TY - JOUR
T1 - A 24-hour lighting scheme to promote alertness and circadian entrainment in railroad dispatchers on rotating shifts
T2 - A field study
AU - Sahin, L.
AU - Figueiro, M. G.
N1 - Funding Information:
The authors wish to acknowledge Metro Istanbul Co., and its former General Manager Kasim Kutlu and former Deputy General Manager Mustafa Metin Yazar, and Project Manager Koksal Kotil; Operation Manager Yildiray Yedikardes; Chief of the Seyrantepe control centre Alper Hakan Arsal; Supervisor of the control centre Bulent Karacuha; and all dispatchers who participated in the study. We also wish to acknowledge project department staff Seyma Eksi, Ebru Aydin, and Emrah Ari for their assistance with the data collection. We would like to express our appreciation to the active General Manager Ozgur Soy for his continuing support. We also thank EAE Lighting Inc., Istanbul, Turkey, for donating the luminaires and electronic control system employed in the study. We also would like to acknowledge Greg Ward, Charles Roohan, Kassandra Gonzales, Allison Thayer, Barbara Plitnick, Andrew Bierman, Sharon Lesage, and David Pedler for their technical and editorial assistance. The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This article was financially supported by Metro Istanbul.
Publisher Copyright:
© The Chartered Institution of Building Services Engineers 2022.
PY - 2022/8
Y1 - 2022/8
N2 - Shift-working railway personnel are highly susceptible to fatigue stemming from poor-quality sleep that can impair the performance of safety-critical functions. Disruption of the 24-h light–dark pattern incident on the retinae appears to play a central role in exacerbating these problems, especially with respect to exposure to light at night and circadian rhythms disruption. This field study tested and demonstrated the effectiveness and acceptability of an intervention (red and blue light combined with white light) to (1) promote circadian alignment, (2) advance the timing of dim light melatonin onset, (3) improve objective and subjective sleep quality, and (4) reduce subjective sleepiness in an operational context compared to a baseline (conventional lighting) condition. The lighting intervention promoted significantly greater synchrony between day-shift participants’ light–dark exposures and rest–activity patterns, but did not significantly advance the timing of dim light melatonin onset. The intervention was also associated with reduced objective sleep disturbances and improved (albeit less robustly) subjective sleep quality, but it only reduced participants’ subjective sleepiness while they were off duty during the day shift. This research demonstrates that lighting interventions can promote circadian alignment and improve sleep quality among railway shift workers and may be translatable to other 24-h industries.
AB - Shift-working railway personnel are highly susceptible to fatigue stemming from poor-quality sleep that can impair the performance of safety-critical functions. Disruption of the 24-h light–dark pattern incident on the retinae appears to play a central role in exacerbating these problems, especially with respect to exposure to light at night and circadian rhythms disruption. This field study tested and demonstrated the effectiveness and acceptability of an intervention (red and blue light combined with white light) to (1) promote circadian alignment, (2) advance the timing of dim light melatonin onset, (3) improve objective and subjective sleep quality, and (4) reduce subjective sleepiness in an operational context compared to a baseline (conventional lighting) condition. The lighting intervention promoted significantly greater synchrony between day-shift participants’ light–dark exposures and rest–activity patterns, but did not significantly advance the timing of dim light melatonin onset. The intervention was also associated with reduced objective sleep disturbances and improved (albeit less robustly) subjective sleep quality, but it only reduced participants’ subjective sleepiness while they were off duty during the day shift. This research demonstrates that lighting interventions can promote circadian alignment and improve sleep quality among railway shift workers and may be translatable to other 24-h industries.
UR - http://www.scopus.com/inward/record.url?scp=85118560028&partnerID=8YFLogxK
U2 - 10.1177/14771535211040985
DO - 10.1177/14771535211040985
M3 - Article
AN - SCOPUS:85118560028
VL - 54
SP - 441
EP - 457
JO - Lighting Research and Technology
JF - Lighting Research and Technology
SN - 1477-1535
IS - 5
ER -