1. CNRS, Aix-Marseille Université, CEREGE UM34, UMR 7330, Aix en Provence, France,
2. International Consortium for the Environmental Implications of Nanotechnology, Aix en Provence, France,
3. Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC, USA,
4. Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, USA,
5. Nicholas School of the Environment, Duke University, Durham, NC, USA,
6. Observatoire des Sciences de l’Univers de Grenoble, France, and
7. Phys Solides Lab, CNRS, UMR 8502, Université Paris 11, Orsay, France