When normalizing the allowable sound pressure on workplaces, the frequency spectrum of noise is broken by nine frequency bands.

The normalized parameters of constant noise are:

sound pressure levelL., dB, in octave bands with medium megometric frequencies 31.5; 63; 125; 250; 500; 1000; 2000; 4000; 8000 Hz;

sound levelLA , dba.

The normalized parameters of non-permanent noise are:

- equivalent (Energy) Sound LevelLA ek, dB a,

-maximum sound levelLA Max, DB A. Excitement At least one of these indicators is qualified as a non-compliance with these sanitary standards.

In accordance with SanPiN 2.2.4 / 2.1.8.10-32-2002, the maximum permissible levels of noise are normalized in two categories of noise norms: the removal of noise in the workplace and the removal of noise in the premises of residential, public buildings and in the residential building.

For tonal and impulse noise, as well as noise created in the premises of air conditioning installations, ventilation and air heating, the remote control should be taken by 5 dB (dBA) fewer values \u200b\u200bspecified in Table. 8.4. of this paragraph and arr. 2 to SanPine 2.2.4 / 2.1.8.10-32-2002.

The maximum sound level for the oscillating and intermittent noise should not exceed 110 dBA. Even short-term stay in zones with sound level or sound pressure level in any octave strip over 135 dB A (dB) is prohibited.

Pow noise in the premises of residential, public buildings and on the territory of residential building.The permissible values \u200b\u200bof the sound pressure levels in the octave bands of the frequencies of the equivalent and maximum sound levels of the penetrating noise into the premises of residential and public buildings and noise on the territory of the residential building are established according to ad. 3 to Sanpin 2.2.4 / 2.1.8.10-32-2002.

Means and methods of protection against noise

The struggle against the noise in production is carried out comprehensively and includes measures of technological, sanitary and treatment-and-prophylactic nature.

The classification of means and methods for protection against noise is given in GOST 12.1.029-80 SSBT "Means and methods of protection against noise. Classification ", SNIP II-12-77" Noise Protection ", which provide for noise protection by the following construction and acoustic methods:

(a) Soundproofing of enclosing structures, sealing of windows, doors, gates, etc., the device of soundproofed cabs for staff; shelter sources of noise into casing;

b) installation of the noise of sound-absorbing structures and screens;

c) the use of aerodynamic noise silencers in internal combustion engines and compressors; sound-absorbing cladding in airways of ventilation systems;

d) creating noise protection zones in various locations of people, using screens and green plantings.

The weakening of noise is achieved by using under the gender of elastic gaskets without tough communication with the supporting structures of buildings, installation of equipment on shock absorbers or special foundations. Sound absorption means are widely used - mineral wool, felt plates, perforated cardboard, wood-fiber plates, fiberglass, as well as active and jet silencers.

Silencersaerodynamic noise is absorption, reactive (reflex) and combined. In absorption

the silencers attenuation of noise occurs in the pores of the sound-absorbing material. The principle of operation of jet silencers is based on the effect of sound reflection as a result of the formation of a "wave plug" in the elements of the muffler. In combination silencers, both absorption and sound reflection occurs.

Soundproofingit is one of the most efficient and common methods for reducing production noise on the path of its distribution. With soundproof devices, it is easy to reduce the noise level by 30 ... 40 DB. Effective soundproofing materials are metals, concrete, wood, dense plastics, etc.

To reduce noise indoors, sound-absorbing materials are applied to the inner surfaces, and space-cutters are placed indoors.

Application of funds individual protection from Shumait is advisable in cases where the means of collective protection and other means do not provide noise reduction to permissible levels.

PPEs make it possible to reduce the level of perceived sound at 0 ... 45 dB, and the most significant fracture of noise is observed in the high frequency area that are most dangerous to humans.

The means of individual protection against noise are divided into anti-shirt headphones, covering the ear sink outside; antioxide liners overlapping an outer hearing pass or adjacent to it; antinoise helmets and helmets; Antinemic costumes. Antically liners are made of solid, elastic and fibrous materials. They are one-time and multiple use. Anti-shit helmets cover the entire head, they are used at very high noise levels in combination with headphones, as well as anti-co-costumes.

Chapter 11 Production Noise

Chapter 11 Production Noise

Noisecall any unwanted sound or a set of such sounds. The sound is a wave-like oscillating process in the form of alternating waves of thickening and discharge of particles of this medium - sound waves.

Sound source can be any oscillating body. When contacting this body with the environment, sound waves are formed. The concentration waves cause an increase in pressure in an elastic medium, and the discharge waves are a decrease. From here there is a concept sound pressure- This is an alternating pressure resulting from sound waves in addition to atmospheric pressure.

Sound pressure is measured in Pascal (1 Pa \u003d 1 N / m 2). The human ear feels a sound pressure from 2-10 -5 to 2-10 2 N / m 2.

Sound waves are carriers of energy. Sound energy, which falls on 1 m 2 surface area, located perpendicular to the propagating sound waves, called the power of soundand it is expressed in W / m 2. Since the sound wave is a oscillatory process, then it is characterized by such concepts as period of oscillation(T) - the time during which one complete oscillation is performed, and frequency of oscillations(Hz) - the number of fluctuations for 1 s. Combustion frequency gives spectrum noise.

Noises contain sounds of different frequencies and differ in each other by the distribution of levels in separate frequencies and the nature of the change in the total level in time. For the hygienic estimate of noise, the sound frequency range is used from 45 to 11,000 Hz, comprising 9 octave bands with medium-beometric frequencies of 31.5; 63; 125; 250; 500; 1000; 2000; 4000 and 8000 Hz.

The hearing body distinguishes not the difference, but the multiplicity of changes in sound pressures, so the intensity of the sound is considered not to assess the absolute value of sound pressure, but its levelthose. the ratio of the pressure being created to pressure adopted per unit

comparison. In the range from the threshold of hearing to the painful threshold, the ratio of sound pressures varies in a million times, therefore, to reduce the measurement scale, the sound pressure is expressed through its level in the logarithmic units - decibels (dB).

Zero decibel corresponds to sound pressure of 2-10 -5 PA, which approximately corresponds to the threshold of tone hearing with a frequency of 1000 Hz.

