Nanoparticle-containing, spray can aerosol: characterization, exposure assessment, and inhalation chamber design.
Chen-BT; Afshari-A; Stone-S; Jackson-M; McKinney-W; Schwegler-Berry-D; Frazer-DG; Castranova-V; Thomas-TA
Proceedings of the AAAR 29th Annual Conference, October 25-29, 2010, Portland, Oregon. Mount Laurel, NJ: American Association for Aerosol Research, 2010 Oct; :110
This report describes the methods developed for reliable characterization of a nanoparticle-containing aerosol released from a consumer spray product. A well-controlled environment was employed to simulate an indoor setting for conducting spray applications in a human exposure scenario. Results indicate that, while aerosol droplets were large with a count median diameter of 22 um during spraying, the final aerosol contained primarily solid TiO2 particles with a diameter of 75 nm. This size reduction was due to the impaction of the droplets on the surface and the fast drying of the aerosol during sampling. In the breathing zone, the TiO2 aerosol, containing primarily single particles (> 90%), had a mass concentration of 3.4 mg/m3, or 1.6 x 105 particles/cm3, with a nanoparticle fraction limited to 170 ug/m3, or 1.2 x 105 particles/cm3. This information was used to estimate the pulmonary dose in an average male adult (= 0.075 ug TiO2 per m2 alveolar epithelium per minute) as well as in a rat (= 0.03 ug TiO2), and, consequently, was used to design an animal inhalation exposure study. An inhalation exposure system consisting of a computer-controlled solenoid ''finger'' for generating spray can aerosol was developed and evaluated. The results demonstrate a great similarity in this solenoid ''finger''-dispersed aerosol compared to the aerosol occurring in the human exposure scenario. The next step would be to initiate an inhalation toxicological study to obtain information on dose-response relationships and to use it to establish a No Effect Exposure Level for setting guidelines for this consumer product.
Aerosol-particles; Aerosols; Aerosol-sampling; Analytical-processes; Inhalation-studies; Laboratory-testing; Nanotechnology; Particulate-dust; Particulates; Particulate-sampling-methods; Risk-analysis; Statistical-analysis
Proceedings of the AAAR 29th Annual Conference, October 25-29, 2010, Portland, Oregon