Silicosis is scarring and thickening of the lungs caused by inhalation of silica dust. Silicosis reduces lung capacity and can cause symptoms such as chronic cough, shortness of breath, and fatigue. It is a rare disease that develops decades after exposure to silica dust.
Risk factors
Workers in construction, mining, and some manufacturing industries are at an increased risk for developing silicosis due to occupational silica exposure. Silica is found naturally occurring in rocks, soil, and sand and is also found in construction materials including concrete and brick. Tasks such as drilling or grinding concrete, sandblasting, and stonecutting can lead to high levels of silica exposure.
The greatest risks of silicosis were observed among workers employed in the mining and primary metal processing sectors. Increased risk of silicosis was also observed among construction industry workers.
Workers in mining and quarrying occupations may be exposed to silica during processes such as drilling, crushing, or blasting rock and stone.
Workers in iron and steel foundries are exposed to silica dust contained in foundry sand [2].
Metal processing occupations involve operating furnaces, metal smelting, moulding, casting, rolling, and extruding, and related activities. Foundry workers have known exposure to silica in foundry sand. Metal workers are involved in metal shaping and forming, including forging, welding and flame cutting which can release silica into the work environment [3].
Workers can be exposed to silica dust during construction processes such as sandblasting, and breaking, grinding, cutting, drilling or sawing silica-containing materials including concrete, brick and mortar [4].
Figure 1. Risk of silicosis diagnosis among workers employed in each industry group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2016
The hazard ratio is an estimate of the average time to diagnosis among workers in each industry/occupation group divided by that in all others during the study period. Hazard ratios above 1.00 indicate a greater risk of disease in a given group compared to all others. Estimates are adjusted for birth year and sex. The width of the 95% Confidence Interval (CI) is based on the number of cases in each group (more cases narrows the interval).
Figure 2. Risk of silicosis diagnosis among workers employed in each occupation group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2016