The noise is classified according to the following features:

Depending on the character spectrumallocate the following noises:

broadbandwith a continuous spectrum width of more than one octave;

tonalin the spectrum of which there are pronounced tones. The tonal nature of noise is set by measuring in the frequency bands in terms of exceeding the level in one strip compared to neighboring at least 10 dB.

By temporary characteristicsthere are noises:

constantthe sound level of which for an 8-hour working day changes in time for no more than 5 dBA;

non-permanentthe noise level of which for an 8-hour working day changes in time at least 5 dBA. Non-permanent noises can be divided into the following types:

- spatteringin time, the sound level of which continuously changes in time;

- intermittentthe sound level of which stepwise changes (by 5 dB-a and more), and the duration of the intervals during which the level remains constant, is 1 s or more;

- impulseconsisting of one or more audible signals, each of which has a duration of less than 1 s; At the same time, sound levels measured according to the temporal characteristics of the "impulse" and "slowly" noiseomer differ in at least 7 dB.

11.1. Sources of noise

Noise is one of the most common adverse factors. production environmentThe impact of which on workers is accompanied by the development of premature fatigues, a decrease in labor productivity, an increase in the overall and professional morbidity, as well as injuries.

Currently, it is difficult to name the production on which there are no higher levels of noise in the workplace. The most noisy includes mining and coal, machine-building, metallurgical, petrochemical, forestry and well-grained, radiotechnical, light and food, meat and dairy industry, etc.

So, in the cold landing shops, the noise reaches 101-105 dBA, in the cloves - 104-110 dBA, in braid - 97-100 dBA, in the separation of seam polishing - 115-117 dba. In the workplaces of Tokarei, milling workers, motorists, Kuznetsov-stampers, noise level ranges from 80 to 115 dBA.

At the factories of reinforced concrete structures, noise reaches 105-120 dBA. Noise is one of the leading professional hazards in woodworking and logging industries. Thus, at the workplace of the frame and cutter, the noise level ranges from 93 to 100 dBA with a maximum of sound energy in the middle and high frequency domain. In the same limits, noise fluctuates in carpentry shops, and logging works (roll, forest routing) are accompanied by noise level from 85 to 108 dBA due to the work of the skiing winches, tractors and other mechanisms.

The overwhelming majority of industrial processes in spinning and weaving shops are also accompanied by the formation of noise, the source of which is the boiler mechanism of the weaving machine, shuttleties shutters. The highest noise is observed in weaving shops - 94-110 dBA.

Studying working conditions on modern sewing factories has shown that the noise level in the workplace of the SWE-Motorest is 90-95 dB with the maximum sound energy at high frequencies.

The most noisy operations in mechanical engineering, including aircraft engineering, automotive, car buildings, etc. It should be considered hard and riveting work using pneumatic instruments, mode tests of engines and their units of various systems, bench tests for the vibrational products, drum cooking, grinding and polishing Details, stampress preparation.

For the petrochemical industry, high-frequency noises of various levels are characteristic due to the discharge of compressed air from the closed technological cycle of chemical industries or

from equipment running on compressed air, such as assembly machines and vulcanization lines of tire plants.

At the same time, in mechanical engineering, as in any other industry, the largest volume of works falls on machine metalworking, where about 50% of all working industries are employed.

The metallurgical industry as a whole can be attributed to the industry with a pronounced noise factor. Thus, intense noise is characteristic of melting, rolling and pipe rolling industries. From the industries relating to this industry, the noisy conditions are characterized by hardware plants equipped with colder machines.

The most noisy processes include noise from an open air jet (blowing), breaking out of the holes of the small diameter, noise from gas burners and the noise formed when spraying metals on various surfaces. Spectra from all these sources is very similar, typically high-frequency, without a noticeable recession of energy to 8-10 kHz.

Woodworking workshops are the most noisy and pulp and paper industries.

The building materials industry includes a number of noisy industries: machines and mechanisms for crushing and grinding of raw materials and the production of precast concrete.

In the mining and coal industries, the operations of mechanized mining of minerals both using manual machines (pneumoperphorators, jackhammers) and with the help of modern stationary and self-propelled machines (combines, drilling machines, etc.) are the most noisy.

The radiotechnical industry is generally relatively less noisy. Only preparatory and preparatory workshops are equipped with equipment characteristic of the machine-building industry, but in a much smaller quantity.

In the light industry both by noise and in the number of employed workers most unfavorable are spinning and weaving productions.

Food industry - the least noisy of all. Characteristic noise generates stream units of confectionery and tobacco factories. However, individual machines of these industries create significant noise, for example, cocoa grain mills, some sorting machines.

Each industry has a workshop or individual compressor stations, supplying compressed air or pumping liquids or gaseous products. The latter are of great distribution in the gas industry as large independent farms. Compressor installations create intensive noise.

Examples of noise characteristic of various industries, in the absolute majority of cases have a common form of spectra: all of them are broadband, with some spage of sound energy in the low (up to 250 Hz) and high (above 4000 Hz) frequencies with levels of 85-120 dBA. The exceptions are noises of aerodynamic origin, where the levels of sound pressure grow from low to high frequencies, as well as low-frequency noise, which in industry compared to those described above are significantly less.

All the noise described characterizes the most noisy production and sections, where physical work is mainly dominated. At the same time, the noise less intense (60-80 dBA) are widely common, which, however, is hygienically meaningful in operations associated with the nervous load, for example, on the control panels, with the machine processing of information and other works that are increasingly distributed.

Noise is also the most characteristic adverse factor in the production environment at the workplaces of passenger, transport aircraft and helicopters; rolling stock of rail transport; marine, river, fishing and other ships; buses, cargo, passenger and special cars; agricultural machinery and equipment; Building, reclamation and other machines.

Noise levels in the cabins of modern aircraft fluctuate in a wide range - 69-85 dBA (main airplanes for airlines with medium and large range). In the cabins of car medium loading capacity at various modes and conditions of operation, the sound levels are 80-102 dBA, in the cabins of heavy vehicles - up to 101 dBA, in passenger cars - 75-85 dBA.

Thus, it is important for the hygienic assessment of noise, it is important to know not only its physical parameters, but also the nature of the human operator's work activity, and, above all, the degree of its physical or nervous load.

