Silicosis is a lung disease caused by breathing in tiny bits of silica, a mineral that can be found in sand, rock, dirt and mineral ores (such as quartz). (1) Over time, an exposure to silica particles may cause scarring in the lungs, resulting in an inflammation of the tissue within the lungs, eventually causing fibrosis, which may harm your ability to breathe efficiently.(2)
Silicosis mostly affects workers exposed to crystalline silica, or silica dust, in occupations such as mining, glass manufacturing, construction work, tunnel work, masonry, sand blasting, ceramics, quarrying, stone cutting and foundry work. (3) Typically silicosis is a chronic disease where symptoms do not develop for many years.
Farmers may also develop silicosis due to an exposure to crystalline silica in the soil of farmland when it's worked, such as plowing or disking. Both plowing and disking may release dust particles into the air that may include silica dust that can be breathed in by the farmer. Breathing in silica dust may irritate the lungs and eventually lead to silicosis.
You get silicosis by breathing in silica dust which irritates the lungs. The development of silicosis causes scarring within your lungs and may cause a buildup of scar tissue possibly resulting in progressive massive fibrosis (PMF) (4).
Silicosis can take weeks to decades of exposure to develop. Once developed, possible side effects may include difficulty breathing, chronic cough, weight loss and fatigue. Over time lung capacity may decrease requiring the support of oxygen or other devices to help with breathing. Silicosis also may increase the risk of other diseases such as tuberculosis, lung cancer, nocardiosis and chronic bronchitis. (4, 5)
There are three types of silicosis:
- Acute silicosis (also known as silicoproteinosis) - takes a few weeks up to a year to develop. Scarring of the lungs is minimal and symptoms may include coughing and a fluid buildup in the lungs resulting in possible low blood oxygen levels.
- Chronic silicosis - takes 10 to 30 years to develop. Scarring of the lungs is more severe and symptoms may include coughing and shortness of breath.
- Accelerated Silicosis - takes under 10 years to develop. Scarring of the lungs is minimal and the symptoms are similar to those of chronic silicosis but the disease develops over a shorter time period.
- Weight loss
- Difficulty breathing
- Scarring of the lungs
- Fluid buildup in the lungs
- Reduced lung capacity
- Low blood oxygen levels (which may lead to cyanosis)
Crystalline silica comes from the breakdown of sand, granite, soil, or other minerals. Silica dust (also known as quartz dust or silicon dioxide) is the most common mineral on the earth's surface. When broken down, the crystalline silica can be distributed through the air in a fine particulate form which can be breathed in by people working on or near the material that is being disturbed. The breakdown of crystalline silica material may include chipping, cutting, drilling or grinding the material into smaller segments/chunks.
There are currently no treatments for silicosis - preventative protection and education is the first and only step for treating silicosis. If you have a concern for developing silicosis due to your profession or hobbies you should use preventative protection to reduce your risk.
When working with or around silica dust, or any dust disturbing job or hobby, wear a protective mask to reduce the amount of silica you breathe in. For example if you are operating a sand blaster for home use, find a respirator that filters out particles (like a half face air purifying respirator) or a respirator that prevents exposure from particles (like a contained environment (CE) abrasive blasting supplied air respirator (SAR).
- Never eat, drink, or smoke near silica dust exposure areas, and wash your hands and face before eating, drinking or smoking.
- Do not use compressed air for dusting areas.
- Try to use wet methods when chipping, sanding, cutting, drilling, and grinding silica containing materials to reduce the amount of dust entering the air.
- Whenever possible substitute non-silica based blasting material for silica based blasting material.
A visit to the doctor is required to diagnose silicosis. A three step process is used to diagnose silicosis. First, the patient must have a known exposure to silica dust (e.g., a job or home near silica dust). Secondly, a chest x-ray must indicate that the patient has damaged lung tissue, and lastly a pulmonary function test must be completed to determine if the patient airways are restricted. A bronchoscopy may also be done using a camera to inspect the lung tissue.
- Silicosis. 2016. American Lung Association. [Accessed October 10, 2016]. http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/silicosis/
- Thomas CR, Kelley TR. A Brief Review of Silicosis in the United States. Environmental Health Insights. 2010; 4:21-26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2879610/
- Silicosis Symptoms, Causes, and Risk Factors. 2016. American Lung Association. [Accessed October 10, 2016]. http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/silicosis/silicosis-symptoms-causes-risk.html
- Learn About Silicosis. 2016. American Lung Association. [Accessed October 10, 2016]. http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/silicosis/learn-about-silicosis.html
- Newman, Lee S. Silicosis. May, 2014. Merck Manual, Environmental Pulmonary Diseases. [Accessed October 10, 2016]. https://www.merckmanuals.com/professional/pulmonary-disorders/environmental-pulmonary-diseases/silicosis