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Author (up) Kantermann, T.
Title Circadian biology: sleep-styles shaped by light-styles Type Journal Article
Year 2013 Publication Current Biology : CB Abbreviated Journal Curr Biol
Volume 23 Issue 16 Pages R689-90
Keywords Human Health; Circadian Clocks/*radiation effects; Female; Humans; *Lighting; Male; *Photoperiod; *Sunlight
Abstract Light and darkness are the main time cues synchronising all biological clocks to the external environment. This little understood evolutionary phenomenon is called circadian entrainment. A new study illuminates our understanding of how modern light- and lifestyles compromise circadian entrainment and impact our biological clocks.
Address Chronobiology – Centre for Behaviour and Neurosciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands. thomas@kantermann.de
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-9822 ISBN Medium
Area Expedition Conference
Notes PMID:23968925 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 501
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Author (up) Kantermann, T.; Roenneberg, T.
Title Is light-at-night a health risk factor or a health risk predictor? Type Journal Article
Year 2009 Publication Chronobiology International Abbreviated Journal Chronobiol Int
Volume 26 Issue 6 Pages 1069-1074
Keywords *Chronobiology Disorders; Circadian Rhythm; Environmental Exposure; Humans; *Light; Neoplasms; Risk Factors
Abstract In 2007, the IARC (WHO) has classified “shift-work that involves circadian disruption” as potentially carcinogenic. Ample evidence leaves no doubt that shift-work is detrimental for health, but the mechanisms behind this effect are not well understood. The hormone melatonin is often considered to be a causal link between night shift and tumor development. The underlying “light-at-night” (LAN) hypothesis is based on the following chain of arguments: melatonin is a hormone produced under the control of the circadian clock at night, and its synthesis can be suppressed by light; as an indolamine, it potentially acts as a scavenger of oxygen radicals, which in turn can damage DNA, which in turn can cause cancer. Although there is no experimental evidence that LAN is at the basis of increased cancer rates in shiftworkers, the scenario “light at night can cause cancer” influences research, medicine, the lighting industry and (via the media) also the general public, well beyond shiftwork. It is even suggested that baby-lights, TVs, computers, streetlights, moonlight, emergency lights, or any so-called “light pollution” by urban developments cause cancer via the mechanisms proposed by the LAN hypothesis. Our commentary addresses the growing concern surrounding light pollution. We revisit the arguments of the LAN theory and put them into perspective regarding circadian physiology, physical likelihood (e.g., what intensities reach the retina), and potential risks, specifically in non-shiftworkers.
Address Institute for Medical Psychology, University of Munich LMU, Munich, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0742-0528 ISBN Medium
Area Expedition Conference
Notes PMID:19731106 Approved no
Call Number IDA @ john @ Serial 134
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Author (up) Kyba, C.C.M.; Kantermann, T.
Title Does ambient light at night reduce total melatonin production? Type Journal Article
Year 2015 Publication Hormones Abbreviated Journal Hormones
Volume Issue Pages
Keywords Human Health; melatonin; ambient lighting; indoor light; sleep; *Circadian Rhythm; chronotype
Abstract It was with great interest that we read the recent study by Hersh et al on the effects of sleep and light at night on melatonin in adolescents. Of particular interest was their focus on electronic use after “lights out”. The authors highlight the importance of understanding what effects this may have on sleep, citing a survey that showed that 72% of American 13-18 year olds regularly use a cellphone or computer before trying to go to sleep. In their study, Hersh et al1 did not observe a significant suppression in urinary morning melatonin (aMT6s) levels with respect to the use of electronic devices between lights off and sleep onset. Therefore, the authors conclude that “nighttime behaviors of adolescents by and large do not impact urinary melatonin levels”. Absence of evidence, however, is not the same as evidence of absence, and we believe that the authors’ conclusion is premature.
