Effects of Ozone on Cells in Vitro

Even low concentrations of O3 (4 ppm) appear to retard cell proliferation and interfere with mitotic activity. The effect of O3 seems to depend not only upon concentration of the gas and length of exposure, but also upon cell density: the greater the numbers, the greater the resistance. It is probable that O3 may damage the cell membrane, as is shown by the increased vacuolar content and consequent “swelling” of the cells. Furthermore, it alters the collagenous-like substance by means of which cells attach themselves to the substratum so that they tend to become detached. Results also suggest that cells in vitro may develop a tolerance to O3. No explanation can be given at present but the possibility suggested by Stokinger, the stimulation of activity of the pentose phosphate pathway, could apply.