What happens to dust in the air you breathe in your lungs?

Here is some information about what happens when you breath in dust……..  I trust you’ll find it informative.


“What happens to dust in the air you breathe in your lungs?Quora – Shreya Thacker, Physical and Respiratory Therapist

Our lungs are self-cleansing.

Throughout the respiratory system, there are various checkpoints that deploy different defenses against the microbes/dust particles.

The first defense is in the form of nasal hair. Nasal hair act like a filter that sifts the inhaled air to remove bacteria/fungi/viruses/any other offensive specks (dust, pollen, etc).

The smaller filtered particles, along with nasal secretions – which is mostly water, form the boogers (yuck, I know).

The larger particles, that often irritate the nasal mucous membranes, trigger a sneeze. This explosive and often violent expulsion of air is usually enough to clear the nose of the irritants.

The second defense is in the form of a sticky, gel-like substance called the mucus. Mucus is famous among children as the snot and among adults as the phlegm.

About a liter of mucus is produced every day by the airways. More, when we’re sick. (This why we don’t notice its presence when healthy)

The purpose of the sticky mucus, among many other things, is to trap dust particles from the inspired air.

The trapped dust and the mucus are constantly moved towards the upper airway (nose and mouth) in a sweeping motion to be expelled by tiny hair-like structures called cilia. Cilia move in a wave-like motion — back and forth — beating 11-14 times/second.

The larger trapped particles that cause throat irritation trigger a cough. The ones in the nose stimulate a sneeze. Alternatively, one could simply spit or blow the mucus out.

However, most of the mucus is swallowed. It passes through the alimentary canal, like food and water, without any adverse effects.

Finally, the smallest of the particles that escape and slide through the cracks in first two defense systems to reach the lungs face the wrath of the immune system.

Macrophages, type of white blood cells, quite literally engulf, ingest, digest, and neutralize the offending agent.

All these mechanisms, when work together, simultaneously and efficiently, ensure the lungs are free of the allergic, disease inducing particles.”


“What are the Effects of Dust on the Lungs? – CCOHS

The lungs are constantly exposed to danger from the dusts we breathe. Luckily, the lungs have another function – they have defense mechanisms that protects them by removing dust particles from the respiratory system. For example, during a lifetime, a coal miner may inhale 1,000 g of dust into his lungs. When doctors examine the lungs of a miner after death, they find no more than 40 g of dust. Such a relatively small residue illustrates the importance of the lungs’ defenses, and certainly suggests that they are quite effective. On the other hand, even though the lungs can clear themselves, excessive inhalation of dust may result in disease.

The lungs are protected by a series of defense mechanisms in different regions of the respiratory tract.

When a person breathes in, particles suspended in the air enter the nose, but not all of them reach the lungs. The nose is an efficient filter. Most large particles are stopped in it, until they are removed mechanically by blowing the nose or sneezing.

Some of the smaller particles succeed in passing through the nose to reach the windpipe and the dividing air tubes that lead to the lungs.
These tubes are called bronchi and bronchioles. All of these airways are lined by cells. The mucus they produce catches most of the dust particles. Tiny hairs called cilia, covering the walls of the air tubes, move the mucus upward and out into the throat, where it is either coughed up and spat out, or swallowed.

The air reaches the tiny air sacs (alveoli) in the inner part of the lungs with any dust particles that avoided the defenses in the nose and airways. The air sacs are very important because through them, the body receives oxygen and releases carbon dioxide.

Dust that reaches the sacs and the lower part of the airways where there are no cilia is attacked by special cells called macrophages. These are extremely important for the defense of the lungs. They keep the air sacs clean. Macrophages virtually swallow the particles. Then the macrophages, in a way which is not well understood, reach the part of the airways that is covered by cilia. The wavelike motions of the cilia move the macrophages which contain dust to the throat, where they are spat out or swallowed.

Besides macrophages, the lungs have another system for the removal of dust. The lungs can react to the presence of germ-bearing particles by producing certain proteins. These proteins attach to particles to neutralize them.

Dusts are tiny solid particles scattered or suspended in the air. The particles are “inorganic” or “organic,” depending on the source of the dust. Inorganic dusts can come from grinding metals or minerals such as rock or soil. Examples of inorganic dusts are silica, asbestos, and coal.

Organic dusts originate from plants or animals. An example of organic dust is dust that arises from handling grain. These dusts can contain a great number of substances. Aside from the vegetable or animal component, organic dusts may also contain fungi or microbes and the toxic substances given off by microbes. For example, histoplasmosis, psittacosis and Q Fever are diseases that people can get if they breathe in organic that are infected with a certain microorganisms.

Dusts can also come from organic chemicals (e.g., dyes, pesticides). However, in this OSH Answers document, we are only considering dust particles that cause fibrosis or allergic reactions in the lungs. We are not including chemical dusts that cause other acute toxic effects, nor long term effects such as cancer for example.

What are the reactions of the lungs to dust?
The way the respiratory system responds to inhaled particles depends, to a great extent, on where the particle settles. For example, irritant dust that settles in the nose may lead to rhinitis, an inflammation of the mucous membrane. If the particle attacks the larger air passages, inflammation of the trachea (tracheitis) or the bronchi (bronchitis) may be seen.

The most significant reactions of the lung occur in the deepest parts of this organ.

Particles that evade elimination in the nose or throat tend to settle in the sacs or close to the end of the airways. But if the amount of dust is large, the macrophage system may fail. Dust particles and dust-containing macrophages collect in the lung tissues, causing injury to the lungs.

The amount of dust and the kinds of particles involved influence how serious the lung injury will be. For example, after the macrophages swallow silica particles, they die and give off toxic substances. These substances cause fibrous or scar tissue to form. This tissue is the body’s normal way of repairing itself. However, in the case of crystalline silica so much fibrous tissue and scarring form that lung function can be impaired. The general name for this condition for fibrous tissue formation and scarring is fibrosis. The particles which cause fibrosis or scarring are called fibrogenic. When fibrosis is caused by crystalline silica, the condition is called silicosis.”

For more information please follow the link above to read the full article

Have a great day! Chris

Dust Monitoring Equipment – providing equipment, services and training in dust fallout management to the mining industry.

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