Dissertations / Theses on the topic 'Health and ecological risk assessment'
To see the other types of publications on this topic, follow the link: Health and ecological risk assessment.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Health and ecological risk assessment.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Pokhrel, Lok R., and Phillip R. Scheuerman. "Ecological Risk Assessment of Zinc Oxide Nanoparticles." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/2962.
Full text
2
Pokhrel, Lok R., Brajesh Dubey, and Phillip R. Scheuerman. "Ecological Risk Assessment of Zinc Oxide Nanoparticles." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/2951.
Full text
3
Doyle, James. "Mass Balance Tracer Techniques for Integrating in situ Soil Ingestion Rates into Human and Ecological Risk Assessments." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20557.
Full textAbstract:
Quantitative soil ingestion studies employing a mass balance tracer approach have been used to determine soil ingestion rate for use in human health risk assessments (HHRAs). Past studies have focused on soil ingestion in populations living in urban/suburban environments and the results have been highly variable. Moreover, there is a paucity of reliable quantitative soil ingestion data to support human health risk assessments of other lifestyles that may be predisposed to ingesting soil, such as indigenous populations following traditional lifestyles. Thus, the primary objective of the research was to determine if populations following lifestyles typical of traditional land use practices in rural or wilderness areas ingest more soil than populations living in urban or suburban environments. Further, the research investigated the use of alternative mass balance tracers, specifically isotopes of the 238U and 232Th decay series, to reduce soil ingestion estimate variability. Mass balance tracer methods were developed and validated in a pilot canine study, and methods using isotope tracers were adapted to permit quantification of sediment ingestion in the benthic fish Moxostoma macrolepidotum (Shorthead Redhorse Sucker). A pilot human soil ingestion study of 7 subjects from an Aboriginal community in British Columbia was conducted over a 3-week period. The mean soil ingestion rate calculated using the daily means of the 4 elemental tracers with the lowest food-to-soil ratios (i.e., Al, Ce, La, Si) was observed to be approximately 74 mg d-1 (standard deviation 91 mg d-1), The median soil ingestion rate was 60 mg d-1, and the 90th percentile was 196 mg d-1. These soil ingestion rate estimates are higher than those currently recommended for HHRAs of adults, and higher than those obtained in most previous studies of adults. However, the estimates are much lower than the earlier qualitative assessments for subsistence lifestyles (i.e., 330-400 mg d-1). The study results also demonstrated that isotopes of the 238U and 232Th decay series radionuclide are not reliable mass balance tracers for estimating soil ingestion in humans; however, they may be useful for quantifying soil and sediment ingestion in wildlife.
4
Sansayavichai, Pathratipa. "An approach designed for regional prospective human health and ecological risk assessment and its application to mercury risks from a coal-fired power plant." Connect to this title online, 2009.
Find full text
5
Smith, David A. "An integrated approach to evaluating the environmental impact following a radiological dispersal event." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1148312072.
Full text
6
Watson, Sarah Louise. "Assessing the Impacts of Unrestricted Pesticide Use in Small-Scale Agriculture on Water Quality and Associated Human Health and Ecological Implications in an Indigenous Village in Rural Panam[aacute]." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5149.
Full textAbstract:
In 2014, the global pesticide industry's projected worth is $52 billion and by 2020, the developing world will make up one-third of the world's chemical production and consumption. Pesticides can have unintended negative consequences for human health and the environment, especially in the developing world where regulations are loose or nonexistent. One country with unrestricted use of pesticides is Panam[aacute], especially in Santa Rosa de Cucunatí. In this indigenous village, small-scale farmers and ranchers spray paraquat, glyphosate, picloram, and 2,4-D at higher elevations than the spring water source of a gravity-fed water system, the river, and the village. The objective of this study was to estimate the concentration of these pesticides in the water system and the river and to perform a human health and ecological risk assessment.
Pesticide fate and transport models in the graphical user interface EXAMS-PRZMS Exposure Simulation Shell (EXPRESS), which was developed by the United States Environmental Protection Agency, were used to predict concentrations of the four mentioned pesticides in drinking water and the river using chemical properties, data from Food and Agriculture Organization and Smithsonian Tropical Research Institute, and the author's experience as a Peace Corps Volunteer. The results from Tier I model FQPA Index Reservoir Screening Tool (FIRST) were used to compare immediate and delayed rain events, noting minimal difference. The Tier II PRZM-EXAMS shell provided estimated drinking water concentration (EDWC) profiles. The paraquat profile was much lower than picloram, glyphosate, and 2,4-D, which had almost identical profiles with peak concentrations around 12 ppm and the average annual concentration 100 ppb.
Average Daily Dose (ADD) via drinking water was calculated for men, women, and children using model results and compared to the oral reference dose (RfD). ADDs only exceeded the RfD with maximum peak EDWCs, implying low risk. However, RfD was used to calculate a breakpoint concentration, the concentration at which each pesticide presents a risk to the consumer. This was then compared to the maximum peak (highest, i.e. worst-case scenario) and annual (lowest, i.e. best-case scenario) EDWC profiles. In the best-case scenario, glyphosate and picloram did not pose a threat, paraquat posed a moderate threat and 2,4-D posed a high threat, with the concentration exceeding the breakpoint for 90 percent of the years. With respect to the worst-case scenario, all four chemicals posed high threats to the consumer. Individual exposure via consumption of fish from the river was calculated using a calculated bioconcentration (BCF) factor and calculated breakpoint concentrations. For the best case scenario, picloram presented a low risk and 2,4-D presented a high risk but for the worst case, both of these chemicals presented a very high risk. An additive exposure of these two human health pathways found that for the best case scenario, exposure from most of the four chemicals did not approach the RfD. However, for the worst-case scenario the exposures were significantly higher than the oral RfD--therefore, between the lowest and the highest concentrations, the general population is at risk.
For the ecological risk assessment, the 96-hour peak profile was compared to the 96-hour lethal dose (LD50); glyphosate posed a high risk to fathead minnows and low risk to bluegills and 2,4-D presented a high risk to fathead minnows, low risk to channel catfish, and very high risk to bluegills. A more general risk assessment compared maximum peak and annual concentrations to the US EPA's aquatic life benchmarks. Glyphosate presented no threat and 2,4-D only presented a threat to plants. For picloram, fish were at very high risk at the chronic level and low risk at the acute level, and plants were at moderate risk. Paraquat presented the most significant threat to aquatic life, exceeding benchmarks for all plants and invertebrates at the chronic level 100 percent of the time. It presented no threat to fish in the best-case scenario, but a high risk for fish at the chronic level in the worst case scenario, as well as very high risk for all invertebrates and plants. Improvements in application and watershed protection as part of a multi-disciplinary approach are proposed in place of technological mitigation strategies. Recommendations for future studies include the development of a developing-world context model and experimental studies in the developing world to compare to model results, where possible.
7
Hack, L. A. "Development and validation of the marine benthic copepod Robertsonia propinqua as a bioindicator to monitor estuarine environmental health." Lincoln University, 2008. http://hdl.handle.net/10182/307.
Full textAbstract:
Studies in the USA have reported that species of meiobenthic copepods can be used as bioindicators of sediment-associated contaminants. The main objective of this research project was to develop and validate methods to assess the effects of estuarine pollution, using the marine benthic copepod Robertsonia propinqua as a bioindicator of environmental health in New Zealand intertidal / estuarine areas. Cultures of R. propinqua were set up and maintained in the laboratory and individuals used in 96h acute and full life-cycle chronic bioassays using the pre-selected contaminants atrazine and zinc sulphate. From the 96h acute experiments it was found that the lethal doses at which 50% mortality occurred (LC50) for exposed nauplii and adult individuals were 7.5 mg/L and 31.8 mg/L, respectively for atrazine and 1.7 mg/L and 2.7 mg/L, respectively for zinc sulphate. This indicated that the nauplii life stage was more sensitive than were the adult life stages for exposure to both contaminants. Based on the 'trigger' values reported (atrazine = 0.013 mg/L, zinc = 0.015 mg/L) in the Australian and New Zealand guidelines for fresh and marine water quality, which provide values at which concentrations of contaminants can occur in the environment before they begin causing effects on aquatic fauna, it is unlikely that the calculated LC50s in the current research will induce biological effects in exposed copepods in the short-term. The calculated LC50 results were then used to further investigate the effects of chronic exposure of sediment-associated contaminants on the complete life-cycle (egg-reproductive adult) of R. propinqua. In a laboratory-based full life-cycle toxicity test, field-collected sediments from polluted sites in the Auckland and Bay of Plenty regions reduced reproductive output (nauplii and copepodite production) of R. propinqua individuals, but the number of males and females, gravid females, clutch size per female and the number of eggs produced were not affected by either the polluted or non-polluted (reference) sediment samples from both field regions. Field investigations of meiofauna community composition in polluted and non-polluted field sites were carried out in 2004 in the Auckland and Bay of Plenty field regions in New Zealand. Greater sediment organic content and a correspondingly deeper redox potential discontinuity layer occurred in all polluted field sites compared with the non-polluted sites. However, species composition could not be used to characterise polluted and non-polluted sites, as there were no dominant taxa which were representative of these sites. The results presented in this thesis indicate that R. propinqua has strong potential to be a good candidate species as a bioindicator of environmental contamination. Furthermore, the full life-cycle toxicity test could be used as a rapid test to detect immediate changes in individual reproduction and development as well as long-term population effects. The technologies developed as part of this research may eventually provide additional tools for commercial environmental consultancies and may compliment existing standard operating procedures for environmental assessments involving pollution of estuarine ecosystems.
