The PARC project aims to support regulatory risk assessment by providing methods, tools and concepts for integrative exposure, risk assessment and health impact assessment. Sixty institutes from twenty European countries join forces to improve risk models to account for chemical mixtures and the diversity of sources and routes.

Developments will be applied to case studies on PFAS, heavy metals, pesticides and phthalates which were previously prioritized by the PARC stakeholders. Innovative methods will be proposed to perform mixture risk assessment. Models will be optimized and combined to estimate risk drivers and main sources and routes of exposure, including occupational sources. Case study results are anticipated in 2024. The results aim to support risk managers and end-users at a national and European level. Additionally, the results will enable stakeholders to take appropriate risk mitigation measures where exposure levels of chemical mixtures exceed acceptable levels. 

Four new reports 

This work is anchored in task 6.2 "Integrative exposure and risk assessment” in PARC, and four reports are now published on the PARC website.

• Roadmap on aggregate exposure strategy through different sources and routes related to general and occupational environments takes into account existing data and models for exposure via single source (e.g. food, soil, water, consumer products, occupational exposure). It also addresses the challenges associated with aggregating multiple exposures. 

• Inventory of Physiologically Based Kinetic (PBK) models for assessing the internal exposure through life addresses the conversion of external exposures into internal doses, accounting for all relevant routes in the human body (inhalation, dermal and oral exposure). This work considers exposure during different life stages (including sensitive time windows in life). The combination of the roadmap for aggregate exposure strategy and the inventory of PBPK models will enable verification of our approach, by comparing predictions of aggregate exposure with human biomonitoring data (being a direct measure of integrative exposure) in case studies on PARC priority chemicals (PFAS, heavy metals, pesticides and phthalates).

• Strategy for mixture risk assessment using human biomonitoring (HBM) data and its application to prioritised mixtures tackles the issue that multiple chemicals may exert common health effects, thus requiring a mixture risk assessment approach. The development of a strategy for mixture risk assessment is case studies of effect (immunotoxicity, nephrotoxicity, neurotoxicity and DNT), according to the EFSA opinion ↗ on scientific criteria for grouping chemicals into these assessment groups.  

• Inventory of existing environmental burden of disease (EBD), health impact assessment (HIA), exposure and exposure-effect data for chemicals prioritized in PARC describes the strategy and available data for integrating exposure data, exposure-effect relationships and health data into environmental burden of disease and health impact for chemicals prioritized in PARC.  

Overall, the four deliverables describe the progress made in the field of integrative exposure and risk assessment during the first year of PARC and form the basis for further developments in creating concepts and tools in the coming years.