11.2. Biological effect of noise

Professor E.TS. made a great contribution to the study of the problem of noise. Andreeva-Galanina. She showed that noise is a common stimulus and affects not only the hearing analyzer, but, in the first place, acts on the structures of the brain, causing shifts in various systems of the body. Manifestations of the noise impact on the human body can be conditionally divided into specificchanges coming in the organ of hearing, and nonspecificarising in other organs and systems.

Aural effects. Changes in the sound analyzer under the influence of noise are the specific reaction of the body on acoustic effect.

It is generally recognized that the leading sign of the unfavorable effect of noise on the human body is a slowly progressive reduction of hearing in the type of cochlear neuritis (as a rule, both ears suffer to the same extent).

Professional decline in hearing refers to the sensorsulene (perceptual) hearing loss. Under this term implies a violation of hearing of a sound pending character.

Reducing the hearing influenced by fairly intensive and long-acting noise is associated with degenerative changes in both the Cortiyev Cortium cells and the first neuron of the auditory path - a spiral ganglia, as well as in the fibers of a cochlear nerve. However, there is no uniform opinion about the pathogenesis of persistent and irreversible changes in the receptor department of the analyzer.

Professional touginess usually develops after a more or less long period of operation in noise. The timing of its occurrence depend on the intensity and frequency-time parameters of noise, the duration of its impact and the individual sensitivity of the hearing body to noise.

Complaints on headache, increased fatigue, noise in ears, which may arise in the first years of work under noise conditions are not specific to damage the auditory analyzer, but rather characterize the reaction of the CNS to the effect of the noise factor. The feeling of decrease in hearing usually occurs significantly later than the appearance of the first audiological signs of the destruction of the auditory analyzer.

In order to detect the earliest signs of noise on the body and, in particular, on the sound analyzer, the most widely used method for determining the temporary displacement of the hearing thresholds (VSD) with different exposure durations and noise character.

In addition, this figure is used to predict hearing loss on the basis of the relationship between the constant impacts of the thresholds (losses) of the hearing (PSP) from the noise operating during the entire operation time in noise, and temporary shifts of thresholds (VSP) during the day exposure of the topics The same noise measured two minutes after the exposure to noise. For example, weak time displacements of the hearing thresholds at a frequency of 4000 Hz for the daily exposure of the noise are numerically equal to constant hearing loss at this frequency for 10 years of work in the same noise. Based on this, you can predict the resulting hearing loss, determining only the shift of the threshold for the daily exposure of noise.

The noise accompanied by vibration is more harmful to the organ of hearing than is isolated.

Extraural effect of noise. The idea of \u200b\u200bnoise disease was developed in 1960-70. On the basis of work on the effect of noise on cardiovascular, nervous, etc. Systems. Currently, it was replaced by the concept of extra -ural effects as non-specific manifestations of noise.

The workers exposed to noise make complaints of headaches of various intensity, often with localization in the forehead area (more often they arise by the end of work and after it), dizziness associated with the body position variable, depending on the effect of noise on the vestibular device, reducing memory , drowsiness, increased fatigue, emotional instability, sleep impairment (intermittent sleep, insomnia, less often drowsiness), pain in the heart, decline in appetite, enhanced sweating and others. The frequency of complaints and their severity depend on the experience of the work, the intensity of noise and its character.

Noise can break the function of the cardiovascular system. Changes in the electrocardiogram in the form of shortening the Q-T interval, lengthening the interval P-q, increase the duration and deformation of the teeth P and S, the displacement of the interval T-S, the change in the voltage of the T. T.

The most unfavorable in terms of the development of hypertensive states is broadband noise with the predominance of high-frequency components and a level of over 90 dBA, especially impulse noise. Broadband noise causes maximum shifts in peripheral blood circulation. It should be borne in mind that if there is an addictive (adaptation) to the subjective perception of noise, it is not observed in relation to developing vegetative adaptation reactions.

According to the epidemiological examination of the prevalence of basic cardiovascular diseases and some risk factors (excessive mass, burdened history, etc.) in women working under the impact of constant production noise in the range from 90 to 110 dBA, it is shown that noise as separately taken factor (excluding common risk factors) may increase frequency arterial hypertension (AG) In women under the age of 39 years (with more than 19 years), only 1.1%, and women over 40 years old - by 1.9%. However, with a combination of noise, at least one of the "common" risk factors can be expected to be expected by 15%.

When exposed to intensive noise 95 dBA and above, a violation of vitamin, carbohydrate, protein, cholesterol and water-salt exchanges may occur.

Despite the fact that noise affects the body as a whole, the main changes are observed by the hearing body, central nervous and cardiovascular systems, and changes in the nervous system may precede violations in the hearing body.

Noise is one of the strongest stressful production factors. As a result of the impact of high intensity noise, changes both in neuroendocrine and in immune systems are simultaneously arising. At the same time, there is stimulation of the front lobe of the pituitary and an increase in secretion by adrenal glands steroid hormonesAs a result of this, the development of the acquired (secondary) immunodeficiency with the involution of lymphoid organs and significant changes in the content and functional state of T- and B-lymphocytes in the blood and bone marrow. The emerging defects of the immune system concern, mainly three main biological effects:

Reduction of anti-infectious immunity;

Creation of favorable conditions for the development of autoimmune and allergic processes;

Reducing antitumor immunity.

The relationship between the incidence and the magnitude of the hearing loss in speech frequencies of 500-2000 Hz is proven, indicating that changes contributing to a decrease in the resistance of the organism simultaneously with a decrease in hearing. With an increase in production noise by 10 dBA, the indicators of the overall incidence of working (both in cases and in days) increase in 1.2-1.3 times.

Analysis of the dynamics of specific and nonspecific disorders with an increase in work experience with noise effects on the example of weaving showed that a polymorphic symptom complex is formed in tapes in tapes, including pathological changes in the hearing body in combination with vegetary-seeking dysfunction. At the same time, the growth rate of hearing losses is 3.5 times higher than the increase in functional disorders of the nervous system. With an experience of 5 years, transient vegal impairment predominate, with more than 10 years - hearing loss. The relationship of the frequency of vegetation dysfunction and the magnitude of the hearing loss is also revealed, which manifests itself in their growth when the hearing is reduced to 10 dB and in stabilization during the progression of hearing loss.

