Presenter:
- Timo Hamers from the Vrije Universiteit Amsterdam (VUA)
The webinar will be on May 7th, 2026 14.00 – 15.00 CET.
Please find the information in the invitation below and use this link to register
For many persistent and mobile chemicals used and produced in Europe, no or limited data is available on toxicity. As traditional in vivo toxicity testing raises concerns regarding limited testing capacity, high costs and animal welfare, novel strategies are required to prioritize chemicals for further toxicity testing, or for efficiently allocating funds for prevention or mitigation efforts. Within the ZeroPM project, we have developed a low-tier risk-based prioritization matrix using in vitro and in silico new approach methodologies (NAMs). In this matrix, the combined estimations of exposure and hazard are used to determine the priority of each chemical. The exposure estimate is based on measured groundwater concentrations calculated to free human plasma concentrations using physiology-based kinetic models, reflecting a worst-case exposure scenario. The hazard is estimated by testing the chemical in in vitro bioassays and deriving benchmark concentrations which were calculated to free medium concentrations using a virtual in vitro distribution model. As a proof-of-concept, the matrix was used to prioritize 9 triazine, 16 triazole and 11 PFAS compounds classified as persistent and mobile. Given the data-richness of these compounds, the predictive value of the NAMs could be evaluated with toxicokinetic and toxicodynamic in vivo data. Based on the known toxicity of the test chemicals, the in vitro methods focused on endocrine disrupting properties, liver toxicity and developmental toxicity. In general, the hazard estimates based on in vitro data were more conservative than based on in vivo data. PFOA was the only tested high priority chemical. Other chemicals were prioritized after PFOA based on lower exposure estimates, but not on lower toxicity estimates. This study demonstrated the applicability of a NAM-based prioritization matrix, but also highlighted the importance of accurate exposure estimations.
Timo Hamers is an environmental toxicologist and associate professor at Vrije Universiteit Amsterdam. His expertise lies in the application, development and optimization of small-scale in vitro bioassays for hazard profiling of individual compounds and complex environmental mixtures of pollutants.
This webinar invitation can be downloaded here.