Dr. ir. M.T.O. (Chiel) Jonker

Dr. ir. M.T.O. (Chiel) Jonker

Assistant Professor
One Health Toxicology
+31 6 42 508 078
m.t.o.jonker@uu.nl

Chiel Jonker is a senior researcher and consultant at the Toxicology division of the Institute for Risk Assessment Sciences (IRAS). His work is focused on exposure assessment of chemicals in the environment and in laboratory settings (in vivo and in vitro (bio)assays). Being trained as an environmental chemist/ecotoxicologist, his environmental research and consultancy activities relate to identifying sources of toxic chemicals and gaining a better understanding of the risks and environmental distribution of these chemicals, as driven by sorption and bioaccumulation processes. Currently, much of Chiel’s attention is directed towards per- and polyfluoroalkyl substances (PFAS); chemicals he also tries to degrade and remove from environmental compartments, in order to reduce human and environmental exposure. Additionally, Chiel has many years of experience in working with very hydrophobic chemicals (for example oil, polycyclic aromatic hydrocarbons, and pesticides such as DDT), for which he has developed specific exposure quantification techniques (passive sampling methods). In the laboratory, he tries to improve the performance and resulting data quality of in vivo and in vitro (bio)assays through better dosing, exposure, exposure quantification, and data interpretation. Here, his scientific motive is developing new and improving existing experimental methods and concepts, with particular emphasis on experimental quality and difficult-to-test chemicals. Crucial to all his work are high-quality chemical analyses (GC-MS; LC-MS) and a thorough understanding of the driving force of chemical properties in exposure assessment.