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Author Shang, Y.-M.; Wang, G.-S.; Sliney, D.; Yang, C.-H.; Lee, L.-L.
Title White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model Type (down) Journal Article
Year 2014 Publication Environmental Health Perspectives Abbreviated Journal Environ Health Perspect
Volume 122 Issue 3 Pages 269-276
Keywords LED; light emitting diode; lighting; retina; Eye Diseases; blue light; Blue-rich light sources
Abstract BACKGROUND: Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic light sources. Chronic exposure to high-intensity light (2,000-10,000 lux) has previously been found to result in light-induced retinal injury, but chronic exposure to relatively low-intensity (750 lux) light has not been previously assessed with LEDs in a rodent model. OBJECTIVE: We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat using functional, histological, and biochemical measurements. METHODS: We used blue LEDs (460 nm) and full-spectrum white LEDs, coupled with matching compact fluorescent lights, for exposures. Pathological examinations included electroretinogram, hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and transmission electron microscopy (TEM). We also measured free radical production in the retina to determine the oxidative stress level. RESULTS: H&E staining and TEM revealed apoptosis and necrosis of photoreceptors, which indicated blue-light induced photochemical injury of the retina. Free radical production in the retina was increased in LED-exposed groups. IHC staining demonstrated that oxidative stress was associated with retinal injury. Although we found serious retinal light injury in LED groups, the compact fluorescent lamp (CFL) groups showed moderate to mild injury. CONCLUSION: Our results raise questions about adverse effects on the retina from chronic exposure to LED light compared with other light sources that have less blue light. Thus, we suggest a precautionary approach with regard to the use of blue-rich “white” LEDs for general lighting. CITATION: Shang YM, Wang GS, Sliney D, Yang CH, Lee LL. 2014. White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model. Environ Health Perspect 122:269-276; http://dx.doi.org/10.1289/ehp.1307294.
Address Institute of Environmental Health, National Taiwan University, Taipei, Taiwan
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0091-6765 ISBN Medium
Area Expedition Conference
Notes PMID:24362357; PMCID:PMC3948037 Approved no
Call Number IDA @ john @ Serial 324
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Author Gil-de-Castro, A.; Moreno-Munoz, A.; Larsson, A.; de la Rosa, J.; Bollen, M.
Title LED street lighting: A power quality comparison among street light technologies Type (down) Journal Article
Year 2013 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology
Volume 45 Issue 6 Pages 710-728
Keywords LED; LED lighting; high-pressure sodium; HPS; outdoor lighting; lighting technology
Abstract High-pressure sodium lamps are currently the main lamps used in public lighting. However, the possibility of using high-power light emitting diode (LEDs) for street lighting is growing continuously due to their greater energy efficiency, robustness, long life and light control. The aim of this paper is to study the power quality of high-power lighting networks based on LED and high-pressure sodium lamps. Both electromagnetic and dimmable electronic ballasts, which can dim the lamp output smoothly and uniformly, have been used connected to high-pressure sodium lamps. High-pressure sodium lamps connected to electronic equipment have been tested with different arc power levels using dimming on a 230 V power supply. The study presented in this paper is completely based on measurements, including harmonic currents in the frequency range up to 150 kHz for all the technologies. The main results show a broadband spectrum in LED lamps which confirms other research in fluorescent lamps powered by high-frequency ballasts. Results also indicate a decrease in the harmonic value with increasing harmonic order, and a decrease in the harmonic value at half load (60%) compared with full load (100%). Although total harmonic distortion of the current is lower with high-pressure sodium lamps connected to electronic rather than electromagnetic ballasts, LED lamps achieved the lowest total harmonic distortion of current.
Address Department of Computer Architecture, Electronics and Electronic Technology, University of Cordoba, Cordoba, Spain
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 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 333
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Author Johansson, M.; Rosen, M.; Kuller, R.
