title: Engineered nanomaterials in rivers--exposure scenarios for Switzerland at high spatial and temporal resolution.
abstract: Probabilistic material flow analysis and graph theory were combined to calculate predicted environmental concentrations (PECs) of engineered nanomaterials (ENMs) in Swiss rivers: 543 river sections were used to assess the geographical variability of nano-TiO(2), nano-ZnO and nano-Ag, and flow measurements over a 20-year period at 21 locations served to evaluate temporal variation. A conservative scenario assuming no ENM removal and an optimistic scenario covering complete ENM transformation/deposition were considered. ENM concentrations varied by a factor 5 due to uncertain ENM emissions (15%-85% quantiles of ENM emissions) and up to a factor of 10 due to temporal river flow variations (15%-85% quantiles of flow). The results indicate highly variable local PECs and a location- and time-dependent risk evaluation. Nano-TiO(2) median PECs ranged from 11 to 1'623 ng L(-1) (conservative scenario) and from 2 to 1'618 ng L(-1) (optimistic scenario). The equivalent values for nano-ZnO and nano-Ag were by factors of 14 and 240 smaller.
authors: Empa - Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, CH-9014 St Gallen, Switzerland.
authors: F
authors: F
authors: Gottschalk
authors: C
authors: C
authors: Ort
authors: R W
authors: RW
authors: Scholz
authors: B
authors: B
authors: Nowack
mesh_terms: D004738:Engineering; D004784:Environmental Monitoring; D008962:Models, Theoretical; D049329:Nanostructures / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D013557:Switzerland; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical