Agronomy Engineer and PhD, Sébastien Denys is Health-Environment-Occupational Director of Santé publique France, the French National Public Health Agency, a department he created in 2019. He has nearly 25 years of experience in the evaluation exposures, risks and impacts of environmental threats on health in support to public policies. Its division pilots various monitoring programs focusing on exposure and health of the main issues related to the environment - chemical substances and asbestos, climate and climate change, air and soil pollution, impact of industrial activity, of work. Its activity is more particularly intended to promote the integration of the results of these programs into public policies and preventive actions, in order to protect and improve health. It contributes to the main public health plans in the fields of environmental health and occupational health and as such participates in the various governance bodies of these plans as well as in various expert groups at national or European level. He currently chairs the climate change and health committee of the International Association of Public Health Agencies (Ianphi).