What is light pollution?


  • The Rise of the Idea of Light Pollution

    As the lighting industry in the world has focused on developing high efficiency lighting products, people can use the lighting as they want to. The night of the city brightly illuminated for 24 hours has been created.
    However, side effects of the light are revealed as we are familiar with brighter nights than days. Recently, there has been a lot of discussion about the side effect of the light called light pollution which is an accumulated problem for a long period of time.

    A phenomenon caused by misguided lighting environment, unwanted light and more lights than needed which bring serious damage to humans and ecosystem.
    Originally, light pollution in astronomy refers to an index of degree of night sky pollution by lights.
    Now, it includes all interference phenomena by misguided or heavy artificial lights which are against original purpose or sphere.

    The Lighting Museum opened The First Light Pollution Photo Contest in 2005 to let our society know the unfamiliar concept of light pollution, and try to inform people about this continually to improve the light environment. In 2009, a public hearing in the National Assembly was held for an establishment of the Light Pollution Control Act, and it became the topic of the year. The Seoul Metropolitan Government highlighted the Light Pollution Control Act in 2009, and the law was proclaimed for the first time in Korea in 2011 with the social recognition. The Environment Ministry established the Light Pollution Control Act in 2012, and the law took effect in 2013. Now, all provincial governments and the nation are trying to manage the light pollution by the law.
  • What Type of Light becomes the Light Pollution?

    Excessive light leak not for the original purpose can be interference light. It called the light pollution harms the ecosystem.

    Light Pollution Terms
    • Coefficient of Utilization : Measure of the effectiveness of an electronic luminary in delivering light to the working plane in a particular area
    • Leaked Light : Excessive light not for the original purpose or particular area.
    • Interference Light : A sort of leaked light containing wrong or over amount, direction and color harms human's activity and living things.

Main Types of Light Pollution

In general, the light pollution is divided into 5 sections including skyglow, glare, light trepass, clutter and over-illumination.

  • Skyglow

    Illumination of the night sky by artificial light which refracted and scattered with vapor, fog and pollutant
    Type : Direct-top light, reflected light, sidelight
    Damage : Astronomical observation disturbance, global warming by rising air temperatures, vegetation growth disturbance, sleep disorder, missing migratory birds

  • Glare

    Short optical disorder by very bright light attack
    Type : Car headlight, high-brightness signboards in the city, heavy outdoor light
    Damage : Blinding glare, disability, discomfort glare, traffic accident, road kill

  • Light Trepass

    Damage caused by unwanted light to unintended areas
    Type : Unplanned streetlight, leaked light of outdoor lighting
    Damage : Poor biorhythm, sleep disorder by heavy lighting

  • Clutter

    Excessive grouping lights in one place
    Type : High-brightness signboards, misguided streetlight, commercial light in big cities
    Damage : Dangerous conditions by optical disorder, traffic accident

  • Over-illumination

    High lighting intensity than needed or unnecessary lighting turned on
    Type : Over lighting condition than needed
    Damage : Loss of energy, exhaustion of the future energy

  • Crops and Light Pollution

    The growth of crops near the night lights is abnormal when they bloom and come into ears. These crops, rice plant, bean, perilla, sesame, red bean, foxtail millet, corn and pumpkin, are growing up normally with 12 hours sunshine and below, but some are overgrown, cannot bear fruit, and having late-blooming phenomena caused by heavy streetlight, car headlight and mega city's lights. Also, spinach, barley, wheat, crown daisy and mustard plant are having some poor harvest problems due to early-blooming phenomena with this light pollution. The luminance of the brightest moment of the full moon is measured 0.3 lx while streetlight is 30 to 50 lx and 250-watt sodium lamp is measured over 10 lx up to 45 meter long. The plants near the streetlight are having a strange rate of metabolism caused by very strong lights even in the night. We can see many cosmos flowers blooming in spring and summer seasons, but the flower should be bloom in the early autumn. Also, the leaves of maple and plane trees are falling late.