8
Davis, Ryan Scott. "An ecological risk assessment for mosquito insecticides." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/davis/DavisR0507.pdf.
Full text
9
Hazlerigg, Charles Rupert Edward. "Fish population ecology and ecological risk assessment." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9678.
Full textAbstract:
Density-dependent processes are crucial in the regulation of fish populations and strongly influence their resilience to exploitation and exposure to toxic chemicals. Multiple density-dependent processes occur at different stages in the life-cycle of fish, and a general pattern of such processes in the ontogeny of fish has been suggested but not clearly demonstrated in natural populations. This thesis aimed to provide a detailed experimental assessment of density-dependent processes through the entire life-cycle, using laboratory and semi-natural populations of zebrafish, Danio rerio, and to explore the implications of these processes for the ecological risk assessment of endocrine disrupting chemicals using an individual-based population model. Results clearly demonstrate the importance of density-dependent mortality in the early juvenile life-stage and density-dependent growth in the late juvenile and adult life-stages consistent with evidence from wild populations of much larger wild species, suggesting the existence of general ontogenetic patterns of density dependence that are invariant to maximum size. Patterns of density dependence found in populations of zebrafish under semi-natural conditions in Bangladesh were similar to those observed in the laboratory, except that the absolute strength of density dependence was higher and consequently, carrying capacity lower, by about two orders of magnitude in the semi-natural populations. A conclusion from these studies is that these patterns of density dependence are applicable generally across the teleost taxa due to developmental similarities. The population model incorporating these patterns of density dependence showed that density dependence compensated for reasonably high levels of disruption for many individual-level endpoints currently used in risk assessment, including fecundity and sex ratio. This indicates that current risk assessment practices are highly conservative and the inclusion of population models such as developed here for zebrafish, could enhance the scientific basis and ecological realism of laboratory derived data used in risk analysis.
10
Chen, Limei. "Nonparametric assessment of safety levels in ecological risk assessment (ERA)." FIU Digital Commons, 2003. http://digitalcommons.fiu.edu/etd/2135.
Full textAbstract:
In ecological risk assessment (ERA), it is important to know whether the exposure that animal species receive from a chemical concentration exceeds the desired safety level. This study examined several statistical methods currently being used in ecological risk assessment and reviewed several statistical procedures related to this subject in the literature. Two large sample nonparametric tests were developed for this study. Monte Carlo study showed that these tests performed well even when the sample size was moderately large. A real data set was used to show that the new methodologies provide a good method for assessing the potential risks of pesticides residues at an investigated site.
11
Whittle, Don. "Stream mesocosms in ecological risk assessment : experimental, analytical and ecological considerations." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339940.
Full text
12
Hayes, Keith Robert. "Quantitive ecological risk assessment a ballast-water case study." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/1230.
Full text
13
Ip, Tsz-kin Derek. "Ecological risk assessments for marine mammals in Hong Kong." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37120694.
Full text
14
Oliveira, Paulo Alexandre da Silva. "Ecological risk assessment of pesticides in maize and tomato crops." Master's thesis, ISA/UL, 2017. http://hdl.handle.net/10400.5/17946.
Full textAbstract:
Mestrado em Engenharia Agronómica - Proteção das plantas - Instituto Superior de AgronomiaFoi realizado um estudo das comunidades de zooplâncton presentes na água de irrigação das culturas de milho e tomate em condições mediterrâneas portuguesas, a fim de vincular possíveis relações entre a exposição a pesticidas e as respostas biológicas. Este trabalho é uma contribuição para melhorar a relevância ecológica da Avaliação do Risco Ambiental de Pesticidas. Um total de 37 espécies de rotiferos e 2 famílias de cladóceros foram identificadas. Os principais componentes do zooplâncton em todos os locais de amostragem foram nauplios e rotíferos que parecem ser menos afetados pelos pesticidas. A concentração de 12 ug / l de clorpirifos reduz o número de macrozooplâncton, permitindo o aumento das densidades de rotiferos. Valores de 3,5-4,7 ug / l de clorantrinaprole e 0,96 ug / l de metribuzina parecem afetar negativamente o tamanho da comunidade de copépodos. As comunidades de Cladóceros e Ostracodes parecem diminuir quando os valores do glifosato estão na faixa de 2,3-3,9 ug / l. Os valores de glifosato (0,66 ug / l), Ampa (0,88 ug / l) e Fosfato (2,38 mg / l) parecem estar ligados a valores mais baixos de índice de riqueza de espécies
N/A
15
DUARTE, Heitor de Oliveira. "A methodology for quantitative ecological risk assessment for industrial accidents." Universidade Federal de Pernambuco, 2011. https://repositorio.ufpe.br/handle/123456789/5960.
Full textAbstract:
Made available in DSpace on 2014-06-12T17:42:48Z (GMT). No. of bitstreams: 2
arquivo7684_1.pdf: 3197582 bytes, checksum: e9a5a1df323907fb05bb3c1b206c2fd5 (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2011Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Recentes acidentes industriais, como vazamentos tóxicos, têm causado danos catastróficos ao meio ecológico (i.e. plantas e animais), de modo que um método efetivo para analisar riscos ecológicos tem sido demandado. Em primeiro lugar, este trabalho tem como objetivo propor uma metodologia capaz de quantificar riscos ecológicos inerentes a eventos raros como acidentes industriais. Utiliza-se a modelagem populacional para simular futuras mudanças na abundância populacional de espécies-chave em risco e, assim, estimar a probabilidade de extinção ou declínio, tempo para extinção e outras medidas, para cada cenário acidental. Assim, foi possível desenvolver uma abordagem que combina os danos ecológicos (previstos através da modelagem populacional) com a frequência de ocorrência do cenário acidental (estimada através de dados históricos e análise de confiabilidade). O resultado é uma curva de risco FN (similar ao resultado de uma análise de risco a humanos), onde N é o declínio populacional médio e F a frequência acumulada de acidentes com declínio maior ou igual a N. Em segundo lugar, o trabalho apresenta uma aplicação da metodologia para quantificar os riscos ecológicos provenientes de acidentes associados ao transporte e manuseio de petróleo que abastece uma refinaria no Complexo Industrial Portuário de Suape-PE, no Nordeste do Brasil. Esta instalação está localizada próxima a um rico ecossistema aquático de alta biodiversidade. A população de uma espécie nativa foi estrategicamente escolhida para representar o ecossistema, alguns cenários de derramamento de petróleo foram simulados e suas frequências de ocorrência estimadas. Para cada cenário acidental, a concentração de óleo que atinge a população foi prevista via modelagem de destino e transporte. Os riscos ecológicos foram quantificados e apresentados em uma curva FN. Uma análise de sensibilidade foi feita para explorar como mudanças em parâmetros específicos causam mudanças nas medidas de risco. Além disso, a incerteza foi medida como um intervalo (limite superior e inferior) para as medidas de riscos com base em cenários pessimistas e otimistas. Finalmente, a metodologia mostrou-se viável, eficiente, conveniente e flexível, apesar de que algumas melhorias ainda podem ser feitas e estas foram propostas para trabalhos futuros
16
Silva, Emília Cardoso Moura da. "Approaches to improve the ecological risk assessment of pesticides in freshwaters." Doctoral thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/9255.
