The dangerous particle size causing pneumoconiosis varies from -
Pneumoconiosis

Pneumoconiosis is an occupational lung disease caused by the inhalation of dust.
The development of pneumoconiosis depends on -


The amount of dust retained in the lungs and airways.
The size, shape of the particles → The most dangerous particle ranges from 1 to 5 µm in diameter because they may reach the terminal small airway and air sacs and settle in their linings.
Particle solubility and physiochemical reactivity.

Additional effects of other irritants (e.g. concomitant smoking).

Important pneumoconiosis

Cool worker's pneumoconiosis (CWP) → Coal Dust
Silicosis (grinder's disease) → Silica dust
Asbestosis → Asbestos Dust
Berylliosis → Beryllium dust
Siderosis → Iron dust
Byssinosis → Cotton dust
100-150µm
50-100µm
10-501µm
1-5µm