What harm does frequent exposure do to the body? Thank you, everyone.

Light pollution is generally divided into three categories in the world, namely white light pollution, artificial sunlight pollution and colored light pollution. White pollution When the sun is strong, the glass curtain wall, glazed tile wall, polished marble and various paints of buildings in the city reflect light, which is bright and dazzling. Experts have found that people who work and live in an environment polluted by white light for a long time will suffer different degrees of damage to their retina and iris, and their vision will drop sharply. The incidence of cataract is as high as 45%. It can also make people dizzy and upset, and even cause insomnia, loss of appetite, depression, physical weakness and other similar symptoms of neurasthenia. In summer, the strong reflected light from the glass curtain wall enters the nearby residential buildings, which raises the indoor temperature and affects normal life. Some glass curtain walls are semi-circular, and the convergence of reflected light is easy to cause fire. Drivers driving in the hot sun will suddenly be attacked by the reflected light from the glass curtain wall, and their eyes will be strongly stimulated, which is prone to car accidents. After the arrival of artificial day and night, the advertising lights and neon lights in shopping malls and hotels are dazzling. Some intense light beams even go straight into the sky, making night like day, which is called artificial day. In such a "city that never sleeps", it is difficult to fall asleep at night, which disturbs the normal biological clock of the human body and leads to low work efficiency during the day. Artificial sunlight can also harm birds and insects, and strong light may destroy the normal reproduction process of insects at night. Color light pollution The black lights, rotating lights, fluorescent lights and flashing color light sources installed in dance halls and nightclubs constitute color light pollution. According to the measurement, the intensity of ultraviolet rays produced by black light is much brighter than that in sunlight, and the harmful effects on human body last for a long time. If people receive this radiation for a long time, they will cause nosebleeds, tooth loss, cataracts, even leukemia and other cancers. The dazzling color light source is not only bad for the eyes, but also interferes with the central nervous system of the brain, making people dizzy, causing nausea, vomiting, insomnia and other symptoms. The latest research by scientists shows that colored light pollution not only damages people's physiological functions, but also affects people's mental health. When it comes to environmental pollution, people often think of black river water (water pollution), roaring machines on the construction site (noise pollution), black smoke from chimneys (air pollution), and garbage all over the mountains (solid waste pollution) ... But experts point out that there is another kind of pollution in people's production and living environment-"light pollution". Moreover, this long-neglected pollution source may become another environmental "killer" that directly affects human health in 2 1 century 1996. The first environmental complaint about refracted light pollution of glass curtain walls in urban buildings appeared in Shanghai, and then the number of complaints about light pollution of glass curtain walls increased everywhere. But it is also the reason why people pay too much attention to it. The scope of the word "light pollution" is locked in the glass curtain wall, while other kinds of light pollution around us are ignored. Light pollution refers to the damage of various light sources to the surrounding environment and people. So what conditions or substances will produce light pollution? For example, neon lights familiar in people's daily life, high beam lights of cars, welding arc lights during welding, aluminum alloy plates in some buildings and other building materials are not light sources that produce light pollution, but sometimes harmful light reflections are produced. Internationally, light pollution is divided into three categories: artificial sunlight pollution, colored light pollution and white light pollution. I. Types of light pollution 1. Artificial daylight After nightfall, advertising lights, neon lights and waterfall lights in shopping malls and hotels are dazzling, and people feel like daytime at night. This is the so-called artificial daylight. Due to the strong light reflection, the nearby room will be as bright as day. In such a "city that never sleeps", it is difficult to fall asleep at night, which disrupts the normal "biological clock" of the human body. Artificial sunlight will also harm birds and insects, because strong light will destroy the normal reproduction of insects at night and destroy the ecological balance. Animal protectors, astronomers and many city residents oppose this kind of artificial sunlight because it wastes electricity and causes a kind of light pollution. Animal protectors say that dazzling light is the chief culprit in killing birds and insects. Because strong light will, for example, find the remains of more than 500 birds under the Washington Monument decorated with China lanterns in an hour and a half. Another example is the giant billboard on Musical Instrument Street in the British Palace. At