In recent years, since the accidents during bathing had become a social problem, we analyzed the trend of them in Sapporo city and aimed to make the results well-known to citizens for prevention. Although bathing-related ambulance runs were 0 .71% of all the called emergency cases, the accidental death accounted for 7.4% of the total death toll, and was 1.5 times the traffic death. 11.7% of the bathing-related ambulance runs was the accidental death and they are estimated about 100,000 or more affairs in the whole country. The elderly aged 65 and over occupied 83.9% of the accidental death during bathing. The incidence of cardio-respiratory arrest showed a lower value of 17.6 persons per 100,000 populations than that of other cities. In the elderly, the sum of cardio-respiratory arrest and a loss-of-consciousness reached by 1.7 times of accidental death. In hot spring areas, compared with Sapporo city excluding hot spring areas, there was lesser proportion of accidental death and serious injury. The proportion in which children and adult ages get injured by fall was higher in the hot spring areas. Since it is thought that accidental death continues to increase, and the role in which bathing plays as a preventive care such as recovery from fatigue and a health promotion is large, the preventive emergency is absolutely important.

  According to the annual report of the Japanese National Police Agency, about 100,000 cases of unnatural death are reported every year. More than 10,0000 of these cases occurred during bathing. In Akita Prefecture, more than 150 cases are reported every year which is represents about 10% of the total unexpected death. According to the epidemiological statistics by our department, sudden death or sudden cardio pulmonary arrest in the hot bath occurs mostly in winter time, from late October to early March, and more than 90% of the decedents are senior population. Although some cardiac or cerebral events might occur during bathing, few cases of those died in the bath tub are autopsied by forensic pathologists. In most cases, the cause of death is suspected by postmortem examination by police surgeon, and the cause of death are generally assigned to ischemic heart attack, cerebral stroke, or unclear cause of drowning. It is often difficult to determine the pathogenesis related to the cause of death in the bathtub even by full autopsy. It is reported that the past and/or present medical history of the deceased persons in the bath tub is reported as hypertension, arrhythmia, ischemic heart disease, or diabetes, it is still unclear what actually triggers a lapse in consciousness in the elderly during bathing. We examined the biodynamic change of elderly volunteers while bathing under actual bathing situations occurring in both the winter and summer seasons. Most subjects decreased the level of blood pressure gradually by bathing regardless the season, and some subjects in the elderly developed ECG changes while bathing such as supraventricular extrasystole or ventricular tachycardia. The body temperature increase to 38°C or more in both the elderly and young groups while bathing. By our observations, lower room temperature in the winter time, hot water immersion may result in risky changes in the above parameters which may partially explain some of the causes of the cases of lapse of consciousness and sudden cardiac arrest in the elderly while bathing.

  To examine effects of travel and spa spring to bath death, that of visitors and residents were extracted from inquests from 1984 to 2007 at Naruko Police Office. Total bath death was 192, of which 128 visitors and 64 residents. Average number of visitors per year was 261,000, and average population of residents was 25,468. During first half period bath death of visitors was 80 and residents 15, whereas during latter half visitors 48 and residents 49. Despite day-trippers were as more as 1.5 times to 2.5 times than visitors, bath death of them was scarcely seen. Average mortality rate of bath death for 100,000 of visitors during first half was 225, and in latter half 174, while that of residents was 4.5 in first half and 17.4 in latter half. Therefore ratio of mortality rate of visitors to residents has been ten times or more. Bath death had increased in winter, at from 20:00 to 2:00, on over 40 Celsius degrees of temperature of bathtub, on 20 Celsius degrees or more of temperature difference between bathtub and room, in seniority from 75 to 85 years old, and in drinkers. It was suggested that because bath death was scarcely seen in day-trippers which were more than visitors, risk factor of bath death was not bathing or hot spring, but any combination of inadequate bathing, travel and staying. The maximum risk factor of bath death seemed to be ageing, and or the travel and staying seemed to become stronger stress for elders.