Résumé
This article is based on a description of the functioning of the Ecocitizen Institute for the Knowledge of Pollution (IECP in French). The aim of this atypical organisation in the French research landscape is to produce, together with the local authorities and residents of the Fos industrial port area, the data on environmental pollution and health that are lacking to inform the public debate. We review two participatory biomonitoring experiments conducted by the IECP: lichen monitoring for air quality assessment and the use of conger eels as a sentinel species for marine environmental quality. Our research argues that situated knowledge, based on different levels of collaboration between scientists and lay people, can contribute to improving the governance of technological risks, not only because it generates new socio-ecosystemic links, but also because it provokes a cosmopolitical shift towards care and precaution. We conclude with the emergence of situated sciences that transform the very way of considering scientific practices when they become sensitive to the common conditions of habitability of the living.