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Silicosis is a progressive disease that belongs to a group of lung disorders called pneumoconioses. Silicosis is marked by the formation of lumps (nodules) and fibrous scar tissue in the lungs. It is the oldest known occupational lung disease, and is caused by exposure to inhaled particles of silica, mostly from quartz in rocks, sand, and similar substances.


It is estimated that there are TWO million workers in the United States employed in occupations at risk for the development of silicosis. These include miners, foundry workers, stonecutters, potters and ceramics workers, sandblasters, tunnel workers, and rock drillers. Silicosis is mostly found in adults over 40. It has four forms:
  • Chronic. Chronic silicosis may take 15 or more years of exposure to develop. There is only mild impairment of lung functioning. Chronic silicosis may progress to more advanced forms.
  • Complicated. Patients with complicated silicosis have noticeable shortness of breath, weight loss, and extensive formation of fibrous tissue (fibrosis) in the lungs. These patients are at risk for developing tuberculosis (TB).
  • Accelerated. This form of silicosis appears after 5-10 years of intense exposure. The symptoms are similar to those of complicated silicosis. Patients in this group often develop rheumatoid arthritis and other autoimmune disorders.
  • Acute. Acute silicosis develops within six months to two years of intense exposure to silica. The patient loses a great deal of weight and is constantly short of breath. These patients are at severe risk of TB.

Causes and symptoms

The precise mechanism that triggers the development of silicosis is still unclear. What is known is that particles of silica dust get trapped in the tiny sacs (alveoli) in the lungs where air exchange takes place. White blood cells called macrophages in the alveoli ingest the silica and die. The resulting inflammation attracts other macrophages to the region. The nodule forms when the immune system forms fibrous tissue to seal off the reactive area. The disease process may stop at this point, or speed up and destroy large areas of the lung. The fibrosis may continue even after the worker is no longer exposed to silica.
Early symptoms of silicosis include shortness of breath after exercising and a harsh, dry cough. Patients may have more trouble breathing and cough up blood as the disease progresses. Congestive heart failure can give their nails a bluish tint. Patients with advanced silicosis may have trouble sleeping and experience chest pain, hoarseness, and loss of appetite. Silicosis patients are at high risk for TB, and should be checked for the disease during the doctor's examination.


Diagnosis of silicosis is based on:
  • A detailed occupational history.
  • Chest x rays will usually show small round opaque areas in chronic silicosis; the round areas are larger in complicated and accelerated silicosis.
  • bronchoscopy
  • lung function tests
It should be noted that the severity of the patient's symptoms does not always correlate with x-ray findings or lung function test results.


Symptom management

There is no cure for silicosis. Therapy is intended to relieve symptoms, treat complications, and prevent respiratory infections. It includes careful monitoring for signs of TB. Respiratory symptoms may be treated with bronchodilators, increased fluid intake, steam inhalation, and physical therapy. Patients with severe breathing difficulties may be given oxygen therapy or placed on a mechanical ventilator. Acute silicosis may progress to complete respiratory failure. Heart-lung transplants are the only hope for some patients.
Patients with silicosis should call their doctor for any of the following symptoms:
  • tiredness or mental confusion
  • continued weight loss
  • coughing up blood
  • fever, chest pain, breathlessness, or new unexplained symptoms

Lifestyle changes

Patients with silicosis should be advised to quit smoking, prevent infections by avoiding crowds and persons with colds or similar infections, and receive vaccinations against influenza and pneumonia. They should be encouraged to increase their exercise capacity by keeping up regular activity, and to learn to pace themselves with their daily routine.

Key terms

Fibrosis — The development of excess fibrous connective tissue in an organ. Fibrosis of the lungs is a symptom of silicosis.
Pneumoconiosis (plural, pneumoconioses) — Any chronic lung disease caused by inhaling particles of silica or similar substances that lead to loss of lung function.
Silica — A substance (silicon dioxide) occurring in quartz sand, flint, and agate. It is used in making glass, scouring and grinding powders, pottery, etc.


Silicosis is currently incurable. The prognosis for patients with chronic silicosis is generally good. Acute silicosis, however, may progress rapidly to respiratory failure and death.


Silicosis is a preventable disease. Preventive occupational safety measures include:
  • controls to minimize workplace exposure to silica dust
  • substitution of substances—especially in sandblasting—that are less hazardous than silica
  • clear identification of dangerous areas in the workplace
  • Informing workers about the dangers of overexposure to silica dust, training them in safety techniques, and giving them appropriate protective clothing and equipment.
Coworkers of anyone diagnosed with silicosis should be examined for symptoms of the disease. The state health department and the Occupational Safety and Health Administration (OSHA) or the Mine Safety and Health Administration (MSHA) must be notified whenever a diagnosis of silicosis is confirmed.



Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


a type of pneumoconiosis caused by the prolonged inhalation of silica dust. adj., adj silicot´ic. In the past it was called such colorful names as potter's asthma, stonecutter's cough, miner's mold, and grinder's rot, according to the occupation in which it was acquired. Today silicosis is most likely to be contracted in such industrial jobs as sandblasting in tunnels and hardrock mining, but it can occur in anyone who is habitually exposed to the dust contained in silica, one of the most common minerals. All types of miners, for example, may be subject to it, from gold miners to coal miners.

