|   | 
Details
   web
Records
Author Boyce, P.R.
Title Review: The Impact of Light in Buildings on Human Health Type Journal Article
Year (up) 2010 Publication Indoor and Built Environment Abbreviated Journal Indoor and Built Environment
Volume 19 Issue 1 Pages 8-20
Keywords Human Health; indoor light; circadian disruption; shift work; oncogenesis; Review
Abstract The effects of light on health can be divided into three sections. The first is that of light as radiation. Exposure to the ultraviolet, visible, and infrared radiation produced by light sources can damage both the eye and skin, through both thermal and photochemical mechanisms. Such damage is rare for indoor lighting installations designed for vision but can occur in some situations. The second is light operating through the visual system. Lighting enables us to see but lighting conditions that cause visual discomfort are likely to lead to eyestrain. Anyone who frequently experiences eyestrain is not enjoying the best of health. The lighting conditions that cause visual discomfort in buildings are well known and easily avoided. The third is light operating through the circadian system. This is known to influence sleep patterns and believed to be linked to the development of breast cancer among night shift workers. There is still much to learn about the impact of light on human health but what is known is enough to ensure that the topic requires the attention of all those concerned with the lighting of buildings.
Address Rensselaer Polytechnic Institute, New York, USA
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 1420-326X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 292
Permanent link to this record
 

 
Author Fonken, L.K.; Nelson, R.J.
Title Illuminating the deleterious effects of light at night Type Journal Article
Year (up) 2011 Publication F1000 Medicine Reports Abbreviated Journal F1000 Med Rep
Volume 3 Issue Pages 18
Keywords Human Health; light at night; artificial light; circadian disruption; Review
Abstract Technological advances, while providing many benefits, often create circumstances that differ from the conditions in which we evolved. With the wide-spread adoption of electrical lighting during the 20(th) century, humans became exposed to bright and unnatural light at night for the first time in their evolutionary history. Electrical lighting has led to the wide-scale practice of 24-hour shift-work and has meant that what were once just “daytime” activities now run throughout the night; in many ways Western society now functions on a 24-hour schedule. Recent research suggests that this gain in freedom to function throughout the night may also come with significant repercussions. Disruption of our naturally evolved light and dark cycles can result in a wide range of physiological and behavioral changes with potentially serious medical implications. In this article we will discuss several mechanisms through which light at night may exert its effects on cancer, mood, and obesity, as well as potential ways to ameliorate the impact of light at night.
Address Department of Neuroscience and The Institute for Behavioral Medicine Research The Ohio State University, Columbus, OH 43210 USA
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 1757-5931 ISBN Medium
Area Expedition Conference
Notes PMID:21941596; PMCID:PMC3169904 Approved no
Call Number IDA @ john @ Serial 241
Permanent link to this record
 

 
Author Cajochen, C.; Frey, S.; Anders, D.; Spati, J.; Bues, M.; Pross, A.; Mager, R.; Wirz-Justice, A.; Stefani, O.
Title Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance Type Journal Article
Year (up) 2011 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol (1985)
Volume 110 Issue 5 Pages 1432-1438
Keywords Adult; Circadian Rhythm/*physiology/radiation effects; Cognition/*physiology/radiation effects; *Computer Terminals; Humans; Light; Lighting/*methods; Male; Photic Stimulation/*methods; Radiation Dosage; Semiconductors; *Task Performance and Analysis; Young Adult; blue light; sleep; circadian disruption
Abstract Many people spend an increasing amount of time in front of computer screens equipped with light-emitting diodes (LED) with a short wavelength (blue range). Thus we investigated the repercussions on melatonin (a marker of the circadian clock), alertness, and cognitive performance levels in 13 young male volunteers under controlled laboratory conditions in a balanced crossover design. A 5-h evening exposure to a white LED-backlit screen with more than twice as much 464 nm light emission {irradiance of 0,241 Watt/(steradian x m(2)) [W/(sr x m(2))], 2.1 x 10(13) photons/(cm(2) x s), in the wavelength range of 454 and 474 nm} than a white non-LED-backlit screen [irradiance of 0,099 W/(sr x m(2)), 0.7 x 10(13) photons/(cm(2) x s), in the wavelength range of 454 and 474 nm] elicited a significant suppression of the evening rise in endogenous melatonin and subjective as well as objective sleepiness, as indexed by a reduced incidence of slow eye movements and EEG low-frequency activity (1-7 Hz) in frontal brain regions. Concomitantly, sustained attention, as determined by the GO/NOGO task; working memory/attention, as assessed by “explicit timing”; and declarative memory performance in a word-learning paradigm were significantly enhanced in the LED-backlit screen compared with the non-LED condition. Screen quality and visual comfort were rated the same in both screen conditions, whereas the non-LED screen tended to be considered brighter. Our data indicate that the spectral profile of light emitted by computer screens impacts on circadian physiology, alertness, and cognitive performance levels. The challenge will be to design a computer screen with a spectral profile that can be individually programmed to add timed, essential light information to the circadian system in humans.
Address Centre for Chronobiology, Psychiatric Hospitals of the University of Basel, Basel, Switzerland. christian.cajochen@upkbs.ch
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 0161-7567 ISBN Medium
Area Expedition Conference
Notes PMID:21415172 Approved no
Call Number IDA @ john @ Serial 293
Permanent link to this record
 

