Light Pollution

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For most of Earth’s history, our spectacular universe of stars and galaxies has been visible in the darkness of the night sky. However, the increasing number of people living on Earth, in addition to the corresponding increase in inappropriate and unshielded outdoor lighting has resulted in the light pollution we are experiencing today.

Light pollution is defined as the excessive and inappropriate artificial light. It includes four components often combined and sometimes overlap.

Glare
A proportion of street light and security lights glare from unshielded lighting is considered a public health hazard especially to the old. Glare light scattering in the eye causes loss of contrast; it sometimes blinds you temporarily leading to unsafe driving conditions, for instance.

Light trespass
When unwanted light enters one’s property; for example, by turning on the lights in a bedroom of a person trying to sleep. This often creates a nuisance, detracts from amenity, and wastes energy and money.

Sky glow
Sky glow is all the reflected light and upward-directed unshielded light combined together and escaping up into the sky. This light is completely wasted, scattering in the atmosphere and detracts from the beauty of the starry sky at night.

Clutter
It refers to the bright, confusing, and excessive groupings of light sources, commonly found in over-lit urban areas. The proliferation of clutter contributes to urban sky glow, trespass, and glare.

 

Effects of Light Pollution
In disrupting ecosystems, light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse the migratory patterns of animals; alter competitive interactions of animals, change predator–prey relations, and cause physiological harm.

Myriads of insects die each year on street lamps, or in the webs of the unnaturally large numbers of spiders that now live on street lamps. This reduces the number of insects available to be eaten and disturbs the food chain. Birds, for their part, become confused in the light cloud and collide with brightly lit high-rise buildings. Some bats avoid the light and flee to darker realms, while many moths are no longer reproducing sufficiently in brightly lit areas.

With respect to adverse health effects, doctors are studying the adverse effects of constant light on the human body. The wavelengths of many LED lamps in the blue range directly affect our hormonal balance by suppressing the production of the sleep hormone; melatonin. This deprives the body of one of its natural defenses against tumors. This also can lead to sleep disorders and other health problems, such as increased headaches, worker fatigue, medically defined stress, some forms of obesity due to lack of sleep and increased anxiety.

With respect to energy wastage, lighting is responsible for at least one-fourth of all electricity consumption worldwide. Over illumination can constitute energy wastage, especially upward directed lighting at night. Energy wastage is also a waste in cost and carbon footprint.

 

Solution
Street lights can be replaced with full-cutoff fixtures and fitted with energy efficient light bulbs. Sign-lighting should preferably be aimed down on signs not upwards. Outdoor security, and display lighting should be fitted with quality shielded flood lights and fitted with efficient lamps directing light at the target area only. Residential flood lights can be shielded to minimize light trespass. Also, avoid over lighting where possible.

Light pollution affects every citizen. It is a serious environmental concern that wastes money and resources while jeopardizing wildlife, environment, health, and human heritage. Every individual can implement practical solutions to combat light pollution locally, nationally, and internationally.
 

References
www.globeatnight.org
www.lrc.rpi.edu
www.darkskiesawareness.org
www.assa.org.au
www.starrynightlights.com
www.universetoday.com
m.spiegel.de
 

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