/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1191/1365782806lrt161oaLighting Research and Technology, 38, 3, pp. 191-223, 2006-09-01 Lighting quality and office work: two field simulation experiments Boyce, P. R.; Veitch, J. A.; Newsham, G. R.; Jones, C.; Heerwagen, J.; Myer, M.; Hunter, C. M. A version of this document is published in / Une version de ce document se trouve dans : Lighting Research and Technology, v. 38, no. 3, Sept. 2006, pp. 191-223 Lighting Research &Technology , v. 38(3) (2006) AbstractThis paper describes two experiments concerning the effects of variations in lighting quality on office worker performance, health, and well-being. Experiment 1 had four experimental conditions: a regular array of fully direct recessed parabolic luminaires; direct / indirect luminaires with no control; direct / indirect luminaires with a switchable desk lamp; and, workstation-specific direct / indirect luminaires with control over the direct portion. Experiment 2 contrasted two conditions with no individual lighting control: a regular array of recessed prismatic lensed luminaires, and suspended direct / indirect luminaires. Participants considered the direct / indirect systems to be comfortable than the direct-only systems, with a further increase in comfort associated with individual control in Experiment 1. There were no simple main effects of lighting quality on the performance of any task, although the expected changes in performance associated with task visibility, practice, and fatigue were found. Interactions between lighting quality and time suggested that having a degree of individual control of lighting tended to maintain motivation and vigilance over the day.

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Objectives Light therapy has shown promise as a nonpharmacological treatment to help regulate abnormal sleep-wake patterns and associated behavioral issues prevalent among individuals diagnosed with Alzheimer’s disease and related dementia (ADRD). The present study investigated the effectiveness of a lighting intervention designed to increase circadian stimulation during the day using light sources that have high short-wavelength content and high light output. Methods Thirty-five persons with ADRD and 34 caregivers completed the 11-week study. During week 1, subjective questionnaires were administered to the study participants. During week 2, baseline data were collected using Daysimeters and actigraphs. Researchers installed the lighting during week 3, followed by 4 weeks of the tailored lighting intervention. During the last week of the lighting intervention, Daysimeter, actigraph and questionnaire data were again collected. Three weeks after the lighting intervention was removed, a third data collection (post-intervention assessment) was performed. Results The lighting intervention significantly increased circadian entrainment, as measured by phasor magnitude and sleep efficiency, as measured by actigraphy data, and significantly reduced symptoms of depression in the participants with ADRD. The caregivers also exhibited an increase in circadian entrainment during the lighting intervention; a seasonal effect of greater sleep efficiency and longer sleep duration was also found for caregivers. Conclusions An ambient lighting intervention designed to increase daytime circadian stimulation can be used to increase sleep efficiency in persons with ADRD and their caregivers, and may also be effective for other populations such as healthy older adults with sleep problems, adolescents, and veterans with traumatic brain injury.

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1177/1477153506070994Lighting Research & Technology, 38, 4, pp. 358-378, 2006 Occupant use of switching and dimming controls in offices Boyce, P. R.; Veitch, J. A.; Newsham, G. R.; Jones, C. C.; Heerwagen, J.; Myer, M.; Hunter, C. M. AbstractAs part of a larger study sponsored by the Light Right Consortium, temporary office workers spent a day in an office working under one of four different lighting installations. For two of these installations the office workers had the freedom to adjust the lighting of the cubicles they occupied: either with a switchable desk lamp, or varying the direct component of a continuously dimmable overhead direct / indirect luminaire. This paper examines the illuminances chosen under these two conditions, compares the results with those found in other field and laboratory studies, and addresses pertinent questions about the behaviour of office workers when they have the freedom to adjust the lighting of their workspaces.

Shift work, especially that involving rotating and night shifts, is associated with an increased risk of diseases, including cancer. Attempts to explain the association between shift work and cancer in particular have focused on the processes of melatonin production and suppression. One hypothesis postulates that exposure to light at night (LAN) suppresses melatonin, whose production is known to slow the development of cancerous cells, while another proposes that circadian disruption associated with shift work, and not just LAN, increases health risks. This review focuses on six studies that employed quantitative measurement of LAN and melatonin levels to assess cancer risks in shift workers. These studies were identified via searching the PubMed database for peer-reviewed, English-language articles examining the links between shift work, LAN, and disease using the terms light at night, circadian disruption, health, risk, cancer, shift work, or rotating shift. While the results indicate a growing consensus on the relationship between disease risks (particularly cancer) and circadian disruption associated with shift work, the establishment of a direct link between LAN and disease has been impeded by contradictory studies and a lack of consistent, quantitative methods for measuring LAN in the research to date. Better protocols for assessing personal LAN exposure are required, particularly those employing calibrated devices that measure and sample exposure to workplace light conditions, to accurately assess LAN’s effects on the circadian system and disease. Other methodologies, such as measuring circadian disruption and melatonin levels in the field, may also help to resolve discrepancies in the findings.