Expression of noise is harmful to humans. Effect of noise on the human body

Noise is random vibrations of various physical nature, characterized by the complexity of the temporal and spectral structure. From a physiological point of view, noise can be called any unwanted sound (simple or complex) that interferes with the perception of useful sounds (human speech, signals, etc.), disturbing the silence and having a harmful effect on a person.

The human body reacts differently to different levels of noise. Level noises 70-90 dB with prolonged exposure lead to disease nervous systemand more 100 dBA - to hearing loss, up to deafness.

Noise creates a significant load on the human nervous system, exerting a psychological effect on it. Noise can increase the levels of stress hormones such as cortisol, adrenaline, and norepinephrine in the blood - even during sleep. The longer these hormones are present in the circulatory system, the more likely they are to lead to life-threatening physiological problems.

According to the guidelines of the World Health Organization (WHO), cardiovascular diseases may occur if a person is constantly exposed to noise at night 50 dBA or higher - such noise is emitted by a street with low traffic. There is enough noise in 42 dBA; to just get irritable - 35 dBA(whispering sound). According to the WHO, thousands of people in the UK and around the world die prematurely from heart problems caused by long-term exposure to high noise levels.

Under the influence of noise from 85 - 90 dB hearing sensitivity decreases at high frequencies. For a long time a person complains of malaise. Symptoms are headache, dizziness, nausea, excessive irritability. All this is the result of working in noisy environments Under the influence of strong noise, especially high-frequency noise, irreversible changes occur in the organ of hearing. At high noise levels, the auditory sensitivity drops after 1 - 2 years, with medium levels - it is detected much later, after 5 - 10 years, that is, hearing loss occurs slowly, the disease develops gradually. Therefore, it is especially important to take appropriate noise protection measures in advance. Nowadays, almost everyone who is exposed to noise at work is at risk of becoming deaf.

It's too noisy in Irkutsk - more than 1/3 of the city's population lives in the zone of acoustic discomfort today. Urban noise in Irkutsk is mainly determined by traffic noise. The ISMU's calculations of the level of traffic noise on the territory of the city made it possible to determine the vulnerable near-highway residential areas, where the noise level exceeds the permissible by 6.5 dBA, and the noise in residential buildings - by 4-13 dBA. The population living in sub-main areas notes a deterioration in health, headaches, sleep disturbances, and functions of cardio-vascular system and the gastrointestinal tract.

An effective way to solve the problem of noise is to reduce its level at the source itself by changing the technology and design of machines. Measures of this type include replacing noisy processes with noiseless ones, shock ones with shockless ones, for example, replacing riveting with soldering, forging and stamping with pressure treatment; replacement of metal in some details with unsonic materials, the use of vibration isolation, mufflers, damping, soundproof casings, etc.

Noise protection implies the following activities.

1) Sound absorption.Sound absorption is the process of converting part of the energy of a sound wave into the thermal energy of the environment in which the sound propagates. For sound absorption, porous (the pores must be open from the side of the sound incidence and be connected to each other) and loose fibrous materials (felt, mineral wool, cork, etc.) are used.

Sound-absorbing materials or structures made of them are reinforced on the enclosing structures of the room without an air gap or at some distance from them.

2) Soundproofing... Sound insulation refers to the process of reducing the level of noise that penetrates through the fence into the room.

The main parameter for assessing the sound insulation of any structure is the Rw index. It shows how many decibels the noise level is reduced when using a soundproof structure. To achieve a comfortable noise level for a person (no more than 30 dB), interior partitions must have an Rw index of at least 50 dB.

Bibliographic reference

“It took decades for us to become imbued with the idea of \u200b\u200bthe dangers of secondhand smoke. But it may take us decades to become aware of the harm caused by 'passive' heightened noise. " Bradley Vite, one of the study authors.

Scientists from New York University have been conducting research for 5 years - how it affects human body noise pollution. And they came to the conclusion that elevated level noise is no less hazardous to health than secondhand smoke.

Until recently, it was believed that increased noise levels caused nothing more than an inconvenience that could be experienced. However, this is not the case.

