The effects of artificial sodium sulfate bathing on cardiopulmonary and neurohumoral systems as compared to plain water bathing were studied on five healthy subjects. The results of bathing tests made for 10 minutes at 42°C were as follows:
1) The body surface temperature was higher in three of the five subjects in artificial sodium sulfate bathing than in plain water bathing. The forehead temperature of all subjects in artificial sodium sulfate bathing was higher than in plain water bathing (p<0.05: at 17, 18min. after bathing). The change in oral temperature also showed the same tendency (p<0.05: at 27min. after bathing).
2) The frequency of respiration was less in artificial sodium sulfate bathing than in plain water bathing. Although the heart rate decreased during artificial sodium sulfate bathing as compared to the case of plain water bathing, a clear difference was not observed after bathing. The systolic blood pressure in four of the five subjects decreased in artificial sodium sulfate bathing compared to plain water bathing. One subject, who exhibited low blood pressure before bathing, was restored to his normal blood pressure after artificial sodium sulfate bathing. The sysytolic blood pressure was lower in artificial sodium sulfate bathing than in plain water bathing. (p<0.03: at 20min. after bathing).
3) The serum levels of noradrenalin, adrenalin, serotonin, ADH, renin, aldoster-one, cortisol, β-endorphine, Na⁺, K⁺, and Cl^- showed no significant differences between the two types of bathing.
4) All subjects felt increased warmth and smoothness of the skin after the artificial sodium sulfate bathing compared to plain water bathing.
The above results suggest that the artificial sodium sulfate bathing is superior to plain water bathing in maintaining body temperature, decreasing blood pressure, and feeling (i. e., body warmth and skin texture) after bathing. These effects result from not only the direct action on the skin but also the indirect action due to absorption of the substance through the skin by the mechanism of artificial sodium sulfate bathing.

The effects of bathing with inorganic salts and carbon dioxide (ISCD) on body temperature, systemic circulation, food ingestion and absorption have been studied in healthy volunteers. The peripheral blood flow in the forearm was found to increase in and after immersion of the forearm into a 25l bathing receptacle containing ISCD, as compared with plain water. The peripheral blood flow tended to increase in a dose-dependent manner with ISCD bathing. The skin core temperature, the skin surface temperature and the peripheral blood flow were significantly higher after ISCD bathing than after plain water bathing. The influences of ISCD bathing on food ingestion and absorption were also studied in healthy volunteers. Blood glucose and insulin levels after food ingestion tended to be suppressed by ISCD bathing as compared with plain water bathing. There was no difference between ISCD and plain water bathing in total protein, total cholesterol, triglyceride, HDL cholesterol, and uric acid levels in the blood. These results suggest that ISCD bathing may contribute to the promotion of human health.

Background: Bathing is an important behavior for keeping the body clean and is one of the habits of daily life. Among other things, bathing is regarded as a means of relieving fatigue, refreshing oneself, benefiting health, and improving sleep. As such it can be considered a health-maintaining activity. Apart from a previous study by the authors, there has been very little research on the relationship between home bathing habits and health. Objective: The aim of this study was, therefore, to clarify how physical and mental health relate to daily bathing in the home, particularly the habit of full bath immersion. Method: The participants were 198 employees of a quasi-drug manufacturing company and their family members who could and cooperated in the present study. The study was conducted as a self-report survey from October 1-30, 2010, with questionnaires being distributed to and collected from subjects before and after this period. Participants were asked about their sex, age, frequency of bathing per week, frequency of use of bath additives per week, temperature of bath water, bathing duration, and water level when in the bath, health, and sleep quality. Health was assessed using the Profile of Mood States (POMS) inventory, and self-rated health and quality of sleep were assessed using a Visual Analog Scale (VAS). Results: Among bathing habits, the group with a high bath frequency had significantly low scores for tension-anxiety and depression-dejection mood scales, and significantly high self-rated health. In the present study, self-rated health and quality of sleep were significantly better in the group who frequently used bath additives. In the full bath group, Fatigue score was significantly low and self-rated health and quality of sleep scores were significantly high. Discussion and Conclusion: Taking a full bath frequently and frequent use of bath additives are bathing habits that increase physical and psychological health in the middle-aged.