Optical microscopy images (100-x) of lung tissue sections. Morphological assessments of lung tissue stained with haematoxylin and eosin of sham (A), control (exposed to compressed air) and TiO2 NP exposed rats by means of inhalation for 6 hours. Responses to nano-TiO2
(C to G) were different in intensity compared to the controls (B), except for the 50 nm SA group (H). The lungs of rats exposed to 5 and 10–30 nm SA aerosols (D and F) as well as rats exposed to 10–30 and 50 nm LA aerosols (E and G) showed more leukocyte infiltration compared to the control group (B).