Sébastien Denys is an agricultural engineer by training and authorized to direct research. His expertise is centered on the impact of the environment on human health and the health of ecosystems. In 2016, when Santé publique France was created, he was appointed Director of the Health-Environment Department and then was commissioned to create the Health-Environment-Work Department in 2018, which he has managed since then. The missions of its Department aim to better understand the impact of the determinants of the general or professional environment on health. As such, it actively participates in the work of the various plans or national plans in the field of environmental health or occupational health. It is also actively involved in the European PARC partnership coordinated by ANSES, which aims to provide innovative risk assessment for chemical substances. He is also chairman of the “climate change and health” committee of the international association of public health agencies – IANPHI.