrost monitoring within global climate-related monitoring programmes. The five-tiered principle proposed for the Global Hierarchical Observing Strategy (GHOST) is applied to the Global Terrestrial Network for Permafrost (GTN-P) monitoring system, and the European network of mountain permafrost boreholes established by the PACE project is discussed in the context of GTN-P. Borehole design and standard PACE instrumentation are described and some preliminary data from selected boreholes are presented. The broader research aims of the PACE programme include geophysical investigations, mapping and GIS strategies, numerical distribution modelling, physical modelling of thaw-related slope processes and mountain permafrost hazard assessment. Copyright © 2001 John Wiley & Sons, Ltd. RÉSUMÉ Le présent article décrit la structure et l'organisation du programme de surveillance du pergélisol et son intégration dans les programmes de surveillance du climat. Le principe à 5 niveaux proposé pour la stratégie d'observation hiérarchique (GHOST) est appliquée au réseau global de surveillance terrestre du pergélisol (GTN-P). Le réseau européen de sondages dans le pergélisol établi par le projet PACE est discuté dans le contexte du GTN-P. La localisation des sondages et l'instrumentation standard de PACE sont décrites et quelques données préliminaires de certains sondages sélectionnés sont présentées. Les recherches du programme PACE comprennent des recherches géophysiques, des stratégies de cartographie et de systèmes d'information géographique, des modèles de distribution numérique, des modèles physiques des processus de versants en relation avec le dégel et enfin des estimations des risques liés au pergélisol de montagne. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Further uses of the heat of oxidation in chemical hazard assessment

PROCESS SAFETY PROGRESS, Issue 1 2003
Laurence G. Britton
Flammability: The "net heat of oxidation" technique described in an earlier publication is extended to predicting the lower flammable limits, lower limit flame temperatures, and limiting oxygen concentrations of chlorinated organic fuels having H:Cl ratios greater than unity. A new Rule is derived for predicting the effect of initial temperature on the lower flammable limits and limiting oxygen concentrations of organic fuels. It is suggested that this Rule be used in preference to the modified "Burgess-Wheeler" Rule. The effect of initial pressure is discussed. Instability: Net heats of oxidation (kcal/mol oxygen) for a series of disparate fuel groups are compared with ",HD," the maximum heat of decomposition (cal/g) calculated using CHETAH methodology. Given the reasonable assumption that CHETAH's "maximum heat of decomposition" cannot exceed the net heat of combustion ",HC," examination is made as to whether the ratio of these parameters (each expressed in units of kcal/mol), coined the "Reaction Heat Ratio" (RH), provides a useful new indicator for instability assessment. Of these parameters, the net heat of oxidation (,HC/S) is the best indicator to help assign NFPA Instability Ratings. However, ,HC/S cannot generally be used to assign ratings for organo-peroxides. Also, its performance as an indicator for hazardous polymerization depends on the ,HC/S difference between the reacting monomer and the polymer product, so it should become increasingly unreliable as the monomer ,HC/S approaches -100 kcal/mol oxygen. The ranking method tacitly assumes organic polymers to have a constant heat of oxidation of about -100 kcal/mol oxygen. Errors in this assumption must invalidate the ranking approach where ,HC/S differences are small. Finally, separate "cut-offs" must be used at each NFPA Instability Rating for organo-nitrates versus other organics containing combinations of CHON atoms. Additional materials need to be examined to extend this preliminary analysis. The net heat of oxidation would be a useful additional output parameter of the CHETAH program, if only for its application in flammability assessment. No conclusions are drawn regarding the usefulness of net heat of oxidation or RH in conducting CHETAH hazard assessments, since this procedure requires consideration of several variables. However, the analysis may be helpful to the ASTM E 27.07 subcommittee responsible for developing the program. For example, the -,HD , 700 cal/g cut-off used to assign a "high" CHETAH hazard rating typically corresponds to organic materials rated NFPA 1, the second to lowest hazard rating. [source]

