1969 Volume 43 Issue 5 Pages 113-119
To approach to the etiology of this misterious disease, SMON, the authors conducted bacteriological and chemical surveys on drinking water at the household of the patients in SMON prevailing Ibara districts, including. Yoshii districts, Okayama prefecture. They were using well water as drinking water. The number of household surveyed and wells checked is eleven and twelve, respectively.
The morbidity of SMON is compared between two categories of area or household; in one, tap water system is available, in the other, only well water is used.
The results are summed up as follows:
1) Four out of 12 wells were found to be chemically spoiled. Nitrogen-nitrite was detected in them.
2) Out of tested 6 wells in Ibara city, four had bacteria count of more than 100/ml in the water, and in Yoshii town, two out of four. In five out of tested 6 wells in Ibara city, E. Coli of more than 10/ml count was observed. In the water of tap water system in these districts, no abnormalities were found.
3) Statistically significant higher morbidity rate in well water users than in tap water users is confirmed.