    Roadside Trees and Light Pollution

    Decorative tying lights for roadside trees in winter season are a cause of death for the trees with problems such as high temperature, heat and heavy light. Decorating trees with over heat and light can be a light torture which having no considerations for the vegetation growth especially in the winter season as a resting phase for the plant.

    Insects and Light Pollution

    Insects are sensitive to light. If firebugs disappear from strong light to the mountain, then moths will be gone because they will fly at the light instead of firebugs. Established night road lamps in reservoirs, forests, rivers and lakes can bring the extinction of specific species, or change of the neighbor ecosystem. Regarded as noise pollution, singing cicada in the deep summer night actually caused by light pollution which providing the disturbance of cicada's ecosystem.

    Lost Birds and Light Pollution

    There are many extinct migratory birds lost their destination without navigation information by stars and moon due to the light pollution, and also hundreds of dying birds hit the bright telecom tower at night. Nocturnal animal owls flying at night are having a survival problem caused by too bright lights.

    Amphibians, Reptiles and Light Pollution

    Excessive light is producing decrease in the number of amphibians and extinction of reptiles. The propagation power of frogs and newts is reducing due to light, and the number of those is reducing as well. Baby sea turtles in Florida barely hatched are dying because they can't approach to the sea with heavy lights.

    Fishes and Light Pollution

    There are a variety of fishes which gather around the light or avoid the light, so excessive light brings poor growth and egg-laying, or extreme egg-laying according to their characters. These homing-instinct fishes, salmon and herring, can easily be prey for flesh-eating fishes as they spin around the night lightings. Also, freshwater fish, sand lance and green hydra can easily be easy targets for the capturing fishes with its nature follow the light.

    Road Kill and Light Pollution

    In case of driving at night, it is necessary to have headlights for the safety of drivers, but, the overuse of high-power electric bulb and illegal high-intensity discharge lamps can bring many road kill accidents of nocturnal wild animals. If animals are exposed to the very bright light, they will stop and stand still or jump into the car instinctively because they are usually weaker than humans about the light and need more time to adapt to the light than people do. Therefore, many rare animals such as elk, wild boar, raccoon, stray cat and wild cat could be hurt or dead by the car lamps.

    Global Warming and Light Pollution

    As energy consumption for the lighting is increasing, released more carbon dioxide will increase the surface temperature of the earth which brings climate change, global warming and destruction of ecosystem.

    Sea Contamination and Light Pollution

    Too much light and many lights near the sea and lake raise red tide phenomena by decrease of zooplankton and excessive propagation of phytoplankton. It is a cause of food chain destruction of underwater creatures and water pollution. The self-purification capacity of water ecosystem is damaged by lights.

    Appearance of the Cities and Light Pollution

    We can easily see similar night street in almost every city of Korea. The exterior illumination of cities in Seoul have luminance of maximum 79 cd/㎡ far exceeded a recommendation of Commission Internationale de I'Eclairage 25 cd/㎡. It is caused by inharmonious colors of outdoor billboards, many different shapes, and disorder and confusion of flash.

    These outdoor billboards need to be have understanding of brightness, color and operating of lights, and consideration of character of cities, feature of streets, and shape of buildings. This light pollution also can be terrible visual pollution harms urban views.

    Astronomical Observation and Light Pollution

    Famous observatories in the world are now moving to deep mountains to escape from heavy lights in cities, because they are not able to observe the night stars by skyglow problems in the big city. 20 years ago, we could enjoy thousands of stars when we looked up at the night sky. Now, we only see just a few stars hazily in some areas, and even cannot see any stars in the mega city. If the light pollution is pervasive continually, 20 years later, any stars cannot be observed in the earth.

    Relation between Poor Human Biorhythm and Light

    All living creatures in the earth are programmed to distinguish the day and night, and operate physiological functions according to a circadian rhythm by the light. This is the laws of nature which has come down from thousands, and millions of years.

    The living creatures should follow the biological cycle and rhythm to be a healthy organism. However, brighter nights than days and too much light disturb the human biological rhythm and physiological functions to lose the healthy life without even knowing it.

