Ozone-Induced Arterial Lesions

Microscopic studies carried out on the lungs of rabbits exposed to 0.4 ppm of ozone for six hours a day, five days a week, for a calendar period of ten months showed both emphysematous and vascular lesions. Small pulmonary arteries (exterior diameters of 105µ to 1,050µ) showed a marked mural thickening. The mean ratio of the thickness of the wall to the diameter of the lumen was greatly reduced in the exposed animals as compared with that of the controls.