title: Conceptual model for assessment of inhalation exposure to manufactured nanoparticles.
abstract: As workplace air measurements of manufactured nanoparticles are relatively expensive to conduct, models can be helpful for a first tier assessment of exposure. A conceptual model was developed to give a framework for such models. The basis for the model is an analysis of the fate and underlying mechanisms of nanoparticles emitted by a source during transport to a receptor. Four source domains are distinguished; that is, production, handling of bulk product, dispersion of ready-to-use nanoproducts, fracturing and abrasion of end products. These domains represent different generation mechanisms that determine particle emission characteristics; for example, emission rate, particle size distribution, and source location. During transport, homogeneous coagulation, scavenging, and surface deposition will determine the fate of the particles and cause changes in both particle size distributions and number concentrations. The degree of impact of these processes will be determined by a variety of factors including the concentration and size mode of the emitted nanoparticles and background aerosols, source to receptor distance, and ventilation characteristics. The second part of the paper focuses on to what extent the conceptual model could be fit into an existing mechanistic predictive model for ''conventional'' exposures. The model should be seen as a framework for characterization of exposure to (manufactured) nanoparticles and future exposure modeling.
authors.affiliation: Køgemestervej 13, Hillerød DK 3400, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schneider
authors.forename: Derk Henri
authors.initials: DH
authors.lastname: Brouwer
authors.forename: Ismo Kalevi
authors.initials: IK
authors.lastname: Koponen
authors.forename: Keld Alstrup
authors.initials: KA
authors.lastname: Jensen
authors.forename: Wouter
authors.initials: W
authors.lastname: Fransman
authors.forename: Birgit
authors.initials: B
authors.lastname: Van Duuren-Stuurman
authors.forename: Martie
authors.initials: M
authors.lastname: Van Tongeren
authors.forename: Erik
authors.initials: E
authors.lastname: Tielemans
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D008420:Manufactured Materials; D008962:Models, Theoretical; D053758:Nanoparticles / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D010316:Particle Size; D018570:Risk Assessment / Q000379:methods; D013997:Time Factors; D014691:Ventilation; D017132:Workplace
chemical_list: D000336:Aerosols; D000393:Air Pollutants