It has been established that in industries with noise levels up to 90-95 dBA, vegetative-vascular disorders appear earlier and are translated over the frequency of cochlear neurites. The maximum development is observed at a 10-year work experience in noise. Only at noise levels exceeding 95 dBA, by 15 years of work in the "noisy" profession, extra -ural effects are stabilized, and the phenomena phenomena begin to prevail.

Comparison of the frequency of hearing loss and neuro-vascular disorders depending on the noise level showed that the growth rate of hearing loss is almost 3 times higher than the growth rate of neuro-vascular disorders (respectively, about 1.5 and 0.5% per dBA), that is, With increasing noise level of 1 dB, hearing loss will increase by 1.5%, and neuro-vascular disorders are 0.5%. At levels of 85 dBA and above for each noise decibel, neuro-vascular disorders occur for half a year earlier than at lower levels.

Against the background of occurring intellectualization of labor, the growth of the specific gravity of the operator professions is noted to increase the meaning of the noise of the average levels (below 80 dBA). These levels do not cause hearing losses, but, as a rule, it is distinguished by interfering, annoying and tiring actions that are summed up with

such from tense labor and with an increase in the experience of work in the profession can lead to the development of extracurral effects that manifest themselves in general general disorders and diseases. In this regard, the biological equivalent of actions on the body of noise and neuro-strained work was justified, equal to 10 dB of noise per category of the labor process (Suvorov G.A. et al., 1981). This principle is based on the active sanitary standards for noise differentiated taking into account the tensions and severity of the labor process.

Currently, much attention is paid to the assessment of the professional risks of the health of working, including those caused by the adverse effects of industrial noise.

In accordance with ISO 1999.2 Standard "Acoustics. Determination of the professional effects of noise and evaluating hearing impairment caused by noise »can evaluate the risk of hearing disorders depending on the exposure and predict the likelihood of occupational diseases. Based on the mathematical model of the ISO standard, the risks of the development of professional hearing loss in percentage, taking into account the domestic criteria of professional hearing loss (Table 11.1). In Russia, the degree of professional hearing loss is estimated at the average hearing loss in three speech frequencies (0.5-1-2 kHz); The values \u200b\u200bof more than 10, 20, 30 dB correspond to the 1st, II, II I-th degree Reducing hearing.

Considering that the decline hearing I-th degrees with rather highly probability can develop and without noise effect as a result age-related changesIt seems to be inappropriate to use the I-Ju degree of hearing decline to assess the safe experience of the work. In this regard, the table presents the calculated working experiences, during which hearing loss of II and III degree may develop depending on the level of noise in the workplace. Data is given for different probabilities (in%).

IN table. 11.1.the data for men are given. In women, due to a slower, than in men, the increase in age-related hearing changes, the data is slightly different: for the experience of more than 20 years, there are more facial experience for 1 year more than in men, and for more than 40 years - for 2 years .

Table 11.1.Work experience before the development of hearing losses exceeding

criterial values, depending on the noise level in the workplace (at 8-hour exposure)

Note. digger means that the work experience is over 45 years.

At the same time, it should be noted that the standard does not take into account the nature of labor activity, as provided for in the noise sanitary standards, where the maximum permissible levels of noise are differentiated by categories of gravity and tensions of labor and thereby cover the nonspecific effect of noise, which is important to preserve health and health. persons operator professions.

11.3. Normation of noise at workplaces

The prevention of the unfavorable effect of noise on the body of working is based on its hygienic rationing, the purpose of which is to substantiate the permissible levels and the complex of hygienic requirements that ensure the prevention of functional disorders or diseases. In hygienic practice, extremely permissible levels (remote control) for jobs that allow deterioration and change of external activity indicators (efficiency are used as a rationing criterion

and performance) with a mandatory return to the previous system of homeostatic regulation of the source functional state, taking into account adaptation changes.

Noise rationing is carried out according to the complex of indicators, taking into account their hygienic significance. The effect of noise on the body is evaluated by reversible and irreversible, specific and non-specific reactions, a decrease in operability or discomfort. To preserve the health, performance and well-being of a person, the optimal hygienic rationing should take into account the type of labor activity, in particular, the physical and non-surreimed components of labor.

The impact of the noise factor on a person consists of two components: load on the hearing body as a system that perceive sound energy is auraral effectand impact on the central links of the sound analyzer as a system for receiving information - extraural effect.To estimate the first component there is a specific criterion - "fatigue of an hearing body", expressed in the displacement of the thresholds of the perception of tones, which is proportional to the magnitude of the sound pressure and the exposure time. The second component was named nonspecific influencewhich one can objectively assess the integral physiological indicators.

Noise can be considered as a factor involved in the efferent synthesis. At this stage, in the nervous system there is a comparison of all possible efferent influences (insertion, reverse and search) in order to develop the most adequate response. The effect of strong production noise is such a factor of the external environment, which by its nature also affects the efferent system, i.e. It affects the process of forming a reflex reaction in the effect of effectant synthesis, but as a flat-end factor. At the same time, the result of the possibility of the situation and starting effects depends on their strength.

In cases of installation on activities, the situation should be an element of stereotype and, therefore, do not cause adverse changes in the body. At the same time, the grave to noise in the physiological sense is not observed, the severity of fatigue and the frequency of nonspecific disorders increases with an increase in the experience of working in noise. Consequently, the mechanism of action of noise can not be limited by the participation factor in

placement afferentation. In both cases (noise and voltage), we are talking about the load on functional systems Higher nervous activity, and, consequently, the genesis of fatigue with such an impact will be similar.

The criterion for the optimal level for many factors, including for noise, one can consider such a state of physiological functions, at which this noise level does not contribute to their voltage, and the last entirely determined by the work performed.

Labor tension consists of elements included in the biological system of reflex activity. Analysis of information, the amount of RAM, emotional voltage, functional voltage of analyzers - all these elements are loaded in the process of work, and naturally, their active load causes the development of fatigue.

