scholarly journals Designing Light for Night Shift Workers: Application of Nonvisual Lighting Design Principles in an Industrial Production Line

2021 ◽  
Vol 11 (22) ◽  
pp. 10896
Author(s):  
Johannes Zauner ◽  
Herbert Plischke
Keyword(s):  
Shift Work ◽  
Industrial Production ◽  
Night Shift ◽  
Stimulus Range ◽  
Automation System ◽  
Shift Workers ◽  
Health And Wellbeing ◽  
Rotating Shift Work ◽  
Lighting Simulation ◽  
Night Shifts

Chronodisruption deteriorates the health and wellbeing of shift workers. Artificial light at night and the lack of light during the day are major contributors to chronodisruption and need to be optimized in shift work scenarios. Here, we present one solution for a lighting and automation system in an industrial production workplace. The setting is a rapidly rotating shift work environment with morning, evening, and night shifts. We describe a procedure to specify the new lighting through a software-agnostic nonvisual lighting simulation for artificial and daylighting scenarios. Through this process, a new luminaire is created, called Drosa, that allows for a large melanopic stimulus range between 412 and 73 lx melanopic equivalent daylight (D65) illuminance vertically at eye level, while maintaining a neutral white illuminance at task level between 1250 and 900 lx, respectively. This is possible through a combination of glare-free spotlights with adjustable areal wing lights. An individually programmed automation system controls the light dosage and timing during the day and night. The work is relevant for other shift work scenarios, where the presented example and the discussed rationale behind the automation might provide insights. The work is further relevant for other lighting scenarios beyond industrial shift work, as the nonvisual lighting simulation process can be adapted to any context.

scholarly journals Disturbances of Autonomic Regulation of Cardiovascular System at Different Working Regimes with Night Shifts

Kardiologiia ◽  
2020 ◽  
Vol 60 (9) ◽  
pp. 62-67
Author(s):  
Yu. A. Merkulov ◽  
A. A. Pyatkov ◽  
S. G. Gorokhova ◽  
D. M. Merkulova ◽  
O. Yu. Atkov
Keyword(s):  
Shift Work ◽  
Spectral Characteristics ◽  
Night Shift ◽  
Autonomic Regulation ◽  
Total Power ◽  
Orthostatic Test ◽  
Heart Rhythm Variability ◽  
Shift Workers ◽  
Rotating Shift Work ◽  
Night Shifts

Aim        To study temporal and spectral characteristics of heart rhythm variability (HRV) in night shift workers.Materials and methods       Along with traditional risk factors, conditions of labor contribute to development of cardiovascular morbidity, including night shift work, which can be associated with disorders of the autonomic regulation detected by analysis of HRV. This study included 100 healthy men. 74 of them were engaged in shift work, including 53 men with rotating shift work, 21 men with fixed night shifts, and 26 men with day-time work. HRV was analyzed by data of 5-min electrocardiogram recording (background recording and orthostatic test).Results   Night-shift workers had decreases in total power of regulation (ТР, SDNN) and in the parasympathetic branch (HF, pNN50). Rotating night-shift workers displayed significant decreases in SDNN and pNN50 and pronounced changes in the VLF / LF / HF ratio in the orthostatic test.Conclusion            In work with night shifts, the type of autonomic regulation differs from the “standard” functioning of the autonomic nervous system (ANS). This study showed different effects of night work regimens on HRV indexes. With the rotating shift work, the ANS dysregulation was more profound and was evident by a significant decrease in the ANS total tone and parasympathetic activity (SDNN, pNN50) compared to night shifts with fixed working hours. The excessive weakening of the parasympathetic component in the passive orthostatic test can be considered as an early marker for ANS maladaptation. 

