Prof. Willie Peijnenburg (1959) is a scientific researcher/project leader at the RIVM Centre for Safety of Substances and Products. Since 2009 he is also a professor by special appointment, occupying the chair of Environmental Toxicology and Biodiversity at the Institute of Environmental Sciences of Leiden University. At the centre of his work are the effects of non-natural stressors on ecosystems. This research is focussing on the combined effects of chemical substances, climate change and human activities on composition and functioning of ecosystems.

Portretfoto Willie Peijnenburg.
Inspired by the demands we place on a sustainable society and a sustainable environment, national and international environment policies are gradually evolving in the direction of a comprehensive assessment of the threats to our environment. I think this is a good development because it does justice to society's broadly supported demand to care, not only for a safe environment, but also for a sustainable development of our society. This calls for a balance between ecological, economic and social interests.

Willie Peijnenburg studied chemistry at Eindhoven University of Technology. In 1988, he earned his PhD at this university with his thesis ‘An Experimental and Quantumchemical Study on the Mechanism and Stereochemistry of Photochemical [1, 3] Sigmatropic Shifts’.

Since 1988, he works as a scientific researcher/project leader at RIVM. In this capacity, he works on risks of stressors for the environment, with an emphasis on quantifying risks associated with chemical substances. Results of the research are used directly in European risk assessments of chemical substances. The goal is to develop simple models that can be used to assess behaviour and effects of chemical substances in the environment. This makes it possible to minimise expenses associated with substance testing and also to limit the use of laboratory animals to a minimum. Research is being done with various domestic and foreign partners. There is particular extensive co-operation with Chinese universities, including a ‘visiting professorship’ at the University of Dalian.

Willie Peijnenburg was involved as a project leader in a number of national and international projects related to risk assessment of substances. This included establishing an information centre for pesticides   in Slovakia and developing a strategy for mapping sediment quality in Bulgaria. He is also the co-ordinator of the CADASTER FP7 project, directed at implementing risk assessment of substances with an emphasis on minimising animal experiments and optimising underlying test strategies ( He is currently partly involved in environmental risks related to nanoparticles.

Areas of expertise

  • Ecological chemistry
  • Ecotoxicology
  • Risk assessment
  • Nano(eco)toxicology