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Author Kocifaj, M.; Solano Lamphar, H.A.
Title Skyglow effects in UV and visible spectra: radiative fluxes Type Journal Article
Year 2013 Publication Journal of Environmental Management Abbreviated Journal J Environ Manage
Volume (down) 127 Issue Pages 300-307
Keywords Animals; Darkness; Environmental Exposure/*analysis; *Light; Models, Theoretical; *Ultraviolet Rays; Light pollution; Optical thickness; Public lighting system; Two stream approximation
Abstract Several studies have tried to understand the mechanisms and effects of radiative transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse radiation at terrain level. In this paper, the downward diffuse radiative flux is computed in a two-stream approximation and obtained ultraviolet spectral radiative fluxes are inter-related with luminous fluxes. Such a method then permits an estimate of ultraviolet radiation if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible flux production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment.
Address ICA, Slovak Academy of Sciences, 9, Dubravska Road, 845 03 Bratislava, Slovak Republic. kocifaj@savba.sk
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Series Volume Series Issue Edition
ISSN 0301-4797 ISBN Medium
Area Expedition Conference
Notes PMID:23792881 Approved no
Call Number IDA @ john @ Serial 265
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Author Kuechly, H.U.; Kyba, C.C.M.; Ruhtz, T.; Lindemann, C.; Wolter, C.; Fischer, J.; Hölker, F.
Title Aerial survey and spatial analysis of sources of light pollution in Berlin, Germany Type Journal Article
Year 2012 Publication Remote Sensing of Environment Abbreviated Journal Remote Sensing of Environment
Volume (down) 126 Issue Pages 39-50
Keywords Light pollution; Artificial lighting; Urban analysis; Remote sensing; GIS; Darkness; Spatial analysis; Light at night
Abstract Aerial observations of light pollution can fill an important gap between ground based surveys and nighttime satellite data. Terrestrially bound surveys are labor intensive and are generally limited to a small spatial extent, and while existing satellite data cover the whole world, they are limited to coarse resolution. This paper describes the production of a high resolution (1 m) mosaic image of the city of Berlin, Germany at night. The dataset is spatially analyzed to identify the major sources of light pollution in the city based on urban land use data. An area-independent ‘brightness factor’ is introduced that allows direct comparison of the light emission from differently sized land use classes, and the percentage area with values above average brightness is calculated for each class. Using this methodology, lighting associated with streets has been found to be the dominant source of zenith directed light pollution (31.6%), although other land use classes have much higher average brightness. These results are compared with other urban light pollution quantification studies. The minimum resolution required for an analysis of this type is found to be near 10 m. Future applications of high resolution datasets such as this one could include: studies of the efficacy of light pollution mitigation measures, improved light pollution simulations, economic and energy use, the relationship between artificial light and ecological parameters (e.g. circadian rhythm, fitness, mate selection, species distributions, migration barriers and seasonal behavior), or the management of nightscapes. To encourage further scientific inquiry, the mosaic data is freely available at Pangaea: http://dx.doi.org/10.1594/PANGAEA.785492.
Address Freie Universität Berlin, Department of Earth Sciences, Institute for Space Sciences, Carl-Heinrich-Becker-Weg 6‐10, 12165 Berlin, Germany
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ISSN 0034-4257 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 188
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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 Journal Article
Year 2014 Publication Environmental Health Perspectives Abbreviated Journal Environ Health Perspect
Volume (down) 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
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ISSN 0091-6765 ISBN Medium
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Notes PMID:24362357; PMCID:PMC3948037 Approved no
Call Number IDA @ john @ Serial 324
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Author Ho, C.Y.; Lin, H.T.; Huang, K.Y.
Title A Study on Energy Saving and Light Pollution of LED Advertising Signs Type Journal Article
Year 2011 Publication Applied Mechanics and Materials Abbreviated Journal Amm
Volume (down) 121-126 Issue Pages 2979-2984
Keywords Advertising Sign; LED; Light Trespass; Luminance Limit; Saving Energy; Vertical Illuminance; *Lighting
Abstract Lighting advertising signs not only play an important role in outdoor lighting environment in Taiwan, but also become the main factor of energy consumption in urban areas at night. Light-emitting diode (LED) has been gradually used in advertising signs due to its advantages. However, in order to be conspicuous and legible in the daytime, signs that are excessively bright may result in considerable light pollution and energy waste at nighttime. Therefore, this research aims to measure the luminance of LED signs and traditional internally lighted signs, and analyze the light trespass from each signage. Based on the research results, the energy consumption from a LED full color screen is 12 times more than a traditional internally lighted sign per day. Statistically, all kinds of LED signs are much higher than traditional internally lighted signs in the percentage of excessive brightness and average luminance value. As for the light trespass, since the vertical illuminance on facade facing the signs increases with the increase of the sign area or the decrease of the distance between the sign and the facade, the vertical illuminance on facade facing the signs would exceed the limit of CIE even if the luminance of the signs achieves the standard of CIE in terms of the general conditions in Taiwan. This happens to LED full color screens in particular and thus results in considerable obtrusive light. To sum up, in order to reduce unnecessary energy consumption and improve the nighttime lighting quality for outdoor environment, this research recommends the luminance limitation for light dimming of LED advertising signs should refer to the zoning, time period, and sign area.
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ISSN 1662-7482 ISBN Medium
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Notes Approved no
Call Number IDA @ john @ Serial 126
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Author Luginbuhl, C.B.; Lockwood, G.W.; Davis, D.R.; Pick, K.; Selders, J.
Title From The Ground Up I: Light Pollution Sources in Flagstaff, Arizona Type Journal Article
Year 2009 Publication Publications of the Astronomical Society of the Pacific Abbreviated Journal Publ Astron Soc Pac
Volume (down) 121 Issue 876 Pages 185-203
Keywords light pollution; Flagstaff; Arizona; measurements; lighting policy; public policy
Abstract We develop an estimate of the complete outdoor lighting of Flagstaff Arizona, as well as lighting-use densities (lumens per acre) for a number of different land uses. We find a total outdoor light output of 173 million lumens (Mlm) including sports lighting, and 139 Mlm without sports lighting, with an uncertainty of about 7%. The average fraction escaping directly upward from light fixtures is estimated to be 8.3%. After correcting approximately for near-ground blocking described in the accompanying paper by Luginbuhl et al., total uplight is estimated at 17.9 Mlm or 12.2 Mlm with and without sports lighting, respectively. Of these 17.9 Mlm, 33% arise from sports lighting, when it is on; when sports lighting is off, commercial and industrial lighting account for 62% with the remainder dominated by residential (14%) and roadway lighting (12%). We show that the 1989 Flagstaff lighting code that limited total outdoor lighting on new construction has reduced the growth rate of lighting, resulting in a 17% growth in light escaping into the sky from 1989 to 2003, compared to a 43% increase expected if the 1989 code had not been enacted. If all legally nonconforming lighting installed before 1989 were to be brought into compliance with the code, we would expect sky glow in Flagstaff to actually decrease by 36% compared to that in 2003; if all lighting, including residential, could be converted to fully shielded fixtures, sky glow would decrease to about half the current value. The implications for the most effective ways to address sky glow through lighting codes are discussed.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6280 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 246
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