1. Twenty-Four-Hour Light Exposure and Melatonin Levels Among Shift Workers.
- Author
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Borugian, Marilyn J., Gallagher, Richard P., Friesen, Melissa C., Switzer, Teresa F., and Aronson, Kristan J.
- Subjects
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PHYSIOLOGICAL effects of light , *SHIFT systems , *EMPLOYEES , *MEDICAL care , *MELATONIN , *CIRCADIAN rhythms - Abstract
Objectives: We sought to measure melatonin levels and 24-hour light intensity exposure in health care workers over a 7-day period in natural occupational and residential settings. Methods: Five office workers and 17 nurses working either days or rotating night and day shifts wore a device to record light intensity exposure for one or two 7-day periods, completed a questionnaire, and provided three saliva samples for melatonin. Results: Rotating shift workers had irregular light exposure patterns and abnormal melatonin levels compared with those working days. In addition to lower-than-normal melatonin levels during sleep periods, rotating shift workers exhibited higher-than-normal melatonin levels on arising and during work. Self-reported years of shift work were correlated with measured melatonin and light. Conclusions: Rotating shift work is supported as a surrogate for exposure to light-at-night and circadian disruption. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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