Since 1933, effects of the internal use of mineral waters in this district were studied by Prof. Dr. T. Misawa and his coworkers concerning gastric and bile secretion, gastrointestinal motility, diuresis, glucose metabolism, anemia and others.
In this report, present status of the internal use of mineral waters in this district, the results of studies on the therapeutic and toxic effects, maximum permissible concentrations of trace elements in the spring waters, several experimental and clinical studies on atherosclerosis etc. will be reported.
I. The present status of internal use of hot spring waters in Kanto district and its environs.
The research was carried out by enquête method. Answers were obtained from 40spa admimistrations. Following results were concluded:
1) In the majority of the spas the internal use of spring waters are uncommon, only at 3 spas (Spas Shima, Kuronagi, Shibu) the internal use is more frequently carried on than the bathing cure.
2) The majority of the visitors take hot spring waters 2 times a day (morning and evening), ca. 100ml at a time, in total usually 5 go (900ml-1000ml), maximum 1.5 sho (2700ml), a day.
3) The majority of patients utilizing the drinking cure are suffering from gastro-intestinal diseases, and rarely from other diseases.
4) For the gastrointestinal disease, sodium chloride waters, sulfur waters and alkaline waters are used mostly and for the constipation hydrogen sulfide waters, sodium bicarbonated waters and sulfated waters were used.
II. Statistical observation on the spa treatment in Shiohara Hot Springs, Tochigi Pref. 1) The patients had predominantly gastrointestinal disorders in Motoyu (pH 6.3, hydrogen sulfide containing sodium bicarbonate and chloride spring).
In Motoyu, the patients with drinking cure suffered from stomach ulcer (15/41), chronic gastritis, duodenal ulcer and gastroptosis with atonia. It seems that they select a spring according to their empirical evaluations.
2) About 87% of the visitors put in practice of drinking of hot spring water in Motoyu. Most visitors take thermal bath 5 to 6 times a day on an average, and drink spring water at the time of bathing, in total 4-6 go (720-1080ml) a day in 18/41 cases, 9-10 go (1620-1800ml) in 12/41 cases.
3) Liver function of patients (B. S. P. test and Gros test) was investigated before and after the cure, but no significant change was observed.
III. Effects of trace elements.
1) Effects of the addition of Cu and/or vitamine C on the absorption of iron in mineral waters from the digestive tract were studied using the radioactive iron experimentally.
Iron absorption from the digestive tract was promoted by the addition of copper, and vitamin C in the test solution. No promoting effect was proved by the addition of copper in the ratio of Fe:Cu=1:1, but it proved most effective with the ratio of
Fe:Cu=2.6:1
2) Maximum permissible amount of Pb, Zn and Cu contained in mineral waters were studied in rabbits experimentally. It was concluded that the maximum permissible dose of orally given Pb, Zn and Cu were between 7.5mg, 20mg or 1.9mg per kg body weight daily by administration for a month, respectively.
This concentration of lead is 100 times higher than that of mineral waters with highest lead content in Japan. And as mineral waters with high zinc or copper content in Japan used to be strongly acid and mostly belong to acid vitriol or acid alum vitriol springs, only daily 10-50ml can be taken after 5-10 times diluted with common water for drinking cure.
The highest record of zinc content in Japan is 965mg/kg ZnSO₄ (Sasakura Hot Spring), therefore there would be no probability of Zn poisoning from drinking cure of mineral waters in Japan, and when taken 25ml of copper containing mineral water daily the maximuan permissible concentration of copper containing waters will be 75mg/kg. Only few of the Japanese mineral waters contain more than