Light pollution

One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies, as follows:[36] According to Mario Motta, president of the Massachusetts Medical Society, "... glare from bad lighting is a public-health hazard—especially the older you become.

[40][41][42] Public discourse surrounding the continuing deployment of satellite constellations includes multiple petitions by astronomers and citizen scientists,[43][44] and has raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight.

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.

[52] The amount of airglow and zodiacal light is quite varied (depending, amongst other things on sunspot activity and the Solar cycle) but given optimal conditions, the darkest possible sky has a brightness of about 22 magnitude/square arc second.

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.

[55] 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.

Research in the late 1990s showed that the entire area consisting of southern England, Netherlands, Belgium, West Germany, and northern France have a sky brightness of at least two to four times normal.

[61][4] Over the past 21 years, China's provincial capital cities have seen a major increase in light pollution, with hotspots along the eastern coastline region.

[76] In 2007, "shift work that involves circadian disruption" was listed as a probable carcinogen by the World Health Organization's International Agency for Research on Cancer.

[85] A more recent discussion (2009), written by Professor Steven Lockley, Harvard Medical School, can be found in the CfDS handbook "Blinded by the Light?".

[101][102][103] Fireflies are well known and interesting to the general public (unlike many other insects)[104] and are easily spotted by non-experts, and, due to their sensibility and rapid response to environmental changes, good bioindicators for artificial night lighting.

Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from four to five million per year to an order of magnitude higher.

Studies carried out by Nederlandse Aardolie Maatschappij b.v. (NAM) and Shell have led to the development and trial of new lighting technologies in the North Sea.

With the exception of the finches, all the English songbirds may be said to be insectivorous, and their diet consists chiefly of vast numbers of very small insects which they collect from the grass and herbs before the dew is dry.

[130] The following picture of the area around the Pinwheel Galaxy (Messier 101) with the apparent magnitude of 7.5m with all stars down to an apparent magnitude of 10m was taken in Berlin in a direction close to the zenith with a fast lens (f-number 1.2) and an exposure time of five seconds at an exposure index of ISO 12800:Some astronomers use narrow-band "nebula filters", which allow only specific wavelengths of light commonly seen in nebulae, or broad-band "light pollution filters", which are designed to reduce (but not eliminate) the effects of light pollution by filtering out spectral lines commonly emitted by sodium- and mercury-vapor lamps, thus enhancing contrast and improving the view of dim objects such as galaxies and nebulae.

Light pollution affects the visibility of diffuse sky objects like nebulae and galaxies more than stars, due to their low surface brightness.

A study presented at the American Geophysical Union meeting in San Francisco found that light pollution destroys nitrate radicals thus preventing the normal night time reduction of atmospheric smog produced by fumes emitted from cars and factories.

"[53] With a focus on shift work and the continued need for 24-hour operations of specific sectors of the economy, researchers are looking at the impact of light pollution on this group of workers.

[7] In 2009, following the United Nations declaration of The Year of Astronomy, researchers urged a better understanding of artificial light and the role it plays in social, economic, and environmental issues.

Coined by Aprana Venkatesan of the University of San Francisco and John Barentine, an astronomer, the term first appeared in August 2023 as a response to an article on the effects of light pollution published in the journal Science.

[145] Venkatesan and Barentine presented an all-encompassing definition that includes the loss of cultural identity and practices, such as storytelling and stargazing, as well as ancient knowledge such as celestial navigation.

[157][158] Many astronomers request that nearby communities use low-pressure sodium lights or amber Aluminium gallium indium phosphide LED as much as possible because the principal wavelength emitted is comparably easy to work around or in rare cases filter out.

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.

The Swiss Agency for Energy Efficiency (SAFE) uses a concept that promises to be of great use in the diagnosis and design of road lighting, "consommation électrique spécifique (CES)", which can be translated into English as "specific electric power consumption (SEC)".

[171] 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.

The Unified System of Photometry allows light fixtures to be designed to reduce energy use while maintaining or improving perceptions of visibility, safety, and security.

[179] An assessment from 2020 shows an increase in citizen awareness in the late 20th century due to availability to internet search engines as well as the ability to engage globally.

[181] This section provides an overview of significant reports that have been published regarding the conservation of natural darkness and the impacts of light pollution on the environment, wildlife, and human health.

Highlighting the disruption to nocturnal wildlife, human sleep patterns, and the erasure of cultural star-linked traditions, such as those of the Maori to the Pleiades, the document calls for targeted strategies to mitigate these impacts.

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