In the Law of People's Republic of China (PRC) on the Prevention and Control of Environmental Noise Pollution formulated by China, the phenomenon that it exceeds the national environmental noise emission standard and interferes with others' normal life, work and study is called environmental noise pollution. The decibel of sound is the unit of sound pressure level, which is recorded as dB. Used to indicate the size of the sound. The "People's Republic of China (PRC) Urban Regional Noise Standard" clearly stipulates the maximum limits of environmental noise in five urban areas:
Sanatorium area, senior villa area and senior hotel area, 50dB during the day and 40dB at night; Areas dominated by houses and cultural and educational institutions, 55dB during the day and 45dB at night; Residential, commercial and industrial mixed zone, 60dB during the day and 50dB at night; Industrial zone, 65dB during the day and 55dB at night; Road traffic trunk roads, inland waterways and railway main and secondary trunk roads in the city are 70dB during the day and 55dB at night (night refers to 22: 00 to 6: 00 the next morning).
According to national standards, the noise in residential areas should not exceed 50 decibels during the day and should be lower than 45 decibels at night. If it exceeds this standard, it will be harmful to human body. So, what is the noise standard of indoor environment? The fourth paragraph of Article 5 of the National Method for Measuring Environmental Noise in Urban Areas stipulates that when measuring noise indoors, the indoor noise limit is lower than the standard value of the area where it is located, that is, 10dB.
Noise pollution is harmful to physical and mental health.
1. Strong noise can cause ear discomfort, such as tinnitus, earache and hearing loss. According to the measurement, noise exceeding 1 15 decibels can also cause deafness. According to clinical medical statistics, if you live in a noise environment above 80 decibels, the number of deaf people can reach 50%. Medical experts believe that family noise is one of the reasons for children's deafness.
2. Reduce work efficiency. The study found that noise exceeding 85 decibels can make people feel agitated, and people will feel noisy and unable to concentrate on their work, resulting in reduced work efficiency.
3. The cardiovascular system is damaged. Noise is a risk factor for cardiovascular diseases, which will accelerate heart aging and increase the incidence of myocardial infarction. Medical experts have proved through human and animal experiments that long-term exposure to noise will increase adrenal secretion in the body, thus raising blood pressure. People who live in noise with an average of 70 decibels for a long time can increase the incidence of myocardial infarction by about 30%, especially at night. The survey found that the myocardial infarction rate of residents living beside the expressway increased by about 30%. 110/textile female workers were investigated. The incidence of hypertension was 7.2%, of which the contact intensity reached 100 dB noise, and the incidence of hypertension reached 15.2%.
4. Noise can also cause nervous system dysfunction, mental disorders, endocrine disorders, and even increase the accident rate. Noisy working environment can lead to dizziness, headache, insomnia, dreaminess, general fatigue, memory loss, fear, irritability, inferiority and even insanity. In Japan, there have been cases in which someone went insane because he couldn't stand the stimulation of train noise and finally committed suicide.
5. Interfere with rest and sleep. Rest and sleep are the necessary conditions for people to eliminate fatigue, restore physical strength and keep healthy. But the noise makes people fidget, making it difficult to rest and fall asleep. When people can't sleep after tossing and turning, they will feel nervous, short of breath, rapid pulse and excited brain, and they will feel tired or weak limbs the next day. Thus affecting work and study, over time will get neurasthenia, manifested as insomnia, tinnitus, fatigue.
6. Damage to women's physiological function. Women are threatened by noise, and there will be irregular menstruation, miscarriage, premature delivery, etc., such as causing female sexual dysfunction, menstrual disorder, and increased abortion rate. Experts conducted a three-year systematic investigation in seven regions, including Harbin, Beijing and Changchun, and found that noise can not only make female workers suffer from noise deafness, but also have a negative impact on their menstruation and fertility. In addition, it can also lead to miscarriage, premature delivery and even teratogenesis in pregnant women. Foreign countries have made a survey on the common situation of miscarriage and premature delivery of pregnant women in a certain area, and found that they live near an airport, and the culprit is the huge noise generated when the plane flies and lands.
7. Noise is more harmful to children's physical and mental health. Because children are immature, tissues and organs are delicate and fragile. Whether it is a fetus or a newborn child in the body, noise will damage the hearing organs, leading to hearing loss or loss. According to statistics, there are more than 70 million deaf people in the world today, and a considerable part of them are caused by noise. Expert research has proved that indoor noise is the main cause of children's deafness. If you live in noise above 85 decibels, the deaf can reach 5%.
8. Noise damage to vision. People only know that noise affects hearing, in fact, noise also affects vision. Experiments show that when the noise intensity reaches 90 decibels, the sensitivity of human visual cells decreases and the reaction time to identify weak light is prolonged. When the noise reaches 95 decibels, 40% people have dilated pupils and blurred vision; When the noise reaches 1 15 dB, the adaptation of most people's eyeballs to light brightness is weakened to varying degrees. Therefore, people who are exposed to noise for a long time are prone to eye fatigue, eye pain, dizziness and tears. At the same time, noise can also make color vision and visual field abnormal. It is found that noise reduces the visual field of red, blue and white by 80%. Therefore, drivers should avoid the noise interference of stereo, otherwise it will easily cause traffic accidents.
The main source of indoor noise
1. Traffic noise. The increasingly developed urban transportation industry has brought convenience and comfort to people's work and life, and also promoted economic development. However, with the increase of urban and rural vehicles and the increase of highway and railway traffic trunk lines, the noise of locomotives and motor vehicles has become the chief culprit of traffic noise, accounting for 75% of urban noise. According to statistics, Beijing is a world-famous noise pollution city. Although the number of urban vehicles is less than one tenth of that of Japan, the noise level is 1 times higher than that of Japan. In particular, some buildings facing the street suffered heavy losses.
2. Industrial machinery noise. This is also the main source of indoor noise pollution. Due to the impact, friction, jet and vibration generated by various power machines and working machines, sounds above 70 to 80 decibels can be generated. The noise of textile workshop, forging workshop, crushing workshop, steel mill, cement plant, air pump room and water pump room is quite large. Although they have done some noise reduction, they still can't fundamentally eliminate the noise generated by the machine itself.
3. Urban building noise. Especially in recent years, the rapid development of urban construction, road construction, infrastructure construction, urban building development, old city reconstruction and indoor decoration of people's homes have all caused urban building noise. The noise of the construction site is generally above 90 decibels, and the highest is 130 decibels.
4. Noise in social life and public places. Such as commercial noise in public places, restaurants, buses, passenger trains, crowds, speakers, etc. According to statistics, the noise of social life and public places accounts for 14.4% of urban noise.
5. Household appliances directly cause indoor noise pollution. With the development of modernization of people's lives, the noise of household appliances is more and more harmful to people. According to the test, the noise generated by TV sets and tape recorders at home can reach 60 to 80 decibels, while that of washing machines is 42 to 70 decibels and that of refrigerators is 34 to 50 decibels. In recent years, family karaoke machines are widely used, and some people only care about their own enjoyment and ignore the happiness of others, which invisibly increases the intensity of noise pollution.