A number of attempts have been made to discover the chemicals which may provide protection against the lethal effects of the air pollutant ozone. The stabilizing effect of zinc on biomembranes in general is reported. It was shown in vivo and in vitro studies that lipid peroxidation in rat liver stimulated by CC1/sub 4/ was substantially decreased by zinc pretreatment. It was also shown that pretreatment of mice with a low dose of zinc (3 uM/kg body weight by gavage for 3 days prior to NO/sub 2/ exposure) prevented the development of lung edema induced by NO/sub 2/ exposure. A possibility is raised that the nutritional status of zinc in animals may affect the response of animals to lethal levels of ozone exposure. With this concept in mind a study was carried out to explore the possibility of using zinc supplementation as a means of protection of animals from ozone toxicity.