Exposure of rats to ozone: evidence of damage to heart and brain.

Ozone is a strong oxidizing agent, and in many locations it is a major atmospheric pollutant. It is phytotoxic and an important cause of lung dysfunction in humans. Recently, a significant association has been established between total atmospheric oxidants, of which ozone is one, and daily cardiovascular mortality rates. In this article, we show that exposure of rats to ozone for 5 days, in a concentration found in major urban centers, results in an increased concentration of thiobarbituric acid-reactive material (an indicator of lipid peroxidation) in heart and brain tissue as well as elevated activity of catalase and glutathione peroxidase (enzymic scavengers of peroxides) in these tissues. We examined the heart anatomically and found evidence of extracellular and intracellular edema. These findings indicate that the heart and brain are damaged by a concentration of ozone present in major urban centers; they may have important implications for chronic illness and degenerative processes in humans.