1. PHYSIOLOGY AND HYGIENE OF
LABOUR. PROPHYLAXIS OF
OVERSTRAIN. PHYSICAL FACTORS
OF PRODUCTION
ENVIRONMENT. PROFESSIONAL
DISEASE. CHEMICAL FACTOR OF
PRODUCTION ENVIRONMENT.
PROFESSIONAL POISONING.
2. • Classification of the dust
•
• 1.2. By chemical composition (origin):
• - inorganic (silicon oxide, asbestos, salt, minerals of ores, metals, soul and others);
• - organic (plant, animal, synthetic organic materials, polymers, plastics, gum, colorants (dye-stuff));
• - microbiological (microorganisms, fungi).
• - mixed (different particles of inorganic, organic and biological nature);
• 1.3. By influence on organism:
• - indifferent;
• - toxic;
• - dermatotropic;
• - pneumotropic;
• - allergenic;
• - cancerogenic and others.
3. • 1.4. By form of the particles:
• - amorphous;
• - fibrous;
• - pointy (spiky) and others (see fig. 12.1).
• 1.5. By size of the particles:
• - aerosuspensions – particles with size more than 100 micrometers;
• - aerosols: large dispersible – sizes 100-10 μm. (proper dust)
• medium dispersible – sizes 10 –0.1 μm. (cloud)
• small dispersible – sizes less than 0.1 μm. (fume or smoke)
• 2.5. By formation mechanism:
• - disintegration aerosols (crashing and processing of the solid rocks and materials);
• - condensation aerosols (agglomeration of the atoms or molecules to dust particles)
•
4. • Physical characteristics and classification of noise
• From physical point of view noise represents chaotic elastic air vibrations
of different frequency, intensity and rhythm. (Music represents harmonious
elastic air vibrations).
• From hygienic point of view noise represents various sounds that hinder a
person to work, rest, and sleep, and has negative, irritating effect on him.
• Sound or vibration frequency is expressed in Hertz (Hz) – quantity of
vibrations per second, and by octave – audio band, the upper level of
which is 2 times bigger than the lower one (16-32 Hz; 100-200 Hz etc.).
Perceived by human ear frequency is in the range of 16-20000 Hz that is
enclosed in 10 octaves.
• According to frequency noise is classified into: low frequency, medium
frequency, high frequency, sonic frequency (when one single frequency
sounds), narrow-band frequency (1-3 octaves sound), wideband frequency
(4-6 octaves sound) and “white noise” (all frequencies sound).