Abstract 14384: Light Therapy Improves Circadian Blood Pressure Control and Glucose Homeostasis in Rotating Night Shift Workers via Mechanisms Independent of Melatonin

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Juliane Hannemann ◽  
Anika Laing ◽  
Benita Middleton ◽  
Jonathan Cridland ◽  
Bart Staels ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Circadian Rhythms ◽  
Glucose Tolerance ◽  
Shift Work ◽  
Therapy Group ◽  
Night Shift ◽  
Light Therapy ◽  
Pressure Control ◽  
Shift Workers ◽  
Night Shifts

Introduction: Night shift work is associated with high rates of hypertension, heart disease, and metabolic syndrome. These cardiometabolic diseases have been linked to the disruption of circadian rhythms in night shift workers. Rotating night shift work is increasingly common in the working population worldwide. Hypothesis: We hypothesized that light therapy might help to normalize disrupted circadian rhythms and stabilize diurnal control of blood pressure and glucose tolerance in rotating night shift workers. Methods: We randomized 24 rotating night shift workers (mean age, 36±13 years, 7 males) who had spent a median of 6 years on rotating night shifts with a median of 6 night shifts/month to 12 weeks of light therapy (light during first half of each night shift and in the morning of off-work days) or no intervention and compared them with 12 daytime workers (37±11 years, 6 males). We measured oral glucose tolerance (OGTT), 24h blood pressure and arterial stiffness, and the circadian profiles of melatonin, cortisol, metanephrine and normetanephrine at baseline, after 12 weeks of intervention, and 12 weeks after the end of intervention. Results: At baseline, fewer night shift workers showed dipper status of blood pressure as compared to daytime workers (21% vs. 55%; p<0.001). After 12 weeks of light therapy, there was a highly significant increase in the proportion of dippers (to 42%; p<0.0001). We also observed a significant decrease in serum glucose during OGTT in the light therapy group (-22%; p<0.05), with no change in serum insulin. Whilst circadian profiles of melatonin and cortisol were unchanged, there was a significant reduction in nighttime plasma metanephrine and normetanephrine levels in the light therapy group (p<0.01). Conclusions: Chronotherapeutic light therapy significantly improves diurnal blood pressure control and glucose tolerance in rotating night shift workers. This effect is unrelated to mechanisms traditionally linked to the circadian clock like melatonin and cortisol, but it is paralleled by reduced catecholamine levels. Our data suggest that chronotherapeutic light therapy may improve the adjustment to atypical working hours in rotating night shift workers, thereby reducing stress and improving cardiometabolic function.

Circadian principles and design of rotating shift work schedules

1986 ◽  
Vol 251 (3) ◽  
pp. R636-R638 ◽  
Author(s):  
F. W. Turek
Keyword(s):  
Circadian Rhythms ◽  
Shift Work ◽  
Sleep Time ◽  
New Work ◽  
Work Schedules ◽  
Work Schedule ◽  
Work Time ◽  
Shift Workers ◽  
Rotating Shift Work ◽  
Night Shifts

Circadian rhythms may be disrupted when shift workers rotate from one work schedule to another. It has been suggested that in order to minimize the time needed to readjust circadian rhythms to a new work schedule the work time of shift workers should be rotated in a delaying rather than an advancing direction. However, delaying or advancing the work time does not imply that the sleep-wake cycle is also shifted in a similar manner. Indeed, after a complete rotation between the day, evening, and night shifts the sleep time will be advanced once, delayed once, and not shifted once, regardless of whether the workers are on a delaying or an advancing work rotation schedule. Thus circadian rhythms are likely to be perturbed in a similar manner whether the work schedule is rotated in a delaying or an advancing direction.

scholarly journals Napping on the night shift and its impact on blood pressure and heart rate variability among emergency medical services workers: study protocol for a randomized crossover trial

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
P. Daniel Patterson ◽  
Leonard S. Weiss ◽  
Matthew D. Weaver ◽  
David D. Salcido ◽  
Samantha E. Opitz ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Emergency Medical Services ◽  
Shift Work ◽  
Crossover Trial ◽  
Night Shift ◽  
Shift Workers ◽  
Randomized Crossover Trial ◽  
Night Shifts

