著者

Naoshi Kakitsuba

出版者

Japanese Society of Human-Environment System

雑誌

人間-生活環境系学会英文誌 (ISSN:13451324)

巻号頁・発行日

vol.20, no.1, pp.1-10, 2018 (Released:2018-06-11)

参考文献数

92

被引用文献数

8 12

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This paper introduces current knowledge on the effects of humidity on physiological and psychological responses. Reviewing this topic is quite challenging, for two reasons. The first is the fact that humidity is not an independent variable, but a dependent one. Since humidity is strongly associated with temperature, the effect of humidity per se may not be clearly defined. The second reason is that the physiological and psychological impacts of humidity have brought attention to various research fields related to human comfort and health, and knowledge has thus been accumulated from various disciplines. To arrange vast amounts of information, therefore, limitations on the scope are required before introduction. This paper investigated four different research fields: thermal physiology; exercise physiology; hygiene; and dermatology. Selected papers were then introduced chronologically to confirm current knowledge in each research field.From the perspective of exercise physiology, the magnitude of heat stress during exercise in hot and humid environments appears to be clearly estimable from the current knowledge. From the perspective of hygiene, inspired gas conditioned to core temperature and fully saturated with water would provide the optimal condition for mucosal health and function. In terms of dermatology, properties of the stratum corneum appear to have been fully clarified, and water diffusion through the skin can be properly estimated from current knowledge. With thermal physiology and engineering related to indoor environments, current knowledge may be sufficient to provide optimal thermal environments in consideration of effect of humidity. However, discrepancies between physiological and psychological responses and large individual differences in psychological responses to variations in relative humidity have not yet been resolved, due probably to unknown mechanisms in the perception of humidity without specific receptors within the skin. Such issues may require further studies in all research fields related to human comfort and health.

著者

Naoshi Kakitsuba Igor B. Mekjavic Tetsuo Katsuura

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.3, pp.403-408, 2007 (Released:2007-07-20)

参考文献数

12

被引用文献数

3 5

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The purpose of the study was to investigate the degree of subject variability in the peripheral and core temperature thresholds of the onset of shivering and sweating. Nine healthy young male subjects participated in three trials. In the first two trials, wearing only shorts, they were exposed to air temperatures of 5°C and 40°C until the onset of shivering and sweating, respectively. In the second experiment, subjects wore a water perfused suit that was perfused with 25°C water at a rate of 600 cc/min. They exercised on an ergometer at 50% of their maximum work rate for 10–15 min. At the onset of sweating, the exercise was terminated, and they remained seated until the onset of shivering, as reflected in oxygen uptake. In the first two trials, rectal temperature (Tre) was stable, despite displacements in skin temperature (Tsk), whereas in the third trial, Tsk (measured at four sites) was almost constant (30–32°C), and the thermoregulatory responses were initiated due to changes in Tre alone. The results of the first two trials established the peripheral interthreshold zone, whereas the results of the third trial established the core interthreshold zone. The results demonstrated individual variability in the peripheral and core interthreshold zones, a proportional correlation between both zones (r=0.87), and a relatively higher contribution of adiposity in both zones as compared with those of other non-thermal factors such as height, weight, body surface area, surface area-to mass ratio, and the maximum work load.