Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany.
Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany.
Sci Total Environ. 2019 Feb 25;653:1025-1033. doi: 10.1016/j.scitotenv.2018.10.293. Epub 2018 Oct 30.
Light is the strongest zeitgeber currently known for the synchronization of the human circadian timing system. Especially shift workers are exposed to altered daily light profiles. Our objective is the characterization of differences in blue-light exposures between day and night shift taking into consideration modifying factors such as chronotype. We describe 24-hour blue-light profiles as measured with ambient light data loggers (LightWatcher) during up to three consecutive days with either day or night shifts in 100 female hospital staff including 511 observations. Linear mixed models were applied to analyze light profiles and to select time-windows for the analysis of associations between shift work, individual factors, and log mean light exposures as well as the duration of darkness per day. Blue-light profiles reflected different daily activities and were mainly influenced by work time. Except for evening (7-9 p.m.), all time windows showed large differences in blue-light exposures between day and night shifts. Night work reduced the duration of darkness per day by almost 4 h (β^ = -3:48 hh:mm, 95% CI (-4:27; -3.09)). Late chronotypes had higher light exposures in the morning and evening compared to women with intermediate chronotype (e.g. morning β^ = 0.50 log(mW/m/nm), 95% CI (0.08; 0.93)). Women with children had slightly higher light exposures in the afternoon than women without children (β^ = 0.48, 95% CI (-0.10; 1,06)). Time windows for the description of light should be chosen carefully with regard to timing of shifts. Our results are helpful for future studies to capture relevant light exposure differences and potential collinearities with individual factors. Improvement of well-being of shift workers with altered light profiles may therefore require consideration of both - light at the workplace and outside working hours.
光是目前已知的最强的生物钟同步授时因子,尤其在改变光照周期的情况下,例如轮班工作。我们的目标是在考虑到变时型等因素的情况下,描述轮班工人的昼间和夜间的蓝光暴露差异。我们描述了 100 名女性医院工作人员在连续三天的白班或夜班期间使用环境光数据记录器(LightWatcher)测量的 24 小时蓝光暴露情况,共记录了 511 次观察。我们应用线性混合模型分析光照情况,并选择分析轮班工作、个体因素、日志平均光照暴露以及每天黑暗持续时间之间关系的时间窗。蓝光暴露情况反映了不同的日常活动,主要受工作时间的影响。除了傍晚(7-9 点)以外,所有时间窗都显示出白班和夜班之间的蓝光暴露存在很大差异。夜间工作使每天的黑暗持续时间减少了近 4 小时(β^=-3:48 hh:mm,95%CI(-4:27;-3.09))。与中间变时型的女性相比,晚变时型的女性在早晨和傍晚的光照暴露更高(例如,早晨β^=0.50 log(mW/m/nm),95%CI(0.08;0.93))。有孩子的女性在下午的光照暴露略高于没有孩子的女性(β^=0.48,95%CI(-0.10;1,06))。选择描述光照的时间窗时应仔细考虑轮班时间。我们的结果有助于未来的研究捕捉相关的光照暴露差异和与个体因素的潜在共线性。因此,改善光照情况改变的轮班工人的幸福感可能需要同时考虑工作场所和工作时间以外的光照。