Full textAbstract:
Doutoramento em Engenharia Agronómica - Instituto Superior de AgronomiaOne of the most important ways of improving agricultural production is the use of plant protection products. As this type of pesticides is used within the catchment area of freshwaters there is a potential for side-effects to occur in aquatic ecosystems. New challenges for risk assessment were addressed to achieve good chemical and ecological status in European water bodies. Site-specific and ecologically-based approaches were developed and applied to three important Portuguese river basins. Better criteria for the assessment of the ecological and chemical status of water bodies was provided by calculating groundwater threshold values for pesticides and by focusing on river basin specific pollutants. A list of priority pesticide mixtures that might pose aquatic risks was obtained by employing risk quotients based on concentration addition as a ‘screening level’ risk assessment of pesticide mixtures, and the multi-substance potentially affected fraction, representing a higher tier, with more practical usefulness and relevancy for risk management. For an integrated assessment of pesticide stress in freshwaters, and moving toward a more holistic approach, chemical analysis were used in combination with effect-based tools, in order to provide a link between chemical and ecological assessments. The results contribute for reducing the risks of pesticides in freshwaters
FCT
17
Su, Yang. "Development of an Ecological Risk Assessment Tool for Trace Organic Compounds." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1428653300.
Full text
18
Ip, Tsz-kin Derek, and 葉子健. "Ecological risk assessments for marine mammals in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B39849132.
Full text
19
Sinnett, Danielle. "Application of ecological risk assessment to community greenspace establishment on contaminated land." Thesis, University of Reading, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525132.
Full text
20
DUARTE, Heitor de Oliveira. "A novel quantitative ecological and microbial risk assessment methodology: theory and applications." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17633.
Full textAbstract:
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-05T15:07:47Z
No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
20160404 Tese final Duarte catalogada formato digital.pdf: 4026733 bytes, checksum: d6ac5259ffcea51116ee53e1ba8c164a (MD5)Made available in DSpace on 2016-08-05T15:07:47Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 20160404 Tese final Duarte catalogada formato digital.pdf: 4026733 bytes, checksum: d6ac5259ffcea51116ee53e1ba8c164a (MD5) Previous issue date: 2016-03-18
CNPq
The environment is a complex system where human, ecological environment (e.g., plants, animals, microbes), materials (eg, pollutants, medical), and meteorological/oceanographic conditions interact. The human impact has potential to cause significant damage to the ecological environment (e.g., potential oil spills on the coast cause risk to coastal ecosystems, tuna industrial fishing cause risk to sharks that are bycaught). Similarly, the human impact may turn against the human itself by favoring the growth of populations of unwanted species (e.g., poor sanitation favors the growth of microbial populations that cause risk of an excessive proportion of sick humans). Therefore, it has been demanded an efficient method of quantifying the risks in systems where plant, animals or microbes populations are involved in order to give support to risk management in environmental issues, fisheries management and public health. First, this paper proposes a methodology capable of quantifying ecological risks (i.e., likelihood of adverse effects on the ecosystem, in the long term, due to exposure to stressors such as chemical, fishing, etc.) or microbial risks (i.e., likelihood of adverse effects in humans, in the long term, due to exposure to microbial pathogens). It uses population modeling to simulate future changes in populations of ecologically important species (e.g., fish, corals, sharks), or undesirable (e.g., parasites), under conditional scenarios simulating the influence humans impacting and/or managing the risks. The risk is calculated in terms of probability of extinction or decline, explosion or growth of these populations over time. Second, the methodology is applied to four case studies in Brazil. Each of them have their specific conclusions, as follows. (1) Ecological Risk Assessment caused by potential maritime accidents in the transportation of oil to the port of Suape. Conclusion: low but significant ecological risk. (2) Ecological Risk Assessment caused by potential maritime accidents in the passage of oil tankers nearby Fernando de Noronha. Conclusion: negligible ecological risk, although a more detailed analysis is required due to limited data. (3) Microbial Risk Assessment to Porto de Galinhas community inherent to sanitation and medical treatment program. Conclusion: high microbial risk, the current sanitation level is not enough to contain the spread of schistosomiasis disease, and periodic treatment of patients is not efficient to reduce risks significantly. (4) Ecological Risk Assessment of tuna industrial fishing in Brazilian waters. Conclusion: industrial tuna fishing does not cause significant risks to the population of Mako sharks in the South Atlantic Ocean. In each case study, several conditional scenarios were simulated for the next 100 years, including adverse scenarios and scenarios with risk control measures. Thus, it was possible to quantify the added risk caused by each adverse condition as well as the reduced risk caused by each control measure. In this way, the manager has objective information to prioritize scenarios and evaluate the cost-effectiveness of control measures. The general conclusion of this work is that the proposed methodology has proven to be practicable, useful and efficient.
O meio-ambiente é um sistema complexo onde interagem humanos, meio ecológico (e.g., plantas, animais, micróbios), materiais (e.g., poluentes, medicinais) e condições meteorológicas/oceanográficas. O impacto humano tem potencial para causar danos significativos ao meio ecológico (e.g., potenciais vazamentos de petróleo na costa causam risco ao ecossistema costeiro, pesca industrial de atum causa risco aos tubarões que são pescados por acidente). Similarmente, o impacto humano pode se voltar contra o próprio humano ao favorecer o crescimento de populações de espécies indesejáveis (e.g., saneamento básico precário favorece o crescimento de populações de micróbios que causam risco de haver uma excessiva parcela de humanos doentes). Portanto, tem sido demandado um método eficiente de quantificar os riscos inerentes a sistemas onde populações de plantas, animais ou micróbios estejam envolvidas, de forma a dar suporte para o gerenciamento dos riscos em problemas de gestão ambiental, gestão pesqueira e saúde pública. Em primeiro lugar, este trabalho propõe uma metodologia capaz de quantificar riscos ecológicos (i.e., probabilidade de ocorrência de efeitos adversos no ecossistema, no longo prazo, devido à exposição a estressores como químicos, pesca, entre outros) ou microbianos (i.e., probabilidade de ocorrência de efeitos adversos em humanos, no longo prazo, devido à exposição a patógenos microbianos). Utilizase a modelagem populacional para simular futuras mudanças nas populações de espécies ecologicamente importantes (e.g., peixes, corais), ou indesejáveis (e.g., parasitas), quando condicionadas a cenários que simulam a influência do humano causando impacto e/ou gerindo os riscos. O risco é calculado em termos de probabilidade de extinção ou declínio, explosão ou crescimento, dessas populações ao longo do tempo. Em segundo lugar, aplica-se a metodologia para avaliar o risco inerente a quatro estudos de caso no Brasil. Cada um deles tem sua conclusão específica, como segue. (1) Análise de Risco Ecológico causado por potenciais acidentes marítimos no transporte de petróleo para o porto de Suape. Conclusão: baixo risco ecológico, porém significativo. (2) Análise de Risco Ecológico causado por potenciais acidentes marítimos na passagem de navios petroleiros ao largo de Fernando de Noronha. Conclusão: risco ecológico negligenciável, mas uma análise mais detalhada é necessária devido à escassez de dados. (3) Análise de Risco Microbiano à comunidade de Porto de Galinhas inerentes ao sistema de saneamento básico e programa de tratamento medicinal. Conclusão: alto risco microbiano, o nível de saneamento básico atual não é suficiente para conter a proliferação da doença esquistossomose, e o tratamento periódico de doentes não é eficiente para reduzir os riscos significativamente. (4) Análise de Risco Ecológico causado pela pesca industrial de atum em águas brasileiras. Conclusão: a pesca industrial de atuns não causa riscos significativos à população de tubarões Mako no oceano Atlântico Sul. Em cada estudo de caso, foram simulados diversos cenários condicionais para os próximos 100 anos, incluindo cenários adversos e cenários com medidas de controle dos riscos. Assim, foi possível quantificar a adição do risco causada por cada cenário adverso e a redução do risco causada por cada medida de controle. Desta forma, o gestor tem informação objetiva para priorizar cenários e avaliar o custo-benefício das medidas de controle. A principal conclusão deste trabalho é que a metodologia proposta provou-se ser praticável, útil e eficiente.
21
Sanchez, André Luís. "Ecological risk assessment in pesticide contamination scenarios: from individuals to ecosystems responses." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18139/tde-06102016-101708/.
