Ecotoxicologia e Avaliação de Risco

Objectives

On completion of the course, the student should be able to: (1) Describe sources and fates of chemicals in the environment (2) Present, explain and predict mechanisms for adverse effects of chemicals (3) Estimate the risk for adverse effects of a chemical on different biological organisation levels based on knowledge about the toxicity, degradability, and bioavailability of the chemical (4) Describe and understand the current ecotoxicology assessment methods , the information that each one can provide and also their application on different environmental problems (5) Develop a basic understanding of risk assessment and its role within the risk management process. (6( Differentiate between risk assessment and risk management. (7) Develop a basic understanding of how to conduct and evaluate an uncertainty analysis for a risk assessment.

Syllabus

Effects of Pollutants on the Biosphere: Biodegradability, Toxicity, and Risks (2) Hazardous and Non-hazardous Substances or Pollutants (Classification of Hazardous Substances, Toxicity and Related Definitions, Factors That Affect the Toxicity of Chemical Substances) (3) Human Health Risk Assessment (Hazard Identification, Dose-Response Assessment, Exposure Assessment, Risk Characterization, Risk Management) (4) Ecotoxicology Methods (Methods of Ecotoxicology, Toxic Endpoints, Bioassays, Ecotoxicity Determination, Short- Time Toxicity Tests, Long-Term Toxicity Tests, Behaviour Tests) (5) Ecological Risk Assessment (6) Risk Assessment (Exposure measurement, toxicology, and epidemiology as ways to assess environmental risk in terms of effects) (7) Modelling effects with Dynamic Energy Budget (DEB) theory.

Prerequisites

It is expected that the student would have background in chemistry, chemical analysis and organic and biochemistry. Knowledge in general biology and ecology could be important but not crucial.

Cross Competence Component

This curricular unit wil developed several soft skills. The promotion of criativity and problem solving will be ehnanced by increasing the laboratory and team work. Several other skils will also be enhanced, namely team work that include preparation and implementation of laboratory work, definition of novel approches to ecotoxicology problems and the consequent creation of new strategies, and the promotion of oral discussions and presentations. The analysis of toxicological effects and risk assessment studies both by reading and interpretation of key scientific papers and also by preparing the laboratory project will allow the contact with the scientific method and the capacity to extrapolate scientific data with effects on the environment. The active learning strategy, where the student has the main role on the learning process, will be implemented as much as possible. Contributes with 10% to the overall evaluation.

Laboratorial Component

The students will develop an ecotoxicological project based on the exposure of a model organism (e.g freshwater fish or invertebrates) to a pollutant (e.g Hg, Cd), followed by a depuration period. During both experimental periods the students will sample and analyse the concentration of the pollutant in the fish tissues/organs as well as biomarkers of biological effects namely enzymatic and non-enzymatic antioxidants (e.g. catalase, glutathione and related enzymes, etc). This project will not only allow to apply the concepts of bioaccumulation and eliminations but also to identifiy toxicological effect of a target organism as a result of a contaminant exposure. In the last laboratoy class the sutdent will usethe modelling component (DEB) using a metabolic model for the organism, the laboratory work will entail working with a code for estimating the effects of toxicants by changing the environmental conditions.

Programming And Computing Component

In the modelling component, the students will work with a code changing the environmental conditions. This will allow the development of the competence of Abstraction (with the handling of data and undertanding of simple functions) and Automation (with the use of simple functions).

Ethical Principles

All members of a group are responsible for the group´s work. In any assessment, every student shall honestly disclose any help received and sources used. In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.