Ecological light pollution
Encyclopedia
Ecological light pollution is the term used to describe the effects of artificial light on individual organisms and on the structure of ecosystems as a whole.
The effect that artificial light has upon organisms is highly variable, and ranges from beneficial (e.g. increased ability for predator species
to observe prey) to immediately fatal (e.g. moths
that are attracted to incandescent lanterns and are killed by the heat
). It is also possible for light at night to be both beneficial and damaging for a species. As an example, humans benefit from using indoor artificial light to extend the time
available for work
and play
, but the light disrupts the human circadian rhythm
, and the resulting stress
is damaging to health
.
Through the various effects that light pollution
has on individual species, the ecology
of regions is affected. In the case where two species occupy an identical niche
, the population frequency
of each species may be changed by the introduction of artificial light if they are not equally affected by light at night. For example, some species of spiders avoid lit areas, while other species are happy to build their spider web directly on a lamp post. Since lamp posts attract many flying insects, the spiders that don't mind light gain an advantage over the spiders that avoid it, and consequently become more common. Changes in these species frequencies can then have knock-on effects, as the interactions between these species and others in the ecosystem are affected and food webs are altered. These ripple effects can eventually affect even diurnal plants and animals. As an example, changes in the activity of night active insects can change the survival rates of night blooming plants, which may provide food
or shelter
for diurnal animals.
The introduction of artificial light at night is one of the most drastic anthropogenic
changes to the Earth, comparable to toxic pollution, land use change
, and climate change
due to increases in the concentration
of green house gases.
, Moon
, and Sun
, as well as from meteorological factors.
can extend out to hundreds of kilometers away from city centers.
of the Earth
results in seasons outside of the tropics
. The change in the length of the day is the key signal for seasonal behavior (e.g. mating season) in non-tropical animals. The presence of light at night can result in "seasons out of time" http://informahealthcare.com/doi/abs/10.1081/CBI-200038144, changing the behavior
and thermoregulation
of affected organisms. This effect can be deadly for small mammals in the winter, since when their body acts as if it's summer they don't maintain an adequate winter body temperature to survive winter nights.
s, toads, insects) is keyed to the lunar cycle. Near city centers the level of skyglow often exceeds that of the full moon
, so the presence of light at night can alter these behaviors, potentially reducing fitness.
and suburban areas, in contrast, clouds enhance the effect of skyglow. This means that the typical level of light is much higher near cities, but it also means that truly dark nights never occur in these areas.
The compound eye of moths results in fatal attraction to light.
Similar disorientation has also been noted for bird species migrating close to offshore production and drilling facilities. 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 early 2007, the lights were installed on the Shell production platform L15. The experiment proved a great success since the number of birds circling the platform declined by 50 to 90%.[56] Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea.
Ceilometer
s (searchlights) can be particularly deadly traps for birds http://www.staplenews.com/home/2010/9/16/10000-birds-trapped-in-the-world-trade-center-light-beams.html, as they become caught in the beam and risk exhaustion and collisions with other birds. In the worst recorded ceilometer kill-off, on October 7–8, 1954, 50,000 birds from 53 different species were killed at Warner Robins Air Force Base.
s contain a non-imaging
photosensor that is the primary regulator of the human circadian rhythm. This photosensor is particularly affected by blue
light, and when it observes light the pineal gland
stops the secretion of melatonin
. The presence of light at night in human dwellings (or for shift workers) makes going to sleep more difficult and reduces the overall level of melatonin in the bloodstream, and exposure to a low-level incandescent bulb for 39 minutes is sufficient to suppress melatonin levels to 50%. Because melatonin is a powerful anti-oxidant, it is hypothesized that this reduction can result in an increased risk of breast
and prostate cancer
.
Other human health effects may include increased headache
incidence, worker fatigue
, medically defined stress
, decrease in sexual
function and increase in anxiety. Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety.
mothers, and their hatchlings are fatally attracted to street
and hotel
lights rather than to the ocean
.
