After having analyzed several surveys on natural inactivation of viruses in water, the authors have attempted to determine the survival life of poliomyelitis virus type 1 in hydrous medium, of known composition, well-buffered and devoid of any bacterial contamination on the one hand, and on the other hand, in a similar medium with addition of organic humate-type substances. The experiment was carried out at 4 degrees C and at laboratory room temperature (18 degrees C-24 degrees C). Results tend to confirm that the presence of humate-type substances seems to have no significant influence on the development of poliomyelitis virus type 1. Moreover, under the experimental conditions used, the survival life of the virus is much longer than the one previously described. It represents an average of 296 days for a storage temperature of 18 degrees C-24 degrees C. It is longer in water kept at 4 degrees C; in fact, according to statistical calculations and to titrations carried out over a period of 550 days, the total disappearance of the virus was detected only after a period of 10 to 15 years.