Did you know that breathing unfiltered air in certain high-risk work environments can lead to a debilitating condition called silicosis? Silicosis can be prevented. Awareness of the threat of silicosis and the ways to decrease the risk of disability or death from this condition could save your life.
Silica is everywhere
Silica is a common component of rock, sand, asphalt, brick, and concrete. When materials containing silica are ground, blasted, drilled, or otherwise disturbed—such as when using power tools during mining and construction work—they produce silica dust known as “respirable crystalline silica.” These particles are so tiny they can easily be breathed into the lungs and become lodged there, or they can cross from the lungs to surrounding tissues.
How does silica cause damage?
Respirable crystalline silica, unlike many other pollutants the lungs encounter, is resistant to the natural cleansing mechanisms of our bodies. Rather than getting eliminated by secretions or cough once inhaled, the particles can become stuck inside, and when that happens, the body can form a scar around the silica. The body can then react to the silica in other harmful ways leading to issues such as lung cancer, chronic obstructive pulmonary disease (COPD), kidney disease, or other autoimmune conditions (rheumatoid arthritis, lupus, progressive systemic sclerosis, etc). The lung scarring seen in silicosis can also lead to lung infections such as tuberculosis and pneumonia. This long-term damage is typical of people exposed to small sources of respirable crystalline silica over periods of 15–20 years.
The onset of the disease is usually hard to detect, due to a lack of obvious symptoms until the late stages of silicosis. Often symptoms will start as excess mucous, an irritating cough, or difficulty breathing with exercise, often over a period of months to years. Sometimes this difficulty with exercise is so subtle that those affected may explain it away as a lack of physical fitness or weight gain. This is why monitoring the lungs by more direct means, such as chest x-ray, may be needed if one works in a high-exposure environment. These symptoms may later progress into chest pain, respiratory distress, swollen legs, blue lips, fever, weight loss, or extreme fatigue. In rare severe exposure events, the symptoms can manifest suddenly and catastrophically.
How can silicosis be prevented?
Prevention of this serious condition is important because there is no way to reverse the damage once silicosis develops. Activities that involve the creation of silica dust should be carefully planned in order to minimize exposure. Although the mortality from silicosis has declined over time, certain occupations remain at high risk despite taking precautions. For example, silicosis continues to occur in people who use abrasive silica-containing blasters despite their use of protective respirators. In this case, finding an alternative abrasive blaster that does not use silica is the best means of prevention.
It is impossible to label all potential sources of silica, but one approach proposed by safety experts includes labeling the power tools associated with creating respirable crystalline silica.
The primary tools of prevention include vacuums and water. These engineering controls are useful to decrease the amount of respirable silica dust that enters the air while working with high-risk materials. For example, water may be used on the stone before polishing, a negative pressure ventilation hood may be used before pouring crystalline silica, or a sweeping powder may be applied to a dirty floor before sweeping up silica-containing dust. The Occupational Safety and Health Administration (OSHA) requires employers to provide education and protection against silicosis on the job including engineering controls and PPE. Healthcare providers are in turn required to report cases of silicosis to their local health departments to identify potentially harmful work practices.
American Lung Association, “Silicosis,” https://www.lung.org/lung-health-diseases/lung-disease-lookup/silicosis
American Thoracic Society, “Adverse Effects of Crystalline Silica Exposure,” https://www.thoracic.org/statements/resources/eoh/506.pdf
National Institute for Occupational Safety and Health, “Crystalline Silica,” https://www.cdc.gov/niosh/topics/silica/default.html
Occupational Safety and Health Administration, “Silica, Crystalline,” https://www.osha.gov/silica-crystalline/health-effects