    Low Melatonin Level and Light

    Melatonin is naturally produced by the pineal gland and inhibited by night light. In case of lack of melatonin which regulates sleep cycles and immune system, mobility rate of many diseases including adult disease is increasing. The lack of melatonin brings the crisis of breast cancer for women and prostate cancer for men.

    Basically, melatonin promotes sleep cycle, stability, antioxidative and anti-aging activities. The melatonin secretion will be decreased as the level of luminance increases, so the heavy light brings a reduction of melatonin. Melatonin is secreted ten times more at night than during the day, and 2 a.m. is the peak time to have it. Therefore, the light pollution can influence reduction of melatonin and people's health.

    Poor Eyesight and Light

    Lighting environment is very important for the eyesight because human eyes are influenced a lot by the light even it is closed. If pregnant woman has bad lighting environment, the eyesight of a fetus will be influenced. It is easy to have poor eyesight and poor healing power of visual cells. Korean children wear glasses the most among OECD countries. It is hard to recover damaged eyesight which was falling by age seven, so the growing children must escape the bad lighting environment.

    Also, there are many vision defects which cannot see dark things well according to an adaption of too bright light such as major supermarket's light, gas station and big signboards' light. Especially, laser beam and too bright light can make the blindness, so we should manage it carefully.

    Sleeping Disorder and Light

    Heavy street lights, residential lights and signboards make sleeping disorder and troubles for residents. In case of lack of sleep and heavy-light environment at night, many disadvantages can be appeared like concentration, memory, creation and discernment loss, high levels of aggression, headache, nerve disorder, depression and myocardial infarction. Moreover, leptin which reduces feeling of hunger will be decreased by the light, so the possibility for obesity goes up high. The lack of sleep makes people sensitive, have low metabolism, and their reaction rate will be halved to compare to normal people in same situations.

    Loss of Energy and Light Pollution

    Americans consume the lighting energy more than they actually need, and the unnecessary energy can provide 50 million-barrels oil per day. We can save about 260647 KWh as 16 million households in Korea turn off the light for just 5 minutes.

    A quarter of total necessary energy for the world is consumed by the lighting, and the world will need 80% enlarged electricity than we currently need in 2030 as we stay the same way of current lighting environment. Humans are wasting too much energy and creating the light pollution by consuming too much lighting than we actually need. Especially, Korea marks the lowest grade of self-supporting energy among OECD countries, but the electric consumption records more than twice the average of other OECD countries.

    Destroyed Cultural Assets and Light Pollution

    Cultural assets can be destroyed by night lights for cultural properties and historic sites when the character of assets and object for preservation are not taken into consideration. If the nice plan for the assets is unconcerned about shape, color, texture and material of true characters of assets, it will be damaged physically as well as its traditional value and natural beauty.

    Outdoor historic sites are threatened by the brilliant lights when we miss the true color of it.

    Disappearance of Healthy Light Environment brings Light Pollution

    Living creatures on the earth maintain our lives, and develop the civilization with the energy of light which provided a proper amount at a proper time for us. However, healthy light is disappearing now with the unnecessary, exaggerate and polluted light environment. The image of light life, creation and coexistence is dropped off as the image of pollution.

    Accidents, diseases and extinction of animals and plants are showing because of the light. Although its potential and utilization are huge, human civilization will lose healthiness and possibilities for development as we cannot deal with the current light pollution which brings a disappearance of healthy light and culture.

    Light Pollution UCC & Photo Contest promotes Valuable Light of Tomorrow

    The reason why the light pollution is so scary, it shows not only the physical environmental pollution but also the loss of philosophy of humanity about the light. If the healthy light misses a original purpose to humans and nature, it is just an illuminant not a light. The Lighting should have the philosophy itself, and just a light without it can be a pollution factor. Now, the light environment and the industry around us have to be healthy, and discussed in depth with many aspects and considerations of ethical, cultural and philosophical points.
    Lighting Museum hopes that many people have opportunities to meet and understand the light pollution with the Light Pollution UCC & Photo Contest. We also hope people work together to prevent light pollution, and make the better light of tomorrow.