Silicosis

Summary

• Silicosis is an occupational lung disease caused by inhaling silica dust
• Inhaled silica causes lung scarring and nodules, and progressively hampers breathing
• Silicosis is irreversible, and there is no cure or specific treatment
• The condition is managed by avoiding further exposure and treating concurrent infections and respiratory complications
• Silicosis can be prevented by maintaining high occupational health standards

Alternative names

Pneumoconiosis

What is silicosis and what causes it?

Silicosis is an occupational lung disease caused by inhaling silica dust. Silica is a common mineral found in many types of rock, thus workers at risk are those involved in activities that produce rock dust, for example sandblasting, stone-cutting and drilling.

Inhaled silica dust particles cause scarring and the development of nodules in the lungs, progressively reducing lung function.

Chronic silicosis, the more common form of the disease, takes many years to develop – 10 to 30 years after the initial exposure.

Acute silicosis develops a few weeks to a few years after massive exposure to silica dust.

What are the symptoms of silicosis?

Symptoms may include:

• shortness of breath
• severe cough
• fatigue
• loss of appetite
• chest pains
• fever

How is a diagnosis made?

Silicosis will be suspected if a person has a history of working in a high-risk environment for silica dust exposure.

The doctor will perform a medical examination, which will include taking a detailed occupational history. Lung function tests will also be performed. The diagnosis is confirmed when chest X-rays and other imaging tests such as a CT scan show typical scarring and nodules in the lungs

How is it treated?

Silicosis is an irreversible condition, and has no cure or specific treatment. Managing the disease involves preventing any further exposure to silica dust, and treating complications of the disease.

People with silicosis may be prescribed medications to help keep the airways open. It is also important that they are regularly tested for tuberculosis, and it is advisable that they are immunised against certain other infections such as flu and pneumonia. In cases where TB has developed, a course of TB drugs will be prescribed.

Patients with silicosis are strongly advised against smoking.

What is the prognosis?

As silicosis progresses, breathing becomes increasingly hindered. In the later stages, the disease can become disabling and is often fatal.

Respiratory failure may result from severe fibrosis and emphysema. Heart failure may also result from decreased lung function.

Complications

People with silicosis are at increased risk for developing certain infections, including tuberculosis and bronchitis. When these diseases co-exist, silicosis progresses more rapidly. Concurrent silicosis and TB are known as silico-tuberculosis.

Rheumatoid arthritis is also more common in men with silicosis.

When to call your doctor

If you have an occupational history of potential exposure to silica dust, you should be examined for silicosis, even if you have no obvious symptoms of the disease.

How can it be prevented?

Silicosis can be prevented if occupational health standards are maintained in the workplace. This involves controlling the amount of silica-laden dust produced, and ensuring workers wear adequate protective clothing.

It is also advised that workers in high-risk industries such as construction and mining have regular medical examinations and X-rays. This is particularly important if a fellow-worker is diagnosed with silicosis.

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