1. Mechanical factors are characterized by kinetic, potential energy and mechanical action on man: elements that move and spin, noise, vibration, shock wave acceleration, gravitational pull, static stress, smoke, fog, dust in the air, abnormal barometric pressure and others.
Occupational noise - a collection of different by the tone and strength sounds which arise from vibrational motions of different bodies and are transmitted in the air.
For long-acting human noise reduced sharpness of hearing, blood pressure changes, diminished attention, increases energy consumption for the same exercise, there is increased jitters.
In areas of trade noise level should not exceed 80 dB, which is the maximum permissible level of noise.
For noise control are used collective (shock-absorbing walls, screens, etc..) and individual (ear plugs, headphones) remedies.
EXAMPLE. Since 2002, our aircraft in terms of noise pollution can not perform landing at European airports. Therefore, our airlines flying on Boeing B-737 (747) and Airbus A-310, A-320.
Vibration - complex oscillating process that occurs at periodic shifts in body weight from equilibrium, as well as a periodic change of body shape that it was in a static state.
With prolonged exposure to vibration in excess of the GDR in workers may experience vibration disease.
The main methods of anti-vibration is the use of spring and rubber gaskets, dampers, shock absorbers, special foundations for equipment, balancing mechanisms, rotating, active methods of suppression of signal.
2. Thermal factors - have heat energy (temperatures of heated and refrigerated items and surfaces, temperatures of fires, chemical reactions, abnormal microclimate parameters).
As a result of high temperatures occur in humans burns, heat stroke. At the result of reduced temperature occur body frostbite and hypothermia.
The main hazards that accompany the action of thermal factors are increased or decreased temperature, toxic products of combustion, smoke, reduced oxygen concentration and increased concentration of carbon dioxide (СО2) and carbon monoxide (CO) emissions. Inhalation of products of combustion air with little oxygen (less than 14%), a high content of carbon dioxide and carbon monoxide coordination is lost, develops poisoning.
Indirect negative factor with significant forms of thermal factors, such as fire, there is a psychological factor that increases the material losses and casualties.
The main methods of preventing and combating manifestations of thermal factors is usage of equipment in a fire- and explosion-proof version, automatic systems for fire prevention, fire and special extinguishing.
3. Electrical factors are electricity, static electricity, ionizing radiation, electric field.
An electric current passing through the human body, causes thermal, electrolytic, mechanical and biological negative effect.
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Common electrical injuries include electric shock, at which the excitation of the muscles of the human body is, which can cause convulsions, stop breathing and heart.
Local electrical injuries include burns, skin metallization, electrical plates, mechanical damage and electrooftalmia.
Factors that affecting the degree of destruction of human by electric shock:
Ä
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Ä voltage
Ä time of passing current through the human body
Ä kind of current (direct or alternating)
Ä current path in the human body,
Ä frequency of alternating current,
Ä total electrical resistance.
Technical remedies against electric current are isolation, grounding, vanishing, low voltage, safety signs, personal protective equipment, and others.
4. Electromagnetic factors are light, ultraviolet and infrared radiation, electromagnetic radiation, magnetic field.
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Sources:
of electromagnetic fields are atmospheric electricity, solar radio emission and galaxies, electric and magnetic fields of the Earth, artificial sources of radiation;
of permanent magnetic fields are electromagnets, solenoids, pulse settings half periodic or capacitor type, molten and metal -ceramic magnets.
Action of electromagnetic fields on humans depends on tension of electric and magnetic fields, energy flow, the oscillation frequency, the size of the irradiated surface of the body and the individual characteristics of the organism.
The negative effect of permanent magnetic and electro-static fields depends on the tension and time of action. As a result of field action that have tension exceeding the maximum permissible level, developing disorders of the nervous, cardiovascular system, digestive organs and some blood biochemical parameters.
The most effective method of protection against electromagnetic radiation is setting reflecting or absorbing screens.
5. Ionizing radiation - is a quantum (electromagnetic and corpuscular) radiation. Influence of such radiation causes appearance of ions from the neutral atoms.
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Ionizing of living matter bring to the disruption of molecular connections and changes in the chemical structure of different compounds. Chemical composition changes of molecules considerable part cause cell ruin.
Diseases caused by ionization can be sharp or chronic.
Sharp destruction comes at irradiation with large doses during the short period of time. Large doses of X-ray and Gamma radiation can entail death.
Safety of workings with radioactive compounds is provided by such way: establishment of maximum allowable irradiation doses by the different types of ionizing radiation; application of defense with time and distance; use of personal protection equipment.
6. Chemical factors – caustic, toxic, poison, flammable and explosive materials.
On the impact for man chemical materials are diveded on:
- Generally toxic,
- Irrigative,
- Sensitizing (after short time influence on organism it causes enhanceable sensitiveness to this material- allergic diseases)
- Carcinogenic (draw development of malignant tumors)
- Mutagene (draw change in the genetic cells code of organism)
Harmful materials often develop complex negative influence on the organism. For example an ammonia has a strong irritating action and simultaneously generally toxic.
On the hazard influence on organism rate harmful and toxic substance are divided on:
I class – extraordinarily dangerous: most chlorine insecticides.
II class – high dangerous: acids, swinging majority of pesticides.
III class – moderately dangerous: a vanillin, mineral oil, synthetic cleansers, tobacco, grain dust.
IV class – low hazard: ammonia, acetone, benzol, ethyl spirit, dust.
In order to eliminate poisoning possibility and appearance of professional production caused diseases there are special maximum allowable concentrations (MAC) of harmful substances in the working environment. These norms are provided by sanitary code.
Maximum allowable concentrations (MAC) of harmful substances in the working environment air are the concentrations, which during 8 hours or another time, but no more than 41 hours per week, everyday work (except weekend) cannot cause disease or deviation in the health state. Such deviations are checked with the help of modern research methods in the period of work or in the remote terms of life of given or next generation.
At simultaneous content in midair working area of a few harmful substances with the same directed action the sum of its actual concentration ratio (S1, S2, S3,…Sn) in midair to its MAC (MAC1, MAC2, MAC3,…MACn) must not exceed 1.
Calculation is carried out with a formula:
7. Biological factors – dangerous and harmful micro and macro organisms, products of their vital activity and vital activity of people.
Influence of separate types of living organisms on a man can in some cases make a serious danger.
Pathogenic microorganisms draw the disease of man, in that number by infectious disease.
Complex of measures for epidemiology safety increasing is directed on:
Removal or dismissing of action even one of next factors:
- Infection source
- Ways of transmission and distribution of infection