As in any case, the response to the impact consists of the components of specific and non-specific characters. What is the proportion of each of these elements in the process of fatigue - the question is unresolved. However, there is no doubt that the impact of noise and tensions of labor cannot be considered one excluding the other. In this regard, the effects mediated through nervous system (fatigue, reduced performance), both for noise, and for labor tensions have high-quality similarity. Industrial and experimental studies using socio-hygienic, physiological and clinical methods and indicators confirmed these theoretical provisions. On the example of the study of different professions, the magnitude of the physiological and hygienic equivalent of noise and the tension of neuro-emotional labor, which was within 7-13 dba, i.e. On average 10 dBA per one category of tension. Therefore, an assessment of the operator's labor process intensity is necessary for a full hygienic assessment of the noise factor in the workplace.

Maximum permissible levels of sound and equivalent levels of sound at workplaces, taking into account the tensions and severity of labor activity are presented in table. 11.2.

A quantitative assessment of the severity and strength of the employment process should be carried out in accordance with the criteria of the Guide 2.2.2006-05.

Table 11.2.Maximum permissible sound levels and equivalent sound levels on workplaces for labor activities of different categories of gravity and tension, dBA

Note.

For tonal and impulse noise, the remote control of 5 dBAs is less than the values \u200b\u200bspecified in the table;

For the noise created in the premises of air conditioning installations, ventilation and air heating, the removal of 5 dBA is less than the actual noise levels in the rooms (measured or calculated) if the latter do not exceed the valuestable. 11.1. (the correction for tonal and impulse noise is not taken into account), otherwise - by 5 dBa less than the values \u200b\u200bspecified in the table;

Additionally, the maximum sound level should not exceed 110 dBA, and for pulse noise - 125 dBa for pulse noise.

Since the purpose of differentiated rationing of noise is the optimization of working conditions, which occurred combined and very tense with severe and very difficult physical labor are not normalized on the basis of the need for their elimination as unacceptable. However, for the practical use of new differentiated norms, both in the design of enterprises and under the current control over noise levels on existing enterprises, a serious problem is to bring the categories of gravity and labor tensions with the types of work and work premises.

Pulse noise and its assessment. The concept of impulse noise is not strictly defined. Thus, in existing sanitary standards, the impulse noise includes noise consisting of one or more sound signals, each duration of less than 1 s, while the levels of sound in dBA, measured according to the characteristics of the "pulse" and "slowly", differ in at least 7 dB.

One of the important factors determining the difference in reactions to constant and impulse noise is the peak level. In accordance with the concept of the "critical level" of noise with levels above a certain, even very short-term, can cause direct injury to the organ of hearing, which is confirmed by morphological data. Many authors indicate different critical level values: from 100-105 dBA up to 145 dBA. Such noise levels are found at work, for example, in blacksmithing shops, the noise from the hammer reaches 146 and even 160 dBA.

Apparently, the danger of impulse noise is determined not only by high equivalent levels, but also an additional contribution of the time characteristics is likely due to the traumatic effect of high peak levels. The distribution of pulse noise levels have shown that, despite the small total response time of peaks with levels above 110 dBA, their contribution to the total dose can reach 50%, and this value of 110 dBA was recommended as an additional criterion in assessing non-permanent noise to the remote control. Sanitary standards.

The above rules are set to 10 dB pulsed noise lower than for permanent noise (i.e., minus 5 dba is made at an equivalent level), and additionally limit the maximum sound level of 125 dB "pulse", but do not regulate peak values. Thereby existing norms

focus on the raw noise effects, since the characteristic of the "pulse" with T \u003d 40 ms is adequate upper departments The sound analyzer, and not possible traumatic action of his peaks, which is generally accepted at the present time.

Noise impact on working, as a rule, is non-permanent in terms of noise and (or) time of its action. In this regard, a concept has been introduced to evaluate non-permanent noise equivalent sound level.The equivalent level is associated with the dose of noise, which reflects the amount of transmitted energy and therefore can serve as a measure of noise load.

The presence in the current sanitary standards of noise in the workplace, in the premises of residential and public buildings and on the territory of residential buildings as a normalized parameter of the equivalent level and the absence of noise as a dose of noise is explained by a number of factors. First, the lack of domestic dosimeters in the country; Secondly, when measuring noise for residential premises and for some professions (workers, whose hearing body is a working body), the energy concept requires corrections made to the measuring instruments, for noise expressions not in sound pressure levels, but in the values \u200b\u200bof the subjective volume.

Given the emergence of a new direction in hygienic science in recent years to establish the degree of professional risk from various factors of the production environment, including noise, should be taken into account in the future, the amount of noise dose with various risk categories is not so much on specific influence (auditory), but Non-specific manifestations (violations) by other organs and systems of the body.

To date, the effect of noise per person has been studied isolated: in particular, industrial noise - on workers of various industries, employees of the administrative and administrative apparatus; Urban and housing noise - on the population of various categories in living conditions. These studies allowed to justify the standards for a permanent and non-permanent, industrial and household noise in various places and the conditions of the person's stay.

However, for the hygienic assessment of the effects of noise on a person in industrial and outgoing conditions, it is advisable to take into account the total noise effect on the body that

it is possible on the basis of the concept of a daily dose of noise, taking into account the types of human life (work, rest, sleep), based on the possibility of cumulation of their effects.

11.4. Prevention of unfavorable noise

Activities for combating noise can be technical, architectural planning, organizational and medical and prohydration.

Technical means of combating noise:

Eliminate the causes of noise or reduced it in the source;

Weakening of noise on transmission paths;

The direct protection of the working or group of workers from the effects of noise.

The most effective means of reducing noise is the replacement of noisy technological operations on low noise or completely silent. Of great importance is the reduction of noise in the source. This can be achieved by improving the design or installation scheme that produces noise, changing the mode of its operation, the equipment of the noise source with additional soundproofing devices or fences located as close to the source (within its near-field). One of the most simple technical means of dealing with noise on the transmission paths is a soundproofing casing that can close a separate noisy machine assembly (for example, gearbox) or the entire unit as a whole. Shells made of sheet metal with inner cladding sound-absorbing material can reduce noise by 20-30 dB. The increase in the soundproofing of the casing is achieved by applying to its surface of vibration-absorbing mastic, which reduces the levels of vibration of the casing in resonant frequencies and rapid attenuation of sound waves.

