Diatoms as a new indicator of metal pollution?
There are thousands of species of diatoms in rivers. These microscopic, unicellular algae react to organic pollution from agricultural and industrial sources, which explains why they are used as biological indicators for the quality of aquatic environments in efforts to implement the European Water framework directive (WFD). Cemagref scientists in Bordeaux, who have studied diatoms for years and participated in developing the diatom biological index (IBD), have discovered that they also react to metallic pollutants, in particular cadmium which is highly toxic. Similar to organic pollutants, contact with metallic pollutants results in a modification in the percentages of diatom species in a given population or in deformations in their silica-based skeleton...