night, the lights are brightly lit, and a beam of laser-like light is emitted in the dark, and planes are often seen nearby. Whether strong light will affect the pilot's line of sight is quite worrying. Neighboring residents, such as residents of Jianwei Garden and Gem House, also complained that the bright lights of billboards reflected their gratitude, making their homes look like daytime, and it was difficult for them to fall asleep after tossing and turning, which led to depression and affected their normal daily life. An important sign of a modern and complex city is that after nightfall, billboards and neon lights in hotels and shopping malls in the noisy city that never sleeps are dazzling, and incandescent lamps shine as bright as day. This dazzling light pollutes people's vision and affects people's physical and mental health. When people step into the busy city streets, they often reflect dazzling white light. Many large shopping malls are decorated with white mirrors or aluminum alloys. What's more, some shopping malls use large mirror glass from beginning to end, which is almost in a mirror world, making people confused. According to the measurement, the reflection coefficient of white paint surface is 69 ~ 80%; The reflection coefficient of mirror glass is 82 ~ 88%, which is about 10 times larger than that of green grass, forest, dark or rough masonry, which greatly exceeds the physiological adaptation range of human beings and becomes a pollution source, endangering human health. White light pollution in some developed countries has begun to formulate corresponding laws to limit and stop it, and has attracted people's attention. In the design and construction departments, it is forbidden to decorate the facades of high-rise buildings and shopping malls with reflective materials, and it is also forbidden to decorate the interior with large mirrors. According to the investigation of Bavarian Environmental Problems and State Development Planning Bureau, among 238 respondents, 2/3 think that artificial sunlight affects health, and 84% report that it affects night sleep. To this end, people have to seal the bedroom windows or install dark curtains. This day and night living environment will do harm to people's psychology. Although people have found that strong light has become another pollution source besides noise, waste gas and waste water, and there are many complaints, it has not attracted the attention of relevant departments and people so far. 2. Color light pollution The black lights, rotating lights, fluorescent lights and flashing color light sources installed in modern dance halls and nightclubs constitute color light pollution. According to the measurement, black light can produce ultraviolet with the wavelength of 250~300 nm, which is much higher than that in sunlight. If people are exposed for a long time, it will induce nosebleeds, tooth loss, cataracts, and even leukemia and other cancers. Color light source is dazzling, which is not only bad for eyes, but also interferes with the central nervous system of the brain, making people feel dizzy, causing nausea and vomiting, decreased eyesight, inattention, low sexual desire and other symptoms. Experiments by researchers at Cambridge University in England have proved that colorful neon lights and dazzling strong light waves can lead to genetic degeneration of a large number of cells in organisms, increase abnormal cells, disturb the natural balance of the body, and cause "light damage syndrome" such as dizziness, irritability and insomnia. According to the investigation and measurement of laser equipment in dozens of dance halls by relevant health departments, the laser radiation pressure in most dance halls has exceeded the limit. This high-density thermal beam is concentrated on the retina after passing through the lens of the eye, and the focal temperature can be as high as 70 degrees Celsius, which is very harmful to the eyes and brain nerves. 3. White light pollution In the sunny season, glazed tile walls, polished marble, aluminum alloy curtain walls, glass curtain walls and various paints of many buildings in the city reflect light, which is bright and dazzling. This is white light pollution. According to the doctor of Futian Hospital, people who work and live in the environment polluted by white light for a long time will suffer different degrees of damage to their retina and iris, and their eyesight will drop sharply. The incidence of cataract is as high as 45%, which can also make people dizzy and upset, and even cause insomnia, loss of appetite, depression, physical weakness and other similar symptoms of nervous decline. In summer, the strong reflected light from the glass curtain wall enters the nearby residential buildings, which raises the indoor temperature and affects normal life. Some glass curtain walls are semi-circular, and the convergence of reflected light is easy to cause fire. Drivers driving in the hot sun will suddenly be attacked by the reflected light from the glass curtain wall, and their eyes will be strongly stimulated, which is prone to car accidents. The human body bears the brunt of light pollution. Instantaneous strong light irradiation can make people temporarily blind, and ordinary light pollution can also cause damage to the cornea and iris of human eyes, inhibit the function of retinal photoreceptor cells, and thus cause visual fatigue and vision decline.