To reduce aerodynamic noise generated by compressors, ventilation installations, pneumatic transport systems, etc., the silencers of active and reactive types are used. The most noisy equipment is placed in soundproofing chambers. With large dimensions of the machines or a significant service zone, equip special cabins for operators.

Acoustic finishing of premises with noisy equipment can provide noise reduction in the reflected audio field area by 10-12 dB and in the direct sound area up to 4-5 dB in octave frequency bands. The use of sound-absorbing cladding for the ceiling and walls leads to a change in the noise spectrum towards lower frequencies, which even with a relatively small reduction in the level significantly improves the working conditions.

In the multi-storey industrial buildings, the protection of premises from structural noise(extending the construction of the building). Its source can be manufacturing equipment that has a tough connection with enclosing structures. The weakening of the transfer of structural noise is achieved by vibration insulation and vibration absorption.

Good protection against shock noise in buildings is the device "floating" floors. Architectural and planning solutions in many cases predetermine the acoustic regime of industrial premises, facilitating or making it difficult to solve problems for their acoustic improvement.

The noise regime of industrial premises is due to dimensions, shape, density and types of arrangement of machines and equipment, the presence of a sound-absorbing background, etc. Planning activities should be directed to the localization of sound and reduce its distribution. Rooms with sources high level Noise, if possible, should be grouped in one zone of the building adjacent to warehouse and auxiliary premises, and separated by PAI corridors with utility rooms.

Considering that with the help of technical means it is not always possible to reduce noise levels in the workplace to regulatory values, it is necessary to apply the means of individual protection of the hearing organ from noise (antifones, plugs). The effectiveness of personal protective equipment can be ensured by the correct selection depending on the levels and spectrum of noise, as well as control over the conditions of their operation.

In a complex of measures to protect a person from adverse action of noise, a certain place is occupied by medical prevention. The most important importance is the conduct of preliminary and periodic medical examinations.

Contraindications for a reception to work, accompanied by noise effect, serve:

Persistent decrease in hearing (at least one ear) of any etiology;

Otosclerosis and other chronic diseases of the ear with an unfavorable forecast;

Violation of the function of the vestibular apparatus of any etiology, including the Menietor's disease.

Taking into account the value of the individual sensitivity of the body to noise, the dispersonal observation of the working first year of work under noise work is extremely important.

One of the directions of individual prophylaxis of noise pathology is to increase the resistance of the body of workers to the unfavorable action of noise. For this purpose, the working noisy professions is recommended daily reception of group vitamins in in an amount of 2 mg and vitamin C in the amount of 50 mg (the duration of the course 2 weeks with a break per week). It should also be recommended to introduce regulated additional interruptions, taking into account the level of noise, its spectrum and the availability of personal protective equipment.

State system of sanitary and epidemiological rationing of the Russian Federation

Federal sanitary rules, norms and hygienic standards

2.2.4 Physical factors of the production environment

2.1.8 Physical environmental factors

Noise at workplaces,

in the premises of residential, public buildings

and on the territory of residential building

Sanitary norms

CH 2.2.4 / 2.1.8.562-96

Ministry of Health of Russia

Moscow

1. Developed by the Research Institute of Labor Medicine Russian Academy Sciences (Suvorov G.A., Waisins L.N., Prokopenko L.V., Kravchenko OK), Moscow Research Institute of Hygiene. F.F. Erisman (Karagodina I.L., Smirnova T.G).

2. Approved and put into effect by the Resolution of the State Committee for Public Administration of Russia of October 31, 1996 No. 36.

3. Instended "sanitary standards of permissible noise levels at workplaces" No. 3223-85, "sanitary standards of permissible noise in the premises of residential and public buildings and in residential buildings" No. 3077-84, "Hygienic recommendations for the establishment of noise levels on workers Places taking into account the tension and gravity of labor "No. 2411-81.

· for the noise created in the premises of air conditioning installations, ventilation and air heating - 5 dBa less than the actual noise levels in the rooms (measured or calculated), if the latter do not exceed the values \u200b\u200bof the table. 1 (The correction for tonal and pulsed noise is not taken into account), otherwise - by 5 dBa less than the values \u200b\u200bspecified in Table. ;

· additionally, the maximum sound level should not exceed 110 dBA, and for pulsed noise - 125 dBA for pulsed noiseI.

5.3.1. Maximum permissible levels of sound pressure in octave bands, sound levels and equivalent sound levels for the main most typical types of labor activity and jobs developed taking into account categories of gravity and labor tensions are presented in Table. .

6. Normated parameters and permissible levels of noise in the premises of residential, public buildings and residential territory

6.1. The normalized parameters of permanent noise are the levels of sound pressure L, dB, in octave bands with medium meterometric frequencies: 31.5; 63; 125; 250; 500; 1000; 2000; 4000; 8000 Hz. For an indicative estimate, it is allowed to use the sound levels L A, DBA.

6.2. The normalized parameters of non-permanent noise are equivalent (energy) levels of sound L AEKV., DBA, and maximum sound levels L amax., DBA.

Evaluation of non-permanent noise for compliance with permissible levels should be carried out simultaneously on the equivalent and maximum sound levels. Exceeding one of the indicators should be considered as a non-compliance with these sanitary standards.

6.3. The permissible values \u200b\u200bof sound pressure levels in octave bands of frequencies, equivalent and maximum sound levels of penetrating noise in the premises of residential and public buildings and noise on the territory of the residential building should be taken in Table. .

Maximum permissible levels of sound pressure, sound levels and equivalent sound levels for the main most typical workshops and jobs

Permissible levels of sound pressure, sound levels, equivalent and maximum sound levels of penetrating noise in premises of residential and public buildings and noise on the territory of residential building

Note.

1. Permissible noise levels from external sources in the premises are established under the condition of providing regulatory ventilation of the premises (for residential premises, chambers, classes - with open versions, fraumugas, narrow windows).

2. Equivalent and maximum levels of sound in dBA for noise created in the territory of automobile, rail transport, 2 m from the enclosing structures of the first echelon of noise protection types of residential buildings, buildings of hotels, hostels facing the main streets of the citywide and district value, iron Roads, allowed to take 10 dba above (correction \u003d + 10 dBA) specified in positions 9 and 10 Table. .

