Silicosis

Silica refers to the compound SiO2, which can be found as amorphous or in a variety of crystalline forms. The most common crystalline form is quartz, one of the most abundant minerals in the Earth’s crust. Other less common forms found in nature include cristobalite and tridymite. Small particle aerosols, including crystalline silica, can be generated by many activities carried out in industries such as construction, manufacturing, and mining. Respirable crystalline silica (RCS) refers to particles small enough to remain suspended in air and be inhaled into the deep lung. Inhaling sufficient amounts of RCS causes a fibrosing interstitial lung disease called silicosis. It also causes or is a risk factor for a spectrum of diseases, including lung cancer, chronic obstructive pulmonary disease, chronic renal disease, increased susceptibility to tuberculosis, and various autoimmune diseases. These adverse outcomes can be prevented by recognizing potentially hazardous conditions and taking steps to control RCS exposures. Unfortunately, despite being preventable, silicosis continues to occur in many settings, including recent outbreaks in emerging settings. In the USA, recently-promulgated regulations by the Occupational Safety and Health Administration (OSHA) provide a comprehensive set of interventions to control RCS exposures and provide RCS-exposed workers with health surveillance for early detection of silicosis. Current treatment options for those with silicosis are limited and primarily consist of avoiding further exposure and symptomatic management, so primary prevention is extremely important.