Without light, there is no color, and everything in the world is dark. For human beings, light is as indispensable as air, water and food. The eye is the most important sensory organ of the human body. The human eye has a strong adaptability to light, and the pupil can be adjusted with the light and shade of the environment. But if you look at things in poor light for a long time, your eyesight will be damaged. On the contrary, strong light can make people's eyes blind instantly, and even cause permanent damage. People must work, study and live in a suitable light environment. On the other hand, human activities may damage the surrounding light environment and make the original direct light environment uncomfortable, which is light pollution. Light pollution is a special kind of pollution, including pollution caused by visible light, laser, infrared ray and ultraviolet ray. Glare is common in visible light pollution. For example, whenever you walk on the road at night, the oncoming headlights of motor vehicles dazzle pedestrians, which is a kind of light pollution called glare. This dazzling light source is not only common on the road, but also often seen in some industrial and mining enterprises. For example, in the process of melting, smelting and welding, extremely strong light is also harmful light pollution. The danger of visible light pollution is the strong light when a nuclear weapon explodes. It can hurt people's eyes in a considerable range. Without proper protective measures, people who have been engaged in welding, smelting and melting glass for a long time will suffer from eye injuries, blind spots in their eyes and cataracts in their old age, which is the result of strong light hurting the lens of their eyes. With the development and prosperity of modern cities, a new kind of urban light pollution is threatening people's health. This new urban light pollution is: shopping malls, companies, office buildings, restaurants, hotels and restaurants in cities and downtown areas; Hair salons and dance halls are decorated with large pieces of mirror glass, stainless steel plates and aluminum alloy doors and windows. Some even use mirror glass from top to bottom, which makes people feel as if they are in the world of mirrors, and the direction is difficult to distinguish, thus causing accidents. After sunset, as night falls, all kinds of billboards, neon lights and waterfall lights on the busy streets of the city light up again, exposing people to artificial sunlight. In modern dance halls, people often use "color light source", "flash light source" and "rotating light source" to pursue the stimulating effect, which is dazzling and puzzling. For these sources of light pollution, scientists at home and abroad believe that urban light pollution will seriously interfere with people's nervous system and affect people's normal visual activities. In the season of strong sunshine, the mirror glass, glazed tiles, stainless steel, aluminum alloy plates, polished granite, marble and high-grade painted lampposts of buildings are dazzling. According to scientific measurement, the light reflection coefficient of these decorative materials is above 69%, even as high as 90%, which is about 10 times larger than that of exterior wall decorative buildings with green spaces, forests, dark colors or rough masonry, and completely exceeds the limit that the human body can bear, resulting in dizziness, headache, mental tension, inattention, palpitation, insomnia and dreaminess, loss of appetite and fatigue. The influence of artificial self-hypnosis on people's physical and mental health can not be ignored. Strong light reflects indoors, destroying people's circadian rhythm, making it difficult for people to fall asleep, even leading to insomnia and neurasthenia, causing mental fatigue at work and prone to safety accidents. Laser pollution laser is a special kind of light emitted by laser, with single color, straight beam and high intensity. At present, there are thousands of laser colors, which have many advantages and are widely used. However, due to the concentrated energy and high brightness of laser, it is more harmful than other rays. If laser energy is continuously emitted, the maximum power can reach tens of thousands of kilowatts, and the instantaneous power can reach trillions of kilowatts. It can pierce a thick steel plate in a few seconds, not to mention people. So the laser fork is called dead light. There are two aspects of environmental pollution caused by laser: many substances (such as dust) vaporize when the laser beam passes through the air, causing air pollution; On the other hand, laser will not only harm the conjunctiva, iris and lens of the eyes, but also directly harm the deep tissues and nervous system of the human body. At present, laser is mainly used in laser industry (cutting, drilling, etc. ), surveying and mapping, medical care and scientific research. Infrared pollution infrared is widely used in military, satellite, industry, agriculture, health research and other fields. Infrared pollution can not be ignored. Infrared ray is a kind of invisible light, and its main function is to generate heat. Strong infrared rays can cause skin damage and burns similar to scalds. Infrared rays are also harmful to human eyes, which will damage the retina of the fundus, and may also cause corneal burns and iris damage. Ultraviolet light pollution ultraviolet light is also a kind of invisible light, which is widely used in production, national defense and medicine. For example, disinfection, sterilization, treatment of certain skin diseases and rickets. It is also used for satellite detection on the ground. But the harm of ultraviolet rays to human body is mainly to human eyes and skin. Long-term overexposure to ultraviolet rays will cause damage to the cornea of eyes from rabbits and cause "photodermatitis" on the skin. In severe cases, it will cause skin desquamation and necrosis, and even cause skin cancer. The harmful effect of ultraviolet rays on the skin is also a kind of light pollution.