Title Individual factors influencing the assessment of the outdoor lighting of an urban footpath Type (down) Journal Article
Year 2011 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology
Volume 43 Issue 1 Pages 31-43
Keywords footpath lighting; pathway lighting; outdoor lighting; lighting perception
Abstract During the hours of darkness, the mobility of young women, the elderly and the disabled is limited in urban areas. In a field study possible predictors of the perceived visual accessibility and the perceived danger of an urban footpath were investigated. Eighty-one people individually walked along the footpath after dark. They subjectively assessed the environment and answered a questionnaire about personality and socio-demographics. Visual accessibility was predicted by visual field, environmental trust and brightness. Danger was predicted by the pleasantness of the lighting, gender, brightness and environmental trust. Consequently, the influence of individual characteristics, including the subjective judgments of brightness and hedonic tone and the personality dimension of trust in the physical environment, should be considered in the design of exterior lighting for urban footpaths.
Address Environmental Psychology, Department of Architecture and Built Environment Lund University, Sweden
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 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 334
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Author Sperber, A.N.; Elmore, A.C.; Crow, M.L.; Cawlfield, J.D.
Title Performance evaluation of energy efficient lighting associated with renewable energy applications Type (down) Journal Article
Year 2012 Publication Renewable Energy Abbreviated Journal Renewable Energy
Volume 44 Issue Pages 423-430
Keywords Renewable energy; Energy efficiency; Ultra capacitor; Light emitting diodes; Metal halide; LED; LED lighting
Abstract Energy efficiency is a primary consideration when designing off-grid renewable energy systems including portable micro-grids. This study focuses on characterizing the potential benefits associated with using energy efficient exterior area lighting commonly associated with remote installations. Light emitting diode (LED) luminaires are becoming more commercially available, and this study compares two LED products designed for exterior lighting to traditional metal halide lamps. The characterization focuses on the use of a diesel generator, battery bank, and a bank of ultra capacitors (UCAPs) to power the lights because these systems are also used to generate or store energy at renewable energy-powered micro-grids. This field-based study quantifies the illuminance provided by each lighting system, diesel consumption rates associated with powering the lights and/or charging the batteries and UCAPs, and the time of operation for each lighting system when powered by a single discharge cycle of the batteries and UCAPs. The energy efficiency benefit of the LED luminaires is offset by their lower illuminance. However, a comparison of lighting standards for specific purposes such as security lighting indicates that LEDs may be appropriate for applications where a metal halide system would provide significantly more illumination than required at a much higher energy cost. For those purposes where higher levels of illuminance are required, the data presented in the paper may be useful in designing a renewable energy-powered micro-grid that uses multiple LED fixtures to illuminate an exterior area that is currently illuminated by a single metal halide light stand.
Address Geological Engineering, Missouri University of Science and Technology, 129 McNutt Hall, 1400 N. Bishop Avenue Rolla, MO 65409, 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 0960-1481 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 335
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Author Kostic, A.; Djokic, L.
Title Subjective impressions under LED and metal halide lighting Type (down) Journal Article
Year 2014 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology
Volume 46 Issue 3 Pages 293-307
Keywords lighting; outdoor lighting; subjective; LED; metal halide; *Safety; Belgrade
Abstract In order to compare subjective impressions created by LED and metal halide ambient lighting, a pilot project was conducted in a Belgrade park. All general requirements for an adequate comparison of subjective impressions were fulfilled. The survey was conducted using a questionnaire related to all aspects the researchers considered relevant for subjective evaluation of illuminated pedestrian paths in parks. It was concluded that the respondents, both those who had and those who did not have previous knowledge in the field of lighting, strongly preferred the use of metal halide lamps for the illumination of parks, which is in opposition to the statements of some LED manufacturers. It was also shown that light level and feelings of safety and comfort are evaluated as most important.
Address Faculty of Architecture, University of Belgrade, Belgrade, Serbia
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 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 336
Permanent link to this record