Quality Assurance of Exposure Models for Environmental Risk Assessment of Substances

Nonfiction, Science & Nature, Mathematics, Applied
Cover of the book Quality Assurance of Exposure Models for Environmental Risk Assessment of Substances by Stefan Schwartz, GRIN Publishing
View on Amazon View on AbeBooks View on Kobo View on B.Depository View on eBay View on Walmart
Author: Stefan Schwartz ISBN: 9783638103749
Publisher: GRIN Publishing Publication: November 6, 2001
Imprint: GRIN Publishing Language: English
Author: Stefan Schwartz
ISBN: 9783638103749
Publisher: GRIN Publishing
Publication: November 6, 2001
Imprint: GRIN Publishing
Language: English

Doctoral Thesis / Dissertation from the year 2000 in the subject Mathematics - Applied Mathematics, grade: 1,0 (A), University of Osnabrück (Institute for Environmental System Research, Mathematics/Computer Science), 247 entries in the bibliography, language: English, abstract: Summary Environmental risk assessment of chemical substances in the European Union is based on a harmonised scheme. The required models and parameters are laid down in the Technical Guidance Document (TGD) and are implemented in the EUSES software. Although the results may have a considerable ecological and economic impact, guidance is rarely given on the applicability of the framework. To fill this gap, an evaluation study of the TGD exposure models was carried out. In particular, the models for estimating chemical intake by humans were investigated. These models, which are a key component in risk assessment, involve a quantification of human contact with environmental contamination in various media of exposure through various exposure pathways. The objective of this study was two-fold: firstly, to develop an evaluation methodology, since no appropriate approach is available in the scientific literature. Secondly, to elaborate applicability and limitations of the models and to provide proposals for their improvement. The principles of model evaluation in terms of quality assurance, model validation and software evaluation were elaborated and a suitable evaluation protocol for chemical risk assessment models was developed. Since scientific theories and the mathematical models embedded therein cannot be proved as true, a pragmatic meaning of validation is required, of which the primary purpose is to increase the level of confidence placed in the model. The accuracy of the model outcome is a necessary, but insufficient criterion for the quality assurance of models. A wider approach is required which examines the scientific inference that can be made about models with regard to their intended purpose. By reviewing the literature on the validation problem, it was found that all the facets of validation can be assigned to generic (internal) and task-specific (external) properties of a model. In this context, sensitivity and uncertainty analyses are essential to tackle the issues of uncertainty. Sensitivity analysis aims to ascertain how a given model depends upon the information fed into it. Uncertainty analysis aims to quantify the uncertainty regarding what comes out of the model. It was argued that targeted uncertainty analysis and sensitivity analysis, as a part of it, is capable of reducing critical uncertainties and represents an essential contribution for assuring the quality of a model. [...]

View on Amazon View on AbeBooks View on Kobo View on B.Depository View on eBay View on Walmart

Doctoral Thesis / Dissertation from the year 2000 in the subject Mathematics - Applied Mathematics, grade: 1,0 (A), University of Osnabrück (Institute for Environmental System Research, Mathematics/Computer Science), 247 entries in the bibliography, language: English, abstract: Summary Environmental risk assessment of chemical substances in the European Union is based on a harmonised scheme. The required models and parameters are laid down in the Technical Guidance Document (TGD) and are implemented in the EUSES software. Although the results may have a considerable ecological and economic impact, guidance is rarely given on the applicability of the framework. To fill this gap, an evaluation study of the TGD exposure models was carried out. In particular, the models for estimating chemical intake by humans were investigated. These models, which are a key component in risk assessment, involve a quantification of human contact with environmental contamination in various media of exposure through various exposure pathways. The objective of this study was two-fold: firstly, to develop an evaluation methodology, since no appropriate approach is available in the scientific literature. Secondly, to elaborate applicability and limitations of the models and to provide proposals for their improvement. The principles of model evaluation in terms of quality assurance, model validation and software evaluation were elaborated and a suitable evaluation protocol for chemical risk assessment models was developed. Since scientific theories and the mathematical models embedded therein cannot be proved as true, a pragmatic meaning of validation is required, of which the primary purpose is to increase the level of confidence placed in the model. The accuracy of the model outcome is a necessary, but insufficient criterion for the quality assurance of models. A wider approach is required which examines the scientific inference that can be made about models with regard to their intended purpose. By reviewing the literature on the validation problem, it was found that all the facets of validation can be assigned to generic (internal) and task-specific (external) properties of a model. In this context, sensitivity and uncertainty analyses are essential to tackle the issues of uncertainty. Sensitivity analysis aims to ascertain how a given model depends upon the information fed into it. Uncertainty analysis aims to quantify the uncertainty regarding what comes out of the model. It was argued that targeted uncertainty analysis and sensitivity analysis, as a part of it, is capable of reducing critical uncertainties and represents an essential contribution for assuring the quality of a model. [...]

More books from GRIN Publishing

Cover of the book The United Kingdom and the EU by Stefan Schwartz
Cover of the book The Liberty of Religious Rights and Religious Education in the Frame of the State Legislation in Hungary by Stefan Schwartz
Cover of the book King Lear: Lear's Language, Beginning vs. End of the Play by Stefan Schwartz
Cover of the book COIN Vignettes - Somalia: Understanding your Environment by Stefan Schwartz
Cover of the book The Ottoman legacy in the Balkans by Stefan Schwartz
Cover of the book Regionale Autonomie als Folge politischer Entwicklungen in Indonesien seit 1998 by Stefan Schwartz
Cover of the book The role of small and medium-sized enterprises (SMEs) in Europe's economy by Stefan Schwartz
Cover of the book Urban Tourism in Hamburg and the World Cup by Stefan Schwartz
Cover of the book 'Gen Xers' and 'Boomers' by Stefan Schwartz
Cover of the book International Business: Foreign market entry principles by Stefan Schwartz
Cover of the book Selling Intervention by Stefan Schwartz
Cover of the book The delimitation of the case system in Russian by Stefan Schwartz
Cover of the book The Palestinian Hamas between islamic religious tradition and modernity by Stefan Schwartz
Cover of the book Die Organisationsverfassung der Societas Privata Europaea (SPE) im Vergleich zur GmbH by Stefan Schwartz
Cover of the book Coursework Consumer Law by Stefan Schwartz
We use our own "cookies" and third party cookies to improve services and to see statistical information. By using this website, you agree to our Privacy Policy