title: Release of silver nanoparticles from outdoor facades.
abstract: 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 micro Ag/l. After a period of one year, more than 30% of the Ag-NP were released to the environment. Particles were mostly <15 nm and are released as composite colloids attached to the organic binders of the paint. Microscopic results indicate that the Ag-NP are likely transformed to considerably less toxic forms such as Ag2S.
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, Uberlandstrasse 133, 8600 Dübendorf, Switzerland. ralf.kaegi@eawag.ch
authors.forename: Ralf
authors.initials: R
authors.lastname: Kaegi
authors.forename: Brian
authors.initials: B
authors.lastname: Sinnet
authors.forename: Steffen
authors.initials: S
authors.lastname: Zuleeg
authors.forename: Harald
authors.initials: H
authors.lastname: Hagendorfer
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Mueller
authors.forename: Roger
authors.initials: R
authors.lastname: Vonbank
authors.forename: Markus
authors.initials: M
authors.lastname: Boller
authors.forename: Michael
authors.initials: M
authors.lastname: Burkhardt
mesh_terms: D007700:Kinetics; D053768:Metal Nanoparticles / Q000032:analysis* / Q000737:chemistry; D008956:Models, Chemical; D010150:Paint / Q000032:analysis*; D011891:Rain / Q000737:chemistry; D012834:Silver / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D012834:Silver