From the Guidelines
Silica exposure is associated with an increased risk of lung cancer, particularly in individuals with silicosis, with a 2.4-fold increase in lung cancer mortality 1. The relationship between silica exposure and lung cancer is complex, with some studies suggesting a weaker association when adjusted for cigarette smoking 1.
- A meta-analysis found a significant overall association between silica dust exposure and lung cancer in people without silicosis, with a relative risk of 1.2 (95% CI, 1.1-1.3) 1.
- However, when limited to studies that adjusted for smoking, the overall results were null (relative risk, 1.0; 95% CI, 0.8-1.3) 1.
- The International Agency for Research on Cancer (IARC) classified crystalline silica as a human carcinogen in 1997 1. The evidence suggests that silica exposure, particularly in occupational settings, may contribute to an increased risk of lung cancer, although the association may be influenced by other factors such as cigarette smoking 1.
- Occupational exposures to silica, such as those experienced by workers in industries involving quarrying, mining, or sandblasting, may increase the risk of lung cancer 1.
- The risk of lung cancer associated with silica exposure may be higher in individuals with silicosis, a lung disease caused by inhalation of silica particles 1.
From the Research
Definition and Causes of Silica
- Silica, also known as silicosis, is an occupational lung disease caused by exposure to respirable crystalline silica dust particles 2, 3, 4.
- The disease is characterized by parenchymal lung injury, inflammation, and lung tissue fibrosis, with clinical manifestations ranging from asymptomatic forms to respiratory failure 2, 3, 4.
Diagnosis and Monitoring
- Diagnosis of silicosis is based on clinical history and radiological findings, with strategies for diagnosis, monitoring, and classification of patients proposed in various guidelines 3, 4.
- There is no effective treatment for silicosis, and once diagnosed, patients must avoid all sources of occupational exposure 3, 4, 5.
Pathogenesis and Treatment
- The pathogenesis of silicosis involves the ingestion of inhaled silica particles by alveolar macrophages, triggering inflammation, generation of nodular lesions, and irreversible fibrosis 6.
- Despite the complexity of the disease, several novel possibilities of therapeutic targeting have been uncovered, including the elucidation of silica-induced inflammation cascades and inflammation-fibrosis relations 6.
- However, there are currently no effective treatments for silicosis, and comprehensive management strategies are needed to improve quality of life and slow deterioration 2, 4, 5.
Occupational Exposure and Prevention
- Occupational exposure to respirable crystalline silica dust particles occurs in many industries, including mining, denim jean production, domestic benchtop fabrication, and jewellery polishing 4, 5.
- Recognition and control of silica hazards are essential, especially in developing countries, to prevent outbreaks of silicosis and reduce the risk of respiratory failure and death 4, 5.