The latest data obtained by experts show that regular increased noise is no less dangerous for us than cigarette smoke from secondhand smoke. Scientists conclude that constant noise of more than 50 decibels increases stress in a person. It also increases general anxiety, can cause hypertension. This leads to a significant increase in the risk of a heart attack.

The EUROBUSINESS company is an authorized installer of air conditioners in Moscow.

Noise is especially unfavorable at night, when the human body must rest. But modern life "makes noise" every day more and more. Landing planes are noisy, freeways are noisy, where traffic does not stop for a minute. A neighbor with a hammer drill behind the wall makes noise, and almost all household appliances make noise. Including climatic. In fact, it is quite difficult to hide from the constant noise even in rural areas. What can we say about cities.

Both equipment manufacturers and consumers do not always pay attention to the selection of solutions with optimal noise parameters. It is considered that "you can be patient" if the ventilation unit makes excessive noise. “Just turn up your TV or turn off the unit at night” - this advice can be heard from the seller - “but the ventilation performance will be very good”.

Meanwhile, studies show that excessive noise is no less harmful than a lack of oxygen.

“It took decades for us to become imbued with the idea of \u200b\u200bthe dangers of secondhand smoke. But it may take us decades to become aware of the harm caused by 'passive' heightened noise. " These are the words of Bradley Vite, one of the study's authors.

What level of noise is dangerous to humans?

The natural noise level is 25-30 decibels. Such noise is not harmful; moreover, it is considered comfortable for humans. In terms of volume, this is comparable to the rustle of leaves on trees - the rustle of foliage is 10-20 dB. Each person has their own individual preferences for the level of noise around.

According to sanitary standards, the noise level two meters from a residential building should not exceed 55 dB. In modern cities, these norms are constantly violated.

During normal conversation of people, the noise level reaches 40-50 decibels, as with a kettle boiling half a meter away from you. A car passing by or a tractor operating 15 meters away generates a noise of about 70 dB. According to experts, the noise level on a 3-4-lane motor road, as well as on the sidewalk next to it, exceeds the norm by 20-25 decibels. The leaders in terms of noise levels are airports and train stations. The volume of the consignment is 100 dB. The noise level in the subway can reach 110 dB. But the noisiest transport is the plane. Even a kilometer from the runway, the noise level from a liner taking off and landing is more than 100 dB.

Constant noise attacks do not go unnoticed. According to GOSTs, constant exposure to noise of 80 dB or more is considered harmful. Production with this noise level is considered harmful. Noise of 130 dB causes physical pain. At 150 decibels, a person loses consciousness. Noise of 180 dB is considered fatal to humans.

Why is heat dangerous?

Death by heat: how the temperature will kill people. Scientists: deaths from heat will increase fivefold by 2080.

Australian scientists have published a new study. According to him, global deaths due to extreme heat will increase fivefold over the next 60 years. According to their forecasts, the number of deaths due to high temperatures associated with global warming will gradually increase every year in the territory of 20 states.

By 2080, the number of victims of global warming in tropical and subtropical regions will increase almost fivefold. This forecast was made by scientists at the Australian Monash University in Melbourne.

Developed a computer model

To estimate the number of heat deaths, scientists have developed a computer model. It covers 20 countries in the period 2031-2080. They took into account the amount of greenhouse gases emitted into the atmosphere when burning fossil fuels. And also, the population density in the regions and various strategies to mitigate the effects of heat.

According to the professor of the London School of Hygiene and Tropical Medicine Antonio Gasparrini, the reason for the study was the fact that tens of thousands of people around the world suffer from health problems caused by climate warming and related to this process abnormally high temperatures.

Scientists also concluded that in the future, periods of abnormally hot weather will repeat more often, and their duration will increase.

“If we fail to slow down climate change, deaths from extreme hot weather will increase. This is especially true for countries located in the equator, ”warned the study's author, Professor Yuming Guo.

Countries at risk

According to experts, residents of tropical countries with a high population density will be the first to feel the negative consequences of global warming. According to the most pessimistic scenario, in the cities of Australia - Brisbane, Sydney and Melbourne - deaths from weather events will increase by 471% compared to 1971-2010. Weather events can mean not only heat and drought, but also a severe storm. And deaths from heat will also increase in India, Greece, Japan and Canada, where wildfires will exacerbate the situation.

