Abstract
Massive pulmonary edema, varying degrees of alveolar hemorrhage and tracheo-bronchial inflammation occur in animals exposed to high concentrations of ozone. Initial exposures to low concentrations of ozone can prevent the formation of edema and death on subsequent severe exposures in mice. This tolerance was shown to be detectable in 24 hours and present for as long as 102 days. Protection is rendered against a challenging dose as high as 2 1/2 times the ld50. The signs caused by exposure suggest that the central nervous system may be affected as well as the lungs.