Figure 4: Vascular Surface Density (Ss Ves, Bl)
The surface of airway blood vessel normalized to the surface of the basement membrane is represented for all four exposure groups at proximal (level 2) and distal (level 6) airways. At the distal airway level the HDMA group had a significantly higher vessel density compared to filtered air (*) and the two ozone groups had a significant decrease in vascular density compared to the HDMA group (**).