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Encyclopedia > Light pollution
Pollution
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Air pollution
Acid rainAir Pollution IndexAir Quality IndexAtmospheric dispersion modelingChlorofluorocarbonGlobal dimmingGlobal warming • Haze • Indoor air qualityOzone depletionParticulateSmogRoadway air dispersion
Water pollution
EutrophicationHypoxiaMarine pollutionOcean acidificationOil spillShip pollutionSurface runoffThermal pollutionWastewaterWaterborne diseasesWater qualityWater stagnation
Soil contamination
Bioremediation • Herbicide • PesticideSoil Guideline Values (SGVs)
Radioactive contamination
Actinides in the environmentEnvironmental radioactivityFission productNuclear falloutPlutonium in the environmentRadiation poisoningradium in the environmentUranium in the environment
Other types of pollution
Invasive speciesLight pollutionNoise pollutionRadio spectrum pollutionVisual pollution
Government acts
Clean Air ActClean Water ActKyoto ProtocolWater Pollution Control Act • Environmental Protection Act 1990
Major organizations
DEFRAEnvironmental Protection AgencyGlobal Atmosphere WatchGreenpeaceNational Ambient Air Quality Standards
Related topics
Natural environment
This time exposure photo of New York City shows sky glow, one form of light pollution. Glow reflected from background clouds demonstrates the upward-directed light, partly caused by unshielded lights.
Example of a bad light pollution source using a broad spectrum metal halide lamp pointing upward towards the sky. Location: Gouda, The Netherlands.

Light pollution is excess or obtrusive light created by humans. Among other effects, it disrupts ecosystems, can cause adverse health effects, obscures stars to city dwellers, interferes with astronomical observatories, and wastes energy. Light pollution can be construed to have two main branches: (a) annoying light that intrudes on an otherwise natural or low light setting and (b) excessive light, generally indoors, that leads to worker discomfort and adverse health effects. Since the early 1980s, a global dark-sky movement has emerged, with concerned people campaigning to reduce the amount of light pollution. It has been suggested that Pollutant be merged into this article or section. ... Air Pollution is a chemical, physical (e. ... The term acid rain also known as acid precipitation is commonly used to mean the deposition of acidic components in rain, snow, dew, or dry particles. ... An air quality measurement station in Edinburgh, Scotland The Air Quality Index (AQI) is a standardized index of the air quality in a given location, given in parts per billion. ... An air quality measurement station in Edinburgh, Scotland The Air Quality Index (AQI) is a standardized indicator of the air quality in a given location. ... Atmospheric dispersion modeling is performed with computer programs that use mathematical equations and algorithms to simulate how pollutants in the ambient atmosphere disperse in the atmosphere. ... Tetrafluoroethane (a haloalkane) is a clear liquid which boils well below room temperature (as seen here) and can be extracted from common canned air canisters by simply inverting them during use. ... Eastern China -- Dozens of fires burning on the surface (red dots) and a thick pall of smoke and haze (greyish pixels) filling the skies overhead. ... Global mean surface temperatures 1850 to 2006 Mean surface temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980 Global warming is the observed increase in the average temperature of the Earths atmosphere and oceans in recent decades and the projected... Haze is an atmospheric phenomenon where dust, smoke and other pollutant particles obscure the normal clarity of the sky. ... Indoor Air Quality (IAQ) deals with the content of interior air that could affect health and comfort of building occupants. ... Global monthly average total ozone amount Ozone depletion describes two distinct, but related observations: a slow, steady decline of about 4 percent per decade in the total amount of ozone in Earths stratosphere since around 1980; and a much larger, but seasonal, decrease in stratospheric ozone over Earths... Particulates, alternatively referred to as particulate matter (PM), aerosols or fine particles, are tiny particles of solid or liquid suspended in a gas. ... Victorian London was notorious for its thick smogs, or pea-soupers, a fact that is often recreated to add an air of mystery to a period costume drama. ... Roadway air dispersion is applied to highway segments Roadway air dispersion modeling is the study of air pollutant transport from a roadway or other linear emitter. ... Water pollution is a large set of adverse effects upon water bodies such as lakes, rivers, oceans, and groundwater caused by human activities. ... Eutrophication is a change in an ecosystem caused by increased growth of a species. ... It has been suggested that Anoxic sea water, Oxygen minimum zone, and Hypoxic zone be merged into this article or section. ... Pumping of highly toxic (dark black) sludge, much seeps back into the ocean in the form of particles. ... Change in sea surface pH caused by anthropogenic CO2 between the 1700s and the 1990s Ocean acidification is the name given to the ongoing decrease in the pH of the Earths oceans, caused by their uptake of anthropogenic carbon dioxide from the atmosphere. ... An oil spill is the unintentional release of liquid petroleum hydrocarbon into the environment as a result of human activity. ... Ship pollution is the pollution of water by shipping! It is a problem that has been accelerating as trade has become increasingly globalized. ... Runoff flowing into a stormwater drain Surface runoff is water, from rain, snowmelt, or other sources, that flows over the land surface, and is a major component of the water cycle[1][2]. Runoff that occurs on surfaces before reaching a channel is also called overland flow. ... Thermal pollution is a temperature change in natural water bodies caused by human influence. ... Wastewater is any water that has been adversely affected in quality by anthropogenic influence. ... Waterborne diseases, according to the World Health Organization, are those which generally arise from the contamination of water by feces or urine, infected by pathogenic viruses or bacteria, and which are directly transmitted when unsafe water is drunk or used in the preparation of food. ... Water quality is the chemical and physical characterization of water. ... Standing water redirects here. ... Excavation of leaking underground storage tank causing soil contamination Soil contamination is the presence of man-made chemicals or other alteration of the natural soil environment. ... Bioremediation can be defined as any process that uses microorganisms, fungi, green plants or their enzymes to return the environment altered by contaminants to its original condition. ... A herbicide is a pesticide used to kill unwanted plants. ... A cropduster spreading pesticide. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... The radiation warning symbol (trefoil). ... This article about actinides in the environment is about the sources, environmental behaviour and effects of actinides in the environment. ... The environmental radioactivity page is devoted to the subject of radioactive materials in man and his environment. ... Fission products are the residues of fission processes. ... Fallout is the residual radiation hazard from a nuclear explosion, so named because it falls out of the atmosphere into which it is spread during the explosion. ... To meet Wikipedias quality standards, this article may require cleanup. ... Radiation Hazard symbol. ... // Radium Radium in quack medicine See the story of Eben Byers for details of one very nasty case which involved a product called Radithor this contained 1 mCi of 226Ra and 1 mCi of 228Ra per bottle. ... Uranium in the environment, this page is devoted to the science of uranium in the environment and in animals (including humans). ... Lantana invasion of abandoned citrus plantation; Moshav Sdey Hemed, Israel The term invasive species refers to a subset of introduced species or non-indigenous species that are rapidly expanding outside of their native range. ... Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. ... Radio spectrum pollution is the straying of waves in the radio and electromagnetic spectrums outside their allocations that cause problems for some activities. ... Visual pollution is the term given to unattractive visual elements of a vista, a landscape, or any other thing that a person might want to look at. ... This article or section does not adequately cite its references or sources. ... The Clean Water Act, 33 U.S.C. Â§ 1251, et seq. ... Kyoto Protocol Opened for signature December 11, 1997 in Kyoto, Japan Entered into force February 16, 2005. ... This act gave authority to Surgeon General to make programs to reduce or eliminate water pollution in rivers, underground rivers, and other waterways. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ... The Department for Environment, Food and Rural Affairs (Defra) is the United Kingdom government department responsible for environmental protection, food production and standards, agriculture, fisheries and rural communities. ... EPA redirects here. ... Global Atmosphere Watchs logo The Global Atmosphere Watch (GAW) is a worldwide system established by the World Meteorological Organization – a United Nations agency – to monitor trends in the Earths atmosphere. ... Greenpeace protest against Esso / Exxon Mobil. ... The National Ambient Air Quality Standards (NAAQS) are standards established by the United States Environmental Protection Agency that apply for outdoor air throughout the country. ... This article does not cite any references or sources. ... Download high resolution version (2272x1704, 194 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (2272x1704, 194 KB) Wikipedia does not have an article with this exact name. ... New York, New York and NYC redirect here. ... Skyglow (or sky glow) is the bright orange glow seen over many cities and towns. ... Image File history File linksMetadata Download high-resolution version (480x640, 15 KB) Example of a bad light pollution source using a broad spectrum metal halide lamp pointing upward towards the sky. ... Image File history File linksMetadata Download high-resolution version (480x640, 15 KB) Example of a bad light pollution source using a broad spectrum metal halide lamp pointing upward towards the sky. ... Metal halide lamps, a member of the high-intensity discharge (HID) family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source. ... Goudas 15th Century Town Hall Flag of Gouda Goudas Cheese Market Gouda (population 71,797 in 2004) is a city in the western Netherlands, in the province of South Holland. ... This article does not cite any references or sources. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: wise man or knowing man) in the family Hominidae (the great apes). ... A coral reef near the Hawaiian islands is an example of a complex marine ecosystem. ... STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... Look up city, City in Wiktionary, the free dictionary. ... A giant Hubble mosaic of the Crab Nebula, a supernova remnant Astronomy is the science of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earths atmosphere (such as auroras and cosmic background radiation). ... MolÄ—tai Astronomical Observatory An observatory is a location used for observing terrestrial and/or celestial events. ... This article does not cite any references or sources. ... The dark-sky movement is a term for people who want to reduce light pollution, in order to reclaim the night sky so people can see the stars, to reduce the effects of unnatural lighting on the environment, and to cut down on energy usage. ...