 
Author Vetter, C.; Juda, M.; Lang, D.; Wojtysiak, A.; Roenneberg, T.
Title Blue-enriched office light competes with natural light as a zeitgeber Type Journal Article
Year (up) 2011 Publication Scandinavian Journal of Work, Environment & Health Abbreviated Journal Scand J Work Environ Health
Volume 37 Issue 5 Pages 437-445
Keywords *Circadian Rhythm; *Color; Humans; *Lighting; *Occupational Health; Sleep; Wakefulness; blue light; circadian disruption; Circadian rhythm; sleep
Abstract OBJECTIVES: Circadian regulation of human physiology and behavior (eg, body temperature or sleep-timing), depends on the “zeitgeber” light that synchronizes them to the 24-hour day. This study investigated the effect of changing light temperature at the workplace from 4000 Kelvin (K) to 8000 K on sleep-wake and activity-rest behavior. METHODS: An experimental group (N=27) that experienced the light change was compared with a non-intervention group (N=27) that remained in the 4000 K environment throughout the 5-week study period (14 January to 17 February). Sleep logs and actimetry continuously assessed sleep-wake behavior and activity patterns. RESULTS: Over the study period, the timing of sleep and activity on free days steadily advanced parallel to the seasonal progression of sunrise in the non-intervention group. In contrast, the temporal pattern of sleep and activity in the experimental group remained associated with the constant onset of work. CONCLUSION: The results suggest that artificial blue-enriched light competes with natural light as a zeitgeber. While subjects working under the warmer light (4000 K) appear to entrain (or synchronize) to natural dawn, the subjects who were exposed to blue-enriched (8000 K) light appear to entrain to office hours. The results confirm that light is the dominant zeitgeber for the human clock and that its efficacy depends on spectral composition. The results also indicate that blue-enriched artificial light is a potent zeitgeber that has to be used with diligence.
Address Institute for Medical Psychology, Centre of Chronobiology, Ludwig-Maximilians-Universitat, 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 0355-3140 ISBN Medium
Area Expedition Conference
Notes PMID:21246176 Approved no
Call Number IDA @ john @ Serial 350
Permanent link to this record
 

 
Author Reiter, R.J.; Rosales-Corral, S.; Coto-Montes, A.; Antonio Boga, J.; Tan, D.X.; Davis, J.M.; Konturek, P.C.; Konturek, S.J.; Brzozowski, T.
Title The photoperiod, circadian regulation and chronodisruption: the requisite interplay between the suprachiasmatic nuclei and the pineal and gut melatonin. Type Journal Article
Year (up) 2011 Publication Journal of Physiology and Pharmacology Abbreviated Journal
Volume 62 Issue Pages 269-274
Keywords Human Health; biological clock; chronodisruption; circadian rhythm; gastrointestinal melatonin; peptic ulcer; pineal gland; suprachiasmatic nucleus
Abstract Biological rhythms are essential for optimal health (1, 2). Throughout the course of human evolution, hominids were exposed to regularly alternating periods of light and dark during every 24-hour period. This evolutionary period, which for humans may have lasted for three million or more years, allowed species to take advantage of the light:dark cycle to adjust their physiology and to synchronize it with the prevailing light:dark environment. To take advantage of this information, vertebrates, including hominids, evolved a group of neurons to monitor the photoperiodic environment and to adjust organismal, organ and cellular function accordingly.

This paired group of light-responsive neurons is located in the mediobasal preoptic area at the diencephalic-telencephalic junction just anterior to the hypothalamus. Since these neurons lie immediately above the decussating axons of the optic nerve, i.e., the optic chiasma, they are named the suprachiasmatic nuclei (SCN) (3, 4). The SCN orchestrate all known circadian rhythms in vertebrates and are referred to as the master biological clock or the central rhythm generator.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 522
Permanent link to this record