Insight into the Behavior of Engineered Aerosolized Nanoparticles: A Method for Understanding their Fate from an Aerosol Release in the Workplace Environment

Abstract

We present a method to assess the behavior of aerosol nanoparticles as a function of time and of selected aerosol chamber and environmental conditions upon exposure to polydisperse silicon dioxide (SiO₂) aerosol nanoparticles (NPs). Through synthesis of SiO₂ aerosol NPs, a well-controlled, stable source of aerosol NPs was used to probe aerosol behavior in an enclosed aerosol chamber. This paper describes a procedure to interface an aerosol chamber downstream of a SiO₂ aerosol NP reactor that is capable of synthesizing SiO₂ NPs with particle diameters from 10 to 100 nm at particle concentrations of ∼10⁴ to 10⁷ particles/cm³. This paper also describes the relative impact on aerosol and aerosol chamber variables, such as chamber volume, the entering aerosol NP size distribution, and environmental parameters, such as relative humidity and ambient particle concentrations, on the observed changes in aerosol NPs over time under unmixed conditions. These findings provide insights into aerosol NP behavior under ideal, well-controlled conditions which can be further refined to include more occupationally relevant conditions that would be important for establishing guidance on suitable workplace containment and controls.

Keywords:

• AEROSOL
• NANOTECHNOLOGY
• ENGINEERED NANOPARTICLES
• OCCUPATIONAL EXPOSURES
• SILICON DIOXIDE