Abstract Background There is an emerging body of evidence that links exposure to shift work to cardiovascular disease (CVD). The risk of coronary events, such as myocardial infarction, is greater among night shift workers compared to day workers. There is reason to believe that repeated exposure to shift work, especially night shift work, creates alterations in normal circadian patterns of blood pressure (BP) and heart rate variability (HRV) and that these alterations contribute to increased risk of CVD. Recent data suggest that allowing shift workers to nap during night shifts may help to normalize BP and HRV patterns and, over time, reduce the risk of CVD. The risk of CVD related to shift work is elevated for emergency medical services (EMS) shift workers due in part to long-duration shifts, frequent use of night shifts, and a high prevalence of multiple jobs. Methods We will use a randomized crossover trial study design with three study conditions. The targeted population is comprised of EMS clinician shift workers, and our goal enrollment is 35 total participants with an estimated 10 of the 35 enrolled not completing the study protocol or classified as lost to attrition. All three conditions will involve continuous monitoring over 72 h and will begin with a 36-h at-home period, followed by 24 total hours in the lab (including a 12-h simulated night shift), ending with 12 h at home. The key difference between the three conditions is the intra-shift nap. Condition 1 will involve a simulated 12-h night shift with total sleep deprivation. Condition 2 will involve a simulated 12-h night shift and a 30-min nap opportunity. Condition 3 will involve a simulated 12-h night shift with a 2-h nap opportunity. Our primary outcomes of interest include blunted BP dipping and reduced HRV as measured by the standard deviation of the inter-beat intervals of normal sinus beats. Non-dipping status will be defined as sleep hours BP dip of less than 10%. Discussion Our study will address two indicators of cardiovascular health and determine if shorter or longer duration naps during night shifts have a clinically meaningful impact. Trial registration ClinicalTrials.gov NCT04469803. Registered on 9 July 2020

scholarly journals Night shift work and the risk of metabolic syndrome: Findings from an 8-year hospital cohort

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261349
Author(s):  
Wan-Ju Cheng ◽  
Chiu-Shong Liu ◽  
Kai-Chieh Hu ◽  
Yu-Fang Cheng ◽  
Kati Karhula ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Shift Work ◽  
Night Shift ◽  
Working Time ◽  
Health Examination ◽  
Long Term Effects ◽  
Time Data ◽  
Shift Workers ◽  
Night Shift Work ◽  
Night Shifts

Objectives Studies concerning the risk of metabolic syndrome associated with night work have shown inconsistent findings, due to imprecise working time data and cross-sectional design. We used register-based daily working time data to examine the risk of incident metabolic syndrome associated with night shift work. Methods Working time data collected between 2010 and 2018 of 5775 Taiwanese hospital workers were used to identify night shift workers and to calculate the number of night shifts. Metabolic syndrome was identified by annual occupational health examination results, which were linked to the working time data. Logistic regression models and generalized estimating equations were used to examine the association between night shift work and metabolic syndrome and the 5 components of metabolic syndrome. Results Night shift work is associated with a higher risk of developing metabolic syndrome (adjusted OR = 1.36, 95% CI = 1.04 to 1.78) and high waist circumference (adjusted OR = 1.27, 95% CI = 1.07 to 1.78) compared to day work. Among night shift workers, increased number of night shifts was associated with high blood pressure (adjusted OR = 1.15, 95% CI = 1.01 to 1.31). Conclusions Night shift work is associated with metabolic risk factors. Long-term effects of circadian rhythm disruption on metabolic disturbances needs to be further studied.

