Release of silver nanoparticles from outdoor facades

Environmental Pollution 158 (2010) 2900e2905

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Release of silver nanoparticles from outdoor facades Ralf Kaegi a, *, Brian Sinnet a, Steffen Zuleeg a, Harald Hagendorfer b, Elisabeth Mueller c, Roger Vonbank b, Markus Boller a, Michael Burkhardt a,1 a

Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland Empa, Swiss Federal Institute for Material Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland c Electron Microscopy ETH Zurich (EMEZ), 8093 Zurich, Switzerland b

We provide direct evidence for the release of silver nanoparticles from exterior paints to the aquatic environment.

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Article history: Received 18 January 2010 Accepted 10 June 2010

In this study we investigate the release of metallic silver nanoparticles (Ag-NP) from paints used for outdoor applications. A facade panel mounted on a model house was exposed to ambient weather conditions over a period of one year. The runoff volume of individual rain events was determined and the silver and titanium concentrations of 36 out of 65 runoff events were measured. Selected samples were prepared for electron microscopic analysis. A strong leaching of the Ag-NP was observed during the initial runoff events with a maximum concentration of 145 m Ag/l. After a period of one year, more than 30% of the Ag-NP were released to the environment. Particles were mostly