Résumé
The paper addresses the different ways of knowing and living with heavy metal pollution through time. It discusses local knowledge about it as well as the work done by scientists to produce data and monitor it since the 1990s. Cadmium, for instance, is very toxic. It accumulates and cannot be eliminated easily by living organisms including humans. However, its chronic effects remain unnoticed unless proper tools are used to make them explicit. We argue that invisibilization is not only a natural property' of the substance but also depends on the way industrial nuisances were dealt with in the past.