Light pollution is caused by inefficient or unnecessary use of artificial light. This is most likely because historically there has not been a large market specifically for full cutoff fixtures, and because people typically like to see the source of illumination. According to design investigations, luminaires with full cutoff distributions (as opposed to cutoff or semi cutoff, compared here)[101] have to be closer together to meet the same light level, uniformity and glare requirements specified by the IESNA. Consensus-based standards or norms that are not based on vision science; Improper design, by specifying higher levels of light than needed for a given visual task; Improper selection of hardware to utilize more energy than needed to accomplish the lighting task; Incomplete training of building managers and occupants to use lighting systems efficiently; Inadequate lighting maintenance resulting in increased. Omissions? A single offending light source often falls into more than one of these categories. [92] Skyglow (the scattering of light in the atmosphere at night) reduces the contrast between stars and galaxies and the sky itself, making it much harder to see fainter objects. Light pollution: Any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste. A common criticism of full cutoff lighting fixtures is that they are sometimes not as aesthetically pleasing to look at. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety. This article is not about radio spectrum light pollution – we will focus on the visible spectrum of light. The Dark-Sky Association was started to reduce the light going up into the sky which reduces visibility of stars (see Skyglow below). Let us know if you have suggestions to improve this article (requires login). The only places in continental Europe where the sky can attain its natural darkness are in northern Scandinavia and in islands far from the continent. Light pollution is a 'blight on the night sky' that is obscuring our view of the stars and should be controlled for the sake of future generations, a group of MPs claim. This reflection can be reduced, however, by being careful to use only the lowest wattage necessary for the lamp, and setting spacing between lights appropriately. [41], The Bortle scale is a nine-level measuring system used to track how much light pollution there is in the sky. Thus, SAFE currently recommends an SEC of two to three watts per meter for roads less than ten metres wide (four to six for wider roads). [52][53] Multiple studies have documented a correlation between night shift work and the increased incidence of breast and prostate cancer. Since lamp posts attract many flying insects, the spiders that don't mind light gain an advantage over the spiders that avoid it. Rich C., Longcore T. 2005, Ecological Consequences of Artificial Night Lighting, Island Press).They are still little known because this field of studies has developed since few years. Light pollution over Las Vegas, Nev., as seen from Dante's View in Death Valley National Park, California, U.S. Therefore, poorly chosen light sources often contribute unnecessarily to light pollution and energy waste. Inspection of the area surrounding Madrid reveals that the effects of light pollution caused by a single large conglomeration can be felt up to 100 km (62 mi) away from the center. Many migratory birds, for example, fly by night, when light from the stars and Moon helps them navigate. Definition of light pollution : artificial skylight (as from city lights) that interferes especially with astronomical observations Examples of light pollution in a Sentence Recent Examples on the Web Asked whether light pollution … [65], Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia, from eating surface algae, causing algal blooms that can kill off the lakes' plants and lower water quality. Light pollution is a major concern for observatories as lights from urban areas compete with lights from stars and planets, reducing visibility of the objects that observatories study. This kind of glare is a particular instance of disability glare, called veiling glare. A full cutoff fixture, when correctly installed, reduces the chance for light to escape above the plane of the horizontal. Specific categories of light pollution include light trespass, over-Illumination, Glare, Light Clutter, and Skyglow. Due to the specificity with their direction of light, full cutoff fixtures sometimes also require expertise to install for maximum effect. It is a contamination that leaves no physical residue but, lengthened over time, leads to problems such as insomnia, fatigue, anxiety or inability to concentrate among many others. For example, lepidopterists and entomologists have documented that nighttime light may interfere with the ability of moths and other nocturnal insects to navigate. The quantity of light pollution from a given area depends on the number and brightness of light sources on the ground, the fraction of light that escapes above the horizontal, the reflectivity of surfaces near the light sources (e.g., roads, pavements, walls, windows), and the prevailing atmospheric conditions. It was also found that there was no correlation between other types of cancer such as cervical or lung cancer and ALAN levels. In view of ongoing progress in lighting technology, target SEC values will need to be periodically revised downwards. The effect of skyglow from a town or city is not necessarily localized; it can be observed far from the main source. [82][83][84] Amphibians and reptiles are also affected by light pollution. Light pollution competes with starlight in the night sky for urban residents, interferes with astronomical observatories,[5] and, like any other form of pollution, disrupts ecosystems and has adverse health effects.[6][7]. With future increase in numbers of satellite constellations, like OneWeb and Starlink, it is feared especially by the astronomical community, such as the IAU that light pollution will increase significantly, beside other problems of satellite overcrowding. Adverse consequences are multiple; some of them may not be known yet. An illustration of both useful light and the components of light pollution are illustrated in Figure 2. [62] Red light suppresses melatonin the least. OSP can be used by lighting engineers immediately, particularly for the investigation of glow and trespass (glare analyses are more complex to perform and current commercial software does not readily allow them), and can help users compare several lighting design alternatives for the same site. Unnatural polarized light sources can trigger maladaptive behaviors in polarization-sensitive taxa and alter ecological interactions.