Correlation between death while bathing and meteorological parameters in the 23 wards of Tokyo

N. Tanaka, N. Miyatake, H. Kinoshita, T. Fukunaga

Abstract: Study’s Objectives. Japanese people bathe every day and every home has a bathtub. The number of deaths while bathing increases during colder months. The present ecological study aimed to determine whether or not low air temperature is associated with death while bathing in Japan.
Materials and Methods. The monthly numbers of deaths while bathing in the 23 wards of Tokyo were obtained from the Tokyo Medical Examiner’s Office and data on air temperature and humidity were obtained from the Japan Meteorological Agency.
Results. The monthly numbers of deaths while bathing significantly and negatively correlated with air temperature and humidity (mean air temperature, r = -0.943; p < 0.0001). A single regression line showed that a decrease in mean air temperature of 1°C corresponded to a monthly increase of 0.095 deaths per 100,000 persons.
Conclusions. Lower air temperature is closely associated with higher rates of death while bathing in the 23 wards of Tokyo, Japan.
Keywords: death during bathing, air temperature, 23 wards of Tokyo, ecological study.