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When talking about pollution there is often one category that is forgotten. That is light pollution. You may be thinking “How can light be polluted?” Well, it’s not the light that is polluted, but the light that is doing the polluting. Light pollution as defined by the Merriam-Webster dictionary is “Light from cities, vehicles, etc., that makes it difficult to see things in the sky (such as stars) at night.”[i] Did you ever go out at night, and see a glow blocking your view of that beautiful night sky? That is light pollution, and if you live in or near a big city you’re probably more familiar with this than if you’re a country boy or girl. Despite the seeming simplicity of the concept of light pollution it is actually a very serious issue. Light pollution can greatly affect the health of humans and animals. It is a very costly and wasteful form of pollution in terms of money and energy. Finally, light pollution is entirely a man-made problem.
Light pollution is very damaging to the health of both humans and animal life. One of the biggest problems associated with light pollution is a disruption of your circadian rhythm. Your circadian rhythm is “Inherent cycle of approximately 24 hours in length that appears to control or initiate various biological processes, including sleep, wakefulness, and digestive and hormonal activity. The natural signal for the circadian pattern is the change from darkness to light. The controlling mechanism for these cyclic processes within the body is thought to be the hypothalamus. Any change in the circadian cycle (such as jet-lag and other conditions associated with travel) requires a certain period for readjustment.”[ii] Basically, your circadian rhythm is what regulates your ability to get a good night’s sleep. Studies conducted at Thomas Jefferson University have shown that exposure to light can disrupt the body’s natural cycle of sleep, and has even been shown to accelerate the growth of tumors within the body.[iii] Studies have also shown that your eyes don’t have to be open to have your sleep affected by light. Even through your closed eyelids, light can penetrate to your brain, and disrupt your natural sleep cycle.[iv]
The effects of light pollution in animals are most visible in birds. According to National Geographic Magazine a bird’s migration schedule is a biologically timed event engineered to ensure the birds’ survival. It has been determined that long artificial days and short nights cause birds to enter their breeding cycles early. Longer days also provide birds with more time to feed. As bird’s gain more fat it is possible for their migration instincts to kick in early. This can have disastrous effects on population, if they arrive at their destination and conditions for nesting and breeding are not right.[v] Another danger, lies in the fact that many species of birds fly at night. Birds are both attracted to and disoriented by light. Because of this fact, some bird populations are being decimated by colliding with buildings in cities that they fly over.[vi] Another interesting aspect of light pollution is that insects are known to gather at any source of light. Anyone who’s lived in the city has seen a swarm of insects gathered around a street light. Many species of bats are now known to feed almost exclusively from around those streetlights.[vii] In addition, many nocturnal animals that live in and around cities are becoming easy targets for predators due to the amount of light. All of this being the case, light pollution is much more serious than its name implies.
Light pollution is a very costly and wasteful form of pollution. The International Dark Sky Association estimates that “one-third of all lighting in the U.S. is wasted, at an annual cost of about 30 million barrels of oil and 8.2 million tons of coal-a total of about U.S. $2 billion.”[viii] According to a report entitled “The Economics of Light Pollution” it is estimated that 2.5% of the entire United States electrical output is expanded on nighttime lighting, which equal to 17.4 billion kilowatt hours of electricity. There are whole countries, such as Ireland and Israel that do not expand that much electricity.[ix] All together lighting accounts for over 12% of all electricity usage in the United States.[x] That being the case, is it any surprise that there is an overabundance of light? You cannot change one thing, and not expect consequences. By flooding the world in light, we are changing the world, and lighting the world is not cheap.
Light pollution, even more so than other forms of pollution, is entirely manmade. Before the invention of the light bulb by Thomas Edison towns were forced to use either natural light, or gas light in order to illuminate their streets. With the invention of the electric light bulb it became possible to illuminate our streets 24/7. This increased the amount of “daylight” during which people could work, and was hailed as a brilliant invention. No one can argue that it was indeed brilliant. However, as man often does we started running without thinking of the consequences. Electricity was used to light cities and towns worldwide, and thus was light pollution born. Now, the night sky is obscured for most of the world by a glow of light. Nocturnal animals are going extinct as they are unable to adapt to artificial life, and their increased risk of predators, and one of the most essential biological functions is being disrupted: our ability to sleep. Light pollution has no easy solution because we have all become used to the convenience of light at all hours of the day and night. We must learn to recognize that too much of anything is a bad thing, and though light drives away the dark, even the dark serves a purpose.
About the Author
Dominick Principe is a graduate of Rowan University with dual Bachelor Degrees in Elementary Education and Writing Arts. He is a prolific reader who devours any book put before him, and feels that life is one great long book without an end. He fills his hours constantly exploring new information, and seeking to educate himself in the ways of the world. He puts all of that knowledge and his passion for learning to good use teaching English as a second language to students of all ages. When his nose isn’t buried in a book, or in class teaching, then he can generally be found typing away at his computer working on some random piece of writing that he was inspired to do.
[iii] Chepesiuk, Ron. “Distracted by the Light.” National Center for Biotechnology Information. U.S. National Library of Medicine, 29 June 2005. Web. 6 Nov. 2014. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627884/>.
[iv] “Preliminary Evidence That Light through the Eyelids Can Suppress Melatonin and Phase Shift Dim Light Melatonin Onset.” BMC Research Notes. BioMed Central. Web. 10 Nov. 2014. <http://www.biomedcentral.com/1756-0500/5/221>.
[v] “Light Pollution – National Geographic Magazine.” Light Pollution – National Geographic Magazine. National Geographic Magazine. Web. 6 Nov. 2014. <http://ngm.nationalgeographic.com/2008/11/light-pollution/klinkenborg-text/2>.
[vi] Chepesiuk, Ron. “Distracted by the Light.” National Center for Biotechnology Information. U.S. National Library of Medicine, 29 June 2005. Web. 6 Nov. 2014. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627884/>.
[vii] “Light Pollution – National Geographic Magazine.” Light Pollution – National Geographic Magazine. National Geographic Magazine. Web. 6 Nov. 2014.
[viii] “Light Pollution Hurts Our Economy and Our Resources.” Light Pollution Wastes Money and Energy. Web. 6 Nov. 2014. <http://physics.fau.edu/observatory/lightpol-econ.html>.
[x] “How Much Electricity Is Used for Lighting in the United States?” Frequently Asked Questions. U.S. Energy Information Administration. Web. 10 Nov. 2014. <http://www.eia.gov/tools/faqs/faq.cfm?id=99&t=3>.