Several biological benefits of the low color temperature light-emitting diodes based normal indoor lighting source

Jiaqi Lin,Xiaolei Wang,Liming Chen,Xu Zhang,Quanwen Liu,Yulian Pang,Can Hong,Hongbo Xin,Xingwei Ding

doi:10.1038/s41598-019-43864-6

Abstract

Currently, light pollution has become a nonnegligible issue in our daily life. Artificial light sources with high color temperature were deem to be the major pollution source, which could induce several adverse effects on human’s health. In our previous research, we have firstly developed an artificial indoor light with low color temperature (1900 K). However, the biological effects of this artificial light on human’s health are unclear. Here, four artificial lights (1900 K, 3000 K, 4000 K and 6600 K) were used to evaluate some biological changes in both human (in total 152 person-times) and murine models. Compared with other three high color temperature artificial lights, our lights (1900 K) presented a positive effect on promoting the secreting of melatonin and glutamate, protecting human’s eyes, accelerating would healing and hair regeneration. These systematical studies indicated that the proposed low color temperature (1900 K) light could provide several significant benefits in human’s daily life.

Highlights

Sun plays a significant role in human life for affecting human biological rhythms as the sole illumination since ancient times[1]
It is worth noting that the blue light appeared in the lights with the color temperature of 3000 K, 4000 K and 6600 K, except 1900 K, which implied that the artificial light (1900 K) could reduce the adverse effect of blue light to eyes[9]
To evaluate the biological effects of artificial lights on sleep, we monitored the melatonin level of 38 volunteers in all who were required to read under the irradiation of the four artificial lights (Fig. S1a,b), respectively

Summary

Introduction

Sun plays a significant role in human life for affecting human biological rhythms as the sole illumination since ancient times[1]. The color temperature of sun changes with time in the day, i.e. from sunrise (2000 K) to noon (6600 K), to sunset (2000 K) in a sunny day[2]. With the changes of color temperature, human being instinctively modify their biological rhythm (sleep-work-sleep) (Fig. 1a). This information indicated that the color temperature of sun is a remarkable factor for affecting human’s life[3]. Before the popularization of artificial lights in human’s life, firelight or candlelight (low color temperature) has been used for illumination with a history of 3.5 million years. The color temperature of illumination sources commonly used in human life is generally in the range of 3000 K–6600 K. We hypothesized that the artificial light (1900 K), similar with sunrise and sunset, would supply some positive effects on human’s biological rhythm and health

Methods

Results

Conclusion