Industrial dust, its effect on the body, control measures

In hygienic practice of industrial dust is classified according to two criteria: origin and dispersion. Origin distinguish organic (plant, animal), inorganic (metal, mineral) and mixed the dust. This classification does not allow sufficient information for hygienic assessment. Important classification of dust on its dispersion and the method of education. There are aerosols disintegration (generated during grinding of solid substances and aerosols condensation (produced by condensation of heated vapor when cooling).
Depending on the dispersion of aerosols are divided into: 1) dust - all solid particles formed during disintegration, regardless of their size; 2) smoke - condensation aerosols with firm a disperse phase. This includes aerosols produced by the incomplete combustion of fuel, the smoke of ammonium chloride and other
With cars hygiene the most adverse particles smaller than 10 microns, because they either slowly settle, or do not settle and long are suspended in the air. On the size of particles depends on the depth of their penetration into the respiratory tract. Larger particles are trapped in the upper respiratory tract, and small penetrate directly into the alveoli.
Among the important elements of the hygienic characteristics of industrial dust are the chemical composition and the amount of dust in these particular circumstances. Dust may contain toxic contaminants (arsenic, lead, chromium and others), admixtures with irritating and allergenic properties. Especially important is the content in dust free silicon dioxide, as it played a specific role in the pathogenesis of diseases of pneumoconiosis. Matters also solubility and consistency of dust.
The content of dust in the air of various industries varies widely. Dust concentration in the air is determined by the gravimetric method in milligrams per cubic meter. The number of non-toxic dust in the premises shall be not more than 10 mg/m3. The exception is dust containing more than 10% quartz, and asbestos dust, for which the maximum permissible concentration of 2 mg/m3. For dust, containing more than 70% of free silicon dioxide, established maximum permissible concentration of 1 mg/m3. Production dust can act on the body in General and particular tissue. Nasopharynx - natural filter where is delayed by up to 50% of dust particles in the size from 1 to 5 microns.
Protecting the deeper parts of the respiratory tract, upper respiratory tract themselves exposed to dust. The systematic impact of dust first, develop hypertrophic catarrhs, then they become atrophic.
The main problem in the dust pathology is the damage lung tissue and the overall effect of dust on the body. By prolonged exposure through inhalation occurs occupational disease pneumoconiosis, characterized by the growth of connective tissue in the lungs and reduction of a respiratory surface. Currently experimentally and clinically proven to pneumoconiosis, i.e. pulmonary fibrosis may occur by inhalation of different types of dust.
The most dangerous form of pneumoconiosis, progressive and after elimination of dust is silicosis. It occurs most often in workers of ore mining, coal, machine building, glass, porcelain and faience industry and other
The etiology of silicosis caused by the presence in the dust free silicon dioxide (SiO2). The development of silicosis promotes disease of the upper respiratory tract. Has the value of individual sensitivity of the organism, work experience.
The main event against dust is a radical change of the technological process, mechanization, automation and sealing it. Encapsulation allows you to close dusty sources, to localize dust. To dust seeped into the room, simultaneously with the seal used aspiration of dust from cover. An important role in the fight against dust plays a rational ventilation. By type of ventilation should be local exhaust hood.
The main source of dust in mines is drilling. Therefore, the change in the method of drilling also serves as a measure of struggle with dust formation. Dry drilling is replaced by moist, i.e. drilling produce at wetting with water (used to 94-99% of our mines). Wet drilling along with its advantages has some drawbacks: water hydrates the clothing, shoes, air. Drilling reduces dust 30-50 times, but does not eliminate it completely, as the smallest particles bad wetted with water. To increase the wettability of dust to the water add mylonaft, sulfinol, etc. To prevent the spread of dust for blasting apply water curtains.

respirator f-45
Fig. 32. Respirator F-45

The risk of silicosis great sandblast casting. Sand particles with impacts on the item are crushed and create the great dust. One of the measures of fight against dust, when such works is to replace peskostruy hydrostream or jobstream.
Measures to combat dust common to all enterprises, are: 1) shelter sources of dust with dust removal from its education; 2) the medical - periodic medical examinations of workers with translation, if necessary, to another job; preliminary medical examinations so that persons with diseases of the upper respiratory tract and lungs not be allowed to work in dusty shops; 3) personal protective equipment (if other measures have not been sufficient to effect, Fig. 32); 4) systematic monitoring of dust content in the air.