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Published on: March 19, 2017
Effect of color temperature on melatonin production for illumination of working environments
Anja Kraneburg1, Steffen Franke2, Ralf Methling2
1Leibniz Research Centre for Working Environment and Human Factors, University of Dortmund, Dortmund, Germany.
Unlabelled:
We studied the influence of correlated color temperature (CCT) of 7 polychromatic white light illuminations (1600 K-14,000 K, 200 lx) in two experiments. Visual performance was tested in 17 students (8 men) during daytime. Visual acuity, contrast sensitivity and sleepiness did not vary with illuminations but polychromatic white light of <2000 K impaired color discrimination. Melatonin synthesis was tested with weekly intervals in 8 trials from 10pm to 2am (7 polychromatic illuminations and a dim light reference (<0.1 lx)) in 16 students (9 men, semi-recumbent position). Melatonin suppression was almost negligible for CCT <2000 K but increased with increasing CCT.
Conclusions:
CCTs <2000 K are not suitable for work places. Polychromatic white light with higher CCTs and significant melatonin suppression is expected to shift the circadian rhythm and to accelerate the adaptation to night work. This effect should be enhanced with elevation of luminance.
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