project

Mixture Toxicity Assessment: Advanced Approaches for Drinking Water Quality

This project addresses the growing concern over the health effects of chemical mixtures, which can differ significantly from the effects of individual chemicals. The challenge is exacerbated by the lack of explicit regulations and standardized protocols for evaluation, particularly in the context of drinking water, even though international organizations such as WHO, OECD, USEPA, and EFSA provide guidance.

The aim of this project is to develop and/or propose a comprehensive framework to assess and manage the risks posed by chemical mixtures in drinking water and its sources, in order to be prepared for evolving regulations and to protect public health. The project will also give a proof of concept to determine specifically relevant bioassays to measure chemical mixtures for specific adverse effects on human health, by a case study on neurotoxicity. The project will also identify which neurotoxicity testing bioassays yield similar results, allowing the extrapolation or combination of findings from well-documented
bioassays with those that have less data.

Significance and results

Water utilities are actively monitoring water quality, but a deeper understanding of chemical mixture effects can help refine existing strategies and improve risk assessment. As scientific knowledge advances, drinking water regulations continue to evolve. Therefore, it is beneficial for drinking water companies to remain proactive. By anticipating changes in regulations and knowing which chemical mixtures may be of concern or which chemicals are disproportionally adding to mixture toxicity, drinking water companies can adapt their strategies. This project provides a basis for accurately predicting the toxicity of chemical mixtures, including emerging contaminants. It enables the identification of high-risk combinations and offers actionable insights for implementing practical testing methods, such as effect-based assays. Follow-up research will build upon these findings, describing the necessary steps and activities to operationalize these methods in real-life water quality assessment.