Britannica Sources used in this answer

How does breathing crystalline silica dust cause silicosis?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A periodic table element square for silicon shows atomic number 14, symbol Si, atomic weight range, electron configuration, and name. Icons indicate it is a solid nonmetal with diamond crystal structure and equal relative strength. Labels explain each property. — silicon Chemical properties of the element silicon.

Silicosis is a chronic respiratory disease caused by the long-term inhalation of silica dust, which is a compound of silicon and oxygen.12

The disease process begins when very small silica particles—typically one to three microns in diameter—penetrate deep into the finer air passages of the lungs. Once there, these particles are ingested by macrophages, which are scavenger cells responsible for protecting the body from foreign invaders.1

Because the macrophages cannot digest the silica particles, the particles kill the cells instead. As these cells die, they accumulate and trigger the formation of nodules of dense fibrous tissue. Over time, these nodules enlarge and merge into fibrotic masses that distort and damage the lung structure. This fibrosis reduces the elasticity of the lungs, impairs gas exchange, and leads to symptoms such as coughing and severe shortness of breath. There is no cure for this condition, making workplace prevention and respiratory protection essential.13