Silicosis: Causes

Silicosis is caused by breathing in high concentrations of silica dust, usually over many years. Shorter periods of more intense exposure may also cause silicosis.

When silica dust enters the lungs, it causes the formation of scar tissue, which makes it difficult for the lungs to take in oxygen. The silica dust may also cause swelling in chest lymph nodes. Silicosis may develop and progress while a worker remains exposed or after exposure to crystalline silica has ended.

Crystalline silica comes in several mineral forms — quartz, tridymite and cristobalite. Natural stone sources of crystalline silica include sandstone, marble and granite. Engineered (artificial) stone typically contains high concentrations of crystalline silica mixed with resin. Some examples of industries where workers may be exposed to silica dust include:

• Engineered stone fabrication   

• Concrete mixing and cutting           

• Sandblasting  

• Brick and stone cutting

• Foundry work

• Construction  

• Mining and quarrying (including metals, stone, aggregate and coal)

• Fracking (hydraulic fracturing for natural gas extraction)

• Pottery and glass making