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Document ID (ISN)112083
CIS number 11-0735
ISSN - Serial title 1080-3548 - International Journal of Occupational Safety and Ergonomics
Year 2010
Convention or series no.
Author(s) Kakooei H., Ardakani Z.Z., Ayattollahi M.T., Karimian M., Saraji G.N., Owji A.A.
Title The effect of bright light on physiological circadian rhythms and subjective alertness of shift work nurses in Iran
Bibliographic information 2010, Vol.16, No.4, p.477-485. Illus. 42 ref.
Abstract In this study, the effects of bright light (BL) on the rhythms in body temperature, plasma melatonin, plasma cortisol and subjective alertness were assessed in 34 shift work nurses at an Iranian university hospital. They were exposed to very BL (4,500 lx) during two breaks (21:15-22:00 and 03:15-04:00) or dim light (300 lx). The subjects were studied under 24h of realistic conditions during which their plasma cortisol and melatonin were measured at 3-h intervals; their body temperature was also measured during and after night shift work. Subjective alertness was evaluated with the Karolinska sleepiness scale. Administration of BL significantly suppressed night-time melatonin levels. A one-way ANOVA revealed that BL tended to increase cortisol levels and body temperature and significantly improved alertness. These results demonstrate that photic stimulation in a hospital setting can have a powerful influence on the adjustment of the circadian system.
Descriptors (primary) Iran, Islamic Republic of; illumination levels; night work; circadian rhythm; fatigue; vigilance; women; hospitals; nursing personnel
Descriptors (secondary) shift work; hormone secretion; body temperature; determination in blood; statistical evaluation
Document type D - Periodical articles
Subject(s) Commerce, services, offices
Occupational physiology
Lighting, colour and vision
Broad subject area(s) Physiology, ergonomics
Browse category(ies) Lighting and colour
Health care services