For countries at risk, scientists also gave a number of recommendations. For example, more and better teaching people how to give first aid. And also, to revise the urban planning policy, expanding the area of \u200b\u200bgreen areas and providing citizens with comfortable housing. The researchers also urge the authorities to provide people with constant access to drinking water.

According to Australian experts, in order to mitigate the predicted consequences, countries should not forget about the Paris Agreement, concluded in 2015. According to him, humanity should not allow an increase in the average temperature of the planet by more than one and a half degrees. The signatory countries are required to cut greenhouse gas emissions by 2050. To do this, they need to reorient their economies towards green technologies.

The general aggressiveness of the population is increasing

A group of researchers from Stanford University has previously stated that global warming could lead to an increase in the number of suicides.

Comparing the rate of increase in the number of episodes with abnormally high temperatures, the scientists found a clear correlation between this rate and the increase in the number of suicides.

According to their calculations, an increase in the average monthly temperature by one degree means an increase in the number of suicides. For example, the increase for the United States was 0.7% additional, and for Mexico it was 2.1%.

The same calculations predict that by 2050, suicides will increase by 1.4% in the United States. And in Mexico by 2.3%. In other words, an additional 14 to 26 thousand people will commit suicide in the United States alone.

The study found that the maximum number of suicides occurs at the beginning of the summer period. At this time, the general aggressiveness of the population also increases. The authors of the work blame the increase in the number of suicides in the heat of the side effects of thermoregulation. As well as other neurological reactions in response to fever. These processes, in turn, can affect people's mental health.

The data obtained are consistent with the results of earlier work. They show that there are more suicides in the summer than in the colder months. Also, the Stanford group analyzed six million Twitter posts made by US residents.

Scientists have established a clear connection between the onset of high-temperature periods and manifestations of the "depressive" language of tweets. He becomes rich in words such as "lonely", "driven", "suicidal", etc.

According to experts, an increase in temperature above the norm by one degree Celsius increases the depression of the American language by 0.79%.

Noise is harmful to health. Noise is fusion different sounds into one discordant sound. It would seem how ordinary sounds can affect our health.

But in fact, sound vibrations negatively affect our well-being. How and why this happens, we will deal with all this below.

In large metropolitan areas, sound pollution is on par with the problem of air pollution.

Scientists have long found out that the inhabitants of large and noisy cities lose their hearing acuity and the population living in them in such conditions loses from ten to twelve years of life.

Normal noise level is between thirty and seventy decibels... However, in large cities the norm exceeds the level of eighty units of measurement of the power of the sound stream.

When the noise level exceeds that very permissible norm, a person blood pressure rises and violated harmony of the heart.

A variety of pleasing sounds, such as the natural environment, are always pleasing to humans. But today such relaxation is not so easy to enjoy.

More and more we have to enjoy transport and industrial sounds that are not so pleasant to the ear.

Noise is the source of many diseases. Various neuroses, pressure rise, headaches, insomnia and decline tone are just one of them.

However, there are a number of serious diseases, such as stomach and intestinal ulcers, skin and gastrointestinal diseaseswhich are directly related to the human nervous system. Therefore, silence is so beneficial for our body.

This is especially important at nightwhen the mind and body are resting and gaining new strength. In these conditions, a calm environment is simply vital.

To avoid many consequences noise waves, Scientists strongly recommend turning off anything that makes even the slightest sound in your home twice a week.

A telephone, computer, refrigerator, washing machine - all these household appliances prevent our body from relaxing and resting.

« Treatment with silence"- this name has many clinics in the West. A huge number of people pay a lot of money to be in silence. In such clinics, there are no televisions, no music, and even no access to the telephone.

Complete soundproofing and detachment from the outside world helps to get rid of many ailments. As the visitors of such hospitals assure, the state of health and health in general improves in three days in silence.

The noise itself is a rather insidious disease, because disturbances in the body do not appear immediately, and the body itself is defenseless in front of sounds. It should be noted that women are much more susceptible to noise illnessesthan men.

