Background

Chemical regulations aim to protect human health and the environment. This is particularly important in workplaces where exposure to chemicals can be significant. Most chemicals used in occupational settings in certain quantities (>1 ton per year) must be regulated, and their toxicity needs to be investigated and documented to ensure worker’s safety. This applies across all sectors where chemicals are part of work processes.

To date, the health effects of chemicals have been studied using animal models, such as rats, mice, and other mammals. Through this approach, toxicologists and regulatory authorities have developed so-called Adverse Outcome Pathways (AOPs)—stepwise diagrams that describe what happens in the organism from the moment of exposure to a chemical until a disease develops. Although these models have often provided a good level of protection for workers, significant biological differences between animals and humans can lead to misinterpretations and potential inaccuracies in chemical risk assessments in the workplace.

This PARC project aims to develop a guidance document for regulatory authorities to improve their evaluation of the human relevance of animal-based AOPs in chemical risk assessment and occupational health settings.

What the Project Investigates

The project will be conducted through case studies in which a group of experts evaluates the human relevance of two AOPs: one related to the development of thyroid cancer and another to developmental abnormalities of the nervous system. These cases are particularly relevant for workers who may be exposed to specific carcinogenic or neurotoxic chemicals in the workplace.

To assess human relevance, the study will use, design, and test a set of questions and considerations aimed at determining whether a mechanism described in animals is also applicable to humans. The goal is to ensure better worker protection by translating findings from animal studies into more precise health assessments for workplaces.

By the end of the study, it is expected that a guidance document will be finalized, featuring concrete questions, evaluations, and examples of how to “translate” animal-based AOPs into more human-specific AOPs, thereby improving worker protection from chemical exposure.

External Collaborators in PARC: 
The project is led by RIVM (Netherlands) and Aristotle University of Thessaloniki (Greece). A total of 11 partners from 8 European countries are involved. 

Financial Contributors: 
Horizon Europe (EU) 

Project Leader (STAMI): 
Graciela López Soop 

Project Staff (STAMI): 
Steen Mollerup, Laura Camassa 

Related Info: 
https://www.eu-parc.eu/ 

IATA: Human relevance (P6.1.1a)