NPLK18000U  Toxicology and Ecotoxicology

Volume 2018/2019
Education

MSc in Environmental Science

 

Content

The course gives a basic overview on fundamentals in both human- and ecotoxicology. Basic toxicological processes encompass toxicokinetic (TK) and toxicodynamic (TD) descriptions of pollutants in organisms. The toxicokinetic processes are what the organism does to the chemical, and can be described through the understanding of Absorption, Distribution, Metabolism and Excretion (ADME) of chemical substances in organisms. The toxicodynamic processes are what the chemical does to the organism: the toxic mechanisms. Toxic mechanisms take place at different organizational levels and on different time scales, from chemical effects on the gene expression level, to effects on cell function, effects on organs, on organism health, growth, reproduction and survival and finally, in an ecotoxicological context also on the population of the organism and on the community of species in the environment. To comprehend toxic mechanisms and the impact of chemicals on humans and the environment, understanding of the whole chain of effects, also called Adverse Outcome Pathways, is important.

The principles of toxicokinetic and dynamic processes for major groups of pollutants will be taught through lectures, theoretical and practical exercises. The students will learn to use on-line databases and computational tools applied in toxicology and ecotoxicology to calculate Effect Concentrations (e.g. EC50), No Observable Adverse Effect Concentrations (NOAECs), Lowest Observable Effect Concentrations (LOECs) and predicted no-effect concentrations (PNEC), and they will learn to critically interpret dose-response data and the parameters derived from them. In addition they will get an introduction to the use of TKTD models, their strengths and weaknesses compared to the more traditional dose-response assessments of toxicity and their use in human- and ecotoxicological research. Also, the students will learn how to predict the effect of chemical cocktails using standard mixture toxicity models, and how to identify potential synergists in a mixture toxicity scenario. Basic statistical considerations and tools to interpret toxicity data (as the pro’s and con’s of significance testing, use of power analysis, recognizing type 1 and type 2 errors, trade-offs between doses and replications in an experiment, weight of evidence approaches for quality assurance of experiments etc) will be introduced, used and discussed. The computational programs used will be Excel, R and OpenModel. The students will have to conduct two laboratory experiments: one in vitro study, investigating effects on an enzymatic or cellular level and one in vivo study, looking at chemical effects on the organismal level. For each of the experiments they will need to use the computational tools conducting either dose-response curves or parameterizing TKTD models. The data has to be interpreted in the theoretical framework of ADME and AOP for their specific toxicant and test, and the results will be presented for and evaluated by their peer students (poster and oral presentation, as well as a scientific manuscript).

Learning Outcome

The main objective of the course is to introduce the fundamental processes important for understanding the mechanisms of chemical toxicity. In addition, the students should get an overview of key methods used in human- and ecotoxicology to investigate these processes, and they should recognize the main strengths and weaknesses of the different methodologies. The students should get practical experience with conducting typical in vitro and in vivo experiments in the laboratory, treat data with proper statistical methods and computational modelling tools, and interpret the data in relation to the scientific literature within the studied topic. Finally the students should acquire skills in communicating scientific results both orally and in writing in different formats.

The course is recommended for students who upon completion of their studies will be employed in sectors dealing with environmental issues, such as public inspection, public health, environmental consulting, medical industry and the bioprocessing industries.

At the end of the course, students will be able to:
 

Knowledge

  • describe the main physico-chemical properties of chemicals important for predicting uptake, distribution, metabolism and excretion processes of chemical pollutants in organisms

  • describe toxicological mode of actions for most important groups of chemical substances to humans and environmental species.

  • define the most vulnerable target processes, organ(s) or organism(s) for most important groups of xenobiotics and interpret the toxicological mechanisms using the AOP-concept

  • demonstrate knowledge on extrapolation from animal to human, and from one species to several species and trophic levels in the environment

  • interpret both acute and chronical toxicity data and evaluate different types of dose-response relationships, TKTD experiment data and results from experiments evaluating the effect of chemical mixtures

  • knowledge of basic statistical considerations when doing toxicity experiments, including choice of number of doses versus number of replications, choice of significance levels, use of power analyses and the occurrence of type 1 and type 2 errors.

     

    Skills

  • Conduct relevant statistical tests to calculate EC50, NOAEC and LOEC and dose-response curves with its associated parameters

  • use relevant software for conducting dose-response analyses, model TKTD processes and calculate mixture toxicity effects (e.g. Excel, R and OpenModel).

  • Use on-line databases to find relevant data toxicological and ecotoxicological properties of chemicals

  • perform simple in vitro and in vivo human toxicological and ecotoxicological laboratory tests and present and interpret the data

  • report laboratory results orally and/or written as a poster or a research manuscript

     

    Competencies

  • integrate principles from chemistry, physics, biology, biochemistry and ecology with mass and energy balances to develop and solve simple toxicological questions

  • apply simplified assumptions and estimate model and design parameters in the face of biological variability and uncertainty in measurement and prediction

Will be announced on Absalon.

Basic knowledge at university BSc-level of 5 ETCS in each of the following topics: human or animal physiology, biochemicstry, organic and inorganic chemmicstry and statistics.

Knowledge of basic environmental chemistry, biology and microbiology will be an advantage
Lectures, theoretical and laboratory exersises, quizzes, discussion of papers and peer-review of presentations.
Written
Oral
Continuous feedback during the course of the semester
Feedback by final exam (In addition to the grade)
Peer feedback (Students give each other feedback)
Credit
7,5 ECTS
Type of assessment
Oral examination, 30 min
The students start with a 5 min presentation of one of the lab-projects. He/she then draws a question in the curriculum, which will form the basis for the further examination.
Exam registration requirements

Hand in of the results of the two labratory assignment in the form required, plus handing in all mandatory theoretical exercises.

Aid
Without aids
Marking scale
7-point grading scale
Censorship form
External censorship
Re-exam

As the ordinary exam.

If exam registration requirements are not met for the ordinary exam, the results of the two laboratory assignment in the form required, plus all mandatory theoretical exercises must be handed in two weeks before reexamination.

 

Criteria for exam assesment

See "Learning outcome"

  • Category
  • Hours
  • Lectures
  • 50
  • Theory exercises
  • 25
  • Practical exercises
  • 25
  • Colloquia
  • 4
  • Course Preparation
  • 101
  • Exam
  • 1
  • Total
  • 206