In the late 1990's, a series of crises led the European Union and EU Member States to reform the organisation of scientific expertise for the governance of health risks. Contrary to what was expected, these reforms did not succeed in restoring trust in scientific expertise and public decision-making. On many occasions – the ongoing Covid-19 pandemic being one of the most recent and challenging ones- opinions by health risk authorities and scientific bodies are still challenged in many ways, in society, the media, or in the political and scientific arenas. Such challenges take place in a social context characterised by the following: increasing socio-technical interdependencies; continuing social concerns with health, safety and environmental protection; political requirements for practical and rapid recommendations or even policy options from scientific expert bodies; reduction of public spending; misconduct in research leading to discredited scientific integrity; digitalisation, etc.

Furthermore, from a social sciences perspective, attention has been drawn in recent years to two major social and scientific dynamics that affect the context of scientific expertise in field of health risks. The first one is linked to the political economy of knowledge. Evidence suggests that, although the reform of public expertise has strengthened its independence, economic interests contribute to the social production of ignorance through knowledge production and its orientation. On one hand, important potential long-term risks remain orphaned from scientific knowledge and, on the other hand, scientific knowledge is not systematically translated into public decisions. This also reinforces distrust of the institutions in charge of health risks. A second contextual change is related to the growing social reflexivity on the systemic dimensions of environmental issues. How should scientific expertise be conducted and communicated in an era which is now frequently referred to as the Anthropocene era, and in which it is increasingly difficult to isolate and separately address environmental risk factors?

All these elements lead to the reconsideration of a common issue: why is scientific expertise credible (or not)? What are the factors that contribute to the credibility of knowledge used for public decision-making? Roughly, depending on the category of actors, three types of answers are generally formulated:
• credibility is mainly a matter of communication and of scientific education;
• credibility requires thinking of alternative ways to produce expertise, combining openness to society, and a separation from economic interests;
• credibility requires broadening the frame of expertise, and developing methodologies which take systemic and complex factors into account, well beyond the traditional paradigm of risk analysis.

In this context, this international symposium will bring together academic scholars, managers of health agencies, scientific experts and stakeholders to discuss and debate on these contemporary challenges, their origins and the various ways
to address them. Due to the health context, the symposium initially planned for July 2020 will now take place in early 2021 as a virtual event with: 
• the afternoon of 20 January, framing presentations
• the afternoon of 21 January, initial lessons learned from the COVID-19 crisis
• a series of 10 thematic webinars held on the afternoons of 26 January, 2 February, 8 February and 9 February.

Most sessions will be in English with simultaneous translation into French.

International scientific committee: Barbara Allen (Virginia Tech), Bernadette Bensaude-Vincent (Paris 1 University), Lynn Frewer (Newcastle University), Stephen Hilgartner (Cornell University), Sheila Jasanoff (Harvard Kennedy School), Ortwin Renn (IASS Potsdam)
National planning committee: Fanny Debil (ANSES), Brice Laurent (CSI), Pierre Benoit Joly (INRAE), Jean-Noël Jouzel (CS0), Alain Kaufman (UniL), Gérard Lasfargues (ANSES), Benoit Vergriette (ANSES)