Fig. 1
Characterization of nano-TiO2. A Representative real-time mass concentration measurements of the nano-TiO2 aerosol during a typical inhalation exposure. The red line represents the target concentration, 12.35 ± 0.13 mg/m3. B Size distribution of the nano-TiO2 aerosol (aerodynamic diameter) using a high-resolution electrical low-pressure impactor (ELPI+). The red line represents a log-normal fit of the histogram (count median diameter = 170) and geometric standard deviation (GSD) or 1.95. C Size distribution of the nano-TiO2 aerosol (mobility diameter) sampled from the exposure chamber using a scanning mobility particle sizer (SMPS—light gray) and an aerodynamic particle sizer (APS—dark gray, negligible values). The red line is representative of a log-normal fit of the histogram (count median diameter = 116 nm) with a GSD or 2.12. D Mass size distribution of TiO2 aerosols sampled from the exposure chamber with a Nano Micro-Orifice Uniform Deposit Impactor (MOUDI 115R, MSP Corp, Shoreview, MN). The red line represents a log normal fit of the data that indicates a mass median aerodynamic diameter (MMAD) of 1.48 µm with a GSD of 2.98