RADIOMIMETIC TOXICITY OF OZONISED AIR

Abstract

A simple way of detecting a morphological red cell effect of ozone in anlmals and in man was found, namely, the sphering of erythrocytes. Thus, the new red cell stants circulating as a flat disc and ends as a spherocyte, the change being promoted by exposure to ozone. It was also found that this change in shape of the suspended cells is greatiy speeded up by x irradiation in vitro, and that this radioinduced acceleration is sensitized by exposure of the animal to low ozone concentrations. It was shown that in the diluted blood of x- irradiated mice, rats, rabbits, and humans who breathed air containing 0.2 to 0.25 ppm of ozone (which can just be detected by smell) a sphering tendency of erythrocytes develops. A further direct demonstration of structural damage caused by ozone was found in the postmitotic nuclei of myocardial fibers of adult rabbits and mice that were exposed to 0.2 ppm of ozone during five hr per day for three weeks. They show rupture of the nuclear envelope and extrusion of nuclear contents which are never observed in the nuclei of normal fibers, but are very similar to nuclear irradiation effects in patients and in x-irradiatedmore » tumor cells. Inbred grey mice exposed to 0.1 or 0.2 ppm of ozone in air for 7 hr/day over three weeks had litters of normal size though the neonatal mortality in the first three weeks was 6.8 and 7.5%, against 1.6% in the controls. In the second litters of parents exposed to 0.1 ppm of ozone in air, this figure was 4.9%. In inbred C57 black mice exposed in the same way to 0.2 ppm of ozone the neonatal mortality in the first three weeks was 34%, against 9% in controls, It is concluded that exposure to low concentrations of ozone, such as produced by commercial ozonizers, is not innocuous. It is noted that health authorities are very much opposed to exposure to the smallest concentrations of oxygen radicals produced by iorizing radiation, whereas they are indifferent or they even encourage the use of an oxidant as powerful and as long-lived as ozone, which is copiously produced at home, in factories, and in hospitals, by so-called fresh air devices. (BBB)« less