Full textAbstract:
Ecological risk assessment (ERA) studies are important to assess environmental changes that have been caused by anthropogenic activities. These integration models show the estimation of adverse risk effects across the levels of biological organization potentially exposed to perturbation, including a better understanding of the ecosystems complexity. It is well known that the pesticide have severe environment effects contributing to biodiversity loss and trophic levels changes. In this context, the aim of this study was to evaluate the ecological risk assessment in pesticide contamination scenarios for aquatic and terrestrial compartments. To attempt it direct and indirect effects on individual response for different biological organization and for multi trophic interactions responses with ecosystems models were evaluated. Thus the environmental impacts in relation to losses and changes of the ecosystems functions and services were analyzed. For this purpose, a risk scenario was designed to compare the Ivermectin contamination exposure routes, via dermal (soil) and oral (food) on Eisenia fetida reproduction tests. An experimental approach was constructed to characterise the effects of the fungicide Scala® (Pyrimethanil) in spraying application comparing to homogenous soil application on a constructed soil multi-species test system. n experiment was performed to reported the effects of the fungicide Mythos® (Pyrimethanil) with terrestrial plant test followed by elutriate test with non-targets freshwater organisms and avoidance test with soil invertebrates and quantify the ecosystems services framework. A holistic higher tier fungicide risk assessment was done with terrestrial and aquatic responses and trophic levels with multitrophic interactions in ecosystem models and supplementary with individuals\' responses. The results obtained suggest that the analyzed reproduction parameters for earthworms were affected with the increase of ivermectin concentrations with statistical significant differences between the contamination exposure routes. The fungicide pyrimethanil has adverse effect on soil invertebrates\' response for the application and spatial distribution with the habitat preferences and foraging abilities has affected directly or indirectly by the fungicide toxicity. The impacts by the runoff and leaching pesticides into adjacent water bodies and surrounding soil showed changes in the organism\'s structure with changes and loss in the provisioning, regulatory and supporting services. The integrated holistic four-tiered fungicide risk assessment showed the possible impacts and the adverse effects on the terrestrial and aquatic organisms, ecosystems and processes in the simulate scenarios. From the results, it is possible to conclude that the experiments performed crossed the multiple aspects of contaminations and show the individuals to ecosystems responses approaches using the exposure routes of contamination, multi trophic interactions of experimental ecosystems models, behavioral, individual and some comparatives responses with aquatic and terrestrial compartments in risk assessment. Furthermore, this study are an important register for the deleterious effects and responses to impacts of pesticides, prompting the possible environmental losses and changes of the ecosystems functions and services in disturbances areas.Os estudos de avaliação de risco ecológico consistem em avaliar os riscos ecológicos ocasionados pelas diversas atividades antropogênicas a um determinado sistema. Essa abordagem de integração reporta a estimativa dos efeitos de risco adverso através dos níveis de organização biológica potencialmente expostos a pertubação, incluindo assim uma melhor compreensão da complexidade dos ecossistemas. É bem conhecido que os pesticidas possuem efeitos nocivos ao meio ambiente, contribuindo para a perda de biodiversidade e mudanças nos níveis tróficos. A partir dessa análise, o objetivo geral desse estudo foi uma avaliação de risco ecológico em cenários de contaminação por pesticidas em relação aos compartimentos terrestres e aquáticos. Para tanto, foram avaliados os efeitos diretos e indiretos sobre as respostas individuais para diferentes níveis de organização biológica e para as interações multitróficas através de modelos ecossistêmicos. Assim, foram analisados os impactos ambientais em relação as perdas e mudanças das funções e serviços dos ecossistemas. Para esse propósito, foram desenvolvidos cenários de risco em relação as rotas de exposição do antiparasitário Ivermectin para a minhoca Eisenia fetida em relação a testes de reprodução, através da via dermal (solo) e oral (comida). Foi construída uma abordagem experimental para caracterizar os efeitos do fungicida Scala® (Pyrimethanil), comparando a aplicação através de pulverização por spray com a aplicação homogênea no solo em um sistema terrestre multiespécies. Experimentos foram realizados para reportar os efeitos do fungicida Mythos® (Pyrimethanil) em plantas terrestres alvo, seguidos por teste com elutriato com organismos de água doce não-alvo e testes de fuga com invertebrados terrestres não-alvo e uma quantificação dos serviços ecossistêmicos. Foi realizada uma avaliação de risco holística do fungicida pyrimethanil com respostas dos organismos terrestres e aquáticos e das interações tróficas através dos modelos ecossistêmicos e complementados com respostas individuais. Os resultados obtidos sugerem que os parâmetros de reprodução para as minhocas foram afetados com o aumento das concentrações de ivermectina com diferenças estatísticas significativas entre as rotas de exposição a contaminação. O fungicida pyrimethanil mostrou efeitos adversos sobre os invertebrados terrestres para as aplicações do pesticida e para a distribuição espacial, sendo as preferências de habitat e habilidade de forageio direta ou indiretamente afetadas pela toxicidade do fungicida. Os possíveis impactos do runoff e lixiviação nos corpos de água e solos adjacentes mostram mudanças na estrutura da comunidade com mudanças e perdas nos serviços ecossistêmicos de provisão, regulação e suporte. A avaliação de risco holística mostrou os impactos e efeitos adversos sobre os organismos terrestres e aquáticos, ecossistemas e processos nos diferentes cenários de simulação. Ao analisar os dados obtidos é possível concluir que os experimentos realizados permeiam os múltiplos aspectos da contaminação por pesticidas, mostrando respostas de indivíduos a ecossistemas através das rotas de exposição da contaminação, interações multitróficas a partir dos experimentos de modelos ecossistêmicos, respostas individuais, comportamentais e comparativas com os sistemas terrestres e aquáticos em avaliações de risco ecológico. Portanto, esse estudo se apresenta como um importante registro dos efeitos deletérios e das respostas dos impactos por pesticidas, levando a possíveis perdas e mudanças das funções e serviços ecossistêmicos em áreas com distúrbios.
22
Leitão, Sara Pais de Almeida da Silva. "New improvements on pesticide ecological risk assessment on the soil-water interface." Doctoral thesis, ISA, 2013. http://hdl.handle.net/10400.5/6449.
Full textAbstract:
Doutoramento em Engenharia Agronómica - Instituto Superior de AgronomiaImproving knowledge to evaluate and reduce pesticide impacts in the environment is a present concern to achieve their sustainable use. With the aim of increasing ecological relevance on the environmental risk assessment of pesticides (ERA), an integrated approach was undertaken linking pesticide fate and effects on aquatic and terrestrial non-target organisms under irrigated crop-based scenarios in Mediterranean realistic conditions, for which there is a lack of studies. Pesticides fate and effects were assessed by adopting an innovative approach embracing different levels of ERA complexity: a refined first-tier with the use of natural soil in ecotoxicological testing, instead of the conventional artificial soil; a refined higher-tier level performing simulations of cropbased agricultural scenarios of maize, potato and onion crops, with the application of the fungicides azoxystrobin and chlorothalonil and the insecticide ethoprophos, using a new semi-field methodology; and an higher tier field study incorporating biological interactions and dynamics of soil fauna communities and environmental factors that determine the effects of pesticides in the field under realistic agricultural practices. This study will increase the knowledge on ecological risks of pesticides under field situations improving decision making towards a sustainable use of pesticides and ecological protection
23
Arumugam, Anandkumar. "Ecological risk assessment of the Miri coast, Sarawak, Borneo: A biogeochemical approach." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/698.
Full textAbstract:
Ecological risk assessment was made along the Miri coast based on trace element concentrations (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Rb, Zn) in the seawater, sediments, and aquatic biota (fish, shrimp, crabs, and bivalves). Prevailing major geochemical processes were identified. Contamination and risk assessment indices were estimated. Sediments were contaminated by Cu and Zn, but in the marine life the remaining metals were within the permissible limits set by international and national guidelines.
24
Ward, Daniel John. "An ecological assessment of secondary poisoning risk in the Australian sugarcane industry." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/31325/1/Daniel_Ward_Thesis.pdf.
Full textAbstract:
Rodenticide use in agriculture can lead to the secondary poisoning of avian predators. Currently the Australian sugarcane industry has two rodenticides, Racumin® and Rattoff®, available for in-crop use but, like many agricultural industries, it lacks an ecologically-based method of determining the potential secondary poisoning risk the use of these rodenticides poses to avian predators. The material presented in this thesis addresses this by: a. determining where predator/prey interactions take place in sugar producing districts; b. quantifying the amount of rodenticide available to avian predators and the probability of encounter; and c. developing a stochastic model that allows secondary poisoning risk under various rodenticide application scenarios to be investigated. Results demonstrate that predator/prey interactions are highly constrained by environmental structure. Rodents used crops that provided high levels of canopy cover and therefore predator protection and poorly utilised open canopy areas. In contrast, raptors over-utilised areas with low canopy cover and low rodent densities, but which provided high accessibility to prey. Given this pattern of habitat use, and that industry baiting protocols preclude rodenticide application in open canopy crops, these results indicate that secondary poisoning can only occur if poisoned rodents leave closed canopy crops and become available for predation in open canopy areas. Results further demonstrate that after in-crop rodenticide application, only a small proportion of rodents available in open areas are poisoned and that these rodents carry low levels of toxicant. Coupled with the low level of rodenticide use in the sugar industry, the high toxic threshold raptors have to these toxicants and the low probability of encountering poisoned rodents, results indicate that the risk of secondary poisoning events occurring is minimal. A stochastic model was developed to investigate the effect of manipulating factors that might influence secondary poisoning hazard in a sugarcane agro-ecosystem. These simulations further suggest that in all but extreme scenarios, the risk of secondary poisoning is also minimal. Collectively, these studies demonstrate that secondary poisoning of avian predators associated with the use of the currently available rodenticides in Australian sugar producing districts is minimal. Further, the ecologically-based method of assessing secondary poisoning risk developed in this thesis has broader applications in other agricultural systems where rodenticide use may pose risks to avian predators.
