Physiological Action of Ozone

Owing to its powerful oxidising properties, ozone is both a deodoriser and a bactericide of considerable efficiency. Schonbein 3 found that air, laden with organic matter liberated in the course of one minute from 4 oz. of putrid flesh, may be completely deodorised by its own volume of air containing 1 volume of ozone per 31 volumes of air. In 1875 Boillot drew attention to the fact that fresh meat may be preserved for upwards of ten days without going bad, if exposed to ozonised air, whilst, if exposed to ordinary air, the meat will putrefy in half that time. These early observations have received ample confirmation in more recent years, and the bactericidal action of ozone is well established.

It is, however, impossible to make a general statement as to the minimum amount of ozone required to sterilise air, because so many factors are involved. Some organisms are more resistant than others, whilst time, temperature, and the presence of moisture have an important influence upon the results. It is interesting to note, however, that Duphil has drawn attention to the paucity of bacteria in the air of Bordeaux - an air that is characterised by its high percentage of ozone.

Unless the proportion of ozone is exceedingly small, the inhalation of ozonised air by human beings is liable to be accompanied by serious disturbances in the animal organism. The lung tissue is injured, the oxygen intake increased, and the output of carbon dioxide decreased. Exposure for a couple of hours to a concentration of 15 to 20 parts of ozone per million of air is not without risk to life, and even 1 part of ozone per million of air irritates the respiratory tract. This latter dilution, however, may not be harmful; in fact it may be directly beneficial in cases of bad ventilation by stimulating the olfactory nerve and thus relieving the monotony of close air. Air containing not more than 5 parts of ozone per million of air has been breathed by children without any ill effect.

At still greater dilutions than the foregoing, the effect of ozone has been repeatedly proved to be beneficial. In cases of anaemia it appears to stimulate the multiplication of blood corpuscles, to increase the appetite, and to raise the general standard of health of the sufferer. Asthma, bronchitis, pleurisy, and pneumonia have likewise been relieved by inhalation of ozonised air, and it is not impossible that similar treatment may prove beneficial to consumptives.

The odour of ozone is so penetrating that 1 part per 2f million of air is perceptible to the sense of smell. This is well under the danger limit mentioned above, so that the normal nose may be taken as a pretty safe guide in determining whether or not ozone is present in beneficial or dangerous quantity.