Silicosis usually takes about 10 years of fairly constant exposure to develop. It may give few warning symptoms. As time goes on, an affected person experiences progressive shortness of breath, along with steady coughing which in the early stages is dry and unproductive of mucus. Later there may be mucus tinged with blood, loss of appetite, pain in the chest, and general weakness. The silica produces a nodular fibrotic reaction that scars the lungs and makes them receptive to the further complications of bronchitis and emphysema; persons with silicosis are also more susceptible to tuberculosis.

Since this is a serious disease, persons who must work near silica should take precautions to breathe as little of it as possible, such as by the use of face masks, proper ventilation, and other safety devices. The cooperation of industry, labor, and government in developing protective measures has made the condition much less common today than it used to be. The occupational safety and health administration (OSHA) notes that silicosis is 100 per cent preventable if employers, workers, and health care providers work together to reduce exposure to the dust. Regular chest x-rays are recommended for all workers at risk as the quickest and easiest way to detect silicosis. If discovered in its early stages, it can usually be arrested by a change of occupation or avoidance of dust inhalation. Once fully developed, however, it rarely yields to treatment.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


A form of pneumoconiosis resulting from occupational exposure to and inhalation of silica dust over a period of years; characterized by a slowly progressive fibrosis of the lungs, which may result in impairment of lung function; silicosis predisposes to pulmonary tuberculosis.
[L. silex, flint, + -osis, condition]
Farlex Partner Medical Dictionary © Farlex 2012


A disease of the lungs caused by continued inhalation of the dust of siliceous minerals and characterized by progressive fibrosis and a chronic shortness of breath.

sil′i·cot′ic (-kŏt′ĭk) adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


Classical silicosis, silicoproteinosis Occupational medicine A form of pneumoconiosis caused by inhalation of silicates/silica dust from industries that process quartz and flint–potteries, foundries, sand pits, construction sites, etc Clinical Emphysema, ↓ respiratory function, pulmonary fibrosis, ↑ susceptibility to TB Radiology Bilateral symmetrical interstitial fibrosis, hilar lymphadenopathy with 'eggshell' calcification Risk factors Mining, stone cutting, quarrying, blasting, road and building construction, foundry workers, abrasives manufacture, and other exposure to silicates; symptomatic disease requires 10+ yrs of exposure. See Acute silicosis, Pneumonoconiosis. Cf Asbestosis.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A form of pneumoconiosis resulting from occupational exposure to and inhalation of silica dust over a period of years; characterized by a slowly progressive fibrosis of the lungs, which may result in impairment of lung function; silicosis predisposes to pulmonary tuberculosis.
Synonym(s): silicatosis.
[L. silex, flint, + -osis, condition]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


A persistent and damaging lung disease caused by long-term inhalation of silica-containing dusts. See also PNEUMOCONIOSIS.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


Form of pneumoconiosis resulting from occupational exposure to and inhalation of silica dust over a period of years.
[L. silex, flint, + -osis, condition]
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
By broadening the story of silicosis to include Andrew and his contemporaries, this study casts doubt on two associated assumptions.
Guidelines for the diagnosis and monitoring of silicosis. Archivos de Bronconeumologia (Eng.
He said crystalline silica was a common mineral found in the earth crust and could cause silicosis, which in severe cases could be disabling, or even fatal.
The initial inflammatory response induced by silica particles in the pulmonary alveoli, chronically maintained by continue exposure (7), is considered the main risk factor for the development of silicosis. Pathological changes might be induced in the long run, which finally lead to the known abnormalities that characterize this occupational lung disease, which is asymptomatic at first and ends in massive pulmonary fibrosis (2) (Figure 1).
Typically, approximately 10-20 years of exposure [2] are required until enough dust has been accumulated to lead to silicosis with obstructive and restrictive ventilation alterations and various symptoms, such as dyspnea or cough.
In this study, nearly 50 % of workers were diagnosed as silicosis with 84 % found to display silicosis in profusion category 1, 10 % silicosis in profusion category 2 and 6 % silicosis in profusion category 3 whereas all the controls had normal chest radiographs.
Only two patients were correctly treated as having TB, both were diagnosed later as also having silicosis. Both patients had sputum smear results which were positive for TB.
The special committee, which had been constituted by the Supreme Court, recommended setting up of silicosis diagnostic centres in all cement factories across the country.
In order to implement the Supreme Court orders to prevent silicosis from spreading, the departments of health, mines and labour as well as Environmental Protection Agency would have to work jointly, he added.
QUETTA: Balochistan Health Secretary Saleh Mohammad Nasir has said that the provincial government is utilising all resources to implement labour safety laws."We are implementing the programme to protect workers in factories across the province from silicosis which is caused by environmental pollution," said the health secretary while presiding over a conference on the safety of workers on Friday.
Advocate Sheraz Zaka, the amicus curie (assistant of the court), argued that Workmen's Compensation Act, 1923 covered the disease of silicosis, a lung disease, but pulmonary Koch was not included in the third schedule of the Act.