What is light pollution?
Light pollution is a new environmental pollution source after waste gas, waste water, waste residue and noise pollution, which mainly includes white light pollution, artificial daytime pollution and colored light pollution. Light pollution is threatening people's health.
White light pollution In the busy streets of the city, many shops decorate their facades with large mirrors or aluminum alloys, and some even decorate their facades with mirrors from top to bottom. People are almost in a mirror world and can't tell the direction. In the season of strong sunshine, the decoration of tempered glass, glazed tile wall, aluminum alloy plate, polished granite, marble and high-grade paint is dazzling. According to the measurement, the reflection coefficient of white paint surface is 69 ~ 80%, while that of mirror glass is 82 ~ 90%, which is about 10 times larger than that of buildings decorated with green grass, forest, dark or rough masonry, which greatly exceeds the human body's tolerance and becomes one of the new pollution sources in modern cities. White light pollution will damage the cornea and iris of human eyes, resulting in decreased vision and increased incidence of cataract.
Man-made daytime pollution When night falls, billboards and neon lights in hotels and shopping malls are dazzling, and some strong beams even go straight into the sky, making the night like day. Artificial sunlight also has adverse effects on people's physical and mental health. Due to the strong light reflection, the nearby rooms can shine like daytime, making it difficult for people to fall asleep at night, disrupting the normal biological rhythm and leading to listlessness. According to a survey abroad, two-thirds of people think that artificial daytime affects their health, and 84% of them report that it will affect their sleep at night. In order to avoid glare, people have to close bedroom windows or install dark curtains. Artificial sunlight can also harm insects and birds, because strong light will destroy the normal reproduction process of nocturnal insects. At the same time, insects and birds will be burned to death by the high temperature around strong light.
Color light pollution The black lights, rotating movable lights, fluorescent lights and flashing color light sources installed in modern dance halls constitute color light pollution, which is harmful to human health. According to the measurement, black light can produce ultraviolet with the wavelength of 250 ~ 320 nm, and its intensity is much higher than that in sunlight. If the human body is exposed to this black light for a long time, it may induce nosebleeds, tooth loss, cataracts, and even leukemia and cancer. The harmful effect of this ultraviolet ray on human body can last for 15 ~ 25 years. Rotating movable lights and colored light sources are dazzling, which is not only bad for eyes, but also interferes with the central nervous system of the brain, causing dizziness, instability, headache, insomnia, inattention, loss of appetite and other symptoms. The flashing neon lights in the ballroom will not only damage people's visual function, but also disturb the internal balance of the human body, making the body temperature, heartbeat, pulse and blood pressure uncoordinated, causing light damage syndrome such as dizziness, irritability, loss of appetite, fatigue and insomnia. Excessive exposure to fluorescent lamps will reduce the body's ability to absorb calcium, leading to calcium deficiency.
Now some luxurious dance halls are equipped with laser devices. 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. When this high-density thermal beam passes through the lens of the eye and focuses on the retina, the temperature of the focusing point can reach 70 degrees Celsius, which is very harmful to the eyes and brain nerves. It will not only damage people's eyesight, but also cause central nervous system diseases such as headache, dizziness, cold sweat, neurasthenia and insomnia.
The latest research by scientists shows that colored light pollution not only damages people's physiological functions, but also affects people's psychology. The measurement of "Chromaticity Effect of Spectral Light" shows that if the psychological effect of white light is 100, blue light is 152, purple light is 155, red light is 158, and black light is the highest, which is 187. If people are exposed to colored lights for a long time, their psychological accumulation effect will also cause burnout, dizziness, loss of libido, impotence, irregular menstruation, neurasthenia and other physical and mental diseases to varying degrees.
At present, although light pollution is not included in the prevention and control of environmental pollution, its harm is obvious, and there is a trend of aggravation and spread. Light pollution has attracted more and more attention of scientists, who are trying to study ways to prevent light pollution. People should also pay attention to prevent all kinds of light pollution from harming health and avoid being exposed to light pollution for too long. We should actively create a beautiful and comfortable environment and minimize the threat of light pollution.