After all, a woman's hearing is able to pick up noise of a higher frequency. Therefore, it is extremely important to be able to independently cope with sound aggressors.

To prevent noise-related diseases in children, first of all, prohibit them from listening to music on headphones.

After school or public and noisy places, teach your child to relax. Read a book with him, take up drawing and enjoy the inner calm sound made only by breathing.

Noise sickness can be treated with noise, however strange it may sound. Get yourself recordings of natural sounds naturesuch as birdsong, sea waves or rain sounds. For example, the Japanese treat insomnia with the sounds of rain.

Therefore, do not hesitate and follow the example of oriental medicine. New age music can be purchased. Many contemporary composers write music for a therapeutic purpose, the discs of which can be purchased in the most ordinary store.

You need to understand that each organism perceives sounds in its own way. Therefore, it will not be so easy to choose the music “for yourself”. To know if you're relaxed enough your body, check your pulse and monitor your breathing.

It should be smooth and calm. Measure these parameters before and after listening to the melody, so you will understand which music is able to relax your body best.

With noise aggressors nearby, you need to try to stay as little time as possible, go out into nature more with family and friends. Find “your” nook and enjoy what nature has given us.

Noise Is a set of sounds that adversely affect the human body and interfere with his work and rest.

The sources of sound are elastic vibrations of material particles and bodies transmitted by liquid, solid and gaseous media.

The speed of sound in air at normal temperature is approximately 340 m / s, in water - 430 m / s, in diamond - 18,000 m / s.

Sound with a frequency from 16 Hz to 20 kHz is called audible, with a frequency of less than 16 Hz - and more than 20 kHz -.

The area of \u200b\u200bspace in which sound waves propagate is called a sound field, which is characterized by the intensity of sound, its speed of propagation and sound pressure.

Sound intensity Is the amount of sound energy transmitted by a sound wave in 1 s through an area of \u200b\u200b1 m 2 perpendicular to the direction of sound propagation, W / m2.

Sound pressure - it is called the difference between the instantaneous value of the total pressure created by the sound wave and the average pressure that is observed in an undisturbed medium. The unit of measurement is Pa.

The hearing threshold of a young person in the frequency range from 1,000 to 4,000 Hz corresponds to a pressure of 2 × 10-5 Pa. The highest value of sound pressure causing painful sensations is called pain threshold and is 2 × 102 Pa. Between these values \u200b\u200blies the area of \u200b\u200bauditory perception.

The intensity of human exposure to noise is estimated by the sound pressure level (L), which is defined as the logarithm of the ratio of the effective sound pressure to the threshold. The unit of measurement is decibel, dB.

At the threshold of audibility at an average geometric frequency of 1,000 Hz, the sound pressure level is zero, and at the threshold of pain it is 120-130 dB.

Noises surrounding a person have different intensities: whispering - 10-20 dBA, colloquial speech - 50-60 dBA, noise from a car engine - 80 dBA, and from a cargo car - 90 dBA, noise from an orchestra - 110-120 dBA, noise during takeoff jet aircraft at a distance of 25 m - 140 dBA, a shot from a rifle - 160 dBA, and from a heavy gun - 170 dBA.

Types of industrial noise

Noise in which sound energy is distributed over the entire spectrum is called broadband; if a sound of a certain frequency is heard, the noise is called tonal; noise perceived as individual impulses (shocks) is called impulse.

Depending on the nature of the spectrum, the noise is divided into low frequency (the maximum sound pressure is less than 400 Hz), mid-frequency (sound pressure within 400-1000 Hz) and high frequency (sound pressure is more than 1000 Hz).

Depending on the time characteristics, the noises are divided into permanent and fickle.

Intermittent noises are hesitant by time, the sound level of which is continuously changing over time; intermittent, the sound level of which drops sharply to the background noise level; impulseconsisting of signals less than 1 s.

Depending on the physical nature, noises can be:

• mechanical - arising from vibration of machine surfaces and during single or periodic shock processes (stamping, riveting, stubbing, etc.);
• aerodynamic - noises of fans, compressors, internal combustion engines, steam and air emissions into the atmosphere;
• electromagnetic - arising in electrical machines and equipment due to the magnetic field caused by electric current;
• hydrodynamic - arising from stationary and non-stationary processes in liquids (pumps).

