When the lung cannot clean itself
Pneumoconiosis literally means 'dusty lung'. It is the family of diseases caused by inhaling fine mineral dust at work over many years. Tiny particles slip past the mucociliary escalator and lodge deep in the lung, where alveolar macrophages swallow them but cannot break them down.
Frustrated, the macrophages release inflammatory signals that, over decades, lay down scar tissue. The result is pulmonary fibrosis: stiff, shrunken lung that cannot expand well. On breathing tests this shows up as a restrictive pattern — small volumes and reduced gas transfer — and the main symptom is slowly worsening breathlessness on exertion.
The three classic dusts
[[silicosis|Silicosis]] comes from crystalline silica — the dust of quarrying, sandblasting, stone-cutting, and, increasingly, cutting engineered stone kitchen countertops. Silica is especially aggressive: heavy exposure can cause disease within a few years, and it also raises the risk of tuberculosis and lung cancer.
[[coal-workers-pneumoconiosis|Coal worker's pneumoconiosis]], or 'black lung', comes from years of breathing coal dust in mines. In its simple form it shows as small spots on the chest X-ray; in its severe 'complicated' form the spots merge into large fibrotic masses that destroy lung function.
[[asbestosis|Asbestosis]] is the diffuse lung scarring caused by asbestos fibres — once widely used in insulation, shipbuilding, and construction. Its needle-like fibres are extraordinarily durable and travel to the pleura, the lining of the lung, as well as the lung tissue itself.
Asbestos has its own shadow
Asbestos is worth singling out because, beyond scarring the lung, it leaves marks on the pleura. The most common are pleural plaques — patches of thickening that are themselves harmless but act as a fingerprint of past exposure. Far more serious is mesothelioma, a cancer of the pleural lining that asbestos uniquely causes, often appearing 30 years or more after exposure.