Duration:2020 - 02/2024
Shortcut: IPA-166-Light
Aims
Light is the most important zeitgeber for the human internal clock. Changing daily light profiles in shift workers can lead to a desynchronization of circadian rhythms and may influence workers health. The aim of this intervention study was to investigate the short- and long-term effects of dynamic lighting at the workplace and individual lighting recommendations for leisure time in shift workers.
Employees of a company were studied in four field phases between October 2021 and February 2023. Two workplace lighting interventions were carried out i) during the day in a group of shift workers without night shift in assembly hall 1 and ii) at night in a group of shift workers with night shift in assembly hall 2. Employees in other areas of the company and in different shift systems served as a comparison group. After the baseline survey T0 (10/2021-11/2021), the lighting was modified in December 2021. Compared to the baseline situation, in assembly hall 1 the melanopic equivalent daylight illuminance (MEDI) was dynamically increased in the morning by varying light colour and luminous flux and lowered towards the evening. In assembly hall 2, the lighting was dynamically increased at night in the first half of the shift and reduced from the middle of the night shift. For the analysis of short-term effects, baseline T0 measurements were compared with the first follow-up T1 (01/2022-02/2022). Longer-term effects were examined with further field pha¬ses one year after T0 and T1 (T2: 11/2022, T3: 01/2023). After T1, further participants were re¬crui¬ted for the comparison group. A randomized subgroup was drawn from all participants of the comparison group to study the effect of individualized lighting recommendations during leisure time with T2 as base¬line and T3 as follow-up. The recommendations were communicated individually after T2 and in T3 via study cell phones and other methods. Health endpoints were assessed using both objective measures (actigraphy, hormone levels in saliva and hair, psychomotor vigilance in the middle of the shift) and subjective measures (sleepiness, individual perception of lighting). In addition, photometric measurements were carried out at the workplace as well as individual light measurements. The statistical analyses included the use of algorithms for deriving the endpoints, multiple imputation methods and descriptive analyses. Depending on the endpoint, the orientational modeling included mixed models considering the repeated measurements per individual and adjustment for important confounders.
Overall, n = 89 people took part in the four field phases, n = 27 were participants in the interventions in the two halls, n = 26 people were selected for the lighting-habits re-commendations during leisure time. Initial analyses show short-term improvements in psychomotor vigilance and sleepiness for the intervention during daytime. For the intervention during the night, longer sleep durations after night shifts were observed in the short term. In the longer term there are indications of higher levels of melatonin and lower levels of cortisol in saliva at the end of the night shift with the night light in¬tervention. Longer sleep durations were observed for early shifts with the recommendations for leisure time. Over the course of the study, the general stress level measured via cortisol in the hair decreased in all groups. Brightness and luminous colour were more frequently perceived as pleasant after the introduction of dynamic lighting.
The initial results indicate that there are no negative influences on health. There are indications of slight positive effects in some of the endpoints.
Scientific publications are currently in preparation.
Abstract of the research project Light and Shift Work (FP-0444) (PDF, 171 kB, accessible)
Burek K, Rabstein S, Kantermann T, ...Lehnert M, Pallapies D, Jöckel KH, Brüning T, Behrens T. Altered coordination between sleep timing and cortisol profiles in night working female hospital employees. Psychoneuroendocrinology 2024; 166: 1070666 doi: 10.1016/j.psyneuen.2024.107066
