Light Pollution: Effect On Humans and Energy Efficient Solutions

Light Pollution: Effect On Humans and Energy Efficient Solutions

What is Light Pollution?

Unless you live out in the country or isolated on a hut in the mountains, you are most likely thankful for the lights that illuminate your freeways and make your neighborhood feel safe. Outdoor lights have no doubt become a necessity in our cities but it has only been in recent years that studies have revealed that too many lights – and the wrong type of lights – can be extremely harmful to the environment in more ways than one. That is because light pollution occurs when humans artificially illuminate the sky. Unshielded lights that point at the horizon or the sky contribute to this problem by increasing the amount of artificial light. This type of pollution continues to spread and intensify in countries throughout the world, and many people remain unaware of its negative impact. In addition, light pollution harms the environment and affects human health in many ways. There are several sources and solutions when it comes to identifying and alleviating light pollution.

There are a few main elements that contribute to light pollution: a) sky glow is a brightening of the sky that comes from man-made and natural factors, such as outside lighting; b) then, there is light trespass. This is when light spills out and illuminates places that it is not needed or desired. Illumination from a streetlight or even a house light can be a cause; c) the third cause is glare. This is brightness that causes discomfort or even disability, such as when headlights from oncoming traffic cause glare and impede your visibility or when a streetlight is so bright it causes discomfort.

Sky glow itself is caused in natural form by sunlight that is reflected off the moon and the Earth. This gives a glow in the upper atmosphere. There is also the sunlight that is reflected off of interplanetary dust. Third is starlight that’s scattered about in the atmosphere, and background illumination that comes from faint stars and nebulae. When you combine this with the human made sources like street lamps and neon signs. Not only does this hinder the ability to see the stars and the night sky clearly, it also harms animals and plants.

Effect on plants and animals:

Artificial lighting has a significant impact on plants and animals. Some plants only bloom at night. Excessively bright skies can prevent this from happening, according to Florida Atlantic University. They also make it more difficult for nocturnal creatures to pollinate these plants. Light pollution disrupts the normal development of deciduous trees. It can cause them to keep their leaves during the winter. If wet snow or ice accumulates on trees with leaves, the extra weight will break their branches. Unnatural lighting interferes with bird migration and insect reproduction as well.

Plants are more biologically active at night, and when the natural ratio of light is affected by manmade light sources, their ability to photosynthesize and properly flourish can be hindered. Think of animals as well. Many animals use the safe protection of darkness to forage, but when their environment is suddenly illuminated by a new light source this can throw all of their routines and rhythms off balance. Studies show that about twenty percent of primates and about eighty percent of marsupials are nocturnal, which obviously is affected by excess light pollution. Bats, rodents, and owls – they are all at risk. Their foraging patterns are compromised, their risk of becoming a predator increases, their biological clocks can be affected, road mortality increases since many animals need a few seconds for their eyes to adjust from darkness to light, and if they are suddenly on a lit road, they may not see a car approaching. Artificially lit areas are not as friendly to animals as they are to us.

There have been studies on mice that prove their biological clocks are affected by light, and in Hawaii the bright lights of a football stadium were so disorienting to certain birds that they mistook the lights for the moon and flew around in circles until they dropped from exhaustion. So you can see, we need to implement solutions for our own safety and for the plants and animals that are harmed.

Effect on humans:

Indoor and outdoor light sources affect basic cycles within the human body. People lived without artificial lighting for thousands of years. Like animals, humans have not been able to fully adapt to this change. For example, the pineal gland creates melatonin during the night. It may not produce this hormone if there is too much light, according to Audubon Magazine. There is a great deal of evidence that insufficient melatonin levels cause cancer. Higher rates of breast cancer have been reported in women who periodically work at night.

Researchers have determined that both indoor and outdoor light pollution affect melatonin levels. Laboratory experiments have recently produced evidence that nighttime light exposure causes cancerous tumors to grow more rapidly. An Israeli study found that regions with high outdoor light pollution have more women with breast cancer, according to Environmental Health Perspectives. Researchers have tentatively linked nighttime light exposure to prostate and colorectal cancer as well. However, there is currently too little evidence to verify this claim.

