What is Silicosis?
Silicosis is a lung affliction caused by breathing dust which contains fine particles of crystalline silica, which comes from chipping, cutting, drilling, or grinding soil, sand, granite, or other minerals. If silica particles are inhaled, they become embedded in the lungs. The lung tissues then react by developing fibrotic nodules and scarring around the trapped particles. The scar tissue makes the lungs hard and stiff. This scarring can greatly reduce the function of the lungs, making it difficult and sometimes painful to breathe.
Any occupation where the earth’s crust is disturbed can cause silicosis. A long list of occupations are known that expose workers to crystalline silica that is inhaled. These include:
- Various forms of mining, such as coal and hard rock mining.
- Construction work.
- Tunnel work.
- Sand blasting.
- Glass manufacturing.
- Ceramics work.
- Steel industry work.
- Stone cutting.
There are four types of Silicosis:
- Chronic simple silicosis
Usually resulting from long-term exposure (10 years or more) to relatively low concentrations of silica dust and usually appearing 10–30 years after first exposure. This is the most common type of silicosis. Patients with this type of silicosis, especially early on, may not have obvious signs or symptoms of disease, but abnormalities may be detected by X-rays. Chronic cough and exertional dyspnea (shortness of breath) are common findings. Radiographically, chronic simple silicosis reveals a profusion of small opacities, typically rounded, and predominating in the upper lung zones.
- Accelerated silicosis
Silicosis that develops 5–10 years after first exposure to higher concentrations of silica dust. Symptoms and x-ray findings are similar to chronic simple silicosis but occur earlier and tend to progress more rapidly. Patients with accelerated silicosis are at greater risk for complicated disease, including progressive massive fibrosis (PMF).
- Complicated silicosis
Silicosis can become «complicated» by the development of severe scarring (progressive massive fibrosis, or also known as conglomerate silicosis), where the small nodules gradually become confluent, reaching a size of 1 cm or greater. PMF is associated with more severe symptoms and respiratory impairment than simple disease. Silicosis can also be complicated by other lung disease, such as tuberculosis, non-tuberculous mycobacterial infection, and fungal infection, certain autoimmune diseases, and lung cancer. Complicated silicosis is more common with accelerated silicosis than with the chronic variety.
- Acute silicosis
Silicosis that develops a few weeks to 5 years after exposure to high concentrations of respirable silica dust. This is also known as silicoproteinosis. Symptoms of acute silicosis include more rapid onset of severe disabling shortness of breath, cough, weakness, and weight loss, often leading to death. The x-ray usually reveals a diffuse alveolar filling with air bronchograms, described as a ground-glass appearance, and similar to pneumonia, pulmonary edema, alveolar hemorrhage, and alveolar cell lung cancer.
Symptoms of Silicosis
Symptoms of silicosis can appear from a few weeks to many years after exposure to silica dust. Symptoms typically worsen over time as scarring in the lungs occurs. Cough is an early symptom and develops over time with exposure to silica dust that is inhaled.
In acute silicosis you may experience fever and sharp chest pain along with breathing difficulty. These symptoms can come on suddenly.
In chronic silicosis, you may only have an abnormal chest X-ray in the beginning and the slowly develop a cough and breathing difficulty. More than a third of people with silicosis have phlegm production and cough. Chronic bronchitis-like symptoms may occur, and the lungs have additional sounds called wheezes and crackles. As extensive scarring progresses over time, you may see signs of chronic lung disease such as leg swelling, increased breathing rate, and bluish discoloration of the lips.
There is no known cure for silicosis, but it is 100 percent preventable. Treatment options are also limited, as physicians ordinarily simply instruct workers to permanently remove themselves from exposure zones, avoid respiratory irritants, and quit smoking. Silicosis often comes with respiratory infections, so antibiotics may also be prescribed.
Patients with silicosis have an increased risk of other problems, such as tuberculosis, lung cancer, and chronic bronchitis. If you are a smoker, quitting may help, as smoking damages the lungs.
If you work in a job that exposes you to silica dust, your employer must, by law, give you the correct equipment and clothing you need to protect yourself. You are responsible for using it—always—and for taking other steps to protect yourself and your family as you leave your job site and head home, a change of clothes is critical to avoid carrying silica dust home.
Engineering controls such as ventilation systems, work displacement, or substitution with an equal-yet-less-hazardous material may be used. Workers should comply with and respect any installed systems. Handling dust properly when it’s created is also important. Dust should never be cleaned with air or other procedures which could reintroduce it into the breathable atmosphere – use wet cleaning methods instead.
NIOSH also recommends that medical examinations occur before job placement or upon entering a trade, and at least every 3 years thereafter.
Compilated by: Paola Perozo