Depending on the nature of the action, the noises are divided into stable, intermittent and howling; the last two are especially detrimental to hearing.

Noise is created by single or complex sources located outside or inside the building - these are, first of all, vehicles, technical equipment of industrial and domestic enterprises, ventilators, gas turbine compressor units, sanitary equipment of residential buildings, transformers.

In the industrial sector, noise is most common in industry and agriculture. A significant level of noise is observed in the mining industry, mechanical engineering, logging and woodworking, and the textile industry.

Effects of noise on the human body

Noise that occurs during the operation of production equipment and exceeds the standard values \u200b\u200baffects the central and autonomic nervous system of a person, and the organs of hearing.

Noise is perceived very subjectively. In this case, the specific situation, the state of health, the mood, the environment matter.

Major physiological effects of noise is that it is damaged inner ear, changes in the electrical conductivity of the skin, bioelectric activity of the brain, heart and respiration rate, general motor activity, as well as changes in the size of some glands of the endocrine system, blood pressure, narrowing blood vessels, dilation of the pupils of the eyes. Those working under conditions of prolonged exposure to noise are irritable, headache, dizziness, decreased memory, increased fatigue, decreased appetite, sleep disturbance. In a noisy background, communication between people deteriorates, resulting in sometimes feelings of loneliness and dissatisfaction, which can lead to accidents.

Prolonged exposure to noise, the level of which exceeds the permissible values, can lead to a person's illness with noise sickness - sensorineural hearing loss. Based on the above, noise should be considered the cause of hearing loss, some nervous disorders, reduced productivity at work and some cases of loss of life.

Hygienic noise regulation

The main purpose of noise rationing at workplaces is to establish the maximum permissible noise level (MPL), which, during daily (except weekends) work, but not more than 40 hours per week during the entire working experience, should not cause diseases or deviations in health detected modern methods research in the process of work or remote periods of life of the present and subsequent generations. Compliance with the remote control for noise does not exclude health problems in hypersensitive persons.

Acceptable noise level - this is a level that does not cause significant concern in a person and significant changes in the indicators of the functional state of systems and analyzers that are sensitive to noise.

The maximum permissible noise levels at workplaces are regulated by SN 2.2.4 / 2.8.562-96 “Noise at workplaces, in premises of residential, public buildings and on the territory of residential buildings”, SNiP 23-03-03 “Noise protection”.

Noise protection measures

Noise protection is achieved by the development of noise-safe equipment, the use of collective protection means and methods, as well as personal protective equipment.

Development of noise-safe equipment - reduction of noise at the source - achieved by improving the design of machines, the use of low-noise materials in these designs.

The means and methods of collective protection are subdivided into acoustic, architectural and planning, organizational and technical.

Acoustic noise protection means:

• sound insulation (installation of soundproof cabins, casings, fences, installation of acoustic screens);
• sound absorption (use of sound-absorbing facings, piece absorbers);
• noise mufflers (absorption, reactive, combined).

Architectural planning methods - rational acoustic layout of buildings; placement in buildings of technological equipment, machines and mechanisms; rational placement of jobs; planning of traffic zones; creation of noise-proof zones in places where people are located.

Organizational and technical measures - change technological processes; remote control and automatic control device; timely scheduled preventive maintenance of equipment; rational mode of work and rest.

If it is impossible to reduce the noise acting on workers to acceptable levels, then it is necessary to use personal protective equipment (PPE) - anti-noise inserts made of ultra-thin fiber "Earplugs" disposable, as well as anti-noise inserts of reusable use (ebonite, rubber, foam) in the form cone, fungus, petal. They are effective in reducing noise at medium and high frequencies by 10-15 dBA. Headphones reduce the sound pressure level by 7-38 dB in the frequency range 125-8000 Hz. To protect against noise exposure with a general level of 120 dB and above, it is recommended to use headsets, headbands, helmets, which reduce the sound pressure level by 30-40 dB in the frequency range 125-8000 Hz.

