RECETOX RI, the Czech node of the EIRENE organized its annual Summer School in the second week of June 2024. This year's topic was the chemical exposure assessment and modeling being a key component of the risk assessment process.
The first part of the training focused on identifying the input data necessary for exposure assessments, including food, indoor and outdoor environments and consumer products. A critical overview was be given to exposure factors and how environmental data can be interpreted and spatially evaluated in the context of exposure assessment.
The second part of the training program focused on learning about the modelling processes, identifying the input data required for model parameterisation and using PBPK models for selected substances to reconstruct or estimate the amount of a chemical to which a person has been exposed (i.e. the exposure dose).
Summary of the tranining:
Exposure assessment is a key component of the risk assessment process, and integrated exposure models rely on environmental data and exposure factors to produce relevant exposure assessments. Understanding the availability and uncertainties in these data is crucial to allow correct selection of inputs and prioritization of exposure pathways within an exposure modeling framework. Implementation of current exposure models requires a breadth of knowledge across diverse pathways, chemicals, and matrices, covering dietary exposure, exposures from consumer products, and environmental levels in indoor and outdoor environments. In recent years, Physiologically Based Kinetic (PBK, also pharmacokinetic PBPK or toxicokinetic PBTK) models have been used in the context of risk assessment to determine biomonitoring equivalents (BE) relevant as regulatory threshold values linked with HBM data. Modelling results can be used to refine the safety levels, either as exposure concentration or tissue concentration under which no adverse effect is expected according to state-of-the art knowledge. PBK models can also compare population subgroups, characterize inter-individual variability, perform extrapolations, and support read-across between similar substances by comparing their concentration kinetic profiles. An integral part of PBK models is their validation and evaluation of uncertainty propagation throughout the modelling process, considering the inaccuracy of input data, model parameters and model structure, necessary for achieving relevant results with a known degree of certainty.
Over 100 environmental health researchers and experts gathered last week in Utrecht for a joint meeting of EIRENE RI and IHEN to report on the progress made in the individual projects and discuss the next steps in Human Exposome research.
Jana Klanova, EIRENE Coordinator, gave a keynote speech at the GCC2024 on "Integrating exposomics into biomedical science.