3. Levels of sound pressure in octave frequency bands in dB, sound levels and equivalent sound levels in dBA for noise generated in rooms and in areas adjacent to buildings, air conditioning systems, air heating and ventilation, etc. engineering equipment, It should be taken by 5 dBa below (amendment \u003d - 5 dBA) specified in Table. (The amendment for tonal and impulse noise in this case should not be taken).

4. For a tonal and impulse noise, an amendment should be taken - 5 dBA.

List of references

1. Guide 2.2.4 / 2.1.8.000-95 "Hygienic Evaluation physical factors Industrial and Environment. "

2. Guidelines 2.2.013-94 "Hygienic criteria for evaluating working conditions in terms of harmfulness and danger of factors of the production environment, gravity, labor intensity."

3. Suvorov G. A., Denisov E. I., Waisins L. N. Hygienic rationing production noise and vibrations. - M.: Medicine, 1984. - 240 s.

4. Suvorov G. A., Prokopenko L. V., Yakimova L. D. Noise and Health (Ecological and hygienic problems). - M: Union, 1996. - 150 s.

The rationing of noise in the workplace is carried out in view of the fact that the human body, depending on the frequency response, responds differently to the noise of the same intensity. The higher the frequency of the sound, the stronger its impact on the human nervous system, i.e. the degree of harmfulness of noise depends on its spectral composition.

The noise spectrum shows how the frequency area accounts for the greatest part of the entire sound energy contained in this noise.

Sanitary rationing of noise is scientific justification An extremely permissible level of noise, which, with daily systematic effects during the entire working time, has no diseases of the human body and does not interfere with normal work.

The requirements for the maximum permissible levels of noise are set out in the sanitary standards of CH 2.2.4 / 2.1.5.562-96 "Noise in the workplace, in the premises of residential, public buildings and in the residential building. Characteristics measured in dBA. The dube measurement unit is an indicator of noise close to the perception of human hearing.

In tab. The values \u200b\u200bof permissible sound pressure levels are given in octave stripes of frequencies and exclude them in the workplace of industrial premises and in the dining rooms of restaurants, cafes, canteens, bars, buffets, etc.

The overall level of sound pressure in the dBA for auditory perception corresponds to noise level at a frequency of 1000 Hz.

Normated sound levels (dBA) by 5 dB above sound pressure levels in an octave strip of 1000 Hz.

The values \u200b\u200bspecified in these norms ensure that no optimal (comfortable) working conditions are achieved, and such a position at which no harmful effect of noise is eliminated or minimized.

Even short-term stay of people in rooms with a sound pressure level of 120 dB at any frequency of the octave strip is prohibited.

Table data can be represented graphically in the form of regulatory curves (Fig.).

Fig. Limit spectra of sound pressure

Each curve has its own index (PS-50 and PS-75), which characterizes the limit spectrum with a medium-meter frequency of 1000 Hz.

To measure the sound pressure level in the DB on each medium-meter frequency of the octave strip and the overall level of sound in the dBA, a set of devices constituting the noise-measuring path (Fig.).

Fig. Structural scheme of Noiseomer

The scheme includes a microphone M, which converting sound vibrations into an electric current, which is enhanced in the amplifier y, passes through an acoustic filter (frequency analyzer) AF, rectifier B and fixed by the directional indicator and with a scale, progressive in dB.

The operation of the noise analyzer is based on the principle of fluctuations in the interference or phenomena of resonant gain.

The noise analyzer is an electrical outline that enhances the oscillations of only the specified frequency, not passing and, therefore, does not enhance the sounds of other frequencies. As a result, the arrow at the output of the device shows the size of the sound energy concluded in this frequency band. By changing the analyzer setting to different frequencies, the sound pressure level is indicated for the frequency band under study, which are made in the form of a noise spectrum.

An acoustic workplace is called the area of \u200b\u200bthe sound field in which the working place is located. In most cases, the working place is considered to be the zone of the sound field at a distance of 0.5 m from the car from the working bodies of the control panel and at an altitude of 1.5 m.

Noise measurement is produced in the following sequence:

reveal the most noisy equipment and measure the spectrum of noise at workplaces;

determine the time for shifting during which the operating is exposed to noise;

compare values \u200b\u200bof the measured noise levels with the values \u200b\u200bof the limit spectrum of existing standards.

Noise - This is an erratic combination of sounds of different frequencies and intensity (forces) arising from mechanical oscillations in solid, liquid and gaseous media that have an adverse effect on the human body.

Noise contamination is one of the forms of physical pollution of habitat, which causes harm to the body that reduces performance, attention.

Cause occurrencenoise can be mechanically, aerodynamic, hydrodynamic and electromagnetic phenomena. The noise accompanies the work of numerous machines and mechanisms.

Hygienic rationing of noise In the workplace, the GOST 12.1.003-83 is determined with the additions of 1989 "Noise. General Safety Requirements" and Sanpin 2.2.4 / 2.1.8.562-96 "Noise in the workplace, in the premises of residential and public buildings and in residential building ".

When normalizing noise, two methods are used:

1. rationing at the limit noise spectrum;

2. rationing of the sound level in decibels A (dBA) on the scale "A" of the noiseomer.

The first method of rationing It is the main noise for constant noise. At the same time, the levels of sound pressures in 9 octave bands from 31.5 to 8,000 Hz are normalized. The rationing is conducted for various jobs depending on the nature of the work performed on them. The maximum permissible levels are related to permanent jobs and to the working areas of the premises and territories.

The rationing also applies to all moving vehicles.

Each of the spectra has its own PS index, where the digit (for example, PS-45, PS-55, PS-75) denotes a permissible sound pressure level (dB) in an octave strip with a medium-meter frequency of 1000 Hz.

The second rationing method The overall noise level (sound) measured on the Summer scale "A". If the scales of the noiseomer "C" reflects the level of sound pressure as a physical quantity, dB, then the scale "A" has a different sensitivity to different frequencies, copying, imitating the sound sensitivity of the human ear. And it is "deaf" at low frequencies and only at a frequency of 1000 Hz sensitivity it is aligned to the sensitivity of the device, the true value of the sound pressure, see Fig.3.