Wichert K, Hoppe R, Ickstadt K, Berhens T, ..., Brüning T, Brauch H, Harth V, Rabstein S. Polymorphisms in genes of melatonin biosynthesis and signaling support the light-at-night hypothesis for breast cancer. Eur J Epidem 2023; 38: 1053-1068 doi: 10.1007/s10654-023-01048-7
Burek K, Rabstein S, Kantermann T, ....Lehnert M, Pallapies D, Jöckel KH, Brüning T, Behrens T. Night work, chronotype and cortisol at awakening in female hospital employees. Sci Rep 2022; 12: 6525 doi: 10.1038/s41598-022-10054-w
SK 2-Leitlinie: Gesundheitliche Aspekte und Gestaltung von Nacht- und Schichtarbeit
Rabstein S, Behrens T, Pallapies D, Eisenhawer C, Brüning T: Schichtarbeit und Krebserkrankungen. Zbl Arbeitsmed 2020; 70: 249-255 DOI: 10.1007/s40664-020-00398-3
Wichert K, Rabstein S, Stanford J, Erbel R, Arendt M, Keimer A, Dragano N, Hoffmann W, Lerch mM, ....Jöckel KH, Brüning T, Behrens T: Associations between shift work and risk of colorectal cancer in two German cohort studies. Chronobiol Int 2020; 37: 1235-1243 DOI: 10.1080/07420528.2020.1782930
Behrens T, Burek K, Pallapies D, Kösters L, Lehnert M, Beine A, Wichert K, Kantermann T, Vetter C, Brüning T, Rabstein S. Decreased psychomotor vigilance of female shift workers after working night shifts. PLoS ONE 2019; 14: e0219087 DOI: 10.1371/journal.pone.0219087
Rabstein S, Burek K, Lehnert M, Beine A, Vetter C, Harth V, Putzke S, Kantermann T, Walther J, Wang-Sattler R, Pallapies D, Brüning T, Behrens T: .Differences in twenty-four-hour profiles of blue-light exposure between day and night shifts in female medical staff. Sci Total Environ 2019; 653:1025-1033 IF: 5.589 DOI: 10.1016/j.scitotenv.2018.10.293
Lehnert M, Beine A, Burek K, Putzke S, Schlösser S, Pallapies D, Bbrüning T, Behrens T, Rabstein S. Vitamin D supply in shift working nurses. Chronobiol Int 2018; 35: 724-729 DOI: 10.1080/07420528.2018.1424719
Burek K, Rabstein S, Kantermann T, ...Lehnert M, Pallapies D, Jöckel KH, Brüning T, Behrens T. Altered coordination between sleep timing and cortisol profiles in night working female hospital employees. Psychoneuroendocrinology 2024; 166: 1070666 doi: 10.1016/j.psyneuen.2024.107066
Wichert K, Hoppe R, Ickstadt K, Berhens T, ..., Brüning T, Brauch H, Harth V, Rabstein S. Polymorphisms in genes of melatonin biosynthesis and signaling support the light-at-night hypothesis for breast cancer. Eur J Epidem 2023; 38: 1053-1068 doi: 10.1007/s10654-023-01048-7
Burek K, Rabstein S, Kantermann T, ....Lehnert M, Pallapies D, Jöckel KH, Brüning T, Behrens T. Night work, chronotype and cortisol at awakening in female hospital employees. Sci Rep 2022; 12: 6525 doi: 10.1038/s41598-022-10054-w
SK 2-Leitlinie: Gesundheitliche Aspekte und Gestaltung von Nacht- und Schichtarbeit
Rabstein S, Behrens T, Pallapies D, Eisenhawer C, Brüning T: Schichtarbeit und Krebserkrankungen. Zbl Arbeitsmed 2020; 70: 249-255 DOI: 10.1007/s40664-020-00398-3
Wichert K, Rabstein S, Stanford J, Erbel R, Arendt M, Keimer A, Dragano N, Hoffmann W, Lerch mM, ....Jöckel KH, Brüning T, Behrens T: Associations between shift work and risk of colorectal cancer in two German cohort studies. Chronobiol Int 2020; 37: 1235-1243 DOI: 10.1080/07420528.2020.1782930
Behrens T, Burek K, Pallapies D, Kösters L, Lehnert M, Beine A, Wichert K, Kantermann T, Vetter C, Brüning T, Rabstein S. Decreased psychomotor vigilance of female shift workers after working night shifts. PLoS ONE 2019; 14: e0219087 DOI: 10.1371/journal.pone.0219087
Rabstein S, Burek K, Lehnert M, Beine A, Vetter C, Harth V, Putzke S, Kantermann T, Walther J, Wang-Sattler R, Pallapies D, Brüning T, Behrens T: .Differences in twenty-four-hour profiles of blue-light exposure between day and night shifts in female medical staff. Sci Total Environ 2019; 653:1025-1033 IF: 5.589 DOI: 10.1016/j.scitotenv.2018.10.293
Lehnert M, Beine A, Burek K, Putzke S, Schlösser S, Pallapies D, Bbrüning T, Behrens T, Rabstein S. Vitamin D supply in shift working nurses. Chronobiol Int 2018; 35: 724-729 DOI: 10.1080/07420528.2018.1424719
The project on the DGUV Research website
White Paper aus dem Ladenburg-Round-Table: CIE Position Statement on Integrative Lighting Recommending Proper Light at the Proper Time
