MERLON · Merging scientific Evidence with Regulatory practices and Leveraging identification Of endocrine disruptors using New approach methodologies

Endocrine disrupting chemicals (EDCs) are substances that alter the function of the endocrine system and negatively affect human and animal health. In recent decades, there has been a significant increase in, for example, reproductive disorders and gender incongruence, along with a decline in fertility rates, all of which may be linked to EDC exposure. The EU has highlighted EDCs as substances of high concern and aims to minimise exposure of humans and the environment by improving regulation and policy. Yet there remain important gaps in our understanding of the impact of exposures at critical life stages and the tools for identification and ultimately regulation of EDCs. The MERLON project addresses these gaps, bringing together world-leading experts in endocrinology, chemical safety assessment, developmental and molecular biology, epidemiology, toxicogenomics, toxicokinetics modelling, regulatory toxicology, psychology, psychiatry and research ethics. We will investigate EDC-mediated effects on sexual development, providing human data on the role of EDC exposure during fetal development and changes in mini-puberty, connecting to puberty, reproductive function, and gender incongruence using existing biobanks and cohorts. MERLON will apply and develop 3R-compliant New Approach Methodologies (NAMs) focusing on sexual development and function and the effects of EDCs thereon. Our cutting-edge approaches incorporate transcriptomics, pharmacokinetic models, biomarker identification and the use of Adverse Outcome Pathways, which we will utilize to develop a roadmap for EDC identification, making the best use of NAMs into the future. With MERLON, we will engage EU risk assessment bodies, public health authorities, regulators, scientists and researchers, healthcare providers and citizens. This will ensure all relevant stakeholders have the evidence they need to minimize EDC exposure and support effective and evidence-based regulations and policies.