TOX-31306 Environmental Risk Assessment of Chemicals


Credits 6.00

Teaching methodContact hours
Group work5
Course coordinator(s)dr. ir. NW van den Brink
Lecturer(s)prof. dr. ir. IMCM Rietjens
dr. ir. NW van den Brink
prof. dr. ir. PJ van den Brink
prof. dr. AA Koelmans
Examiner(s)dr. ir. NW van den Brink
prof. dr. ir. PJ van den Brink
prof. dr. AA Koelmans

Language of instruction:


Assumed knowledge on:

For this course, knowledge is assumed on the hazard assessment of chemicals, on environmental fate and behaviour of chemicals, and on exposure assessment. Prerequisite knowledge can be gained in Environmental Toxicology (TOX-30806), Chemical Stress Ecology and Risk Assessment (AEW-30806), Water Quality (AEW-31306), Soil Pollution and Soil Protection (SOQ-21306), and Soil Quality (SOQ-21806).


At Wageningen University several courses are focused on processes underlying the environmental impact of chemicals on human and environmental health (e.g. Environmental Toxicology (TOX30806), Chemical Stress Ecology and Risk Assessment (AEW30806)). Within these natural sciences- oriented courses, the existing regulations and the methods for the assessment of the environmental risks of chemicals and contaminants for human and environmental health are only touched upon. However, environmental risk assessment of chemicals is essential for safe use and application of products, for protecting the quality of our living environment for all species including man, as well as for taking decisions in subsequent risk management, risk communication and risk governance activities. Different regulatory frameworks exist to assess Environmental Risks of chemicals, each with specific focus, scientific underpinning and technical approaches (toolkits). Examples of such frameworks are REACH, Plant Protection Product and Biocide Directives of the EU, the Water Framework Directive of the EU and also the derivation of Environmental Quality Standards for soil, water and atmosphere. Environmental Quality Standards can be applied in site-specific risk assessments of chemicals, although alternative approaches are more and more demanded in order to achieve case- specific, tailor- made solutions.
In order to comply with such different regulatory frameworks, there is a high demand for well-trained risk assessors, who have the conceptual synopsis of the different approaches and even more who have the scientific and technical knowledge and skills to design and conduct environmental risk assessments. This course, Environmental Risk Assessment of Chemicals (ERAC), is set up to meet this need and has therefore great societal urgency. It will provide students with the know-how and dexterity to perform risk assessments in different settings/roles, e.g. as a regulator, in an academic setting or as a consultancy advisor. Students will gain deep insight in 1) prospective environmental risk assessment, i.e. assessment of risks of chemicals prior to market authorisation and use, 2) retrospective environmental risk assessment, i.e. risks of chemicals after their use and environmental release, and 3) environmental risk assessment of legacy contaminants resulting from historic use and release and/or from natural sources (e.g. PCBs, dioxins and heavy metals). Differences and similarities between the different regulatory framework will be explained, and developments in the regulation of new emerging compounds will be covered. Students will learn to apply approaches and techniques within the different frameworks to real life examples. A major theme in this course is how to deal with the uncertainty and limited availability of data for decision making in environmental risk assessment and how to ascertain that the majority of environmental species are adequately protected without the need for testing all of them. The concepts and approaches in environmental risk assessment will also be compared in a wider context with other risk assessment-frameworks especially those for food-related chemicals, which also include environmentally relevant regulated chemicals and contaminants.
Risk assessment is an integration of natural sciences and social sciences. ERAC, with a prima focus on the technical concepts and skills needed in the different Risk assessment frameworks, will connect the more natural science-oriented courses on environmental impact of chemicals with the more social science- and policy-oriented courses on risk governance (ENP35806) and environmental economics (ENR21306). The target groups of the course are students of MES, MML, MEE, MAM, MBI.

Learning outcomes:

After successful completion of this course students are expected to be able to:
- create a vision on the concepts of prospective and retrospective environmental risk assessment;
- reflect upon communalities and differences between environmental risk assessment and risk assessment for human health and food;
- recognize the evolution of regulatory frameworks by studying past, present and future frameworks that are presently under construction;
- integrate science and process based knowledge with the abovementioned concepts in the design, conduction and interpretation of environmental risk assessment of chemicals in different frameworks at play in the EU (e.g. Plant Protection Products and biocide registration, REACH, Site Specific environmental risk assessment, Water Framework Directive, setting of environmental quality standards) ;
- compile and evaluate inputs for environmental risk assessment in different settings and frameworks, and reflect upon the potential impact of uncertainty;
- analyse concepts of read across between chemicals and interpolation between species and cases;
- critically conduct the technical and computational steps in environmental risk assessment in different settings and frameworks, integrated with the relevant stakeholders;
- interpret results of environmental risk assessment and provide input for risk management, risk communication and risk governance.


Lectures on the different aspects of environmental risk assessment (24 lectures, 12 by lecturers and 12 by experts from the field, in-class). This will provide the students with the fundamentals of ERA under different regulatory frameworks and future perspectives (learning outcomes 1, 2 and 3).
Computational practicals on environmental risk assessment (20 hours, in-class). These practicals will enable the students to acquire the knowledge and expertise to perform the specific steps and routines of environmental risk assessment under different regulatory frameworks (learning outcomes 4,5 and 6).
Group assignment on the assessment of environmental risks on a compound (prospective environmental risk assessment) and a site (retrospective environmental risk assessment) (2 times 24 hours, in (2.5 hours) and out-of-class (21.5 hours)). These group assignments will be conducted in cooperation with real stakeholders, in a realistic setting. This will provide the students with the insight that environmental risk assessment is performed in a multifactorial setting, with different societal stakes (learning outcomes 7 and 8).
Lectures and computational practicals will be evaluated at the individual level. Group assignments will be judged group wise.


Assessment will be based on three outcomes;
- exam: the written exam assesses the theoretical base of environmental risk assessment by means of open questions (25%);
- computational skills: a test of the ability of the student to select the proper information and to compute the technical Risk Indicators for the different environmental risk assessment frameworks (25%);
- group assignments: evaluation of (joint) reports and presentations on a prospective and a retrospective environmental risk assessment (each assignment 25%, 50% in total).


Course will be based on hand outs from lectures and a manual for the computational practical exercises and group assignments. These will be integrated into a reader.

Restricted Optional for: MESEnvironmental SciencesMSc6WD