Silicosis is a pneumoconiosis, meaning a lung disease caused by dust. It is caused by breathing in ‘respirable’ particles containing crystalline silicon dioxide (SiO2), commonly called silica. Respirable means the airborne dust fraction that can penetrates deep into the pulmonary alveolar region of the lungs.
What workers are at risk?
Quartz is the most common type of crystalline silica. It is the second most abundant mineral in the earth’s crust meaning silica is found in most rock beds and their sands.
Fine silica dust is formed during breaking, cutting, dressing and polishing stone particularly with tools such as saws, hammers, chisels, pitchers, airguns and angle grinders.
Workers at risk include those in:
- Mining
- Quarrying
- Tunneling
- Construction
- Stone cutting and installation including composite stone used in kitchen, bathrooms, laundries.
- Glass manufacture
- Sand blasters
- Abrasives manufacturing
- Slate works
- Foundries
- Pottery and ceramic manufacture
- Brick and tile manufacture
- Landscapers who cut stone.
The World Health Organization (WHO) recommends all workers exposed to crystalline silica should undergo lifelong health surveillance with annual questionnaire and spirometry and periodic chest x-rays.
How does silica cause disease?
Respirable Crystalline Silica damages lungs in a number of ways. There is a direct cytotoxic action by the crystals on lung tissue. The crystals are also swallowed by immune cells (macrophages)in the lungs. They attempt to chemically destroy the crystals but they themselves die and the toxic chemicals release further damage the lung tissue. New immune cells come to try the same process with the same result. This creates on ongoing cycle of scarring and swelling in the lungs and the chest lymph nodes that continues after silica exposure ceases.
Three types of silicosis occur:
Chronic silicosis
Results from long-term exposure to low concentrations of silica dust for periods more than 20 years. This is the most common form of silicosis.
Accelerated silicosis
Occurs after exposure to higher concentrations of silica over a shorter period of time such as 5 to 15 years.
Acute silicosis
Results from short-term exposure to very high concentrations of silica. The lungs become very inflamed and can fill with fluid, causing severe shortness of breath and a low blood oxygen levels.
Symptoms of Silicosis
These are subtle at first and gradually increase as the scarring of the lungs progresses.
Symptoms include:
- Cough
- Excess phlegm production
- Susceptibility to chest infections
- Shortness of breath
- Weight loss
Silicosis is also known to create other health problems. These include:
- Autoimmune Connective tissue diseases, including rheumatoid arthritis, scleroderma and systemic lupus erythematosus. These can affect all body organs
- Lung cancer
- A high susceptibility to contract Tuberculosis
Monitoring and Diagnosis
A Jobfit health practitioner will take a medical and occupational history to understand if silica exposure may have occurred in the past. This includes worker hobbies.
A physical exam will be performed with a Lung Function test (spirometry) and a chest x-ray. It is preferred that workers have their chest x-ray a week prior to the appointment so the result can be discussed.
Further testing will be advised if required, for example High Resolution Chest CT scan.
Can silicosis be treated?
No. There is no specific treatment for silicosis. Once diagnosed removing the worker from dust exposure and any other respiratory irritants is critical to prevent the disease from getting worse. Workers are encouraged to quit smoking and are provided regular flu and pneumonia vaccines. Supportive treatments are used to minimise symptoms including cough medicine, puffers (if effective) and oxygen. People with severe silicosis may need to have a lung transplant.
PREVENTION IS KEY
- Recognise what materials contain silica, move to non or low silica content materials where possible
- Use low dust methods of work (wet cutting)
- Use of extraction ventilation
- Good housekeeping – regular removal of surface dust with vacuum.
- Dust monitoring
- All workers should wear effective respiratory protection when working with Respirable Crystalline Silica products
Please contact us for more information on our Crystalline Silica Health Screening services, or call 1300 61 61 65.