(e.g. Daphnia
) exhibit diel vertical migration
. That is, they actively change their vertical position inside of lakes throughout the day. In lakes with fish
, the primary driver for their migration is light level, because small fish visually prey on them. The introduction of light through skyglow
reduces the height to which they can ascend during the night. Because zooplankton feed on the phytoplankton
that form algae
, the decrease in their predation upon phytoplankton may increase the chance of algal bloom
s, which can kill off the lakes' plants and lower water quality
.
dependent. While human beings cannot see ultraviolet light, it is often used by entomologists to attract insects. Generally speaking, blue light is more likely to be damaging to mammal
s because the non-imaging photoreceptors in mammalian eyes are most sensitive in the blue region. This means that if traditional vapor discharge streetlamps are replaced by white
LED
s (which generally emit
more of their radiation
in the blue part of the spectrum
), the ecological impact could be greater even if the total amount of radiated light is decreased.
window
s or asphalt
reflect highly polarized light. Many insects are attracted to polarized surfaces, because polarization is usually an indicator for water. This effect is called polarized light pollution
, and although it is certainly a form of ecological photopollution, "ecological light pollution" usually refers to the impact of artificial light on organisms.
The effect that artificial light has upon organisms is highly variable, and ranges from beneficial (e.g. increased ability for predator species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
to observe prey) to immediately fatal (e.g. moths
Moths
Moths may refer to:* Gustav Moths , German rower* The Moths!, an English indie rock band* MOTHS, members of the Memorable Order of Tin Hats...
that are attracted to incandescent lanterns and are killed by the heat
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
). It is also possible for light at night to be both beneficial and damaging for a species. As an example, humans benefit from using indoor artificial light to extend the time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
available for work
Work
Work may refer to:Human labor:* Employment* House work* Labor , measure of the work done by human beings* Manual labor, physical work done by people* Wage labor, in which a worker sells their labor and an employer buys it...
and play
Play
Play may refer to:* Play , enjoyment by animals including humans* Play , structured literary form of theatre-Bands:* Play , Mexican band* Play , Swedish band-Albums:...
, but the light disrupts the human circadian rhythm
Circadian rhythm
A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...
, and the resulting stress
Stress (biology)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
is damaging to health
Health
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
.
Light pollution
Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light.The International Dark-Sky Association defines light pollution as:...
has on individual species, the ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
of regions is affected. In the case where two species occupy an identical niche
Ecological niche
In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...
, the population frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
of each species may be changed by the introduction of artificial light if they are not equally affected by light at night. For example, some species of spiders avoid lit areas, while other species are happy to build their spider web directly on a lamp post. Since lamp posts attract many flying insects, the spiders that don't mind light gain an advantage over the spiders that avoid it, and consequently become more common. Changes in these species frequencies can then have knock-on effects, as the interactions between these species and others in the ecosystem are affected and food webs are altered. These ripple effects can eventually affect even diurnal plants and animals. As an example, changes in the activity of night active insects can change the survival rates of night blooming plants, which may provide food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
or shelter
Shelter
Shelter is a basic architectural structure or building that provides cover. The word may also refer to:-Places:*Port Shelter, Hong Kong*Shelter Bay , various locations*Shelter Cove , various locations...
for diurnal animals.
The introduction of artificial light at night is one of the most drastic anthropogenic
Anthropogenic
Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity and other resources. The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian...
changes to the Earth, comparable to toxic pollution, land use change
Land Use, Land-Use Change and Forestry
Land use, land-use change and forestry is defined by the United Nations Climate Change Secretariat as "A greenhouse gas inventory sector that covers emissions and removals of greenhouse gases resulting from direct human-induced land use, land-use change and forestry activities."LULUCF has impacts...
, and climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
due to increases in the concentration
Concentration
In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Four types can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration...
of green house gases.
Natural light cycles
The introduction of artificial light disrupts several natural light cycles that arise from the movements of the EarthEarth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, and Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, as well as from meteorological factors.