25
Rahman, Md Khalilur. "Fish-based assessment of ecological health of English lowland rivers." Thesis, University of Hull, 2001. http://hydra.hull.ac.uk/resources/hull:11842.
Full textAbstract:
Riverine fisheries in England are under pressure from a variety of activities, including increasing intensification of land-use, urbanisation, rising demands for water abstraction, pollution, proliferation of exotic species, climate change and recreational activities. As a result, the integrity of English rivers has changed. In this study, an attempt was made to measure the ecological health of 22 English lowland rivers from the Thames, Trent and Yorkshire Ouse catchments using a variety of tools. The objective was to modify the Index of Biotic Integrity (IBI) for use on English lowland rivers and compare it with existing indices. A number of diversity indices, Margalef (DMg), Simpson (Dsm) and ShannonWiener (H') were used to evaluate the status of fisheries in the study rivers. The Abundance / Biomass (ABC) method and computer-based multivariate analyses, UPGMA, TWINS PAN, DECORANA, were also used to evaluate the status of fish communities. In addition to these indices, the ABC method and multivariate analyses, the IBI, a multimetric index was also used to evaluate the ecological health of study rivers. The IBI is based on structural and functional attributes of fish communities and is capable of evaluating health and condition of an aquatic ecosystem. The IBI requires a reference condition with which to compare the output. In English rivers, no pristine (reference) sites were considered available, consequently best available data were used to develop a reference condition. In this study, the IBI was modified from Karr (1981), which was based on 12 metrics (community characteristics) of fish assemblages. For the study rivers, 15 metrics which described the status of the fish communities were selected to calculate the IBI. Each metric was scored on a simple scale from 0 (absence) to 5 (high quality). The sum of all the metrics (range 0 - 75) was used to assign sites to qualitative classes of biotic integrity. Six integrity classes on a continuous scale were chosen with the following class boundaries: Excellent (56 - 75), Good (42 - 55), Fair (28 - 41), Poor (16 - 27), Very Poor (1 - 15) and No Fish (0). In the study rivers, the DMg, Dsm and H' indices were unable to measure anthropogenic impacts on fish communities as all these indices were based on structural properties of fish communities. These indices also failed to take account of the presence of juveniles in the fish community in a river. Moreover, these indices were influenced by dominant species abundance and sampling strategies, giving an inaccurate assessment of the status of the fisheries. The ABC method was better at evaluating fish communities than diversity indices as the method considered fish abundance and biomass. However, the method did not include functional components of the fish community and was over influenced by juvenile fishes. Consequently, the ABC method was not considered a good indicator of ecosystem health based on fish assemblages. The UPGMA, TWINSPAN and DECORANA analyses, successfully grouped and separated river reaches with rich or poor fish stocks. These analyses however, did not take into account the functional attributes of the fish communities and were not sufficient to explain the status of a fishery without support from other indices. The IBI assessed the ecological health of the middle and lower reaches of the study rivers more accurately than the other diversity indices, ABC method and multivariate analyses. The selected IBI metrics were able to evaluate many perturbations and disturbances as the metrics represented both structural and functional attributes of fish communities. The DMg, Dsm, H', ABC, UPGMA, TWINSPAN and DECORANA were designed to highlight a specific attribute and lost information during calculation but the IBI included a greater variety of information and produced an appropriate index. Spearman's rank correlation indicated the IBI outputs were more similar to diversity indices than other measures, as significant relationships were found between the IBI and DMg, the IBI and Dsm, and the IBI and H' at a = 0.01 level. Significant relationships were probably due to the use of fish density and abundance in the models. However, this did not mean that all diversity indices and the IBI were similar in measuring ecological conditions of a river, rather it was probably numerical similarity. No significant relationship was found between the IBI and ABC, as the ABC index was a ratio of abundance and biomass while the IBI used absolute values of biomass and abundance separately. All the diversity indices, ABC method and multivariate analyses mentioned reinforced the view that the IBI developed in this study was an appropriate index at evaluating ecological health of the middle and lower reaches of the study rivers. The IBI, however, failed to predict the quality of the fisheries in headwater streams because of the exclusion of salmonid species, minor species and general low species diversity found in these zones. Consequently, it was identified that reference conditions and metrics chosen for the middle and lower reaches of the study rivers were not appropriate to assess the ecological health of headwaters. The existing monitoring programmes of the Environment Agency (EA) for fishery data collection, were considered appropriate for calculating IBIs. Sampling strategies of the EA, i.e. daytime, electric fishing both in summer and winter periods irrespective of lunar cycle and breeding season were also considered acceptable to calculate the IBI. Further research was recommended to test the IBI on a wide range of rivers to assess whether the IBI is appropriate for assessing ecological health of middle and lower reaches of rivers in all regions of the UK. Separate IBIs for headwaters, still waters and estuaries were proposed as these zones / waterbodies have different fish communities. Investigation should be directed at developing a simplified IBI using other cost-effective data sources if suitable resources are not available. It is also recommended that the possibility of including the IBI in wider aquatic resource monitoring programmes (e.g. WFD) be investigated. It is also recommended that the possibility of using the IBI to detect change in the pre and post implementation periods of any management action or anthropogenic activity be investigated. Research is also needed to integrate the IBI with other bioassessment methods (e.g. Habitat index, Diatom index, Microinvertebrate index, Chemical index and GQA index). For more effective application and understanding, the IBI may be built into a GIS (Geographical Information System) environment. It is suggested that a suitable computer package be developed to simplify calculations of the IBI. The interpretation should however, be carried out by the fishery manager or scientist.
26
JIANG, HUAN. "Ecological Risk Assessment of Salts in Swedish Freshwater Ecosystem : A preliminary assessment for invertebrates and vertebrates." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-16578.
Full text
27
Negreiros, Gustavo Hees de. "Understanding and modeling ecological processes controlling flammability in seasonally dry evergreen forests of the Brazillian Amazon /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/5528.
Full text
28
Peters, Jaime Louise. "Generalised synthesis methods in human health risk assessment." Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/30474.
Full text
29
Takacs, P. "Evaluation of probabilistic ecological risk assessment methodology using aquatic microcosms and azinphos-methyl." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0002/MQ43226.pdf.
Full text
30
Pham, Vivian G. "Ecological Risk Assessment of Heavy Metal Content in the Hatillo River, Costa Rica." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/scripps_theses/571.
Full textAbstract:
Rivers all around the world have become increasingly polluted with heavy metals, largely due to industrialization and urbanization. Organisms exposed to high concentrations of heavy metals have shown evidence of biotoxicity and physical deformities. With biomagnification in mind, the possibility that this contamination may soon directly affect humans is a real concern, and policies in manufacturing industries worldwide may have to be reformed. In this study, we measured the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) in the Hatillo River and compared these values to those measured in the Tarcoles River, a highly polluted river, and Terciopelo Creek, a relatively clean river. The results showed that the Hatillo River had significantly lower levels of most detected heavy metals than both the Tarcoles and Terciopelo. Overall, sediments in all rivers showed high levels of heavy metal content--especially in chromium, copper, nickel, and lead--which could build up and affect organisms over a long period of time.
31
Alcaraz, Cristina. "A community risk assessment of Huntington Park, California." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1588575.
Full textAbstract:
The purpose of the study was to conduct a community risk assessment of the city of Huntington Park, California by utilizing the Communities That Care model to identify the most concerning risk factors for delinquency and school dropout. Forty-seven indicators measuring 18 risk factors were gathered from public sources. Data from Huntington Park was compared to data from Los Angeles County and California. The risk factors of main concern for the community appeared to be transition and mobility, low neighborhood attachment and community disorganization, extreme economic deprivation, family management problems, academic failure beginning in elementary school, early and persistent antisocial behavior, friends who engage in the problem behavior and early initiation of the problem behavior. Efforts to reduce involvement in delinquency and school dropout should target the community, school and peer and individual domains. Suggestions for evidence-based programs and approaches to reduce the most salient risk factors are provided.
32
Gerber, Liezel. "Biodiversity risk assessment of South Africa’s municipalities." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/1614.