Reduced levels of melatonin have a significant impact on sleep patterns and body temperature. The full effect of this remains unknown. The National Institute of Environmental Health Sciences issued a report on light pollution in 2006. It suggested that nighttime light exposure may contribute to diabetes and obesity. There is also a possibility that it promotes cardiovascular disease. One study found that indoor night lights cause nearsightedness in children, according to Audubon Magazine. Additional studies remain necessary to confirm these findings.

Light pollution also has a major impact on the human mind. Nighttime light exposure creates inflammation in the brain's hippocampus, according to The Huffington Post. This frequently causes depression. Both depression and excessive lighting can prevent people from obtaining sufficient sleep. WebMD warns that inadequate sleep causes auto accidents, heart disease, diabetes and high blood pressure. It promotes obesity by creating a false sense of hunger. A person's skin will age rapidly if he or she doesn't sleep enough.

What is the solution?

The National Park Service recommends that people use shielded fixtures to prevent light pollution. This type of lamp has an opaque shield that surrounds the sides and top of the lighting element. It's helpful to turn off unnecessary lights and install low-wattage bulbs. Timers and motion detector lights limit extraneous lighting as well. It is much easier to control indoor light pollution. People benefit from using dark curtains or Venetian blinds in their bedrooms. The most effective option is to sleep in a room with no windows. Electronics also illuminate portions of many bedrooms. It's best to avoid falling asleep while watching television. If the TV set has a sleep timer, use this feature to automatically turn it off after a few hours. Some alarm clocks have dimmer switches that reduce the brightness of their screens. If everyone makes an effort to prevent light pollution, it will improve human health, protect the environment and conserve a great deal of energy. Other solutions involve replacing halogen bulbs with LED lights outdoors. If the lights also point down rather that up at the sky this makes a major difference. LED lights are also less expensive to tax payers. If we also reduce the lighting in our cities only to what is needed when it is needed, this will go a long way to reducing light pollution. A lot of research and technology have been in motion to try and lessen the damage of light pollution. Studies show that excess light can actually worsen smog in urban areas. Each night NO2 (nitrate radical) is broken down and NO3 neutralizes a portion o the nitrogen oxides which help lessen smog, With excess light pollution this natural process does not work as well, leading to excess smog.

Of course we want to be safe, and we are living in a non-stop, twenty-four hour society in many of our cities. Restaurants and shops need to have lights on at night to attract customers and help the economy, but we all need to do our part and be mindful of the type of lights we use and how long we use them. Many state and local ordinances have been put into place and lamp technology has greatly advanced in recent years. Typical requirements are full cutoff luminaries, wattage limitations, minimum light levels, source limits, controls over when lights are on, curfews, and the eradication of certain forms of lighting altogether. These rules also make sure lights are installed correctly to limit spill light and uplight, or light radiation towards the sky.

Advancements have been made, but we all need to do our part to lessen and reduce light pollution so we can be safe, have vibrant nightlife, and also limit and reduce the harm we inflict upon our environment. Stay mindful of the night lighting at your own home, check for ways to reduce light pollution, and we can have the best of both worlds.



References:

http://physics.fau.edu/observatory/lightpol-environ.html

http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/abstract.asp

http://ngm.nationalgeographic.com/2008/11/light-pollution/klinkenborg-text

http://www.darksky.org/

http://www.njaa.org/light.html

http://www.astro.caltech.edu/palomar/lp.html

http://www.astrosociety.org/education/publications/tnl/44/lightpoll.html

http://science.nasa.gov/science-news/science-at-nasa/2001/ast01nov_1/

http://nelpag.harvee.org/

http://www.utahskies.org/light-pollution/



Additional Resources

To gain a deeper understanding of light pollution, browse the International Dark-Sky Association's website. The New Jersey Astronomical Association offers facts about the effects of light pollution on astronomers. Florida Atlantic University supplies information about the economic impact of this phenomenon. To learn more about the causes and effects of light pollution, visit National Geographic.