FIG. 7.

Acute pulmonary first WLL fluid LDH dose responses after exposure to TiO₂ NPs. First WLL fluid LDH was determined at 1, 3, and 7 days postexposure as an indicator of the cytotoxicity. Panel (A) First WLL fluid LDH activities determined after exposure to NS. Panel (B) First WLL fluid LDH activities determined after exposure to NB1. Panel (C) First WLL fluid LDH activities determined after exposure to NB2. Values represent means ± SE (n = 6–8). For a given postexposure time, bars with different letters are significantly different (p < 0.05). Bars with two letters indicate differences exist between this bar and both lower and/or higher doses at the same postexposure time.