Rotating night shift work and non-alcoholic fatty liver disease among steelworkers in China: a cross-sectional survey

2020 ◽  
Vol 77 (5) ◽  
pp. 333-339 ◽  
Author(s):  
Shengkui Zhang ◽  
Yongbin Wang ◽  
Zhende Wang ◽  
Han Wang ◽  
Chao Xue ◽  
...  
Keyword(s):  
Shift Work ◽  
Average Length ◽  
Night Shift ◽  
Average Frequency ◽  
Cumulative Number ◽  
Shift Workers ◽  
Alcoholic Fatty Liver ◽  
Night Shift Work ◽  
Cumulative Length ◽  
Night Shifts

ObjectivesIn a 24/7 society, the negative metabolic effects of rotating night shift work have been increasingly explored. This study aimed to examine the association between rotating night shift work and non-alcoholic fatty liver disease (NAFLD) in steelworkers.MethodsA total of 6881 subjects was included in this study. Different exposure metrics of night shift work including current shift status, duration of night shifts (years), cumulative number of night shifts (nights), cumulative length of night shifts (hours), average frequency of night shifts (nights/month) and average length of night shifts (hours/night) were used to examine the relationship between night shift work and NAFLD.ResultsCurrent night shift workers had elevated odds of NAFLD (OR, 1.23, 95% CI 1.02 to 1.48) compared with those who never worked night shifts after adjustment for potential confounders. Duration of night shifts, cumulative number of night shifts and cumulative length of night shifts were positively associated with NAFLD. Both the average frequency of night shifts (>7 nights/month vs ≤7 nights/month: OR, 1.24, 95% CI 1.06 to 1.45) and average length of night shifts (>8 hours/night vs ≤8 hours/night: OR, 1.27, 95% CI 1.08 to 1.51) were independently associated with overall NAFLD after mutually adjusting for the duration of night shifts and other potential confounders among night shift workers. No significant association was found in female workers between different exposure metrics of night shift work and NAFLD.ConclusionsRotating night shift work is associated with elevated odds of NAFLD in male steelworkers.

scholarly journals Associations of Short Sleep and Shift Work Status with Hypertension among Black and White Americans

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mirnova E. Ceïde ◽  
Abhishek Pandey ◽  
Joe Ravenell ◽  
Margaret Donat ◽  
Gbenga Ogedegbe ◽  
...  
Keyword(s):  
Shift Work ◽  
Night Shift ◽  
Self Report ◽  
White Americans ◽  
Short Sleep Duration ◽  
Shift Workers ◽  
Short Sleep ◽  
Black And White ◽  
Interview Survey ◽  
Rotating Shift Work

Objective. The purpose of this study was to investigate whether short sleepers (<6 hrs) who worked the non-day-shift were at greater likelihood of reporting hypertension and if these associations varied by individuals’ ethnicity.Methods. Analysis was based on the 2010 National Health Interview Survey (NHIS). A total of 59,199 American adults provided valid data for the present analyses (mean age =46.2±17.7years; 51.5% were female). Respondents provided work schedule and estimated habitual sleep durations as well as self-report of chronic conditions.Results. Of the sample, 30.8% reported a diagnosis of hypertension, 79.1% reported daytime shift work, 11.0% reported rotating shift work, and 4.0% reported night shift work. Logistic regression analysis showed that shift work was significantly associated with hypertension among Blacks [OR = 1.35, CI: 1.06–1.72.P<0.05], but not among Whites [OR = 1.01, CI: 0.85–1.20, NS]. Black shift workers sleeping less than 6 hours had significantly increased odds of reporting hypertension [OR = 1.81, CI: 1.29–2.54,P<0.01], while their White counterparts did not [OR = 1.17, CI: 0.90–1.52, NS].Conclusions. Findings suggest that Black Americans working the non-day-shift especially with short sleep duration have increased odds of reporting hypertension.

Interindividual Differences in Adjustment to Shift Work

1976 ◽  
Vol 20 (22) ◽  
pp. 510-514 ◽  
Author(s):  
Torbjörn Akerstedt
Keyword(s):  
Shift Work ◽  
Night Shift ◽  
Age Groups ◽  
Well Being ◽  
Shift Workers ◽  
Younger Age ◽  
Mental Demands ◽  
Sleep Length ◽  
Housing Standards ◽  
Night Shifts