Light pollution is a side effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, commercial properties, offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North America, Europe, and Japan, but even relatively small amounts of light can be noticed and create problems. Lighting refers to either artificial light sources such as lamps or to natural illumination of interiors from daylight. ... Commercialism redirects here. ... Wall Street, Manhattan is the location of the New York Stock Exchange and is often used as a symbol for the world of business. ... A property is an intrinsic or extrinsic quality of an object—where an object may be of any differing nature, depending on the context and field — be it computing, philosophy, etc. ... An office is a room or other area in which people work, but may also denote a position within an organisation with specific duties attached to it (see officer, office-holder, official); the latter is in fact an earlier usage, office as place originally referring to the location of one... This article or section does not cite any references or sources. ... A streetlight in front of a red sky at night A street light, also known as a light standard, is a raised light on the edge of a road, turned on or lit at a certain time every night. ... Telstra Stadium in Sydney, Australia is capable of being converted from a rectangular rugby football field to an oval for cricket and Australian rules football games This article is about the building type. ... World map showing the location of Europe. ...


With recent advances in private spaceflight, the prospect of space-based orbiting billboards appearing in the near future has provoked concern that such objects may become another form of light pollution. With this in mind, the United States Federal Aviation Administration sought permission, in May 2005, to enforce a law prohibiting "obtrusive" advertising in earth orbit [1] [2]. Similar intentions are yet to be expressed by authorities in most other countries, however. This space for sale Private spaceflight is flight above 100km Earth altitude conducted by an entity other than a government. ... “FAA” redirects here. ... 2005 : January - February - March - April - May - June - July - August - September - October - November - December- → Wikimedia Commons has media related to: May 2005 Deaths in May May 26: Eddie Albert May 25: Ismail Merchant May 25: Sunil Dutt May 25: Graham Kennedy May 22: Thurl Ravenscroft May 21: Howard Morris May 21...

Contents

Light pollution as a problem

"Light pollution" (also known as photopollution, luminous pollution) refers to light that is considered annoying, wasteful or harmful. It also causes damage to the environment and health, as do other forms of pollution such as air pollution, noise pollution, water pollution and soil contamination. Air Pollution is a chemical, physical (e. ... Noise pollution (or environmental noise in technical venues) is displeasing human or machine created sound that disrupts the environment. ... Water pollution is a large set of adverse effects upon water bodies such as lakes, rivers, oceans, and groundwater caused by human activities. ... Excavation of leaking underground storage tank causing soil contamination Soil contamination is the presence of man-made chemicals or other alteration of the natural soil environment. ...


