Potentiation of the virucidal activity of sterilized natural waters.

After heat, conductivity has been described as the second most inactivating factor of viruses in surface waters. Using poliovirus-1, we showed that a highly significant linear relationship between virus inactivation rate and water conductivity can be obtained for most of the tested sterilized water samples. Using sterile saline solutions, we demonstrated that this apparent relationship is false, i.e., virus inactivation rate is not affected by water conductivity alone. With the hypothesis that salts may serve to potentiate the antiviral activities of certain microbiological substances that are supposed to be found in the tested samples, we can explain the apparent relationship observed in this study and in similar ones. As a consequence, an effective water treatment could be responsible for the removal of both viruses and some virus-inactivating factors. Alternatively, virus-inactivating capability of a given water resource could be enhanced along with its hardness or its degree of mineralization.