320 3-shift workers, 30 2-shift workers and 30 day workers filled out a questionnaire on work hours and well-being. For 3-shift workers highest ratings of well-being were reported for the afternoon shift, followed by morning, and night shifts. Two-shift workers gave ratings identical to those of the 3-shift workers on corresponding shifts. Multivariate analysis showed that neuroticism, mental demands on the job and, to some extent, also housing standards accounted for variance in well-being on the night shift. When sleep length was used as the dependent variable the most important predictors were age and experience of shift work. Finally, it was found that, above the age of 45, well-being on the night shift decreased with increased experience of shift work. In younger age groups no relations of this kind were found. (Age was held constant in all analyses.) It was suggested that the relations found may indicate the existence of a process of accumulation of costs of adjustment starting around the age of 45.

scholarly journals Social jetlag and sleep debts are altered in different rosters of night shift work

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262049
Author(s):  
Swaantje Casjens ◽  
Frank Brenscheidt ◽  
Anita Tisch ◽  
Beate Beermann ◽  
Thomas Brüning ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Sleep Deprivation ◽  
Sleep Duration ◽  
Shift Work ◽  
Night Shift ◽  
Shift Workers ◽  
Social Jetlag ◽  
Sleep Debt ◽  
The Impact ◽  
Night Shifts

Background Night and shift work are suspected to cause various adverse effects on health and sleep. Sleep deprivation through shift work is assumed to be compensated on free days. So far it is not clear how different shift systems and shift lengths affect sleep structure on work and free days. Especially working night shifts disrupts the circadian rhythm but also extended working hours (12h) might affect sleep characteristics. Hitherto, the magnitude of sleep debt, social jetlag, and Locomotor Inactivity During Sleep (LIDS) in different shift systems is unknown. Methods Here, we investigated the impact of five different shift rosters on sleep in 129 industrial workers from Germany. Permanent night work with multiple shift systems with and without night shifts and with different shift lengths were compared. Wrist-activity was monitored over 28 days revealing sleep on- and offsets as well as LIDS as proxy for sleep quality. Overall, 3,865 sleep bouts comprising 22,310 hours of sleep were examined. Results The mean daily age-adjusted sleep duration (including naps) was 6:43h and did not differ between shift workers of different rosters. However, sleep duration on workdays was particularly low in rotational shift systems with 12h-shifts (5:00h), while overall sleep debt was highest. Shift workers showed a median absolute social jetlag of 3:03h, which differed considerably between shift types and rosters (p<0.0001). Permanent night workers had the highest social jetlag (5:08h) and latest mid-sleeps on workdays and free days. Sleep quality was reduced in permanent night shift workers compared with shift workers in other rosters and differed between daytime and nighttime sleep. Conclusions Shift work leads to partial sleep deprivation, which particularly affects workers in 12h-shifts and permanent night shifts. Working these shifts resulted in higher sleep debts and larger absolute social jetlag whereas sleep quality was especially reduced in permanent night shift workers compared with shift workers of other rosters.

scholarly journals Napping on the Night Shift and Impact on Blood Pressure and HRV among EMS Workers

2021 ◽  
Author(s):  
Ektha Parchuri ◽  
James Paule
Keyword(s):  
Blood Pressure ◽  
Shift Work ◽  
Night Shift ◽  
Shift Workers ◽  
Frequent Use ◽  
Long Duration ◽  
High Prevalence ◽  
Circadian Patterns ◽  
Night Shifts ◽  
Over Time

Recent evidence linking exposure toshift work to cardiovascular disease (CVD) as well as incidence of myocardial infarction seems to be greater among night shift workers compared to day workers. Repeated exposure tonight shift work causes disruptions in normal circadian patterns of blood pressure (BP) and heart rate variability (HRV), which cause anincreased risk of CVD. Recent data suggest that allowing shift workers to nap during night shifts may help to normalize BP and HRV patterns and, over time, reduce the risk of CVD. The risk of CVD related to shift work is elevated for emergency medical services (EMS) shift workers due in part to long-duration shifts, frequent use of night shifts, and a high prevalence of multiple jobs. Therefore, the effect of SBP and HRV in EMS night shift workers is analyzed through stimulated night work and it's effect on CVD is characterized.

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