See also

Industrial noise protection

The main activities to combat noise are technical measures that are carried out in three main areas:

• elimination of the causes of noise or its reduction at the source;
• attenuation of noise along transmission paths;
• direct protection of workers.

The most effective noise reduction tool is replacement of noisy technological operations with low-noise or completely silent, but this way of dealing with noise is not always possible, therefore, it is of great importance to reduce noise at the source - by improving the design or circuit of that part of the equipment that produces noise, using materials with reduced acoustic properties in the design, equipment at the source of additional noise soundproofing device or fence located as close to the source as possible.

One of the simplest technical means of dealing with noise along transmission paths is soundproof enclosurecovering a separate noisy part of the machine.

A significant effect of reducing the noise from the equipment is provided by the use of acoustic screens that block the noisy mechanism from the workplace or the service area of \u200b\u200bthe machine.

The use of sound-absorbing claddings for finishing the ceiling and walls of noisy rooms (Fig. 1) changes the noise spectrum towards lower frequencies, which, even with a relatively small decrease in the level, significantly improves working conditions.

Figure: 1. Acoustic treatment of premises: a - sound-absorbing facings; b - piece sound absorbers; 1 - a protective perforated layer; 2 - sound-absorbing material; 3 - protective fiberglass; 4 - wall or ceiling; 5 - air gap; 6 - a plate made of sound-absorbing material

To reduce aerodynamic noise, use mufflers, which are usually divided into absorption ones, using the lining of the surfaces of air ducts with sound-absorbing material: reactive types of expansion chambers, resonators, narrow branches, the length of which is equal to 1/4 of the wavelength of the sound to be muffled: combined, in which the surfaces of the reactive mufflers are lined with sound-absorbing material; screen.

Considering that with the help of technical means it is not always possible to solve the problem of reducing the noise level, great attention should be paid to the use of personal protective equipment: headphones, earbuds, helmets that protect the ear from the harmful effects of noise. The effectiveness of personal protective equipment can be ensured by their correct selection depending on the levels and spectrum of noise, as well as by monitoring the conditions of their operation.

Everyone knows that air pollution negatively affects human health. However, this factor is inferior in its harmfulness to the noise that surrounds us civilization.

ABOUT harmful influence noise on the human body was known even in ancient China - execution by noise was considered the most cruel there.

Nowadays, noise has become our constant companion. Children especially suffer from this. It has been established: the higher the level of environmental noise, the worse it affects the mental state of children, especially premature babies.

In the last century, Robert Koch wrote: "Someday humanity will be forced to fight noise as decisively as it fights cholera or plague." This time has come.

Modern medicine considers noise to be one of the formidable enemies of human health. If he works under conditions of noise stress, he quickly gets tired, he has insomnia, loss of appetite. Noise can cause hypotension, which is now most common in children and adolescents. With age, such patients are at risk of hypertension. High noise levels increase the incidence of peptic ulcer, gastritis, and, definitely, nervous diseases.

In the future, in addition to hearing disorders, cardiovascular diseases may occur, hypertonic disease, metabolism, thyroid activity are disrupted. Under the influence of noise, the activity of the brain is disrupted - memory, mental performance decreases. In severe cases, mental disorders can develop.

Effect of noise level

According to the Austrian scientist Griffith, noise shortens a person's life by 8-12 years. Why? Hearing aid a person perceives sound power in the range of 0-140 decibels (dB). Low-intensity noises have a beneficial effect on a person, especially on his psyche.

Therefore, the noise of leaves, rain, sea surf, melody of lullabies, which sound with a frequency similar to that of the eardrum, have healing properties.

The rustle of leaves is perceived by a person at a level of 5-10 dB, wind noise - 10-20, whispering - 30-40, quiet conversation - 50-60, loud conversation - 60-70, in apartments that overlook the street with heavy traffic if the windows are closed, the noise reaches 60-80 dB, and if the windows are open - 80-100 dB; the sound of a jet plane - 140 dB.

Noise of 20-30 dB is practically harmless to humans, it is a natural sound field, without which life is impossible.

• 30-35 dB in nature reserves;
• 34-37 dB in dormitories (houses, hospitals, apartments);
• 56-66 dB in shops, factories and the like.