Address Deutsches GeoForschungsZentrum GFZ, Telegraphenberg, 14473 Potsdam, Germany; kyba(at)gfz-potsdam.de
Corporate Author Thesis
Publisher Hellenic Endocrine Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1236
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Author (up) 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.
Title Differences in twenty-four-hour profiles of blue-light exposure between day and night shifts in female medical staff Type Journal Article
Year 2019 Publication Science of The Total Environment Abbreviated Journal Science of The Total Environment
Volume 653 Issue Pages 1025-1033
Keywords Human Health
Abstract 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 (beta = −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 beta = 0.50 log(mW/m2/nm), 95% CI (0.08; 0.93)). Women with children had slightly higher light exposures in the afternoon than women without children (beta = 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0048-9697 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2139
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Author (up) Wahl, F.; Kantermann, T.; Amft, O.
Title How much Light do you get? Estimating Daily Light Exposure using Smartphones Type Conference Article
Year 2014 Publication Proceedings of the 2014 ACM International Symposium on Wearable Computers Abbreviated Journal Proc. of the 2014 ACM International Symposium on Wearable Computers
Volume n/a Issue n/a Pages 43-46
Keywords Instrumentation; light exposure; context inference, light intensity; light intake; circadian clock; circadian rhythm; mobile sensing
Abstract We present an approach to estimate a persons light exposure using smartphones. We used web-sourced weather reports combined with smartphone light sensor data, time of day, and indoor/outdoor information, to estimate illuminance around the user throughout a day. Since light dominates every human’s circadian rhythm and influences the sleep-wake cycle, we developed a smartphone-based system that does not re- quire additional sensors for illuminance estimation. To evaluate our approach, we conducted a free-living study with 12 users, each carrying a smartphone, a head-mounted light reference sensor, and a wrist-worn light sensing device for six consecutive days. Estimated light values were compared to the head-mounted reference, the wrist-worn device and a mean value estimate. Our results show that illuminance could be estimated at less than 20% error for all study participants, outperforming the wrist-worn device. In 9 out of 12 participants the estimation deviated less than 10% from the reference measurements.
Address ACTLab, Chair of Sensor Technology, University of Passau (florian.wahl@uni-passau.de)
Corporate Author Thesis
Publisher ACM Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1206
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Author (up) Zerbini, G.; Kantermann, T.; Merrow, M.
Title Strategies to decrease social jetlag: Reducing evening blue light advances sleep and melatonin Type Journal Article
Year 2018 Publication The European Journal of Neuroscience Abbreviated Journal Eur J Neurosci
Volume in press Issue Pages
Keywords Human Health
Abstract The timing of sleep is under the control of the circadian clock, which uses light to entrain to the external light-dark cycle. A combination of genetic, physiological and environmental factors produces individual differences in chronotype (entrained phase as manifest in sleep timing). A mismatch between circadian and societal (e.g., work) clocks leads to a condition called social jetlag, which is characterized by changing sleep times over work and free days and accumulation of sleep debt. Social jetlag, which is prevalent in late chronotypes, has been related to several health issues. One way to reduce social jetlag would be to advance the circadian clock via modifications of the light environment. We thus performed two intervention field studies to describe methods for decreasing social jetlag. One study decreased evening light exposure (via blue-light-blocking glasses) and the other used increased morning light (via the use of curtains). We measured behaviour as well as melatonin; the latter in order to validate that behaviour was consistent with this neuroendocrinological phase marker of the circadian clock. We found that a decrease in evening blue light exposure led to an advance in melatonin and sleep onset on workdays. Increased morning light exposure advanced neither melatonin secretion nor sleep timing. Neither protocol led to a significant change in social jetlag. Despite this, our findings show that controlling light exposure at home can be effective in advancing melatonin secretion and sleep, thereby helping late chronotypes to better cope with early social schedules.
Address Institute of Medical Psychology, LMU Munich, Munich, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-816X ISBN Medium
Area Expedition Conference
Notes PMID:30506899 Approved no
Call Number GFZ @ kyba @ Serial 2138
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