Dynamic lighting during nurses’ shift work improved alertness, mood and modified circadian rhythm

The constant lighting in nurses’ stations exacerbate sleep disorders and cognitive problems among shift nurses, necessitating dynamic lighting for health interventions. This study simulated the bright lighting of morning (300 lx vertical illuminance at eye level, 5000K) during the early phase of shift work (4 hours) and maintained normal lighting (300 lx horizontal illuminance at the desktop, 5000K) in the latter phase. The effects of different lighting methods on nurses' sleep, fatigue, and mood were compared. Twenty shift nurses were randomly assigned into two groups: a portable lighting group (PLG) using task lamps and a ceiling lighting group (CLG) employing architectural luminaires. The intervention spanned 6 consecutive shift cycles (5 days each cycle), with the first and the sixth cycles under static lighting. Results demonstrated that post-intervention, all participants exhibited reduced scores in sleep, fatigue, subjective sleepiness, and mood scales, indicating improved sleep, fatigue alleviation, and emotional regulation. These improvements persisted even after the lighting intervention. The CLG showed significantly greater enhancements in sleep, fatigue, and mood than the PLG, meaning the ceiling lighting more effectively. This study provides empirical evidence for optimizing healthy lighting in nurses’ stations, highlighting the needs of further optimization of lighting methods and spectrum.