Full textAbstract:
Thesis (MSc (Botany and Zoology))--University of Stellenbosch, 2005.South Africa is one of the most biodiverse countries in the world and even with conservation initiatives in place continues to face biodiversity loss. There is a need to prioritise areas for conservation as resources for conservation purposes are limited in South Africa. From prioritisation methods reviewed it was found that prioritisation indices normally use one or a combination of variables that measure stock; and/or variables that measure threat.
33
Rose, Robyn Ilene. "An ecological risk assessment of BT transgenic sweet corn on non-target arthropod communities." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2451.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Entomology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
34
Mellet, Bernice. "Ecological risk assessment of fisheries on sea turtles in the South Western Indian Ocean." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/9957.
Full textAbstract:
The SWIO is an area of great biodiversity and included in the diverse species that occupy the region are five species of sea turtles that include green turtles, hawksbills, leatherbacks, loggerheads and olive ridleys. Despite considerable conservation efforts at sea turtle rookeries in the South Western Indian Ocean, only green and loggerhead turtle populations have shown an increase in population size in recent years (<10 years), whereas leatherbacks remained stable and hawksbills and olive ridleys declined. This begs the question if fisheries (or other offshore pressures) are responsible for slowing the recovery of these populations in the region, and if so, which specific fisheries are responsible for this trend? Several offshore (mostly industrial) and coastal (mostly artisanal) fisheries overlap with sea turtle distribution at sea. Industrial fisheries that are globally known to have a demonstrable impact on sea turtle populations are longline and to a lesser extent purse seine fisheries, whilst prawn trawl, gillnet and beach seine fisheries are coastal fisheries with a known negative impact on sea turtle populations. Holistic conservation strategies should be developed that include both land and sea protection for sea turtle species. It is thus necessary to identify and manage offshore threats including fisheries activities, particularly those fisheries that are showing the highest risk to sea turtle populations. This prompted an investigation into the bycatch rates and mortality of all sea turtle species that occur in the SWIO region in several offshore and coastal fisheries including both industrial (longline, purse seine and prawn trawl) and artisanal (including gillnet and beach seine) fisheries. The specific aims were (i) to identify and quantify the interactions (and if possible mortality) of sea turtle species in fisheries and (ii) to identify vulnerable species/populations to fishing operations using a semi-quantitative Ecological Risk Assessment (ERA) in the form of a Productivity-Susceptibility Analysis (PSA). Published information, online databases and technical reports were used as data sources to establish a database containing essential information regarding fishing effort and sea turtle bycatch in the region. The existing information was used to map fisheries extent and effort within the region, and to perform bycatch calculations. Interactions and mortality rates for sea turtles in five fisheries were quantified using bycatch rates from regional studies. Between 2000 – 2011, industrial longline and purse seine fisheries captured sea turtles at a rate of 4 388 indiv.y-1, with the mortality rate being 189 indiv.y-1. The bulk of these interactions were in the longline industry that captured 4 129 ± 1 376 indiv.y-1, with a corresponding mortality rate of 167 ± 53 indiv.y-1. The most commonly caught species (in longlines) were loggerheads and leatherback turtles, but the greatest impact is expected to be on the leatherback population due to the high interaction rate relative to population size. The bycatch (259 ± 34 indiv.y-1) and mortality (20 ± 2 indiv.y-1) rates of sea turtles in the purse seine fishery was considerably lower than the longline fishery. The purse seine fishery thus does not seem to have a significant impact on sea turtle populations in the SWIO. The impact of all forms of fish aggregation devices were excluded from the analysis as the impacts of these are poorly documented. Coastal prawn trawl, gillnet and beach seine fisheries captured an estimate of between 50 164 - 52 370 indiv.y-1 from 2000-2011. The highest bycatch rate was estimated for gillnet fisheries (40 264 indiv.y-1) followed by beach seine fisheries (9 171 indiv.y-1) and prawn trawl fisheries (at 1089 – 2795 indiv.y-1). The gillnet fishery could be responsible for slowing the recovery rate of green turtle and leatherback populations in the SWIO due to the high capture rates in this fishery compared to the population sizes of the species. Beach seine and prawn trawl fisheries are not expected to be hamper the recovery rate of any of the populations in the SWIO due to the low levels of interactions and low mortality rates compared to the population sizes. There are however very few data available regarding the bycatch of sea turtle species within these fisheries, highlighting the need for further research regarding this. A productivity-Susceptibility Analysis (PSA) was used to evaluate the relative vulnerability of species to fisheries, and is frequently applied in data poor situations. Limited data on sea turtle life history characteristics and population dynamics of species in the SWIO prompted the use of a PSA to determine the species most vulnerable to fisheries in the region. Results of the PSA indicated that gillnet fisheries poses the largest fishery-related threat to sea turtle populations, specifically the green and leatherback populations. The longline fishery that poses a particular threat to the leatherback population in the SWIO is also a particular concern. A cumulative impact assessment (combining fisheries and other threats) indicated that the SWIO leatherback population is extremely vulnerable to the combination of threats that influence this population in the SWIO. Even though individual fisheries may pose a small threat, the cumulative impacts of the fisheries can lead to severe impacts on populations such as slowing the recovery rate of populations. There are however significant data gaps that require attention in order to fully assess the impact of these fisheries on sea turtle populations. Despite the fact that fisheries are not implicated as a mayor reason for the decline in the hawksbill and olive ridley populations in the region, these two species are in decline indicating that there are other factors responsible for the decline not yet identified. It however remains imperative to reduce the mortality from all sources to ensure the continued viability of sea turtle populations in the region.
35
Claassen, Marius. "The development and application of ecological risk assessment in South African water resource management." Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1006177.
Full textAbstract:
The provision of goods and services by aquatic ecosystems plays an important role in socio-economic development and livelihoods in the southern African region. Water resource management in South Africa developed from an agrarian and pastoral focus up to 1956 to also supporting mining and industrial activities. This led to the introduction of the resource water quality objectives and pollution prevention approaches, which balanced the needs for development and protection. Prior to 1994, access to water resources was limited to riparian property owners and a minority of the population who controlled industrial and mining activities. The establishment of a democratic government amplified the need for accelerated socio-economic development, with equity, efficiency and sustainability being the principles of such development. New approaches were needed, which could achieve these development objectives and secure the resource base for future generations. An overview of the scientific process highlighted a risk based approach as potentially supporting the much needed balance between development and protection. The aims of this thesis is to develop a framework and process for the application of ecological risk assessment to water resource management in South Africa, to use case studies to draft guidelines for ecological risk assessment and to assess the degree to which ecological risk assessment can contribute to effective water resource management in South Africa. The United States Environmental Protection Agency’s guidelines for ecological risk assessment were identified amongst international best practice as meeting the requirements for local application. A framework was drafted for ecological risk assessment in South Africa, with the main phases being to agree on objectives, formulate the analysis plan, analyse information, characterise risk and manage risk. Modifications from the Environmental Protection Agency’s process include the order of activities in the first phase, the explicit testing of hypotheses and clarification of the evaluation of existing data or collection of new data. An industrial effluent case study was used to assess the applicability of the proposed framework. The case study dealt specifically with the assessment of risks posed by current conditions and long term licence conditions. The framework was found to be useful to identify weaknesses in the established monitoring programme and to evaluate lines of evidence to assess the degree to which the stated conditions would have unacceptable consequences. The study highlighted several weaknesses in the suggested framework, of which the most critical is the interpretation of the risk hypothesis as a testable null hypothesis. It became clear that cause-effect relationships should be stated as the risk hypothesis, whereas the assessment should evaluate expressed or expected conditions against a risk profile for a given stressor to benefit fully from the risk assessment approach. Changes to the framework terminology were suggested as well as nested feedback loops to allow for iterative processes where new information becomes available. The proposed guidelines incorporate the learning from the case study application as well as feedback from a peer review process. The guidelines incorporate the suggested actions under each phase as well as notes providing the rationale for each step. Three case study outlines were provided to assist users with the interpretation of the guidelines in different applications. The proposed guidelines are applied in an ecological Reserve determination case study, which specified the ecological water quality requirements. The study found that a risk-based approach was followed in the development of the water resource management policy, but the Reserve determination method is generally hazard based, with site specific modifications of the target values being allowed on a conservative basis. The case study highlighted a lack of readiness of water resource managers to accommodate scientific results expressed as probability distributions in support of management decisions. The thesis is concluded with a discussion of the key learning points of the ecological risk assessment development process. The evaluation highlights the move from stating and testing a null hypothesis to stating the risk hypothesis and evaluating the stated conditions against a risk profile. Several implementation challenges are highlighted, with specific recommendations made for adopting the proposed guidelines.
36
Kapo, Katherine E. "Eco-Epidemiological Analysis for Screening-Level Ecological Risk Assessment: A Geographic Information Systems Approach." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1246903901.