Many people wish to reduce light pollution. However, it is unrealistic to expect populations to significantly reduce their light pollution, due to industrial society's economic reliance on man-made light. Detractors posit that light pollution is a problem similar to traditional forms of pollution. 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. The case against light pollution is strengthened by a range of studies on health effects, suggesting that excess light may induce loss in visual acuity, hypertension, headaches and increased incidence of carcinoma. In sociology, industrial society refers to a society with a modern societal structure. ... For the physical concepts, see conservation of energy and energy efficiency. ... In psychology, habituation is an example of non-associative learning in which there is a progressive diminution of behavioral response probability with repetition of a stimulus. ... Lighting efficiency is a measure of how much visible light is given off from a light source per unit of energy. ... Traditional Snellen chart used for visual acuity testing. ... This article or section does not cite any references or sources. ... A headache (cephalalgia in medical terminology) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... In medicine, carcinoma apanting dog named rufis It is malignant by definition: carcinomas invade surrounding tissues and organs, and may spread to lymph nodes and distal sites (metastasis). ...


Several industry groups also recognize light pollution as an important issue. For example, the Institution of Lighting Engineers in the United Kingdom provides its members information about light pollution, the problems it causes, and how to reduce its impact[1].


Since not everyone is irritated by the same lighting sources, it is common for one person's light "pollution" to be light that is desirable for another. One example of this is found in advertising, when an advertiser wishes for particular lights to be bright and visible, even though others find them annoying. Other types of light pollution are more certain. For instance, light that accidentally crosses a property boundary and annoys a neighbor is generally wasted and pollutive light. This article or section is not written in the formal tone expected of an encyclopedia article. ... Commercialism redirects here. ... This article or section does not cite any references or sources. ...


Disputes are still common when deciding appropriate action, and differences in opinion over what light is considered reasonable, and who should be responsible, mean that negotiation must sometimes take place between parties. Where objective measurement is desired, light levels can be quantified by field measurement or mathematical modeling, with results typically displayed as an isophote map or light contour map. Authorities have also taken a variety of measures for dealing with light pollution, depending on the interests, beliefs and understandings of the society involved. Measures range from doing nothing at all, to implementing strict laws and regulations about how lights may be installed and used. Broadly speaking, Negotiation is an interaction of influences. ... A mathematical model is an abstract model that uses mathematical language to describe the behaviour of a system. ... Elevation contour map A contour line shows elevation. ... Authority- is a very talented rocknroll band out of Columbia, S.C. This power rock trio has its roots in rock, funk, hardcore, and a dash of hip hop. ...


Types of light pollution

Light pollution is a broad term that refers to multiple problems, all of which are caused by inefficient, annoying or arguably unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, clutter, and sky glow. It is common, however, for annoying or wasteful light to fit several of these categories.


Light trespass

Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor’s fence. A common light trespass problem occurs when a strong light enters the window of one's home from outside, causing problems such as sleep deprivation or the blocking of an evening view. Sleep deprivation is a general lack of the necessary amount of sleep. ...


Light is particularly problematic for amateur astronomers, whose ability to observe the night sky from their property is likely to be inhibited by any stray light from nearby. Most major optical astronomical observatories are surrounded by zones of strictly-enforced restrictions on light emissions. It has been suggested that this article or section be merged with Skygazing. ... Amateur astronomy, often called back yard astronomy, is a hobby whose participants enjoy observing celestial objects. ...


A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light tresspass. To assist them the International Dark-Sky Association has developed a set of model lighting ordinances. U.S. federal agencies may also enforce standards and process complaints within their areas of jursidiction. For instance, in the case of light tresspass by white strobe lighting from communication towers in excess of FAA minimum lighting requirements the FCC maintains a database of Antenna Structure Registration information which citizens may use to identify offending structures and provides a mechanism for processing consumer inquiries and complaints. The International Dark-Sky Association (acronym: IDA) is a US-based non-profit organisation incorporated in 1988 by a group of astronomers in order to encourage darker skies (through lighting that creates less skyglow) in the USA, and, eventually, throughout the world by the setting up of other national organisations... U-shaped Xenon Flash Lamp A xenon flash lamp is a gas discharge lamp designed to produce extremely intense, incoherent, full-spectrum white light for very short durations. ... FAA may refer to: Federal Aviation Administration in the United States Fleet Air Arm in the UK Royal Navy Fuerza Aérea Argentina in Argentina This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The abbreviation FCC can refer to: Face-centered cubic (usually fcc), a crystallographic structure Federal Communications Commission, a US government organization Farm Credit Corporation/Farm Credit Canada, a Canadian government organization Families with Children from China, an adoption support organization Florida Christian College, a college in central Florida Fresno City...


Over-illumination

Main article: Over-illumination

Over-illumination is the excessive use of light. Specifically within the United States, over-illumination is responsible for approximately two million barrels of oil per day in energy wasted. This is based upon U.S. consumption of equivalent of 50 million barrels per day of petroleum [2], noting that 60% of U.S. supply is from nuclear power, natural gas, hydroelectric and other non-petroleum sources. Equivalent barrels per day of petroleum is simply an easy to visualize representation of energy use from all sources. It is further noted in the same U.S. Department of Energy source that over 30 percent of all energy is consumed by commercial, industrial and residential sectors. Energy audits of existing buildings demonstrate that the lighting component of residential, commercial and industrial uses consumes about 20 to 40 percent of those land uses, variable with region and land use. (Residential use lighting consumes only 10 to 30 percent of the energy bill while commercial buildings major use is lighting[3].) Thus lighting energy accounts for about four or five million barrels of oil (equivalent) per day. Again energy audit data demonstrates that about 30 to 60 percent[3] of energy consumed in lighting is unneeded or gratuitous. This cosmetics store has lighting levels over twice recommended levels and sufficient to trigger headaches and other health effects Over-illumination is the presence of lighting intensity (illuminance) beyond that required for a specified activity. ... A nuclear power station. ... Natural gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide. ... Hydroelectric dam diagram The waters of Llyn Stwlan, the upper reservoir of the Ffestiniog Pumped-Storage Scheme in north Wales, can just be glimpsed on the right. ... Pumpjack pumping an oil well near Lubbock, Texas Ignacy Łukasiewicz - inventor of the refining of kerosene from crude oil. ... A residential area is a type of land use where the predominant use is residential. ...


