Among numerous forms of environmental pollution, light pollution is probably the least recognized type. Although light pollution does not seem to be as detrimental to health as air or water pollution, it is an environmental quality problem with several negative implications for humans, animals and birds. Simple control measures can resolve the problem, thereby saving energy and cost.
Light Pollution: Causes, Impacts and Control Measures
Excessive, poorly directed or obtrusive artificial light causes hostile effects on living beings. Simple steps can resolve the problem offering environmental and financial benefits
What Causes Light Pollution and How Can We Control It?
What is Light Pollution?
Also known as luminous pollution or photo pollution, light pollution refers to excessive or misdirected artificial light that alters the natural night sky. It is caused by misdirected and poorly designed light sources. Light pollution occurs in a number of forms:
- Glare from un-shielded lighting
- Light trespass: unwanted light enters one’s territory just like light entering in one’s bedroom at night time
- The reduced visibility at night is often a consequence of an atmospheric phenomenon known as sky glow. The light emanating from poorly designed or inappropriately directed lamps such as flood lights gets reflected and scattered from liquid and solid particles suspended in the air; as this light returns to the eyes of the people on ground, it obliterates their view of the sky.
Impacts of Light Pollution
Glare from security flood lights, road lamps and misdirected yard lights can cause discomfort for many people. Excessive light can affect our body cycles causing sleeping disorders, severe headaches, stress, anxiety and obesity; some think it may lead to cancer as well.
Light pollution reduces the visibility of stars and other heavenly objects, thus causing difficulties for amateur and professional astronomers. Since nocturnal lighting consumes electricity, which is often generated by burning of fossil fuels, light pollution contributes to air pollution in an indirect way.
Light pollution can also have adverse impacts on animals and birds. For instance, many migratory birds use the light of moon and stars for navigation at night. Nonetheless, as they fly past urban and suburban areas, they might be disoriented by excessive glare from artificial light. As a consequence, migrating birds often collide with tall sky scrapers and die.
Light pollution is also accused of disrupting ecosystems especially affecting nocturnal wildlife; for instance undue night light is said to pose profound impact on sleep/awake cycles of insects; nevertheless, scientists are pursuing to collect some conclusive evidence in this regard.
Controlling Light Pollution
Light pollution can be reduced by using properly designed, energy-efficient light fixtures aimed at directing the light downward. By using this approach, lights with lower wattage can be used resulting in significant energy and monetary savings. Alternatively, the number and brightness of lights can be reduced, thereby reducing unwanted glare and increasing visibility effectively.
Use of low pressure sodium (LPS) light sources for street lighting, parking lot lights and security lamps is also useful in minimizing the adverse effects on astronomical activities. Not only they reduce sky glow, they are one of the most energy-efficient light sources.
By enforcing appropriate laws and regulations, communities, parks, and even entire countries can cater the problem of light pollution effectively.
- 2011, Curley, Robert, New Thinking about Pollution, Britannica Educational Publishing.
- 2004, Pollution, A to Z, Thomson Gale.
- Globe at Night, What is Light Pollution, retrieved on 29th June, 2015.