The climatology of small-scale orographic precipitation over the Olympic Mountains: Patterns and processes

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 633 2008
Justin R. Minder
Abstract The climatology of small-scale patterns of mountain precipitation is poorly constrained, yet important for applications ranging from natural hazard assessment to understanding the geologic evolution of mountain ranges. Synthesizing four rainy seasons of high-resolution precipitation observations and mesoscale model output (from the Penn State/NCAR MM5), reveals a persistent small-scale pattern of precipitation over the ,10 km wide, ,800 m high ridges and valleys of the western Olympic Mountains, Washington State, USA. This pattern is characterized by a 50,70% excess accumulation over the ridge crests relative to the adjacent valleys in the annual mean. While the model shows excellent skill in simulating these patterns at seasonal time-scales, major errors exist for individual storms. Investigation of a range of storm events has revealed the following mechanism for the climatological pattern. Regions of enhanced condensation of cloud water are produced by ascent in stable flow over the windward slopes of major ridges. Synoptically generated precipitation grows by collection within these clouds, leading to enhanced precipitation which is advected by the prevailing winds. Instances of atypical patterns of precipitation suggest that under certain conditions (during periods with a low freezing level, or convective cells) fundamental changes in small-scale patterns may occur. However, case-studies and composite analysis suggest that departures from the pattern of ridge-top enhancement are rare; the basic patterns and processes appear robust to changes in temperature, winds, and background rainfall rates. Copyright © 2008 Royal Meteorological Society [source]

Effect of an Integrated Public Health Curriculum in an Emergency Medicine Residency

ACADEMIC EMERGENCY MEDICINE, Issue 2009
Marian Betz
Background: Emergency departments (EDs) serve as a central point of interaction between the public and the medical system. Emergency physicians need education in public health in order to optimize their clinical care and their ability to evaluate potential public health interventions in the ED. Methods: As part of the Centers for Disease Control and Prevention (CDC) and the Association of American Medical College's (AAMC) national initiative for "Regional Medicine-Public Health Education Centers-Graduate Medical Education", we designed and implemented a new public health curriculum for the emergency medicine residents. Over four sessions during regular didactic time, we used a modular approach to link a basic public health principle, such as environmental hazard assessment, to a relevant clinical topic, such as violent patients and ED safety. Each session emphasized resident involvement, including small group work and role-plays. Journal clubs and quality assurance projects supplemented the curriculum. We sought resident feedback through focus groups and anonymous online pre- and post-tests for each session. Assessment: Both before and after the curriculum, 76% of responders felt it was important for physicians to receive training in public health. The program appeared to have a positive effect on residents' comfort level with various public health topics, and felt the residency program had taught them the skills necessary to implement public health principles in clinical practice (23.8%, versus 11.5% before; p<0.05). Conclusions: Integration of public health principles into existing clinical curricula in emergency medicine may increase resident interest and knowledge. Combining public health and emergency medicine topics in regular didactic conferences facilitates public health education for residents. [source]

Preliminary Results of In-situ Stress Measurements along the Longmenshan Fault Zone after the Wenchuan Ms 8.0 Earthquake

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2009
Manlu WU
Abstract: Four months after the Wenchuan Ms 8 earthquake in western Sichuan, China, in situ stress measurements were carried out along the Longmenshan fault zone with the purpose of obtaining stress parameters for earthquake hazard assessment. In-situ stresses were measured in three new boreholes by using overcoring with the piezomagnetic stress gauges for shallow depths and hydraulic fracturing for lower depths. The maximum horizontal stress in shallow depths (,20 m) is about 4.3 MPa, oriented N19°E, in the epicenter area at Yingxiu Town, about 9.7 MPa, oriented N51°W, at Baoxing County in the southwestern Longmenshan range, and about 2.6 MPa, oriented N39°E, near Kangding in the southernmost zone of the Longmenshan range. Hydraulic fracturing at borehole depths from 100 to 400 m shows a tendency towards increasing stress with depth. A comparison with the results measured before the Wenchuan earthquake along the Longmenshan zone and in the Tibetan Plateau demonstrates that the stress level remains relatively high in the southwestern segment of the Longmenshan range, and is still moderate in the epicenter zone. These results provide a key appraisal for future assessment of earthquake hazards of the Longmenshan fault zone and the aftershock occurrences of the Wenchuan earthquake. [source]

