Silica is a mineral found in sand, rocks, and soil. Silica dust is produced during work processes such as digging and blasting, or grinding, drilling, or sawing silica-containing materials. Silica is used as an abrasive, insulator, and filler in a number of industries.
Silica causes lung cancer, silicosis (scarring of the lungs), chronic obstructive pulmonary disease, autoimmune disease, and chronic kidney disease . CAREX Canada estimates that approximately 380,000 Canadians are occupationally exposed to silica .
Burden of Cancer Results
Approximately 570 lung cancers are attributed to occupational silica exposure each year, based on 2011 cancer statistics. This amounts to 2.4% of all lung cancers diagnosed annually. The cost of these cancers is approximately $562 million.
Most silica-related occupational cancers occur among workers in the construction, manufacturing, and mining sectors (see pie chart).
Occupational exposure limits for silica vary across provinces. Adopting and enforcing a limit of 0.025 mg/m3 (8-hour time-weighted average) for respirable silica in all workplaces across Canada would help to reduce exposure. Ongoing measurement and exposure monitoring are also necessary to ensure levels are kept below the limit.
Related OCRC Research
- Lung cancer in Ontario (results from the Occupational Disease Surveillance System)
- Silicosis in Ontario (results from the Occupational Disease Surveillance System)
- Lung cancer and chronic respiratory disease in the Ontario mining industry
- Silica exposure in a mining exploration operation
- International Agency for Research on Cancer. IARC Monographs Volume 100C: Arsenic, Metals, Fibres, and Dusts (2012).
- CAREX Canada. Silica Occupational Exposure Profile.