This method is used to estimate constant and non-permanent noise. The sound level is associated with the limit spectrum (PS) dependence:

L a \u003d Ps + 5, dBA.

Normated parameter non-permanent noise L and eq. (DBA) is an equivalent sound level of sound that has the same impact as permanent noise. This level is measured by special integrating noiseomers or calculated by the formula. When measured, they are recorded on the sheets by the chemicals or read with the noiseomer readings and these are specially processed.

For tonal and impulse The noise of the remote control should be taken by 5 dBa less than the values \u200b\u200bspecified in Guest

Maximum permissible sound levels and equivalent sound levels at workplaces according to CH 2.2.4 / 2.1.8-562-96 is established depending on the categories of gravity and labor tension. The standard prescribes zones with a sound level of more than 80 dBA to designate special signs working in them to provide PPE. In areas where sound pressure levels exceed 135 dB in any of the octave bands, the temporary stay of a person is prohibited.

Measuring noise are carried out in order to determine the levels of sound pressures on workersand evaluating compliance with their current standards, as well as to develop and evaluate noise reduction activities.

The main device for measuring noise is a sound meter. The range of measuring noise levels is usually 30-130 dB at frequency boundaries of 20-16,000 Hz.

Measuring noise at workplaces are produced at the ear level when not less than 2/3 of installed equipment. New domestic Skummers VSM-003-M2, VSM-201, VSM-001 and foreign firms are used: Robotron, Bruhl and Kier.

Establishing the noise characteristics of stationary machines Made by the following methods (GOST 12.0.023-80):

1. Method of free sound field (in open space, in ground cameras);

2. Method of the reflected sound field (in reverb chambers, in alloying rooms;

3. Method of an exemplary source of noise (in conventional rooms and in reverb chambers)

4. Measurement of noise characteristics at a distance of 1m from the outdoor circuit of the machine (in the open space and in a muffled chamber).

The most accurate are the first two methods. In the passport to the noise car, the level of sound power and the nature of the noise direction is viewed.

In the free sound field, the audio intensity decreases in proportion to the square of the distance from the source. The reflected field is characterized by constant sound pressure levels at all points.

The purpose of measurements is to provide appropriate working conditions, obtaining objective data on the machine, evaluation of constructive perfection and quality of manufacture. Measurements are carried out in 3-points, including workplace. Measurements in the cabins are carried out with closed windows and doors.

2.Vides emergency rescue work, ways to maintain and base management.

The level of emergency and rescue and other urgent works in the elimination of emergencies and their consequences largely depends on the clear work of the head of the object, the Chairman of the Commission on emergency situations (CCD), governing body (headquarters, department, sectors for Civil Affairs) and formation commanders. The procedure for the organization of work, their types, volume, techniques and methods of conducting depends on the situation that established after the accident, the degree of damage or destruction of buildings and structures, technological equipment and aggregates, the nature of damage to utility and fires and fires, features of the construction of the territory of the object, residential sector and other conditions.

In the event of a production accident, the workers and employees of the enterprise about the danger are immediately carried out. If a leakage (emission) of potent poisonous substances occurred at the enterprise during an accident, then the population residing in the immediate vicinity of the object and in the directions of the possible propagation of poisonous gases.

The head of the object Head (Chairman of the object of the object) reports on the accident and measures taken into higher authorities (authorities) for production subordination and the territorial principle of the CCD. Immediately organizes intelligence, assesses the situation, makes a decision, sets the tasks and manages emergency and rescue and other urgent work.

Emergency and rescue work has to be carried out with explosions, fires, collaps, collaps, after hurricanes, tornadoes, strong storms, with floods and other disasters. Emergency medical (prefigured) help must be rendered directly at the site of work, then the first medical and evacuation into medical institutions for specialized treatment. The provision of assistance to victims in most cases does not tolerate delay, since after an expiration of even a minor time, all efforts may be useless.

The federal law "On emergency and rescue services and the status of rescuers" establishes a number of important principles of rescue services and formations. It:

Priority tasks to save the lives and the preservation of the health of people who are in danger;

Unitimate guidance;

Risk justification and security during the ASDR;

The constant readiness of emergency rescue services and formations to operational response to emergencies and work on their liquidation.

In accordance with the Regulations on the RSCs, leadership of the EFC liquidation works, i.e. First of all, the CSD, is one of the main tasks of the KSC of the executive authorities of the constituent entities of the Russian Federation, the KSC of local governments and the COP of enterprises and organizations.

However, Federal law "On emergency rescue services and the status of rescuers" it was established that the heads of emergency and rescue services and the formations that arrived in the Emergencies zone were the first to commit themselves to the authority of the head of the emergency to eliminate the emergency in accordance with the legislation of the Russian Federation.

No one has the right to interfere in the activities of the head of the Emergencies Ministry of Emergencies, otherwise he is in order to remove it in the prescribed manner from the execution of duties and adopting a guideline or appointing another official. Decisions of the head of emergency response in the emergency area are mandatory for citizens and organizations located there.

The specifics of rescue work is that they must be performed in a short time. For specific conditions, they are determined by various circumstances. In one case, this is the salvation of people who were under the wreckage of buildings designs, among the damaged technological equipment, in the diluted basements. In another, this is the need to limit the development of the accident to prevent the possible offensive of the catastrophic consequences, the emergence of new foci of fires, explosions, destruction. In the third, the fastest restoration of disturbed utility and energy networks (electricity, gas, heat, sewage, plumbing).

Not to take into account the great importance of the time factor when carrying out urgent work is also impossible, including even if there are no injured in needing emergency. In order to ensure the protection of public order and the safety of the property, commandant posts, posts of regulation, protection and cordon, and checkpoints and patrols are also organized.

For the immediate leadership of emergency rescue and other urgent works on each site or object of work, the head of the site is appointed from among the responsible officials of the object specialists of the GO services or employees of the Affairs and Emergencies authorities. It puts specific tasks to the attached to the formations, organizes food, shifts and rest of the personnel. Commands of formations, the head resembles the main techniques and methods of performance, determines measures for medical and logistical support, the period of start and end of work.