An alternative calculation starts with the fact that commercial building lighting consumes in excess of 81.68 terawatts (1999 data) of electricity [4], according to the U.S. DOE. Thus commercial lighting alone consumes about four to five million barrels per day (equivalent) of petroleum, in line with the alternate rationale above to estimate U.S. lighting energy consumption.


Over-illumination stems from several factors:

  • Not using timers, occupancy sensors or other controls to extinguish lighting when not needed.
  • Improper design, especially of workplace spaces, by specifying higher levels of light than needed for a given task.
  • Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed .
  • 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 stray light and energy costs.

Most of these issues can be readily corrected with available, inexpensive technology; however, there is considerable inertia in the field of lighting design and with landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly public awareness would need to improve for industrialized countries to realize the large payoff in reducing over-illumination. ... Lighting refers to either artificial light sources such as lamps or to natural illumination of interiors from daylight. ... An office is a room or other area in which people work, but may also denote a position within an organisation with specific duties attached to it (see officer, office-holder, official); the latter is in fact an earlier usage, office as place originally referring to the location of one... In the law of real property, fixtures are anything that would otherwise be a chattel that have, by reason of incorporation or affixation, become permanently attached to the real property. ... The light bulb is one of the most significant inventions in the history of the human race, illuminating the darkness of the evening and bringing light indoors at all times in order focus on the task at hand. ...


Glare

Glare is the result of excessive contrast between bright and dark areas in the field of view. For example, glare can be associated with directly viewing the filament of an unshielded or badly shielded light. Light shining into the eyes of pedestrians and drivers can obscure night vision for up to an hour after exposure. Caused by high contrast between light and dark areas, glare can also make it difficult for the human eye to adjust to the differences in brightness. Glare is particularly an issue in road safety, as bright and/or badly shielded lights around roads may partially blind drivers or pedestrians unexpectedly, and contribute to accidents. Night-vision is seeing in the dark. ... This article refers to the sight organ. ...


Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies[4]. According to this classification:

  • Blinding Glare describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies.
  • Disability Glare describes effects such as being blinded by an oncoming cars lights, with significant reduction in sight capabilities.
  • Discomfort Glare does not typically cause a dangerous situation in itself, and is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods.

The Sun (Latin: Sol) is the star at the center of the Solar System. ...

Clutter

Clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertising surrounds the roadways. Depending on the motives of the person or organization who installed the lights, their placement and design may even be intended to distract drivers, and can contribute to accidents. Clutter may also present a hazard in the aviation environment if aviation safety lighting must compete for pilot attention with non-relevant lighting. For instance runway lighting may be confused with an array of suburban commercial lighting and aircraft collision avoidance lights may be confused with ground lights. Alternate meanings: Accident (fallacy), Accident (philosophy), Accident (movie), Accident, Maryland An accident is something going wrong. ... Mountain road with hairpin turns in the French Alps For other uses, see Road (disambiguation). ... This article does not cite any references or sources. ... Aviation refers to flying using aircraft, machines designed by humans for atmospheric flight. ...


Sky glow

Los Angeles at night, with a brightly illuminated sky.
Los Angeles at night, with a brightly illuminated sky.
Main article: Sky glow

Sky glow refers to the "glow" effect that can be seen over populated areas. It is the combination of light reflected from what it has illuminated and from all of the badly directed light in that area, being refracted in the surrounding atmosphere. This refraction is strongly related to the wavelength of the light. Rayleigh scattering, which makes the sky appear blue in the daytime, also affects light that comes from the earth into the sky and is then redirected to become sky-glow, seen from the ground. As a result, blue light contributes significantly more to sky-glow than an equal amount of yellow light. Sky glow is of particular irritation to astronomers, because it reduces contrast in the night sky to the extent where it may even become impossible to see the brightest stars. Download high resolution version (900x432, 167 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (900x432, 167 KB) Wikipedia does not have an article with this exact name. ... Flag Seal Nickname: City of Angels Location Location within Los Angeles County in the state of California Coordinates , Government State County California Los Angeles County Mayor Antonio Villaraigosa (D) Geographical characteristics Area     City 1,290. ... Skyglow (or sky glow) is the bright orange glow seen over many cities and towns. ... Rayleigh scattering causing the blue hue of the sky and the reddening at sunset Rayleigh scattering (named after Lord Rayleigh) is the scattering of light, or other electromagnetic radiation, by particles much smaller than the wavelength of the light. ... Amateur astronomy, often called back yard astronomy, is a hobby whose participants enjoy observing celestial objects. ...

Ciudad de México at night, with a brightly illuminated sky.
Ciudad de México at night, with a brightly illuminated sky.

Astronomers have begun to use the Bortle Dark-Sky Scale, to quantify sky glow, since it was published in Sky & Telescope magazine.[5] The Bortle Scale rates the darkness of the sky, inhibited by sky glow, on a scale of one to nine, providing a detailed description of each position on the scale. Image File history File links Download high-resolution version (1536x1024, 611 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Light pollution Skyglow ... Image File history File links Download high-resolution version (1536x1024, 611 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Light pollution Skyglow ... Mexico City (Spanish: Ciudad de México) is the federal capital of, and largest city in, Mexico. ... The Bortle Dark-Sky Scale measures light pollution in the night sky and its interferences with it. ... Sky & Telescope is a monthly magazine providing articles and information on all aspects of astronomy, space exploration, telescope equipment, and amateur telescope making and use. ...


Measurement of light pollution and global effects

False colors show various intensities of artificial light — both direct and indirect — that reach space (Image credit: P. Cinzano)
Composite image of the Earth at night, as viewed from a satellite.

Measuring the effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light. This is caused by two main sources: airglow and scattered light. Image File history File links Light_pollution_europe. ... Image File history File links Light_pollution_europe. ... Image File history File links Earth_night. ... Image File history File links Earth_night. ... An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ...


At high altitudes, primarily above the mesosphere, UV radiation from the sun is so intense that ionization occurs. When these ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow. The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the earth's shadow. The mesosphere (from the Greek words mesos = middle and sphaira = ball) is the layer of the Earths atmosphere that is directly above the stratosphere and directly below the thermosphere. ... The airglow is the very weak emission of visible light by the earths atmosphere, which means that the night sky is never completely dark. ...


Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the milky way, but also sunlight that is reflected and backscattered from interplanetary dust particles (the so-called Zodiacal light). The zodiacal light in the eastern sky before the beginning of morning twilight. ...


The amount of airglow and zodiacal light is quite variable but given the most optimal conditions the darkest possible sky has a brightness of about 22 magnitude/square arcsecond. If a full moon is present, the sky brightness increases to 18 magnitude/sq. arcsecond, 40 times brighter than the darkest sky. In densely populated areas a sky brightness of 17 magnitude/sq. arcsecond is not uncommon, or as much as 100 times brighter than is natural. Airglow made visible from aboard the ISS (NASA) The fact that the sky isnt absolutely dark at night can easily be observed. ...


To precisely measure how bright the sky gets night time satellite imagery of the earth is used as raw input for the number and intensity of light sources. These are put into a physical model[6] of scattering due to air molecules and aerosoles to calculate cumulative sky brightness. Maps that show the enhanced sky brightness have been prepared for the entire world[5].


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 away from the center. Global effects of light pollution are also made obvious. The entire area comprising of southern England, Netherlands, Belgium, west Germany, and northern France have a sky brightness of at least 2 to 4 times above normal (see right). The only place on continental Europe where the sky can attain its natural darkness is in northern Scandinavia.


In North America the situation is comparable. From the east coast to west Texas up to the Canadian border there is very significant global light pollution.


Consequences of light pollution

Light pollution indicates wasted energy, obscures the night sky, harms human health, disrupts ecosystems and can reduce security. In ecology, an ecosystem is a community of organisms (plant, animal and other living organisms - also referred as biocenose) together with their environment (or biotope), functioning as a unit. ...


Energy waste

Lighting consumes one fourth of all energy consumed worldwide, and case studies have shown that several forms of over-illumination constitute energy wastage including un-useful upward direction of night-time lighting, as upward-directed light does not usually provide useful or intended illumination. Lighting refers to either artificial light sources such as lamps or to natural illumination of interiors from daylight. ... This cosmetics store has lighting levels over twice recommended levels and sufficient to trigger headaches and other health effects Over-illumination is the presence of lighting intensity (illuminance) beyond that required for a specified activity. ...


Effects on human health and psychology

Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks[7] use human health as an explicit criterion for proper interior lighting. 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[8][9][10][11]. Health can be defined negatively, as the absence of illness, functionally as the ability to cope with everyday activities, or positively, as fitness and well-being (Blaxter 1990). ... A headache (cephalalgia in medical terminology) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... The word fatigue is used in everyday living to describe a range of afflictions, varying from a general state of lethargy to a specific work induced burning sensation within muscle. ... In medical terms, stress is the disruption of homeostasis through physical or psychological stimuli. ... Human sexuality is the expression of sexual feelings. ...


Common levels of fluorescent lighting in offices are sufficient to elevate blood pressure by about eight points. There is some evidence that lengthy daily exposure to moderately high lighting leads to diminished sexual performance. Specifically within the USA, there is evidence that levels of light in most office environments lead to increased stress as well as increased worker errors.[12][13] However, such high interior lighting levels are not typical outside.


Several published studies also suggest a link between exposure to light at night and risk of breast cancer, due to suppression of the normal nocturnal production of melatonin. [14][15] Breast cancer is cancer of breast tissue. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ...


Disruption of ecosystems

Life existed with natural patterns of light and dark, so disruption of those patterns influences many aspects of animal behavior.[16] Light pollution can confuse animal navigation, alter competitive interactions, change predator-prey relations, and influence animal physiology.


Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia, from eating surface algae, helping cause algal blooms that can kill off the lakes' plants and lower water quality. [17] Light pollution may also affect ecosystems in other ways. For example, Lepidopterists and entomologists have documented that night-time light may interfere with the ability of moths and other nocturnal insects to navigate.[18] Night blooming flowers that depend on moths for pollination may be affected by night lighting, as there is no replacement pollinator that would not be affected by the artificial light. This can lead to species decline of plants that are unable to reproduce, and change an area's longterm ecology. Species Subgenus Daphnia Subgenus Hyalodaphnia D. galeata Subgenus Ctenodaphnia Daphnia are small, mostly planktonic, crustaceans, between 0. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Algal blooms can present problems for ecosystems and human society An algal bloom is a relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic system. ... A lepidopterist is a person who catches and collects, or simply studies, lepidopterans, members of an order comprising butterflies, skippers, and moths. ... Entomology is the scientific study of insects. ... A Phalaenopsis flower Rudbeckia fulgida A flower, (<Old French flo(u)r<Latin florem<flos), also known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... A pollinator is the agent that moves pollen from the male anthers of a flower to the female stigma of a flower to accomplish fertilization or syngamy of the female gamete in the ovule of the flower by the male gamete from the pollen grain. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta—liverworts Anthocerotophyta—hornworts Bryophyta—mosses Vascular plants (tracheophytes) †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls Lycopodiophyta—clubmosses †Trimerophytophyta—trimerophytes Pteridophyta—ferns and horsetails Seed plants (spermatophytes) †Pteridospermatophyta—seed ferns Pinophyta—conifers Cycadophyta—cycads Ginkgophyta—ginkgo Gnetophyta—gnetae Magnoliophyta—flowering plants... This article or section does not cite any references or sources. ...


Migrating birds can be disoriented by lights on tall structures. Estimates by the U.S. Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from 4-5 million per year to an order of magnitude higher.[19] The Fatal Light Awareness Program (FLAP) works with building owners in Toronto, Canada and other cities to reduce mortality of birds by turning out lights during migration periods. Motto: Diversity Our Strength Map of Ontario Counties, Toronto being red Area: 641 sq. ...


