Thesis (Ph.D.)--Tufts University, 2000. / Adviser: Stephen H. Levine. Submitted to the Dept. of Civil Engineering. Includes bibliographical references (leaves 259-277). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

The thesis presents an analysis of environmental risks. Their causes and potential dangerous after-effects which might materialize in the Czech Republic. The theoretical part focuses on the list of current legal environmental risk management standards and points out potential environmental threat sources that might have detrimental impact within both the Czech Republic. In the field research part environmental risk factors and their consequences within the Czech Republic and the South Bohemia region are described. The reserach results have been used to suggest several feasible measures that should help to improve environmental risk prevention, and which should also enhance the risk analysis process carried out by crisis management bodies.

Engineered nanomaterials (ENMs) have been increasingly used in various applications. Often, the ENMs are functionalised with a surface coating to enhance their properties. Decades of research has provided information on mostly pristine and unmodified ENMs, while ecotoxicity of coated ENMs and how their hazard changes with age in soils is still uncertain. The thesis aimed to determine the toxic effects and bioaccumulation potential of CuO ENMs and CdTe quantum dots (QDs) with different chemical coatings (carboxylate, COOH; polyethylene glycol, PEG; ammonium, NH4+) on the earthworm (Eisenia fetida), and compare the effects to their metal salt (CuSO4) or micron-sized counterpart. Then, to determine if any observed toxicity was altered after ageing the soils for up to one year. Incidental plant growth was studied in the exposure soils to maximise the scientific value of the earthworm tests. Toxic effects of CuO ENMs were also assessed in Caenorhabditis elegans exposed in liquid and soil media to understand effects of the media and method of dosing on ENM toxicity. CuO ENMs were equally toxic to earthworms, or less toxic to plants than the dissolved Cu; whereas CdTe QD ENMs were more toxic than the micron-sized CdTe QDs. There was a coating effect in both, CuO and CdTe QD ENM experiments, the -COOH coated ENMs were most toxic in the fresh soil study, while -NH4+ coated ENMs were most toxic in the aged soil study. Despite the similarities in the toxicity ranking, the biological effects exerted were different between CuO and CdTe QD ENMs. In C. elegans exposures, the ENMs were more hazardous than dissolved Cu, but ranking of ENMs depended on the media and method of dosing. The results suggest the coating effect is determined by the reactivity of the coating in a given media, and it also depends on the core of the ENMs. As such, coating and ageing effects should be considered in the risk assessment of ENMs.

Barragens pode ser considerando como risco potencial, o conhecimento da forma provável que se comportaria uma onda de cheia (escoamento crítico), provocado pelo rompimento de barragem é muito importante para as populações que residem à jusante do barramento, como acontece em São José do Jacuípe. Isto por que em caso de rompimento torna-se necessário existir plano de evacuação para área afetada a jusante. Neste sentido destaca-se a utilização de modelos ambientais aliados ao SIG como eficaz ferramenta que possibilita mapear áreas com susceptibilidade a inundação em caso de rompimento. O HEC-RAS surge como poderoso modelo hidrológico capaz de efetuar o modelo para rompimento de barragem em integração com o Sistema de Informação Geográfica. E para classificar o grau de risco da população a jusante é fundamental a adoção de metodologia que contemple as variáveis inerentes à importância deste empreendimento, por tanto será utilizado à metodologia de Menescal (2001) por abarcar todas as facetas importantes de segurança de barragem. / Dams can be considering as a potential risk, knowledge of probable way to behave a flood wave (critical flow) caused by dam break is very important for people living on the bus downstream, as in São José do Jacuípe. This is because in case of breakage becomes necessary to have the evacuation plan for the downstream affected area. In this sense there is the use of environmental models combined with GIS as an effective tool that makes it possible to map areas with susceptibility to flooding in the event of disruption. The HEC-RAS comes as powerful hydrological model able to make the model for dam breaking in integration with Geographic Information System. And to classify the degree of risk of downstream population is essential to adopt methodology that considers the variables inherent importance of this project for both will be used to Menescal methodology (2001) to cover all the important facets of dam safety.