Full text
37
Duodu, Godfred Odame. "Characterisation, source apportionment and ecological risk assessment of some pollutants in Brisbane river sediment." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/103672/1/Godfred%20Odame_Duodu_Thesis.pdf.
Full textAbstract:
This thesis presents the first simultaneous analysis of heavy metals and organic residues in Brisbane River sediment after the 2011 and 2013 floods. New methods for rapid analysis of elements in sediment and assessment of ecological risk were developed. The thesis provides crucial information regarding levels, distribution, sources and ecological risks of the pollutants in the sediment. This will assist in risk management and formulation of effective pollution mitigation. The generic outcomes of this thesis are expected to provide essential guidance for monitoring and regulation of pollutants in urban waterways worldwide.
38
Bruce, Erica Dawn. "Modeling toxic endpoints for improving human health risk assessment." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1277.
Full text
39
Kentel, Elçin. "Uncertainty Modeling Health Risk Assessment and Groundwater Resources Management." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11584.
Full textAbstract:
Real-world problems especially the ones that involve natural systems are complex and they are composed of many non-deterministic components. Uncertainties associated with these non-deterministic components may originate from randomness or from imprecision due to lack of information. Until recently, uncertainty, regardless of its nature or source has been treated by probability concepts. However, uncertainties associated with real-world systems are not limited to randomness. Imprecise, vague or incomplete information may better be represented by other mathematical tools, such as fuzzy set theory, possibility theory, belief functions, etc. New approaches which allow utilization of probability theory in combination with these new mathematical tools found applications in various engineering fields. Uncertainty modeling in human health risk assessment and groundwater resources management areas are investigated in this thesis.
In the first part of this thesis two new approaches which utilize both probability theory and fuzzy set theory concepts to treat parameter uncertainties in carcinogenic risk assessment are proposed. As a result of these approaches fuzzy health risks are generated. For the fuzzy risk to be useful for practical purposes its acceptability with respect to compliance guideline has to be evaluated. A new fuzzy measure, the risk tolerance measure, is proposed for this purpose. The risk tolerance measure is a weighed average of the possibility and the necessity measures which are currently used for decision making purposes. In the second part of this thesis two decision making frameworks are proposed to determine the best groundwater resources management strategy in the Savannah region, Georgia. Groundwater resources management problems, especially ones in the coastal areas are complex and require treatment of various uncertain inputs. The first decision making framework proposed in this study is composed of a coupled simulation-optimization model followed by a fuzzy multi-objective decision making approach while the second framework includes a groundwater flow model in which the parameters of the flow equation are characterized by fuzzy numbers and a decision making approach which utilizes the risk tolerance measure proposed in the first part of this thesis.
40
Albering, Harmina Jannette. "Environmental health risk assessment evaluation of some default assumptions /." [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Maastricht University [Host], 1998. http://arno.unimaas.nl/show.cgi?fid=8395.
Full text
41
Kroner, Oliver. "The Alliance for Risk Assessment Dose-Response Framework: Practical Guidance for Risk Practitioners." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1314053236.
Full text
42
Ngan, Wai-tak Eden. "Health risk assessment of toxic air pollutants in Hong Kong /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18733979.
Full text
43
Sorenson, Mary T. "Deterministic vs probabilistic ecological risk assessment modeling at hazardous waste sites : a comparative case study." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/25303.
Full text
44
Shaw, Brenda Jo. "Evaluation of risks to human health in Hong Kong from consumption of chemically contaminated seafood : a risk assessment approach /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14723657.
Full text
45
Schad, Thorsten [Verfasser]. "Xplicit – a modelling framework for ecological risk characterisation at landscape-scales in regulatory risk assessment and risk managementof plant protection products / Thorsten Schad." Landau : Universitätsbibliothek Landau, 2013. http://d-nb.info/1037920015/34.
Full text
46
Chang, Chun-Ming, and 張浚銘. "Human Health and Ecological Risk Assessment of Biofuel Products." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/87159443682471974659.
Full textAbstract:
碩士國立高雄師範大學
生物科技系
101
The dwindling fossil fuel sources and the creasing dependency on imported crude oil have led to a major interest in expanding the use of bioenergy in many countries. Furthermore, the addition advantage of biofuels is reduction in air pollutant and emission of greenhouse gas. Therefore, Taiwan is promoted the use of E3（gasoline with addition of 3％ ethanol）and B2（diesel fuel with addition of 2％ ethanol）in 2007 and 2010, respectively. Biofuel will alter the distribution of petroleum contaminants in soil and groundwater. Groundwater contamination by gasoline and other petroleum-derived hydrocarbons released from underground or above ground storage tanks is a serious and widespread environmental problem. The problem of petroleum contaminants will become complicated after biofuels widely utilized. The objective of this study is to assess health and ecological risk when biofuel spill occurs. The results of this study can be used as a reference for risk management. Conventional octane number 95 gasoline, ethanol-blended gasoline (i.e., E3, E10, E25 and E85) and biodiesel (i.e., B2, B5 and B20) were studied. The framework of human health risk assessment used in this study is adopted from “Risk Assessment Guidance for Superfund Human Health Evaluation Manual” from United States Environmental Protection Agency（USEPA）in 1989. The assessment endpoint is the adverse health effects of human. In the ground water media, concentration of petroleum contaminants was estimated by the LevelⅢ Fugacity Model. US EPA human exposure assessment models have been used to evaluate the exposure dose via inhalation, ingestion and dermal contact pathway, when human use groundwater. The risk characterization of human non-carcenogenic risk is estimated by hazard quotient（HQ）value. Carcinogenic risk was assessed by multiplying total exposure by the carcinogenic slope factor for each pathway. The framework of ecological risk assessment used in this study is adopted from “Guideline of Ecological Risk Assessment” from USEPA in 1998. The assessment endpoint is the mortality of aquatic and terrestrial organisms. In the aquatic and terrestrial ecosystem, exposure dose and concentration of biota was estimated by the RAIDAR Model and LevelⅢ Fugacity Model. The risk characterization of biota is estimated by risk quotient（RQ）value. The result of human carcinogenic risk assessment was assessed, which was higher than the threshold value（10-6） that general people can withstand. This indicates potential cancer risks for the exposed population. The results show that human use contaminated water as drinking water will ingest benzene. It exposes the highest carcinogenic risk for E3 gasoline. The result of human non-carcinogenic risk assessment was assessed, which was lower than the accepted threshold value（1）that ordinary people can withstand. This indicates no potential health hazards for the exposed population. The result show that human use contaminated water as drinking water or dermal clean water will ingest MTBE or absorb aliphatics C8-C10 from derma, respectively. The highest non-carcinogenic risk was exposed by conventional research octane 95 gasoline. Human use contaminated groundwater as clean water will inhale naphthalene vapor or absorb aliphatics C16-C21 from derma, respectively. It is the highest non-carcinogenic risk for B20 diesel. The hazard of the E85 gasoline and B5 diesel is the lowest for human health. Since the biofuel will alter the distribution of petroleum contaminants in groundwater, more contaminates will be anticipated in the exposure pathway. Ecological risk assessment results indicate that the aquatic and terrestrial total ecological risk index is lower than the threshold value（1）, this indicates no potential hazard for the exposed biota. By evaluating the results, it is clearly that m,p-xylene in gasoline pose the highest risk for terrestrial avian scavenger in contaminated food chain. In addition to, pyrene in biodiesel blended diesel pose the highest risk for terrestrial avian omnivore in the terrestrial ecosystem. The hazard of the E85 gasoline and B20 diesel is the lowest. Because E85 gasoline and B20 diesel contains less petroleum contaminants. Comprehensive ecological risk assessment results demonstrate that biofuels are the most serious impact for terrestrial organisms. The results conclude that differences in chemical properties and environment range lead to profound differences in the concentration of exposure and risk from emission to target biota. The implications of these results and draw attention to the insights gained about ecological risks and effective chemicals management associated with biofuels.
47
He, Yi-Rong, and 何怡蓉. "Health and Ecological Risk Assessment for Arsenic Contaminated Site in Guandu." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/02070178322819809650.
