A study of human adaptability to regional light conditions

本研究从不同季节、不同地区的光照条件下人类对环境适应的角度进行。比较了4个季节（春季、夏季、秋季和冬季）和3个地区（福冈/日本、波兹南/波兰和河内/越南）参与者在日常生活中接受的日常活动、睡眠因素、褪黑激素节律和照明条件（照度和波长）。在日本，褪黑激素节律有明显的季节性变化。与其他季节相比，秋季褪黑素分泌峰值较高，分泌高峰出现的时间较晚。在波兰和越南没有发现褪黑激素分泌的季节性变化。3个地区的褪黑素分泌峰值和峰值时间存在显著差异。此外，受试者接受的光照条件存在季节性和地区性差异，本研究表明人体褪黑素节律具有季节性和地区性差异。这是人类在自然环境中适应和进化的证据之一。因此，当我们的生活环境从现在开始变得更加人工化时，人们担心这些人工环境会对人类的生物节律产生严重影响。在未来居住环境的设计中，我们需要考虑人类健康和舒适生活的人工环境条件以及人类对环境的适应能力。

This study was performed from a viewpoint of the human adaptation to environment under the light in different seasons and regions. The daily activity, sleep factors, melatonin rhythms, and lighting conditions (illuminance and wavelength) the participants received in daily life were compared between 4 seasons ( spring, summer, autumn and winter) and 3 regions (Fukuoka/Japan, Poznan/Poland and Hanoi/Vietnam). In Japan, the clear seasonal variation was seen in melatonin rhythm. The peak value of melatonin secretion was higher and the peak time of melatonin secretion seems delay in autumn as compared with other seasons. The seasonal variations of melatonin secretion were not seen in Poland and Vietnam. There were significant differences in peak value and peak time of melatonin secretion among 3 regions. Moreover, there were seasonal variations and regional differences in light conditions the participants received.This research showed that the human melatonin rhythm has seasonal and regional variation. This is one of the proofs human being has adapted and evolved under natural environment. Therefore, when our living environment becomes more artificial from now on, it is anxious that those artificial environments have serious influences on human biological rhythms. In the case of the design for future living environment, we need to consider the conditions of the artificial environment where human can be healthy and live comfortably with human adaptation ability to environment.