Other well-known casualties of light pollution are sea turtle hatchlings emerging from nests on beaches. It is a common misconception that hatchling sea turtles are attracted to the moon. They are not; rather, they find the ocean by moving away from the dark silhouette of dunes and their vegetation, a behavior with which artificial lights interfere.[20] Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea. Genera Family Cheloniidae (Oppel, 1811) Caretta Chelonia Eretmochelys Lepidochelys Natator Family Dermochelyidae Dermochelys Family Protostegidae (extinct) Family Toxochelyidae (extinct) Family Thalassemyidae (extinct) Sea turtles (Chelonioidea) are turtles found in all the worlds oceans except the Arctic Ocean, and some species travel between oceans. ...


Nocturnal frogs and salamanders are also affected by light pollution. Since they are nocturnal, they wake up when there is no light. Light pollution may cause salamanders to emerge from concealment later, giving them less time to mate and reproduce.


A book that collects together research on the subject was recently released.[21]


Loss of safety

It is generally agreed that many people require light to feel safe at night, but campaigners for the reduction of light pollution often claim that badly or inappropriately installed lighting can lead to a reduction in safety if measured objectively, and that at the very least, it is wrong to assume that simply increasing light at night will lead to improved safety.


The International Dark-Sky Association claims there are no good scientific studies that convincingly show a relationship between lighting and crime. Furthermore, the association claims that badly installed artificial lights can create a deeper contrast of shadows in which criminals might hide [22]. The New England Light Pollution Advisory Group claims that some light emitted by some fixtures can be a significant hazard to motorists, pedestrians, and bicyclists due to their scattering of light and glare [6].


The specific effects of outdoor lighting on safety are still a topic of debate, and formal research in the area is not well established.


Reducing light pollution

Reducing light pollution implies many things, such as reducing sky glow, reducing glare, reducing light trespass, and reducing clutter. The method for best reducing light pollution, therefore, depends on exactly what the problem is in any given instance. Possible solutions include:

  • Utilizing light sources of minimum intensity necessary to accomplish the light's purpose.
  • Turning lights off using a timer or occupancy sensor or manually when not needed.
  • Improving lighting fixtures, so that they direct their light more accurately towards where it is needed, and with less side effects.
  • Adjusting the type of lights used, so that the light waves emitted are those that are less likely to cause severe light pollution problems.
  • Evaluating existing lighting plans, and re-designing some or all of the plans depending on whether existing light is actually needed.

Improving lighting fixtures

A flat-lens cobra luminaire, which is a full-cutoff fixture, may be effective in reducing light pollution. It ensures that light is only directed below the horizontal, which means less light is wasted through directing it outwards and upwards.
A flat-lens cobra luminaire, which is a full-cutoff fixture, may be effective in reducing light pollution. It ensures that light is only directed below the horizontal, which means less light is wasted through directing it outwards and upwards.
This drop-lens cobra luminaire allows light to escape sideways and upwards, where it may cause problems.
This drop-lens cobra luminaire allows light to escape sideways and upwards, where it may cause problems.

The use of full cutoff lighting fixtures, as much as possible, is advocated by most campaigners for the reduction of light pollution. It is also commonly recommended that lights be spaced appropriately for maximum efficiency, and that lamps within the fixtures not be overpowered. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ...


A full cutoff fixture, when correctly installed, reduces the chance for light to escape above the plane of the horizontal. Light released above the horizontal may sometimes be lighting an intended target, but often serves no purpose. When it enters into the atmosphere, light contributes to sky glow. Some governments and organizations are now considering, or have already implemented, full cutoff fixtures in street lamps and stadium lighting.


The use of full cutoff fixtures may help to reduce sky glow by preventing light from escaping unnecessarily. Full cutoff typically reduces the visibility of the lamp and reflector within a luminarie, so the effects of glare may also be reduced. 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. However full cutoff fixtures may also trap more light in the fixture than other types of luminaires, corresponding to lower luminaire efficiency.


The use of full cutoff fixtures may allow for lower wattage lamps to be used in the fixtures, producing the same or sometimes a better effect, due to being more carefully controlled. In every lighting system, some sky glow also results from light reflected from the ground. 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.[23]


A common criticism of full cutoff lighting fixtures is that they are sometimes not as aesthetically pleasing to look at. 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. Due to the specificity with their direction of light, full cutoff fixtures sometimes also require expertise to install for maximum effect.


Another criticism of full cutoff lighting, particularly in the USA, is that luminaires with full cutoff distributions typically have to be closer together than other light distributions used to meet the same roadway lighting requirements specified by the Illuminating Engineering Society of North America, in terms of light level, uniformity and glare [24] [25] [26] [27]. The issue is very complex: the spread of light from any lamp depends largely on the design of the optics inside, and full-cut-off types are not *necessarily* closer together than the old stock that they replace - on the M5 motorway in SW England, for example, new FCOs were installed further apart than the old, deep-bowl types they replaced, on columns of similar height. Due to the complexity of roadway lighting design, sometimes existing lighting was not optimized at its design, so there is significant room for improvement. However, according to published research (see previous ref.s), when lighting designs are optimized, using full-cut-off luminaires does typically correspond to increased initial costs, maintenance costs, operating costs, energy use, energy pollution, and possibly light pollution, compared to using other distributions to meet the same roadway lighting requirements.[citation needed]


Adjusting types of light sources

Several different types of light sources exist, each having different properties that determine their appropriateness for certain tasks, particularly efficiency and spectral power distribution. It is often the case that inappropriate light sources have been selected for a task, either due to ignorance or because more sophisticated light sources were unavailable at the time of installation. Therefore, badly chosen light sources often contribute to light pollution unnecessarily. By re-assessing and changing the light sources used, it is often possible to reduce pollutive effects.


