Effects of variable lighting intensities and colour temperatures on sulphatoxymelatonin and subjective mood in an experimental office workplace.
Workplace illumination is of paramount importance in determining the employee's productivity and well-being. Moreover, light exerts non-visual effects with respect to biological rhythms. In this study, we investigated the impact of different lighting conditions (500-1800 lx, 6500 K; 500 lx, 4000 K) on sulphatoxymelatonin (aMT6-s) and subjective mood in an experimental office accommodation. Urinary aMT6-s concentrations were significantly decreased at all days of the experiment in both lights. On day 3, differences between aMT6-s concentrations in specimen collected at 05:00 p.m. and at 09:00 a.m. were significantly higher under variable lighting conditions. Analyses of a mood rating inventory revealed a benefit of variable light with respect to the dimensions of "Activity", while "Deactivation" and "Fatigue" were increased in regular light on day 1. "Activity", "Concentration", and "Deactivation" changed in opposite directions when comparing variable with regular illumination on two consecutive days. In conclusion, variable light exerts a potential advantage in indoor office accommodations with respect to subjective mood, although no unequivocal differences in the profile of aMT6-s were found as compared to regular light.
Hoffmann
Georg
G
Institute for Leisure, Travel, and Alpine Medicine, University for Health Sciences, Medical Informatics, and Technology, Eduard Wallnoefer-Zentrum 1, A-6060 Hall, Austria. georg.hoffmann@umit.at
Gufler
Veronika
V
Griesmacher
Andrea
A
Bartenbach
Christian
C
Canazei
Markus
M
Staggl
Siegmund
S
Schobersberger
Wolfgang
W
D000328:Adult; D000339:Affect; D002940:Circadian Rhythm; D003116:Color; D018592:Cross-Over Studies; D006801:Humans; D008027:Light; D008029:Lighting; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D019798:Neopterin / Q000652:urine; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D013696:Temperature; D014796:Visual Perception; D017132:Workplace
C054513:6-sulfatoxymelatonin; D019798:Neopterin; D008550:Melatonin