What to know
Breathing dust from crystalline silica can lead to lung disease. Silica causes inflammation and scarring in the lungs. Excessive exposure to respirable crystalline silica (RSC) can lead to permanent lung damage called silicosis. It is a progressive, debilitating, and sometimes fatal disease. Excessive RCS exposure can also cause other serious diseases including lung cancer, chronic obstructive pulmonary disease (COPD), certain autoimmune diseases, and chronic renal failure.
Symptoms
Symptoms may include:
- Cough
- Fatigue
- Shortness of breath
- Chest pain
There is no known cure for silicosis. Some patients may require a lung transplant. Workers exposed to silica and those who have silicosis are also at increased risk of tuberculosis (TB). TB is a contagious and potentially life-threatening infection.
Excessive exposure to RSC also causes other serious diseases including:
Diagnosing
There are three components to diagnosing silicosis:
- The worker must have a history of being exposed to respirable crystalline silica.
- There must be findings from medical imaging like chest X-rays or high-resolution computed tomography (HRCT) scans or from histopathologic evaluation of lung tissue samples that are consistent with silicosis.
- Other possible causes of the worker's lung disease must be ruled out.
Findings of silicosis are possible with chest x-rays, but HRCT scans have greater sensitivity.
Timeline
The time from initial exposure to when symptoms first appear (the latency period) depends on duration and intensity of exposure. Higher exposures result in shorter latency periods and faster disease development.
There are different types of silicosis. The type with the quickest onset is acute silicosis. This can occur after a few weeks or months of exposure to very high levels of RCS. Acute silicosis causes parts of the lung fill with fluid typically causing severe illness or death.
Accelerated silicosis occurs after high levels of exposure and typically occurs after 5 to 10 years. Chronic silicosis is the most common type. It occurs after 10 or more years of exposure to lower levels of RCS. Both accelerated and chronic types of silicosis have the same radiographic appearance and are set apart based on their different latency periods.
Periodic medical monitoring helps to detect silicosis at early stages. This is important so workers can avoid further exposure and limit disease progression. Healthcare providers who suspect a patient's health problems are caused by RCS should report to their local or state health department.