Figure 2.

Time course of changes in BALF cellular and biochemical parameters following single high dose exposure to TiO₂ NPs. The numbers of cells (A), macrophages (B), and neutrophils (C), and LDH (D) and β-glucuronidase activities (E) were assessed 4, 8, 24 hr and 7 days post inhalation (blue squares) or instillation (green circles) exposure. Values are group means ± SE (n = 5) and are represented as a percentage of respective controls. *, significantly different from corresponding controls; Φ, significantly different between exposure methods (p < 0.05).