Some types of light sources, in order of energy efficiency, are:

Type of light source Colour Efficiency
(lumens per watt)
Low pressure sodium yellow 80 - 200
High pressure sodium pink/amber-white 90 - 130
Metal Halide bluish-white/white 60 -120
Mercury Vapour blue-greenish white 13 - 48
Incandescent yellow/white 8 - 25

Many astronomers prefer their neighboring societies to use low pressure sodium lights as much as possible, because the single wavelength involved is comparably easy to filter. The low cost of operating sodium lights is another feature. 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. Similar programs are now in place in Arizona and Hawaii. The lumen (symbol: lm) is the SI unit of luminous flux. ... The watt (symbol: W) is the SI derived unit of power, equal to one joule per second. ... A LPS / SOX streetlight at full power A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... A LPS / SOX streetlight at full power A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... Metal halide lamps, a member of the high-intensity discharge (HID) family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source. ... A Mercury-vapor lamp is a gas discharge lamp which uses mercury in an excited state to produce light. ... An incandescent lamp bulb and its glowing filament. ... Year 1980 (MCMLXXX) was a leap year starting on Tuesday (link displays the 1980 Gregorian calendar). ... Nickname: Location of San Jose within Santa Clara County, California. ... A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... The Lick Observatory is an astronomical observatory, owned and operated by the University of California. ... Official language(s) English Capital Phoenix Largest city Phoenix Area  Ranked 6th  - Total 113,998 sq mi (295,254 km²)  - Width 310 miles (500 km)  - Length 400 miles (645 km)  - % water 0. ... Capital Honolulu Largest city Honolulu Area  Ranked 43rd  - Total 10,931 sq mi (29,311 km²)  - Width n/a miles (n/a km)  - Length 1,522 miles (2,450 km)  - % water 41. ...


Disadvantages of low pressure sodium lighting are that fixtures must usually be larger than competing fixtures, color cannot be distinguished — due to its emitting only a single wavelength of light (see security lighting) — and conflicts with yellow traffic lights are observed. Due to the substantial size of the light emitting part of the lamp, the arc tube, control of light emissions from low pressure sodium luminaires is very difficult resulting in higher amounts of light pollution from luminaires running these lamps than any other light source except fluorescent tubes. This has led many authorities to instead adopt more controllable high pressure sodium lighting for their street lights. In the field of physical security, security lighting is often used as a preventative and corrective measure against intrusions or other criminal activity on a physical piece of property. ... Traffic lights can have several additional lights for filter turns or bus lanes. ...


Because of the scatter of light by the atmosphere, particularly Rayleigh scattering, different sources produce dramatically different amounts of skyglow from the same amount of light sent into the atmosphere. This is a basic result of the fact that the sky is blue, and so reflects violet and blue light (shortest wave radiation) much more than any others (longer wave radiation.) A simple metric for this phenomenon is the Rayleigh Scatter Index, discussed in a brief article and a 2003 presentation to both the IDA Conference and the IESNA, which indicates that high pressure sodium produces roughly one-third to one-half of the skyglow that typical metal halide does, based on the same amount of light entering the atmosphere. Rayleigh scattering causing the blue hue of the sky and the reddening at sunset Rayleigh scattering (named after Lord Rayleigh) is the scattering of light, or other electromagnetic radiation, by particles much smaller than the wavelength of the light. ...


Re-designing lighting plans

In some cases, evaluation of existing plans has determined that more efficient lighting plans are possible. For instance, light pollution can be reduced by turning off unneeded outdoor lights, and only lighting stadiums when there are people inside. Timers are especially valuable for this purpose.


One example of a lighting plan assessment can be seen in a report originally commissioned by the Office of the Deputy Prime Minister in the United Kingdom, and now available through the Department for Communities and Local Government.[28] The report details a plan to be implemented throughout the UK, for designing lighting schemes in the countryside, with a particular focus on preserving the environment. The Department for Communities and Local Government is a United Kingdom government department. ...


In another example, the city of Calgary has recently replaced most residential street lights with models that are comparably energy efficient [7]. The motivation is primarily operation cost and environmental conservation. The costs of installation are expected to be regained through energy savings within six to seven years. Nickname: Motto: Onward Location of Calgary within census division number 6, Alberta, Canada. ...


The Swiss agency for energy efficiency (SAFE) uses a concept which promises to be of great use in the diagnosis and design of road lighting, i.e. "consommation électrique spécifique (CES)", which can be translated into English as "specific electric power consumption (SEC)".[8] Thus, based on observed lighting levels in a wide range of Swiss towns, SAFE has defined target values for electric power consumption per metre for roads of various categories. Thus, SAFE currently recommends an SEC of 2 to 3 watts per meter for roads of less than 10 metre width (4 to 6 watts per metre for wider roads). Such a measure provides an easily applicable environmental protection constraint on conventional "norms", which usually are based on the recommendations of lighting manufacturing interests, who may not take into account environmental criteria. In view of ongoing progress in lighting technology, target SEC values will need to be periodically revised downwards.


Organizations

As well as a variety of local groups, several large organizations have evolved, with the primary goal of informing and campaigning about light pollution.

  • The International Dark-Sky Association (IDA) campaigns for reduced light pollution, mostly in the USA but with a world-wide reach.
  • The Campaign for Dark Skies (CfDS) is part of the British Astronomical Association, and campaigns for reduced light pollution in the United Kingdom.
  • IDA-UAI-CieloBuio, Italian joint organization by local IDA representative, Unione Astrofili Italiani, CieloBuio volunteer people.
  • The Association Nationale pour la Protection du Ciel Nocturne[9] (ANPCN) campaigns for the reduction of light pollution in France.

The International Dark-Sky Association (acronym: IDA) is a US-based non-profit organisation incorporated in 1988 by a group of astronomers in order to encourage darker skies (through lighting that creates less skyglow) in the USA, and, eventually, throughout the world by the setting up of other national organisations... The Campaign for Dark Skies (CfDS) is the United Kingdoms main anti-light-pollution campaign group. ... The British Astronomical Association, BAA, is the main national association of amateur astronomers in the UK. It was founded in London in 1890. ... CieloBuio-Coordinamento per la protezione del cielo notturno (in English coordination for the protection of the night sky) is an Italian non-profit organization whose goal is the safeguarding of the night sky by promoting the culture of an eco-compatible lighting and conducting information campaigns on the phenomenon called...

See also

The use of street lighting was first recorded in London in 1417 when Sir Henry Barton, the mayor, ordered lanterns with lights to be hanged out on the winter evenings between Hallowtide and Candlemasse. ... Lighting refers to either artificial light sources such as lamps or to natural illumination of interiors from daylight. ... This cosmetics store has lighting levels over twice recommended levels and sufficient to trigger headaches and other health effects Over-illumination is the presence of lighting intensity (illuminance) beyond that required for a specified activity. ... There are numerous health hazards that can affect people in their natural environment. ... National Dark-Sky Week is a week during which people all over the United States turn out their lights in order to observe the beauty of the night sky without light pollution. ... A Dark Sky Preserve is a region where light pollution control is enforced. ...

