Polarization is a property of light waves that describes the orientation of their oscillations. Polarized light pollutionGábor Horváth, György Kriska, Péter Malik, Bruce Robertson. (2009) Polarized light pollution: a new kind of ecological photopollution. Frontiers in Ecology and the Environment 7:6, 317-32
/ abs/10.1890/080129 Online Access
2009/08 is a subset of the various forms of

light pollution Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day ...

referring specifically to polarized light. In nature,

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

and

water vapor (99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous pha ...

polarize the

sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...

(which itself is slightly polarized). By receiving the direction of polarized photons, some species can correct their course during

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

. Artificial polarization of natural or artificial light can disrupt the behavior of these species and the ecosystems in which these species play an important role.

Pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...

is one example of this.

History of this notion

Jean-Baptiste Biot Jean-Baptiste Biot (; ; 21 April 1774 – 3 February 1862) was a French physicist, astronomer, and mathematician who co-discovered the Biot–Savart law of magnetostatics with Félix Savart, established the reality of meteorites, made an early ba ...

and his successors have shown that solutions of organic products, such as

fructose Fructose, or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galacto ...

sucrose Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined ...

, can polarize light. However, only in recent decades has it been realised that the polarized light may play an important role in

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

s, especially in the insect world. More recently, when the concept of

emerged, the question of the possible impacts of the artificial polarization of light has arisen. Gábor Horváth and his team have proposed that this new term needs to be better described and understood in order to better address the specific ecological consequences (direct or delayed in space and time) of light that was polarized (at source or by interacting with objects made or modified by humans).

Impact on insects

A representative example is the

ecological trap Ecological traps are scenarios in which rapid environmental change leads organisms to prefer to settle in poor-quality habitats. The concept stems from the idea that organisms that are actively selecting habitat must rely on environmental cues to h ...

caused by asphalt surfaces polarizing light in a similar way as ponds do. Research has shown swarms of mayflies are laying their eggs on roads rather than rivers or ponds. Many insects have aquatic larval stage, and they largely depend on visual cues such as the light reflection of ponds or rivers to find egg-laying places. They therefore often mistake asphalt surface for water and lay eggs directly on the road, leaving the eggs to dehydrate and die under the sun.

References

{{DEFAULTSORT:Polarized light pollution Light pollution Polarization (waves)