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Silicosis is a disease of the lungs resulting from lengthy and repeated exposure to airborne crystallized silica. Both medical professionals and those who work in mines, quarries, and foundries have long recognized silicosis. Its current name is attributed to Visconti and derives from the Latin term silex. Since silica makes up approximately 12% of the earth's crust, any occupation that involves work with sand or rock is likely to involve exposure to this mineral.
Repeated exposure to silicon dioxide or crystallized silica causes fine levels of dust to be deposited in the lungs. As more dust is deposited, the lungs react in several ways. They become inflamed, create lesions, and then form nodules and fibroids. Often, there are no perceivable symptoms for a number of years, so silicosis is frequently difficult to diagnose at its onset.
As silicosis advances, however, symptoms in varying degrees of severity begin to occur. Those affected may experience shortness of breath, fever, chest pain, exhaustion and dry cough. More advanced forms of the disease will show cyanotic mucus membranes and asthma or other breathing difficulties, similar to advanced emphysema.
The disease may also leave the lungs more vulnerable to tuberculosis, and has also been linked to the development of autoimmune disorders such as lupus and rheumatoid arthritis. Since silicosis affects the lungs, it can also affect the vessels leading to the heart, so heart disease and enlargement are common. In the 1990s, silicon dioxide was classified as a known carcinogen, and as such, silica exposure is now linked to the development of lung cancer.
Compute tomography (CT) scans and x-rays recognize the lesions and nodules associated with silicosis. Diagnosis is also aided by examining the symptoms of those who may be exposed to silicon dioxide. OSHA recommends examining all co-workers of a patient with this disease, since even the most benign contact to silica dust can, over time, lead to its development. For example, a supervisor of a drilling operation who does not actually drill materials may still be at risk if he or she is on the job site.
There is no cure for silicosis. It is an irreversible condition which can only be addressed by treating the symptoms. Such treatments may include cough syrups, bronchodilators (asthma medication), antibiotics and anti-tubercular medications. In advanced cases, oxygen is required to address cyanosis and oxygen deprivation. Additionally, those afflicted are advised to avoid exposure to smoking, to any further silica and to other lung irritants.
Since no proven cure for silicosis has been identified, emphasis has shifted to prevention. In well-developed countries, workers who are exposed to silica use special respirators to prevent dust from getting into their lungs. Special filters for drilling equipment have been developed and dry mining is infrequent. Anything that can reduce the silica dust content in the air, particularly the use of water, is employed to make working conditions safer.
Much of the listed precautions developed because of the liabilities for employers, as well as the risk to workers. Silica exposure lawsuits abound. When the West first began to industrialize, silicosis contraction was almost a certainty if one was employed as a miner or bricklayer.
In 1930, at least 200 workers died after three months of daily exposure to huge amounts of silica when constructing the Hawk's Nest Tunnel in West Virginia. This tragedy received national attention and influenced employers to find safer methods of working the earth. Currently, awareness and government regulations are resulting in fewer new cases of silicosis. Unfortunately, many newly industrialized countries skimp on the cost of prevention at the expense of their workers. These countries will expectedly see a rise in contraction of silicosis until they evolve guidelines protecting their workers.