POPs , schwer abbaubare Chemikalien

CHEMIE IN UNSERER ZEIT (CHIUZ), Issue 3 2007
Gerhard Lammel Professor
Abstract POPs, persistent organic pollutants, sind in der Umwelt schwer abbaubare, gleichzeitig bioakkumulative und toxische Stoffe. Die meisten sind mittelflüchtig und lipophil. Sie werden in der Atmosphäre zu einem erheblichen Teil an Aerosolpartikel sorbiert und nach Ablagerung am Boden oder Deposition in den Ozean in die Atmosphäre zurück verflüchtigt und können so mehrere Emissions-Transport-Depositions-Zyklen durchlaufen. Die Transport- und Verteilungsmuster und das Ferntransport-Potenzial sind damit ganz anders als bei herkömmlichen Luftschadstoffen, deren Transport nach Ablagerung aus der Atmosphäre endet. Dass weite Strecken durch mehrere, jeweils kürzere Wege überwunden werden können, wird als Grashüpfer-Effekt bezeichnet. Eine wichtige Hypothese der Umweltchemie besagt, dass die beobachtete Anreicherung von vielen persistenten und bioakkumulativen Schadstoffen in den Polargebieten, fernab der Anwendungsgebiete eine Konsequenz des Grashüpfer-Effekts sei in Verbindung mit stärkerer Kondensation in kalten Gebieten. Die Lipophilie ist die Voraussetzung für die Bioakkumulation und beeinflusst die Verteilung der Stoffe über mehrere Umweltmedien. Weil es sich bei den POPs im Allgemeinen um teilhalogenierte Stoffe handelt, ist der atmosphärische Abbau zumeist langsamer als für andere Luftschadstoffe, aber schneller als in den anderen Umweltkompartimenten, in denen erst bei Verweildauern von Monaten von Persistenz gesprochen wird. Ferntransport-Potenzial und Persistenz eines Stoffes sind wichtig für die Einschätzung der Gefährdung, die von ihm ausgeht. Sie sind das Ergebnis des Zusammenwirkens physikalisch-chemischer Stoffeigenschaften mit den in Raum und Zeit variablen Umweltbedingungen. Sie variieren deswegen in Raum und Zeit. POPs, persistent organic pollutants, are slowly degradable, bio-accumulative and toxic substances. Most of them are semivolatile and lipophilic. In the atmosphere they sorb to aerosol particles, and upon deposition to soil or water surfaces they may return through volatilisation, enabling them to undergo sequential cycles of emission, atmospheric transport and deposition. These patterns of transport and distribution as well as the long-range transport potential differ significantly from those of conventional air pollutants, which undergo only one such cycle. The capability to travel long distances by several hops is called the grasshopper effect. According to a key hypothesis of environmental chemistry the accumulation of persistent and bio-accumulative pollutants in polar regions, far from the areas of usage, is due to the combination of the grasshopper effect and enhanced condensation in cold areas. Lipophilicity is a prerequisite for bio-accumulation and influences the partitioning among environmental media (multicompartment compounds). As POPs are typically halogenated compounds, chemical degradation in the atmosphere is in most cases slower than of other air pollutants, but faster than in the other environmental compartments, where persistence coincides with residence times of months. The long-range transport potential and persistence are crucial for chemical hazard assessment. These characteristics result from the combined action of physico-chemical properties and environmental conditions variable in time and space. Hence, they vary in time and space. [source]

