Occupational Diseases / / May 14, 2016
Industrial dust floating in the air is called the working area and slowly settling solid particles ranging in size from a few tens of micrometers to share.Dust is an aerosol, in which the dispersion medium is air and the solids - the dispersed phase.
number of industrial processes that can take place intense dust emission is extremely large.Most dust exposure are many operations in the mining and coal industry, in mechanical engineering (electric welding, The iron, copper and steel workshops, especially chipping and grinding work), in whiteware, textile, flour-milling industry, and others.
industrial dust is classified by the method of formation, chemical composition and size of dust particles.
By way of education:
1) aerosol disintegration, when the dust formed by mechanical action on a solid (crushing, erasing);
2) condensation aerosol formed from the vapor material when cooled (electric welding aerosol, vapor, zinc oxide, iron, etc.).
The chemical composition:
a) plant (grain, flour, cotton, etc.).
b) animal (wool, hair, leather, bone, etc.).;
c) protein (production of protein-vitamin concentrates - IOO).
a) mineral (silica, silicate, etc.).
b) metal (iron dust, zinc, lead, etc.).;
a) mineral and metal (a mixture of iron dust and silica compounds, silica and coal, etc.).
b) a mixture of organic and inorganic (dust and grains of soil, sand and cotton, etc.).
a) visible - the size of dust particles greater than 10 microns, falls out of the air quickly;
b) the microscopic - the size of the dust particles from 10 to 0.25 microns from the air falls slowly;
c) ultramicroscopic - the size of dust particles less than 0.25 microns long in the air, subject to the laws of Brownian motion.
Diseases caused by dust
Dust may have different effects on the body: irritating, allergenic, fibrogenic, toxic.
In a production environment capable of dust lead to the development of occupational diseases: pneumoconiosis, dust bronchitis, bronchial asthma.There may be local and defeat: dermatitis, acne, asbestos warts, conjunctivitis, rhinitis.Some dusts are carcinogenic effect (asbestos).Systematic work with dust may cause increased incidence of workers with temporary disability (colds, bronchitis, pneumonia, tuberculosis, and others.), Which is associated with a reduction in the overall reactivity of the organism.
greatest fibrogenic activity have a quartz-bearing dust, aerosols disintegration with the size of dust particles up to 5 microns (especially dangerous fraction 1-2 mm), and the condensation aerosol particles less than 0.3-0.4 microns.For the development of dust bronchitis primary importance are particles larger than 5 microns.
An additional factor determining the pathological effects of dust, is the form of dust particles.Platelet-shaped particles (mica schists, and some others) are retained longer in the air in a suspended state, and the particles are elongated and fusiform (asbestos, etc.) Penetrate into the deeper respiratory tract and cause of their trauma.
dissolves quickly dust is well displayed and have little pathological effects.Poorly soluble dust linger long in the respiratory tract and have a more pronounced effect.
In particular, kvartseoderzhaschaya dust lingers long in the respiratory tract's, dissolves slowly in biological media to form silicic acid, which is one of the leading factors in the development of silicosis.
attaches importance elektrozaryazhennosti dust particles relevant to the resistance of the aerosol.Several
dusts possesses the absorbency attributes motes can carry the molecules of gases (CO, CO2, methane) that may be a source of toxicity.
Dust can also be a carrier of bacteria, spores, eggs of helminths.
gravimetric method is used for evaluation of dust.dust mass is expressed in milligrams per 1 m3 of air (mg / m3).