Particles ranging in size from 1 to 100 microns can become atmospheric pollutants depending on their source, physical characteristics, and atmospheric conditions. We will not consider other air pollutants such as vapors, which are particularly fine particles resulting from chemical processes in the air, or environmental air pollution originating outside the workplace. The control, prevention, and measures taken to prevent air pollution in the workplace and the surrounding environment are similar.

Part I

The geometry, structure, and origin of dust.

Particles ranging in size from 1 to 100 microns can become atmospheric pollutants depending on their source, physical characteristics, and atmospheric conditions. We will not consider other air pollutants such as vapors, which are particularly fine particles resulting from chemical processes in the air, or environmental air pollution originating outside the workplace. The control, prevention, and measures taken to prevent air pollution in the workplace and the surrounding environment are similar.

Sources and examples of particularly hazardous dust in the workplace:

-mineral powder derived from sources and processes in which silicon is released.

-iron powder, such as copper, cadmium, and their compounds;

– dust from chemical processes, pesticides, etc.;

- plant-based powders such as wood dust, cotton, tea, pollen, etc.;

-spore and soil dust;

Asbestos is a mineral that is particularly dangerous when inhaled. Asbestos can be found in older buildings in pipe insulation, walls, and other areas.

From the perspective of When discussing the impact of dust on human health, the term "aerodynamic diameter of dust particles" is used, which is measured in microns. The dust particles inhaled by a person depend on the aerodynamic size of the dust, the concentration of dust in the air, and even the person’s breathing pattern. What proportion of the respirable¹  Dust particles reach the lungs, and where they settle depends on their aerodynamic size. If the particles are soluble, they could enter the bloodstream and accumulate in organs other than the lungs. This is the case with prolonged inhalation of lead fumes. There is also insoluble dust that causes a local reaction in the body. In this case, the accumulation of particles in the human body depends on their aerodynamic size. When particles measuring 30 µm or larger are inhaled, they are deposited on the inner walls of the nasal cavity. Finer particles could penetrate deep into the lungs, where the cleansing mechanism is much less effective. When particles penetrate deep into the lungs, this can lead to serious diseases such as silicosis (an occupational disease found among miners, glassmakers, stonemasons, and others). The disease is caused by the penetration of silica into the lungs.

particulate matter

Smaller particle sizes increase the likelihood that dust will reach deeper into the respiratory tract. Particles measuring 2 µm are much more dangerous than those larger than 10 µm because they penetrate more easily. Penetration into the lungs depends primarily on particle size, not on particle weight.

To quantify the number of particles per unit volume, they must be separated based on their aerodynamic dimensions. The inhalable fraction is separated¹  and the much more dangerous respirable dust that penetrates deep into the lungs² fraction of the dust. For example, when silicon is present in the air, it is necessary to determine the respirable fraction of the dust.

Powder with a mineral composition It is generated during rock extraction and processing. Plant dust is generated during drying and packaging. The amount—and thus the concentration—of dust in the air depends on the energy expended in the processing, extraction, and other related operations. Air movement can cause dust pollution. The method of transporting loads, as well as the filling and emptying of bags and containers, can be sources of dust formation in the work environment.

If local dust pollution cannot be prevented, dust particles may enter the atmosphere and contaminate areas located at great distances from the source.

Moistened materials generate significantly fewer dust emissions.

Sources of dust emissions:

Mining, loading and unloading operations, stonework, road and residential construction, and all processes involving the processing of rock and mineral products.

Foundry and Metallurgical Processes;

All processes involving abrasive polishing, such as paint or rust removal, cleaning of buildings and small objects, and glass cutting and processing.

Ceramics and glassmaking;

Agricultural activities – soil cultivation, intensive livestock farming, drying of plant products, treatment with pesticides, fertilizers, etc.

Food production and the use of additives;

All loading and unloading processes, as well as the transport of powdered or granular materials.

Any ignition powder At certain concentrations, it can cause an explosion. Self-igniting dust on the ground can become airborne at a certain point, increase in volume, and cause an explosion that is triggered by the ignition of a flammable gas. This can occur with plant and organic materials, as well as with metal and oxidizable dust. Static electricity is very dangerous in such cases. Preventive measures include storing materials and raw materials in such a way as to prevent spillage and the spread of dust, preventing ignition, installing safety valves, and storing materials in an oxygen-depleted environment.

1. “Inhalable fraction of dust for non-fibrous dusts” refers to the mass fraction of all airborne particles that is inhaled by humans through the nose and mouth.
2. “Respirable fraction of non-fibrous dust” refers to the mass fraction of inhaled particles that penetrates the airways not lined with ciliated epithelium. “Respirable fraction for fibrous dusts” is the fraction of all particles characterized by a length greater than 5 micrometers, a diameter less than 3 micrometers, and a length-to-diameter ratio greater than 3.