Competitive binding comparison of endocrine-disrupting compounds to recombinant androgen receptor from fathead minnow, rainbow trout, and human

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007
Vickie S. Wilson
Abstract Typically, in vitro hazard assessments for the identification of endocrine-disrupting compounds (EDCs), including those outlined in the Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) Tier 1 Screening protocols, utilize mammalian receptors. Evidence, however, exists that fish sex steroid hormone receptors differ from mammalian receptors both structurally and in their binding affinities for some steroids and environmental chemicals. Most of the binding studies to date have been conducted using cytosolic preparations from various tissues. In the present study, we compare competitive binding of a set of compounds to full-length recombinant rainbow trout androgen receptor , (rtAR), fathead minnow androgen receptor (fhAR), and human androgen receptor (hAR), each expressed in COS cells. Saturation binding and subsequent Scatchard analysis using [3H]R1881, a high-affinity synthetic androgen, revealed an equilibrium dissociation constant (Kd) of 0.11 nM for the rtAR, 1.8 nM for the fhAR, and 0.84 nM for the hAR. Compounds, including endogenous and synthetic steroids, known mammalian antiandrogens, and environmental compounds, were tested for competitive binding to each of the three receptors. Overall, agreement existed across receptors as to binding versus nonbinding for all compounds tested in this study. Minor differences, however, were found in the relative order of binding of the compounds to the individual receptors. Studies such as these will facilitate the identification of EDCs that may differentially affect specific species and aid in the development and support of future risk assessment protocols. [source]

Enhancing technology development through integrated environmental analysis: Toward sustainable nonlethal military systems

INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 2 2010
Oral S. Saulters
Abstract New technologies are not only critical in supporting traditional industrial and military success but also play a pivotal role in advancing sustainability and sustainable development. With the current global economic challenges, resulting in tighter budgets and increased uncertainty, synergistic paradigms and tools that streamline the design and dissemination of key technologies are more important than ever. Accordingly, a proactive and holistic approach can facilitate efficient research, design, testing, evaluation, and fielding for novel and off-the-shelf products, thereby assisting developers, end users, and other diverse stakeholders in better understanding tradeoffs in the defense industry and beyond. By prioritizing mechanisms such as strategic life-cycle environmental assessments (LCEA); programmatic environment, safety, and occupational health evaluations (PESHE); health hazard assessments (HHA); and other innovative platforms and studies early within systems engineering, various nonlethal military technologies have been successfully developed and deployed. These efforts provide a framework for addressing complex environment, safety, and occupational health risks that affect personnel, infrastructure, property, socioeconomic, and natural/cultural resources. Moreover, integrated, comprehensive, multidisciplinary, and iterative analyses involving flexible groups of specialists/subject matter experts can be applied at various spatiotemporal scales in support of collaborations. This paper highlights the Urban Operations Laboratory process utilized for inclusive and transformative environmental analysis, which can translate into advantages and progress toward sustainable systems. Integr Environ Assess Manag 2010;6:281,286. © 2009 SETAC [source]

Human Instability in Flood Flows,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2008
S.N. Jonkman
Abstract:, Loss of human stability in flood flows and consequent drowning are a high personal hazard. In this paper, we review past experimental work on human instability. The results of new experiments by the Flood Hazard Research Centre (FHRC) are also reported. These new results show that low depth/high velocity flood waters are more dangerous than suggested based on previous experimental work. It is discussed how human instability can be related to two physical mechanisms: moment instability (toppling) and friction instability (sliding). Comparison of the test results with these physical mechanisms suggests that the occurrence of instability in the tests by FHRC is related to friction instability. This mechanism appears to occur earlier than moment instability for the combination of shallow depth and high flow velocity. Those concerned to identify locations where high flood flows could be a threat to human life need to modify their hazard assessments accordingly. [source]