Diurnal (solar) cycle
The most obvious change in introducing light at night is the end of darkness in general. The day/night cycle is probably the most powerful environmental behavioral signal, as almost all animals can be categorized as nocturnal or diurnal. If a nocturnal animal is only active in extreme dark, it will be unable to live in lit areas. The most acute affects are directly next to streetlights and lit buildings, but the diffuse light of skyglowSkyglow
Skyglow is the illumination of the night sky or parts of it. The most common cause of skyglow is artificial light that emits light pollution, which accumulates into a vast glow that can be seen from miles away and from high in the sky...
can extend out to hundreds of kilometers away from city centers.
Seasonal (solar) cycles
The axial tiltAxial tilt
In astronomy, axial tilt is the angle between an object's rotational axis, and a line perpendicular to its orbital plane...
of the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
results in seasons outside of the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
. The change in the length of the day is the key signal for seasonal behavior (e.g. mating season) in non-tropical animals. The presence of light at night can result in "seasons out of time" http://informahealthcare.com/doi/abs/10.1081/CBI-200038144, changing the behavior
Behavior
Behavior or behaviour refers to the actions and mannerisms made by organisms, systems, or artificial entities in conjunction with its environment, which includes the other systems or organisms around as well as the physical environment...
and thermoregulation
Thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...
of affected organisms. This effect can be deadly for small mammals in the winter, since when their body acts as if it's summer they don't maintain an adequate winter body temperature to survive winter nights.
Lunar cycles
The behavior of some animals (e.g. coyotes, batBat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s, toads, insects) is keyed to the lunar cycle. Near city centers the level of skyglow often exceeds that of the full moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, so the presence of light at night can alter these behaviors, potentially reducing fitness.
Cloud coverage
In pristine areas, clouds blot out the stars and darken the night sky, resulting in the darkest possible nights. In urbanUrban
Urban means "related to cities." It may refer to:*Urban, California, former town in El Dorado County*Urban area, geographical area distinct from rural areas*Urban , given name and surname*Urban , Danish free daily newspaper...
and suburban areas, in contrast, clouds enhance the effect of skyglow. This means that the typical level of light is much higher near cities, but it also means that truly dark nights never occur in these areas.
Insects
The attraction of insects to artificial light is one of the most well known examples of the effect of light at night on organisms. When insects are attracted to lamps they can be killed by exhaustion or contact with the lamp itself, and they are also vulnerable to predators like bats.The compound eye of moths results in fatal attraction to light.
Birds
Lights on tall structures can disorient migrating birds. Estimates by the U.S. Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from 4 to 5 million per year to an order of magnitude higher. 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.Similar disorientation has also been noted for bird species migrating close to offshore production and drilling facilities. 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 early 2007, the lights were installed on the Shell production platform L15. The experiment proved a great success since the number of birds circling the platform declined by 50 to 90%.[56] Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea.
Ceilometer
Ceilometer
A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere.-Optical Drum Ceilometer:...
s (searchlights) can be particularly deadly traps for birds http://www.staplenews.com/home/2010/9/16/10000-birds-trapped-in-the-world-trade-center-light-beams.html, as they become caught in the beam and risk exhaustion and collisions with other birds. In the worst recorded ceilometer kill-off, on October 7–8, 1954, 50,000 birds from 53 different species were killed at Warner Robins Air Force Base.
Humans
At the turn of the century it was discovered that human eyeHuman eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
s contain a non-imaging
Imaging
Imaging is the representation or reproduction of an object's outward form; especially a visual representation .- Imaging methodologies and technologies :...
photosensor that is the primary regulator of the human circadian rhythm. This photosensor is particularly affected by blue
Blue
Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...
light, and when it observes light the pineal gland
Pineal gland
The pineal gland is a small endocrine gland in the vertebrate brain. It produces the serotonin derivative melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions...
stops the secretion of melatonin
Melatonin
Melatonin , also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes...
. The presence of light at night in human dwellings (or for shift workers) makes going to sleep more difficult and reduces the overall level of melatonin in the bloodstream, and exposure to a low-level incandescent bulb for 39 minutes is sufficient to suppress melatonin levels to 50%. Because melatonin is a powerful anti-oxidant, it is hypothesized that this reduction can result in an increased risk of breast
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
and prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
.
