Fig. 2.

A1, B1, and C1 (high power) and A2, B2, and C2 (low power): representative histological sections of mouse lungs stained with hematoxylin and eosin after exposure to ozone showing enlargement of alveolar space after 3 and 6 wk of exposure. A1 shows lungs from an air-exposed mouse for 3 wk, and A2 an air-exposed mouse for 6 wk. B1 and B2 are representative lung sections from ozone-exposed mice for 3 wk, and C1 and C2 from ozone-exposed mice for 6 wk, showing the degree of alveolar space enlargement. D–F: representative histological sections of mouse airway and lungs stained with hematoxylin and eosin showing the degree of submucosal airway inflammation in the 3- and 6-wk-exposed mice and the flattening of the airway epithelium (arrow) seen particularly after 6 wk of exposure. There is also evidence of enlargement of the alveoli in the ozone-exposed mice.