Therapists believe that noise of 60-80 dB causes disorders of the autonomic nervous system in a person, 90-110 dB - hearing loss. And the noise of 115-120 dB is the "pain threshold" when the sound as such is no longer heard, but pain in the ears is felt. At 140-145 dB, eardrums can even burst. Noise of 150 dB is simply unbearable, 180 dB is fatal to humans. According to the Institute of Hygiene and Medical Ecology of the National Academy of Medical Sciences of Ukraine, the permissible noise level for adolescents is 70 dB, for adults - 90 dB.

Children who live in urban noise have mental retardation. And frequent visits by teenagers to discos can lead to hearing loss, because there "sounds" 105-110 dB, and in the case of amplification of speakers - up to 120 dB, which is equivalent to the roar of an electric train.

Scientists have also established a direct link between noise intoxication and heart disease.

Influence of infrasounds

The most harmful to humans are infra- and ultrasounds. The fact is that a person, unlike many animals, does not hear them, and therefore does not have the ability to defend against their harmful effects. It should be noted, however, that the degree of their influence depends on the frequency and time of their action. By the way, heartbeat, lung vibrations, bowel movements, vibrations vocal cords are also accompanied by the generation of infrasounds, but they are unlikely to harm us.

In nature, sources of infrasound are microseismic vibrations of the earth's surface, volcanic eruptions, and interactions of the Earth's geological platforms before the formation of faults.

In an industrialized society, sources of infrasound are automobile, aircraft and rocket engines, loudspeakers and even organ pipes.

Infrasounds are perceived by our smaller friends - dogs, reptiles, fish (even aquarium ones). Therefore, you need to carefully monitor their behavior: if they react violently - be intent, danger is near.

According to research data from the Moscow Technical University of Communications and Informatics, infrasound with a frequency of 1.2 Hz predetermines a decrease in arterial blood pressure in humans, weakness; 2.6 Hz - allergies, dermatitis, impotence.

Infrasounds with a frequency of 5-10 Hz, which are especially dangerous for human health (they resonantly affect cells of living tissue, which have a natural frequency of approximately 8 Hz).

Such infrasounds are harmful internal organs human: at a frequency of 5 Hz, the liver is damaged, 6 Hz - motion sickness develops, 7 Hz - the heart may stop and blood vessels burst.

Infrasounds of high power affect the human psyche: there is drowsiness, a feeling of fear, and the like.

But the main consequence of the action of infrasound on living organisms is a violation of the vestibular apparatus.

Infrasound of significant intensity can cause not only changes in auditory sensitivity, but also painful sensations, difficulties in speech and voice modulation, impaired respiratory activity, and changes in the a-rhythms of the brain.

Ultrasounds (frequency over 20,000 Hz) are also not perceived by our ear.

In the conditions of modern civilization, numerous processes are a powerful source of ultrasound. industrial production and transport. Their propagation speed depends on the properties of the medium. It is now known that low-intensity ultrasounds have a beneficial effect on living objects, and high-intensity ultrasounds have a detrimental effect (they destroy living cells). In particular, the mechanical factor predetermined by ultrasonic radiation leads to dysfunction of certain parts of the body, for example, to blockade of small capillaries by red blood cell clots.

Thermal effects associated with the absorption of ultrasonic radiation by biological tissue, as a result of which part of the energy is transferred to it. This energy is converted into heat and leads to an increase in the body temperature of living organisms.

The physicochemical effect is predetermined by changes in the permeability of biological membranes and diffusion processes. The influence of ultrasound on high-molecular compounds was established: vitamins, hormones, enzymes. Ultrasound promotes the release of biologically active substances from the organs and tissues of the body.

However, there is no sharp boundary between the zones of action of ultrasound of low and high intensity. It all depends on the nature of the biological object and a large number of external factors.

Therefore, of all noise stimuli, the greatest harm is caused by street noises, mostly generated by vehicles.

Limiting the level of noise intrusion into our lives means maintaining our health.

Aria Gvozdikovskaya
candidate of biological sciences,
member of the International Ecological Club;

Mikhail Kurik
doctor of Physical and Mathematical Sciences, Professor,
Director of the Institute of Human Ecology;