Other human health effects may include increased headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
incidence, worker fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...
, medically defined stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
, decrease in sexual
Human sexuality
Human sexuality is the awareness of gender differences, and the capacity to have erotic experiences and responses. Human sexuality can also be described as the way someone is sexually attracted to another person whether it is to opposite sexes , to the same sex , to either sexes , or not being...
function and increase in anxiety. Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety.
Turtles
Lights from seashore developments repel nesting Sea turtleSea turtle
Sea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...
mothers, and their hatchlings are fatally attracted to street
Street
A street is a paved public thoroughfare in a built environment. It is a public parcel of land adjoining buildings in an urban context, on which people may freely assemble, interact, and move about. A street can be as simple as a level patch of dirt, but is more often paved with a hard, durable...
and hotel
Hotel
A hotel is an establishment that provides paid lodging on a short-term basis. The provision of basic accommodation, in times past, consisting only of a room with a bed, a cupboard, a small table and a washstand has largely been replaced by rooms with modern facilities, including en-suite bathrooms...
lights rather than to the ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
.
Zooplankton
ZooplanktonZooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
(e.g. Daphnia
Daphnia
Daphnia are small, planktonic crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style...
) exhibit diel vertical migration
Diel vertical migration
Diel vertical migration, also known as diurnal vertical migration, is a pattern of movement that some organisms living in the ocean and in lakes undertake each day. Usually organisms move up to the epipelagic zone at night and return to the mesopelagic zone of the oceans or to the hypolimnion zone...
. That is, they actively change their vertical position inside of lakes throughout the day. In lakes with fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, the primary driver for their migration is light level, because small fish visually prey on them. The introduction of light through skyglow
Skyglow
Skyglow is the illumination of the night sky or parts of it. The most common cause of skyglow is artificial light that emits light pollution, which accumulates into a vast glow that can be seen from miles away and from high in the sky...
reduces the height to which they can ascend during the night. Because zooplankton feed on the phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
that form algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, the decrease in their predation upon phytoplankton may increase the chance of algal bloom
Algal bloom
An algal bloom is a rapid increase or accumulation in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration...
s, which can kill off the lakes' plants and lower water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...
.
Effects of different wavelengths
The effect that artificial light has upon organisms is wavelengthWavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
dependent. While human beings cannot see ultraviolet light, it is often used by entomologists to attract insects. Generally speaking, blue light is more likely to be damaging to mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s because the non-imaging photoreceptors in mammalian eyes are most sensitive in the blue region. This means that if traditional vapor discharge streetlamps are replaced by white
White
White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
s (which generally emit
Emit
Emit may refer to: melisa*Emit, North Carolina, an unincorporated community*Em:t Records, a British record label that specializes in ambient music...
more of their radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
in the blue part of the spectrum
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
), the ecological impact could be greater even if the total amount of radiated light is decreased.
Polarized light pollution
Artificial planar surfaces, such as glassGlass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
window
Window
A window is a transparent or translucent opening in a wall or door that allows the passage of light and, if not closed or sealed, air and sound. Windows are usually glazed or covered in some other transparent or translucent material like float glass. Windows are held in place by frames, which...
s or asphalt
Asphalt
Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...
reflect highly polarized light. Many insects are attracted to polarized surfaces, because polarization is usually an indicator for water. This effect is called polarized light pollution
Polarized light pollution
Polarization is a property of light waves that describes the orientation of their oscillations. Polarized light pollution is a subset of the various forms of light pollution referring specifically to polarized light....
, and although it is certainly a form of ecological photopollution, "ecological light pollution" usually refers to the impact of artificial light on organisms.
External links
- List of peer reviewed ecological light pollution research papers
- Fatal Light Awareness Program (FLAP) (Toronto)
- "Ecological Consequences of Artificial Night Lighting" (2002 conference, by the Urban Wildlands Group)
- International Dark-Sky Association