Fig. 3

Number size distribution of the aerosols and respective deposition in inserts. Aerosols were generated by nebulization of suspensions of TiO₂ (NMs 105, 101, 100) and CeO₂ (NM212) at concentrations of 1 g/L (light grey), 5 g/L (dark grey), 10 g/L (black). The size distributions of the NMs in the aerosols were measured using a SMPS and an OPC, and particles ranged from 10 to 1095 nm and 300 to 34 000 nm, respectively (a). The deposition of the NMs on the TEM grids was assessed after exposure (b). TEM grids were placed on the apical side of inserts and exposed 3 h to aerosols generated with suspensions of 10 g/L in the nebulizer. After exposure, the grids were analyzed by TEM to assess the sizes, shapes and distributions of the deposited NMs