Université Laval, Department of Oto-Rhino-Laryngology and Ophthalmology/Centre de recherche Université Laval Robert-Giffard, 2601 de la Canardière, F-4500, Quebec City, Canada.
Prog Neuropsychopharmacol Biol Psychiatry. 2010 Oct 1;34(7):1236-42. doi: 10.1016/j.pnpbp.2010.06.027. Epub 2010 Jul 3.
Bright light at night paired with darkness during the day seem to facilitate adaptation to night work. Considering the biological clock sensitive to short wavelengths, we investigated the possibility of adaptation in shift workers exposed to blue-green light at night, combined with using blue-blockers during the day.
Four sawmill shift workers were evaluated during two weeks of night shifts (control and experimental) and one week of day shifts. Throughout the experimental week, ambient light (approximately 130 lx) was supplemented with blue-green light (200 lx) from 00:00 h to: 05:00 h on Monday and Tuesday, 06:00 h on Wednesday and 07:00 h on Thursday. Blue-blockers had to be worn outside from the end of the night shift until 16:00 h. For circadian assessment, salivary melatonin profiles were obtained between 00:00 h and 08:00 h, before and after 4 experimental night shifts. Sleep was continuously monitored with actigraphy and subjective vigilance was measured at the beginning, the middle and the end of each night and day shifts. The error percentage in wood board classification was used as an index of performance.
Through experimental week, melatonin profiles of 3 participants have shifted by at least 2 hours. Improvements were observed in sleep parameters and subjective vigilance from the third night (Wednesday) as performance increased on the fourth night (Thursday) from 5.14% to 1.36% of errors (p=0.04).
Strategic exposure to short wavelengths at night, and/or daytime use of blue-blocker glasses, seemed to improve sleep, vigilance and performance.
夜间的亮光和白天的黑暗似乎有助于适应夜班工作。考虑到生物钟对短波长敏感，我们研究了在夜班期间暴露于蓝绿光下的轮班工人适应的可能性，同时在白天使用蓝光阻断剂。
四名锯木厂轮班工人在两周的夜班（对照和实验）和一周的白班期间接受评估。在整个实验周期间，从 00:00 到 05:00 点，在周一和周二、周三的 06:00 点和周四的 07:00 点，环境光（约 130 lx）通过补充蓝绿光（200 lx）进行补充。从夜班结束到 16:00 点，必须佩戴蓝光阻断剂。为了评估昼夜节律，在 4 个实验性夜班前后，在 00:00 至 08:00 点之间获得唾液褪黑素图谱。使用活动记录仪连续监测睡眠，在每个夜班和白班的开始、中间和结束时测量主观警觉性。木板分类错误的百分比用作性能指标。
通过实验周，3 名参与者的褪黑素图谱至少发生了 2 小时的变化。从周三的第三个晚上开始，睡眠参数和主观警觉性得到改善，从周四的第四个晚上开始，性能从 5.14%提高到 1.36%的错误率（p=0.04）。
夜间战略性暴露于短波长，和/或白天使用蓝光阻断剂眼镜，似乎可以改善睡眠、警觉性和性能。