Agricultural production and human activities in a watershed can expose the watershed to environmental degradation, pollution problems, and a decrease in water quality if resources and activities within a watershed are not managed carefully. In order to best utilize limited resources and maximize the results with respect to time and money spent on nonpoint source (NPS) pollution control and prevention, the environmental risk must be identified so that areas with a higher quantified environmental risk can be targeted. The objectives of the research presented in this master thesis were to develop a procedure to quantify environmental risk of nutrient loadings to surface waters and to demonstrate the procedure on a watershed. A procedure to quantify environmental risk of nutrient loadings to surface waters was developed. The risk is identified as the probability of occurrence of a nonpoint source (NPS) pollution event caused by a runoff event multiplied by the consequences to a biological or chemical endpoint. The procedure utilizes the NPS pollution model ANSWERS-2000 to generate upland pollutant loadings to receiving waters. The pollutant loading impact on stream water quality is estimated using the stream module of Hydrologic Simulation Program FORTRAN (HSPF). The risk is calculated as the product of probability of occurrence of a NPS event and consequences of that event. The risk quantification procedure was applied to a watershed in Virginia. Total phosphorus (TP) loadings were evaluated with respect to resultant in-stream dissolved oxygen (DO) concentration. The TP loadings were estimated in ANSWERS-2000 then the consequences were estimated in HSPF. The results indicated that risk was higher for the smaller, more frequent storms indicating that these smaller, more frequent loading events represent a greater risk to the in-stream water quality and ecosystem than larger events. While the probability of occurrence of lower TP loading was higher because they were caused by smaller, more frequent storms, the consequences were less for the same events. The developed procedure can provide watershed stakeholders and managers with a useful tool to quantify the environmental risk a watershed is exposed to as a result of different land management and development scenarios. The scenarios can then be compared to identify a risk level that is considered acceptable. The procedure can also be used by policymakers to set a cap on the risk a certain activity can expose a watershed to. / Master of Science

No description available.

Introduction: This study considered the role that safety, health and environmental (SHE) risk culture should play in the improvement of SHE risk management. The study focused on the perception of SHE risk culture at management and non-management levels in a manufacturing organisation in South Africa. SHE risk culture was viewed in terms of tone from the top and operational understanding of the risk management process. Method: A SHE risk culture questionnaire was created based on information available in the academic literature. The aim of this exploratory questionnaire was to assess the status of the SHE risk culture within the targeted organisation and to recommend improvements. The questionnaire included items designed to assess five aspects of SHE risk culture: understanding of the SHE risk approach; understanding of SHE risks and controls; SHE risk involvement and buy-in; communication; and governance, leadership and accountability. The target group for this study consisted of operations personnel and risk and SHE employees at different levels in the company. Survey data were obtained from 224 employees from a wide range of jobs in the company. Results: The data from the Likert-scale items in the questionnaire showed a number of significant differences between the perceptions of managers and non-managers with respect to the status of the SHE risk culture in the organisation. These differences indicated that management felt more comfortable with their understanding of the SHE risk approach, of the actual SHE risks, and of risk management controls than the non-management group. Also, management showed greater support for, and buy-in to, the SHE risk approach than the non-management group. In addition, participants shared their views of how the SHE risk culture in the organisation may be improved. The top five recommendations were: improve communication on SHE risk culture; standardise the SHE risk management approach; enhance SHE risk-related training to build capacity and understanding; emphasize the significance of leadership’s approach to embedding the SHE risk culture; and acknowledge the importance of involving employees in the development and implementation of the desired SHE risk culture. Conclusion: This study illustrated the importance of a number of factors required to improve the SHE risk culture in the organisation both in terms of tone from the top and operational understanding of SHE risks: they include well-structured communication; standardising and simplifying SHE risk management; SHE risk capacity building; and encouraging employee participation when developing and improving the desired SHE risk culture. The central role played by leadership to set the tone from the top and lead by example when implementing the desired organisational SHE risk culture was also highlighted by the participants. Practical application: This study provides evidence-based guidance for the manufacturing sector on how to evaluate and improve a desired SHE risk culture. The paper also shows how the concept of risk culture can be applied to SHE risk culture. The questionnaire used in this study can be used by management teams wishing to get an understanding of the prevailing SHE risk culture in their organisations. The results of the survey can be used to inform change interventions to improve the existing SHE risk culture in the organisation studied. The questionnaire should also be useful for further research on the concept of risk culture and in particular SHE risk culture.

