From 1930, the Russian physician Professor A.L. Tchijewsky, working in the Central Laboratory for Air Ion Research in Moscow, investigated with a scientific staff the already then known growth inhibition and bactericidal effect of air ions on microorganisms. M. Pyrogenes, vibrio cholerae (pathogen of cholera) and S. Typhosis were the first objects of research. They determined a rapid decrease in the air under artificial negative air ionization.

These studies have been confirmed by a large number of studies made in the United States of America. However, this did not happen until after 1940, and due to the language barrier, this research had been unknown in America. Unipolar ionized air, both positive and negative, also increases the death rate of escherichia coli (coli bacterium found in human and animal intestines), neurospora crossa (red mold) and penicillum notatum. Altogether one determined unanimously that negative air ions are stronger in this influence than the positive ones.

By artificial air ionization with negative air ion generators, one is able to reduce infectious germs in addition to all other properties important for humans and animals, which are still to be discussed. This is a very simple and cheap means to reduce the risk of infection, as it exists in schools, offices, stores etc., to a minimum.