References

  1. ^ No billboards in space, FAA says, MSNBC.com, May 19, 2005
  2. ^ Federal Aviation Administration (19 May 2005). "Miscellaneous Changes to Commercial Space Transportation Regulations; Proposed Rule". National Archives and Records Administration, Federal Register. 70 (96): 29163-29168. (pdf)
  3. ^ Lumina Technologies, Santa Rosa, Ca., Survey of 156 California commercial buildings energy use, August, 1996
  4. ^ "Light Pollution: Responses and Remedies" By Bob Mizon. ISBN 1-85233-497-5 (Springer, 2001)
  5. ^ Bortle, John E.. "Observer's Log — Introducing the Bortle Dark-Sky Scale", Sky & Telescope, February 2001. 
  6. ^ P. Cinzano and F. Falchi and C.~D. Elvidge (2001). "The first world atlas of the artificial night sky brightness". MON.NOT.ROY.ASTRON.SOC. 328: 689-707. 
  7. ^ Gary Steffy, Architectural Lighting Design, John Wiley and Sons (2001) ISBN 0-471-38638-3
  8. ^ Susan L. Burks, Managing your Migraine, Humana Press, New Jersey (1994) ISBN 0-89603-277-9
  9. ^ Cambridge Handbook of Psychology, Health and Medicine, edited by Andrew Baum, Robert West, John Weinman, Stanton Newman, Chris McManus, Cambridge University Press (1997) ISBN 0-521-43686-9
  10. ^ L. Pijnenburg, M. Camps and G. Jongmans-Liedekerken, Looking closer at assimilation lighting, Venlo, GGD, Noord-Limburg (1991)
  11. ^ Igor Knez, Effects of colour of light on nonvisual psychological processes, Journal of Environmental Psychology, Volume 21, Issue 2, June 2001, Pages 201-208
  12. ^ Craig DiLouie, Advanced Lighting Controls: Energy Savings, Productivity, Technology and Applications The Fairmont Press, Inc., (2006) ISBN 0-88173-510-8
  13. ^ Bain, A., “The Hindenburg Disaster: A Compelling Theory of Probable Cause and Effect,” Procs. NatL Hydr. Assn. 8th Ann. Hydrogen Meeting, Alexandria, Va., March 11-13, pp 125-128 (1997)
  14. ^ Scott Davis, Dana K. Mirick, Richard G. Stevens (2001). "Night Shift Work, Light at Night, and Risk of Breast Cancer". Journal of the National Cancer Institute 93 (20): 1557-1562. 
  15. ^ Eva S. Schernhammer, Francine Laden, Frank E. Speizer, Walter C. Willett, David J. Hunter, Ichiro Kawachi, Graham A. Colditz (2001). "Rotating Night Shifts and Risk of Breast Cancer in Women Participating in the Nurses' Health Study". Journal of the National Cancer Institute 93 (20): 1563-1568. 
  16. ^ T. Longcore and C. Rich (2004). "Ecological light pollution". Frontiers in Ecology and the Environment 2(4): 191-198.  (pdf)
  17. ^ Marianne V. Moore, Stephanie M. Pierce, Hannah M. Walsh, Siri K. Kvalvik and Julie D. Lim (2000). "Urban light pollution alters the diel vertical migration of Daphnia". Verh. Internat. Verein. Limnol. 27: 1-4. 
  18. ^ Kenneth D. Frank (1988). "Impact of outdoor lighting on moths". Journal of the Lepidopterists' Society 42: 63-93.  (Reproduced on-line in part, by the International Dark-Sky Association.)
  19. ^ D. Malakoff (2001). "Faulty towers". Audubon 103(5): 78-83. 
  20. ^ M. Salmon (2003). "Artificial night lighting and sea turtles". Biologist 50: 163-168.  (pdf)
  21. ^ Catherine Rich and Travis Longcore (2006). Ecological consequences of artificial night lighting. Island Press. ISBN 1-55963-128-7.  (Available in December 2005.)
  22. ^ IDA's Position on Lighting and Crime. International Dark-Sky Association Website. Retrieved on 28 October 2006.
  23. ^ [NYSERDA-Planners] "NYSERDA How-to Guide to Effective Energy-Efficient Street Lighting for Planners and Engineers." (October 2002). New York State Energy Research and Development Authority. (Also available online.)
  24. ^ D. Keith, “Roadway Lighting Design for the Optimization of UPD, STV and Uplight”, Journal of the IES, v29n2
  25. ^ D. Keith, “Unit Power Density Evaluation of Roadway Lighting Systems”, Journal of the IES, v31n2
  26. ^ D. Keith, “Evaluating Lighting System Components Through Comparison of Roadway UPD Values”, Journal of the IES, v32n1
  27. ^ D. Keith, “Correlations of Roadway UUD Values to UPD, Uplight and Classification”, Journal of the IES, v32n1
  28. ^ Towards good practice. Lighting in the countryside. Retrieved on 28 October 2006. Department for Communities and Local Government, United Kingdom.

External links

Wikimedia Commons has media related to:
category:Light pollution

Campaign groups

Research about light pollution

Collections of links related to light pollution

  • Open Directory Project: Light Pollution

  Results from FactBites:
 
Light Pollution Information by Starry Night Lights (1222 words)
In a nutshell, Light Pollution is misdirected or misused light...
Light pollution is a problem that affects much of the world’s population.
In a nutshell, light pollution is misdirected or misused light generally resulting from an inappropriate application of outdoor lighting.
light pollution: Definition and Much More from Answers.com (4601 words)
The case against light pollution is strengthened by a range of studies on health effects, suggesting that excess light may induce loss in visual acuity, hypertension, headaches and increased incidence of carcinoma.
Light trespass is particularly annoying for amateur astronomers, whose ability to observe the night sky from their property is likely to be inhibited by any stray light from nearby.
Lighting consumes one fourth of all energy consumed worldwide, and case studies have shown that commonly 50 to 90 percent of building lighting is unnecessary for the purposes required.
  More results at FactBites »

 
 

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