[76]. ", https://en.wikipedia.org/w/index.php?title=Light_pollution&oldid=993341315, Articles with Italian-language sources (it), Articles with dead external links from December 2017, Articles with permanently dead external links, Articles with dead external links from July 2018, Short description is different from Wikidata, Articles with unsourced statements from October 2017, Wikipedia articles in need of updating from September 2019, All Wikipedia articles in need of updating, Articles with unsourced statements from February 2013, Articles needing additional references from December 2008, All articles needing additional references, Articles needing additional references from July 2010, Articles with unsourced statements from February 2017, Creative Commons Attribution-ShareAlike License. Even at apparent clear night skies there can be a lot of stray light that becomes visible at longer exposure times in astrophotography. Light pollution – extent, societal and ecological impacts as well as approaches, Office of Technology Assessment at the German Bundestag (TAB), Non-technical resource guide (web and published materials) to light pollution issues, Interactive Map of City Lights at Academo.org, Light Pollution and the UK's changing skies, "LED light pollution: Can we save energy and save the night? Some species of frogs and salamanders utilize a light-dependent "compass" to orient their migratory behaviour to breeding sites. What is light pollution? This is one factor that has caused newer telescopes to be built in increasingly remote areas. Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination. LPR filters reduce the brightness of the object under study and this limits the use of higher magnifications. Light pollution can be reduced by using well-designed light fixtures with modern optical controls to direct the light downward and also by using the minimum amount of wattage for the area to be illuminated. Light pollution is a side-effect of industrial civilization. Light pollution, the excessive or inappropriate use of outdoor artificial light, is affecting human health, wildlife behavior, and our ability to observe stars and other celestial objects. [15] The U.S. Green Building Council (USGBC) has also incorporated a credit for reducing the amount of light trespass and sky glow into their environmentally friendly building standard known as LEED. Unfortunately, due to continued lack of accurate information,[106] many lighting professionals continue to disparage low-pressure sodium, contributing to its decreased acceptance and specification in lighting standards and therefore its use. In 1980, for example, San Jose, California, replaced all street lamps with low pressure sodium lamps, whose light is easier for nearby Lick Observatory to filter out. A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. In disrupting ecosystems, light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. Studies carried out by Nederlandse Aardolie Maatschappij b.v. (NAM) and Shell have led to development and trial of new lighting technologies in the North Sea. In every lighting system, some sky glow also results from light reflected from the ground. [81] Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea. This is caused by two main sources: airglow and scattered light. ", "Night shift work, light at night, and risk of breast cancer", "Rotating night shifts and risk of breast cancer in women participating in the nurses' health study", "Of mice and women: light as a circadian stimulus in breast cancer research", "Event—Circadian Disruption and Cancer on Nature Network", 10.1890/1540-9295(2004)002[0191:ELP]2.0.CO;2, "Urban light pollution alters the diel vertical migration of Daphnia", Confirmed: Night Lights Drive Pollinators Away From Plants, "Artificial Night Lighting Reduces Firefly (Coleoptera: Lampyridae) Occurrence in Sorocaba, Brazil", "Bioluminescent beetles (Coleoptera: Elateroidea: Lampyridae, Phengodidae, Elateridae) in the municipalities of Campinas, Sorocaba-Votorantim and Rio Claro-Limeira (SP, Brazil): biodiversity and influence of urban sprawl", "Insect declines and agroecosystems: does light pollution matter? "The impact of light source spectral power distribution on sky glow", "Evaluating Potential Spectral Impacts of Various Artificial Lights on Melatonin Suppression, Photosynthesis, and Star Visibility", Coconino County Lighting and General Codes, Arizona IDA presentation on Lighting issues (PowerPoint), The City of Calgary: Envirosmart Streetlight Retrofit Program, Lighting Research Center Develops Framework for Assessing Light Pollution, Rensselaer Polytechnic Institute's Lighting Research Center, Sydney Outdoor Lighting Improvement Society, Illinois Coalition for Responsible Outdoor Lighting, Indexed list of peer reviewed light pollution research papers, "Lighting and Astronomy: Light Pollution", "The Disappearance of Darkness" History of Light Pollution, Technical slide show "Lamp Spectrum and Light Pollution: The Other Side of Light Pollution", European Light pollution—technical articles, U.S. National Parks technical article "Modeling Light Pollution from Population Data", The Challenge article "Is Light Pollution Killing Our Birds", "Ecological Consequences of Artificial Night Lighting", Light pollution and the protection of the night environment, Cégep de Sherbrooke Light pollution research activities, Examples of the good, bad and ugly lighting. Simply put, light pollution (LP) is an excessive and obtrusive source of artificial light, mainly created by The effectiveness of using full cutoff roadway lights to combat light pollution has also been called into question. In another example, the city of Calgary has recently replaced most residential street lights with models that are comparably energy efficient. It can confuse animal navigation, alter competitive interactions, change predator-prey relations, and cause physiological harm. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies, as follows:[24]. (IARC Press release No. Therefore, the overall performance of existing systems could be improved more by reducing the number of luminaires than by switching to full cutoff designs. Campaigners also commonly argue that full cutoff fixtures are more efficient than other fixtures, since light that would otherwise have escaped into the atmosphere may instead be directed towards the ground. 180). It is most severe in highly industrialized, densely populated areas of North America, Europe, and Japan and in major cities in the Middle East and North Africa like Tehran and Cairo, but even relatively small amounts of light can be noticed and create problems. Adverse consequences are multiple; some of them may not be known yet. Excessive groupings of light that are bright and confusing, commonly found in over-lit cities and inhabited areas. [69][70][71] Fireflies are well known and interesting to the general public (unlike many other insects)[72] and are easily spotted by non-experts, and, due to their sensibility and rapid response to environmental changes[73] good bioindicators for artificial night lighting. For applications requiring more precise direction of light (such as narrow roadways) the native lamp efficacy advantage of this lamp type is decreased and may be entirely lost compared to high pressure sodium lamps.