Introduction: This study considered the role that safety, health and environmental (SHE) risk culture should play in the improvement of SHE risk management. The study focused on the perception of SHE risk culture at management and non-management levels in a manufacturing organisation in South Africa. SHE risk culture was viewed in terms of tone from the top and operational understanding of the risk management process. Method: A SHE risk culture questionnaire was created based on information available in the academic literature. The aim of this exploratory questionnaire was to assess the status of the SHE risk culture within the targeted organisation and to recommend improvements. The questionnaire included items designed to assess five aspects of SHE risk culture: understanding of the SHE risk approach; understanding of SHE risks and controls; SHE risk involvement and buy-in; communication; and governance, leadership and accountability. The target group for this study consisted of operations personnel and risk and SHE employees at different levels in the company. Survey data were obtained from 224 employees from a wide range of jobs in the company. Results: The data from the Likert-scale items in the questionnaire showed a number of significant differences between the perceptions of managers and non-managers with respect to the status of the SHE risk culture in the organisation. These differences indicated that management felt more comfortable with their understanding of the SHE risk approach, of the actual SHE risks, and of risk management controls than the non-management group. Also, management showed greater support for, and buy-in to, the SHE risk approach than the non-management group. In addition, participants shared their views of how the SHE risk culture in the organisation may be improved. The top five recommendations were: improve communication on SHE risk culture; standardise the SHE risk management approach; enhance SHE risk-related training to build capacity and understanding; emphasize the significance of leadership’s approach to embedding the SHE risk culture; and acknowledge the importance of involving employees in the development and implementation of the desired SHE risk culture. Conclusion: This study illustrated the importance of a number of factors required to improve the SHE risk culture in the organisation both in terms of tone from the top and operational understanding of SHE risks: they include well-structured communication; standardising and simplifying SHE risk management; SHE risk capacity building; and encouraging employee participation when developing and improving the desired SHE risk culture. The central role played by leadership to set the tone from the top and lead by example when implementing the desired organisational SHE risk culture was also highlighted by the participants. Practical application: This study provides evidence-based guidance for the manufacturing sector on how to evaluate and improve a desired SHE risk culture. The paper also shows how the concept of risk culture can be applied to SHE risk culture. The questionnaire used in this study can be used by management teams wishing to get an understanding of the prevailing SHE risk culture in their organisations. The results of the survey can be used to inform change interventions to improve the existing SHE risk culture in the organisation studied. The questionnaire should also be useful for further research on the concept of risk culture and in particular SHE risk culture.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2011. / Please refer to full text for abstracts

Abandoned metal mines in the Tamar catchment, south west England, represent a significant threat to surface water quality via generation of acid mine waters. Currently the River Tamar fails environmental quality standards (EQS) established under the Water Framework Directive (2000/60/EC) for dissolved Cu (x ̅ = 0.19 ± 0.05 μmol L-1) and Zn (x ̅ = 0.19 ± 0.06 μmol L-1, both 1997-2007) downstream of historic mining area of Gunnislake. The aim of this study was to quantify the risk to surface water quality by diffuse drainage generated by mine waste tips. For the first time, a GIS model was compiled and used to generate a priority list of known areas of mine waste, based on physical and environmental factors. The methodology was consistent with European guidance documentation published to meet the requirements of the Mining Waste Directive (2001/21/EC) and has since been applied, in a modified form, to other catchments in south west England. Two study sites, with contrasting mineralogy and hydrology, scored highly in the model and were the subject of field investigations from 2007-2009. These were Devon Great Consols (DGC), an abandoned Cu-As mine near Gunnislake and Wheal Betsy (WB), an abandoned Pb-Ag mine, near Mary Tavy. At each site, surface waters and shallow groundwaters were sampled and analysed for dissolved metals (including Al, Cu, Zn, Mn, Pb, Ni, and Cd), metalloids (As, Sb), major ions and anions. Samples of four selected mine waste tips were also gathered and subjected to a range of laboratory leaching experiments including the novel application of a dynamic upflow percolation test, based on an existing European method (CEN TS 14405). Leachates generated by the waste tips in the field were highly variable and elevated with respect to EQS for Al (up to 1850 μmol L-1), Cu (570 μmol L-1), Zn (34 μmol L-1), Ni (3.8 μmol L-1), Cd (0.17 μmol L-1), Mn (216 μmol L-1), Fe(537 μmol L-1) , As (380 μmol L-1) and Sb (5.4 μmol L-1). Estimated annual fluxes of dissolved metals were predicted using average rainfall data and catchment areas calculated in ArcHydro9 to estimate the annual discharge of waters from the tip. These calculations showed annual contaminant flux from the tips to exceed, or be of the same order of magnitude to, major adit discharges in the catchment (e.g. Cu 50900-66900 mol y-1 at DGC and 470 mol y-1 Cd at WB) and represented a significant contributor to metal flux in the Tamar catchment. Primary sulphide minerals in the waste were generally highly altered and metals (Pb, Cu, Zn, and Mn) and As were found to be strongly associated with secondary iron minerals, precipitated under oxic conditions. In finer wastes, sorption to clay minerals was also found to be very important for the retention of dissolved metals, particularly Pb. Concentrations of contaminants in column field leachates were similar for most metals (Cu, Zn, Mn, Ni and Cd) and may provide a useful tool for prediction of leachate composition. However, sorption and release of metals and As to the secondary phases and clays were highly sensitive to pH change and where laboratory experiments did not replicate field pH, discrepancies between in situ and laboratory results were observed up to two orders of magnitude in scale (particularly for As and Pb).