Pneumoconiosis

Definition
Pneumoconiosis is the term used for a lung disease caused by chronically inhaling mineral dust particles, usually through occupational or environmental exposure. These particles can become permanently deposited in the lungs, sometimes leading to lung damage and impaired lung function.

Causes/associated factors
Three common types of pneumoconiosis are anthracosis, silicosis and asbestosis. Most of these diseases develop over a long period of time after repeated exposure to industrial dust particles. However, acute forms of the disease can develop in shorter periods of time with exposure to high dust concentrations.
Coal worker's pneumoconiosis
Coal worker's pneumoconiosis (CWP), sometimes called black lung disease or anthracosis, is a lung disease caused by inhaling coal mine dust. CWP is more common among coal workers in the eastern United States who mine anthracite (hard) coal than workers in the western United States who mine bituminous (soft) coal. The condition is caused by inhaling coal dust over a period of years, usually 10 or more. It typically develops slowly and causes a minor decrease in lung function. Eventually, the dust accumulation may scar and stiffen lung tissue, making breathing difficult.

Silicosis
Silicosis is caused by inhaling fine particles of silica found in sand, quartz, flint and other sources of stone. Occupational risk for silicosis is highest in people who work in mining, stone cutting, quarrying (especially granite), blasting, farming, road and building construction, and manufacturing of abrasives, polishes, filters, pottery, glass, tiles and bricks. Automotive repair technicians and medical and dental lab workers may also have an occupational risk.

Researchers believe silica dissolves slowly in the lungs and produces a chemical reaction that poisons the cells. With chronic silicosis, symptoms typically appear after 10 to 20 years of exposure. The dust in your lungs may cause a tissue reaction that leads to the development of nodules (growths) in the lungs. If the nodules enlarge and multiply, you may experience impaired lung function and shortness of breath. With acute silicosis, symptoms may develop within one to three years if you have intense exposure to silica through activities such as sandblasting in confined spaces, tunneling through rock in an area with a high quartz content, or manufacturing abrasive soaps.

People who have silicosis have an increased risk of pulmonary tuberculosis (an infectious disease of the respiratory system), as well as a risk of developing lung cancer.

Asbestosis
Asbestos -- a cancer-causing material -- is a naturally occurring fibrous mineral that can be mined and milled. Asbestosis is caused by inhaling asbestos fibers. These fibers cannot be easily removed from the body and may cause scarring or fibrosis (the abnormal formation of tissue) in your lungs. As the disease progresses, enlarged air spaces may develop within the fibrous walls of the lungs, creating honeycombed areas. These changes interfere with lung functioning and may even cause permanent lung damage. Complications of the scarring may affect the lining surrounding the lungs and heart.

Asbestos can be found in some construction products used for insulation, shingles, siding, concrete, ceiling tiles and flooring. Asbestosis often develops in people who have occupational exposure to asbestos, including construction workers, demolition workers and people who restore older homes. Until recently, the automotive, shipbuilding, construction and textile industries also commonly used asbestos. Nonoccupational exposure is currently a main cause of public concern, especially among family members of people who work with asbestos and people who live, work or go to school in buildings constructed with asbestos products. Exposure can occur when the asbestos particles are airborne, such as when asbestos products are crushed into powder, are simply not intact or settle on someone's clothing.

Studies show that smoking tobacco magnifies the negative health effects of inhaling mineral dusts. However, the risk of developing lung cancer is significantly higher in smokers who are also exposed to asbestos.


Signs/symptoms
Symptoms of pneumoconiosis may include:
shortness of breath
weight loss
fever
weakness
chest pain related to the lining of the lungs
a cough that may produce mucus
changes in a typical cough pattern or sputum (saliva, mucus or other material brought up through clearing the throat or coughing)

Diagnosis
Early detection is important, especially since pneumoconiosis is often present for years before respiratory symptoms develop. For each type of pneumoconiosis, diagnosis is typically based on your history of exposure, as well as chest X-rays, lung function tests and an arterial blood gas analysis (a measurement of the oxygen and carbon dioxide in the blood). Results of lung function tests are often normal until late in the disease, however. A high-resolution CT scan (a computer-generated, cross-sectional picture of internal body parts) may also be done. This test is more sensitive than a chest X-ray in detecting changes in lung tissue. Tuberculin skin tests are often done when occupational lung disease is evaluated. Occasionally, a bronchoscopy (examination of the lung tissue) or lung biopsy (taking a tissue sample for further examination) may also be done to exclude other diseases and confirm the diagnosis.

Treatment
Short of a lung transplant, there is no cure for pneumoconiosis. Treatment for most types of pneumoconiosis is typically supportive and individualized. Generally, it's important to prevent exposure to the harmful dust particles. If you smoke, quit. Your doctor may recommend cough medicines, as well as antibiotics for pneumonia, tuberculosis or other lung infections. If you've developed emphysema, bronchodilators can help dilate your airways to make breathing easier. You may also receive oxygen to relieve shortness of breath. Regular medical exams and early treatment of respiratory illnesses are also important, as well as yearly flu shots and pneumococcal vaccines as recommended.
If you're in the early stages of your career, recognize the potential health risks of long-term occupational exposure. You may want to consider a career change. If you choose to remain in your current job, make every effort to work in an area with a reduced amount of dust. In any case, discuss the risks and options with your doctor.


Complications
Complications of dust-related conditions may include:
progressive massive fibrosis (the abnormal formation of tissue) of the lungs
an increased susceptibility to respiratory infections
chronic bronchitis (inflammation of the bronchial tubes, the air passages in the lungs)
respiratory failure
heart disease
In some cases, dust-related conditions may be fatal. Certain types of cancer are also related to pneumoconiosis. Again, smokers who are exposed to asbestos significantly increase the risk of lung cancer. Mesothelioma, a rare cancer of the lining in the chest or abdominal cavity, is associated with exposure to a type of asbestos fiber called crocidolite. Exposure to crocidolite may also affect family members of asbestos workers, as well as those living near the work facility.


Pregnancy-specific information
Pregnancy is not typically associated with the development of pneumoconiosis. However, be careful to avoid unnecessary exposure to any environmental chemicals or dusts. Discuss any concerns you may have with your doctor.

Senior-specific information
Symptoms and complications of pneumoconiosis may be more severe for older adults.

Prevention
When appropriate precautions are taken, health and regulatory experts say pneumoconiosis can be completely prevented. Limit exposure to mineral dust by wearing appropriate personal protective equipment, such as a dust mask, respirator, filtering device or powered air-supply device. Follow federal and environmental occupational safety recommendations carefully, including the Codes of Federal Regulation (CFR), which outline measures to reduce the occupational risks of certain diseases. Finally, don't smoke! Exposure to tobacco smoke remains the greatest risk factor for lung disease and it greatly increases the risk for many of the complications of pneumoconiosis.
If you're concerned about the possibility of asbestos exposure in your home or are considering renovating an older home, you may want to consult a certified inspector for an assessment. If absebestos is found, a technician certified in asbestos-abatement techniques will be needed to remove the asbestos from your home. If you suspect you've been exposed to asbestos through construction materials, send samples of the product in question to a lab for testing. You'll be given options for how to best manage the situation.

Note: Each state may have specific workers' compensation rules about the handling of situations regarding pneumoconiosis. Certain lung specialists, radiologists and legal groups may be consulted to represent these patients to their employers.