Full textAbstract:
碩士國立臺灣大學
環境工程學研究所
96
The heavy metals in the soils and the groundwater were investigated in Taipei in 2007, and found that the concentration of Arsenic is extraordinarily high in Guandu. The agricultural land is main polluted source, so the pollutant could enter the food-chain through the absorbance by the plants. Besides, the local ecosystem is the most direct receptor that exposed to the pollutant. Therefore, the study is based on the results of “Monitoring and investigation of heavy metals in soil of Taipei City”, and carries out health and ecological risk assessment in Guandu. The medium includes soil, air, groundwater and food chain on health risk assessment in this study, and the potential harmful effects of receptors were assessed by direct and indirect exposure routes. The result of health risk assessment shows that the carcinogenic and non-carcinogenic risks of residents and tourists on site 1 are less than the standard (<10-6). The carcinogenic and non-carcinogenic risks of farmers and self-contained farmers exceed the standard (>10-6). The indicators contain rice, earthworms and sparrows on ecological risk assessment in this study, and the potential harmful effects of receptors were assessed by direct and indirect exposure routes. The results show that the risk of rice in three sites is lower than toxic level. The RQs of earthworms and sparrows in site 1 are close to 1, and that in site 2 and 3 are less than 1. Health and ecological risk assessment were integrated in this study. Through the assessment, important factors are confirmed and resulting risks quantified and thus the management and policy determination for remediation of the contaminated site can be suggested.
48
Madanire-Moyo, Grace Nyepai. "A comparative evaluation of ecosystem health of selected water bodies in the Olifants and Limpopo River systems using the health assessment index and parasite diversity as indicators." Thesis, 2011. http://hdl.handle.net/10386/438.
Full textAbstract:
Thesis (Ph.D. (Zoology)) --University of Limpopo (Turfloop Campus), 2011South Africa's water resources are limited and scarce in global terms, due to the fact that the country's climate varies from desert to semi-desert in the west to sub-humid along the coastal area. The country is also expected to experience further variability in rainfall, reduced precipitation and increased evaporation as a result of climate change. At the projected population growth and economic development rates, it is unlikely that the projected demand on water resources in South Africa will be sustainable. An additional concern is the declining water quality due to domestic, mining and industrial pollution, and eutrophication as well as salinisation due to agricultural pollution. Thus, aquatic ecosystems must be protected, monitored and managed to ensure sustainable resource use. The aim of the study was to evaluate and compare possible environmental deterioration by analysing fish health and parasite diversity in three dams within the Limpopo and Olifants River Systems by using the fish Health Assessment Index (HAI) and the Inverted Parasite Index (IPI). The intention of the study was to substantiate the theories behind the HAI and IPI in a bid to augment strategies to manage water quality, fish health and aquatic biodiversity. Seasonal surveys were carried out between April 2008 and April 2010 at three localities. The Luphephe-Nwanedi Dams are in a Nature Reserve located in a rural catchment, the Flag Boshielo Dam in an industrualised and mining catchment whereas the Return Water Dam is located on a platinum mining premise. Clarias gariepinus (Burchell, 1822) and Oreochromis mossambicus (Peters, 1852) were collected with the aid of gill nets and used as indicator fish species. Fish were examined for external parasites after which they were weighed and measured. Blood was drawn and skin smears were made. The skin smears were examined with a dissecting microscope for the presence of parasites. Fish were killed, dissected and then examined as prescribed in the fish HAI. From the ecto- and endoparasite data collected, infection statistics and ecological parameters were calculated. The HAI values were calculated for each fish species at each sampling site. To verify the results of the HAI, water quality was included in the studyThe nutrients and mining related pollutants of the three dams differed to a great extent and showed a similar increasing trend in the order: Luphephe-Nwanedi Dams < Flag Boshielo Dam < Return water Dam. Our results were consistent with previous work describing Luphephe-Nwanedi Dams as essentially unimpacted and Flag Boshielo Dam as impacted with a combination of mining and agricultural effluents. The results have shown that the Return Water Dam is an extremely polluted site with high levels of nutrients and metals. Fish health of both species responded similarly to polluted sites although mean population HAI results showed that C. gariepinus was more affected in terms of haematocrit necropsy-related alterations. The top six metrics that correlated most to fish health scores were nearly the same for both species (i.e. haematocrit values, inverted ectoparasite index, condition of the kidney, liver, gills and skin). The parasite community of C. gariepinus comprised 19 metazoan species. Seventeen parasite species were recovered from fish sampled from Luphephe-Nwanedi Dams compared to 11 at Flag Boshielo Dam and four at the Return Water Dam. The parasite community of O. mossambicus comprised 20 metazoan species. A total of 19 species, 17 species, and 4 species of metazoan parasites from O. mossambicus were obtained from Luphephe-Nwanedi Dams, Flag Boshielo Dam and the Return Water Dam, respectively. In both fish species, the Shannon Wiener Index, the inverse Simpson Index, equitability and the number of metazoan parasite individuals were highest in fish from Luphephe-Nwanedi Dams. The results of this study emphasized the negative impacts of urbanization, agricultural and mining activities on the environment. The fish hosts collected in the mining premise supported the poorest and least diverse parasite communities of all sampled sites, with virtual depletion of both heteroxenous and monoxenous species. The Return Water Dam may therefore be regarded as a simulation model for a severely environmentally deteriorated, impoverished habitat, in which all or part of the intermediate hosts have been depleted, enabling the survival of hardy parasite species only. Further studies should address the identification of parasite life stages that are more sensitive to pollutants
The National Research Foundation,the Flemish Interuniversity Council(VLIR-UOS),and the Division for Research Administration and Development,University of Limpopo
49
Anhalt, Ashley, Tawnya Peterson, Paul Tratnyek, Joseph Needoba, and Amanda Mather. "Exploring Holistic Approaches to the Characterization of Particles in the Environment." 2011. http://hdl.handle.net/10150/196809.
Full textAbstract:
Most of the main determinants of water quality either consist of, or are controlled by, particles. Previous water quality research has focused on particular particles in isolation or in binary combinations. In this project, we are taking a holistic approach to the characterization of the particle load in water, focusing on the collective properties of the particles rather than individual components. Because the characterization of particles is often time-consuming, applying an informatics-based approach could speed up the evaluation of water quality and the assessment of treatment effectiveness. Further, the breadth of potential changes that could be detected using this multiplex approach may far surpass the abilities of current approaches to monitor threats to water quality. Among the instruments capable of rapidly detecting and manipulating cells is imaging flow cytometry, which distinguishes cell shape and unique fluorescence properties associated with cell types. Sets of images and corresponding data from a 1.5-year time series of samples from the Columbia River were studied and the different particle properties analyzed. Principal Component Analysis (Empirical Orthogonal Function analysis) was applied in order to reduce the number of variables and identify patterns in particle characteristics when compared to environmental data collected from the observation station. The first three principal components were extracted and the dominant characteristics identified: the most prominent variables are particle size, particle color, and fluorescent qualities (transparency and phytoplankton pigments). Further work will relate these top principal components to specific environmental factors that determine water quality.
50
Higgins, C. A., R. M. Wilson, N. Sandstrom, Bruce B. Dawson, Gary S. (Gary Seymour) 1966 Mann, P. J. Allard, and Randy F. Baker. "Post closure human health and ecological risk assessment at Teck Cominco's Kimberley operations, BC : overview of regulatory process and findings of the problem formulation." 2004. http://hdl.handle.net/2429/8705.
Full textAbstract:
The Sullivan sulphide ore body was discovered in 1892; Teck Cominco Metals Ltd. (Teck Cominco) and its predecessors operated underground lead/zinc mining, milling, and other industrial operations from 1909 until December 2001. The total area of land disturbance (mine, associated facilities and waste impoundments only) is on the order of 1,090 ha. Since the 1960s, Teck Cominco has been planning and implementing measures to restore and/or protect the environment impacted by mining activity. In 1991, at the request of the BC Ministry of Energy and Mines, Teck Cominco developed a comprehensive Decommissioning and Closure Plan that is being implemented under Mines Act Permit M-74.
The BC Ministry of Water, Land and Air Protection required site investigations and remediation to address contaminants and impacts not addressed in the Closure Plan (e.g., hydrocarbons). Remediation has included contaminant removal (where possible), and risk assessment/risk management, to meet Teck Cominco’s post closure objectives. The main contaminants are metals generated directly from mining activity (e.g., waste rock piles, tailing impoundments, fugitive dust) and from subsequent releases due to acid rock drainage.
The Risk Assessment (RA) Problem Formulation (PF) for human, terrestrial and aquatic components is complete, and the RA is nearing completion. The PF process was successful in screening out receptor/contaminant combinations where negligible risks were predicted using conservative assumptions, and in identifying specific receptor/contaminant combinations that require additional investigation. The St. Mary River and Mark Creek are identified as primary receiving environment components and are key drivers of the RA. A hydrogeological and geochemical assessment of upgradient waste impoundments is being conducted concurrently with the RA to allow predictions of post closure groundwater and surface water concentrations.
This paper focuses on the environmental regulatory framework, and the challenges faced due to two parallel regulatory processes under the Mines Act and Waste Management Act. An overview is also provided regarding the approach taken to conducting this RA at a large mine site where both anthropogenic activities and natural mineralization have resulted in elevated metals concentrations.