What is pneumoconiosis

Pneumoconiosis is a general term given to any lung disease caused by dusts that are breathed in and then deposited deep in the lungs causing damage ¹⁾. Pneumoconiosis is usually considered an occupational lung disease because exposure to the dusts that can cause pneumoconiosis often are found in the workplace.

Different types of dust cause different types of pneumoconiosis; however, not all types of dust are known to cause pneumoconiosis.

Pneumoconiosis occupational lung disease includes asbestosis, silicosis and coal workers’ pneumoconiosis, also known as “Black Lung Disease.”

The severity of pneumoconiosis varies widely depending on the type of dust, how much of the lungs are affected and how intense the dust exposure was. The risk is generally higher when people have been exposed to mineral dusts in high concentrations and/or for long periods of time. Inadequate or inconsistent use of personal protective equipment such as respirators (specially fitted protective masks) is another risk factor since preventing dusts from being inhaled will also prevent pneumoconiosis. Pneumoconiosis does not generally occur from environmental (non-workplace) exposures since dust levels in the environment are much lower.

Pneumoconiosis sometimes causes no symptoms and is diagnosed during workplace surveillance programs that test workers to find early signs of pneumoconiosis using chest X-rays and/or spirometry (a breathing test to check how well air goes in and out of lungs). In rare cases, pneumoconiosis can be very severe and cause death.

If you have been exposed to asbestos, silica, coal dust or other toxic dusts and have respiratory symptoms such as cough or shortness of breath, you should consult your healthcare provider.

Key facts

• Pneumoconiosis is caused by workplace exposure to airborne dusts that are breathed into the lung.
• Exposure to asbestos, silica, and coal dust are the most common causes of pneumoconiosis. Most types of dust are not known to cause pneumoconiosis.
• There is no cure for pneumoconiosis, but it can be prevented with appropriate respiratory protection.

Type of pneumoconiosis

Breathing in dust or other particles in the air is responsible for some types of pneumoconiosis. Specific types include

• Coal worker’s pneumoconiosis (black lung disease) among coal miners, from inhaling coal dust
• Farmer’s lung, from inhaling farm dust
• Asbestosis, from inhaling asbestos fibers
• Siderosis, from inhaling iron from mines or welding fumes
• Silicosis, from inhaling silica dust

Coal workers pneumoconiosis

Coal worker’s pneumoconiosis is also known as black lung disease, is a lung disease that results from breathing in dust from coal, graphite, or man-made carbon over a long time.

Coal workers pneumoconiosis occurs in two forms:

1. Simple coal workers pneumoconiosis
2. Complicated coal workers pneumoconiosis (also called progressive massive fibrosis).

Your risk for developing coal workers pneumoconiosis depends on how long you have been around coal dust. Most people with this disease are older than 50. Smoking does not increase your risk of developing coal miners pneumoconiosis, but it may have an added harmful effect on the lungs.

If coal workers pneumoconiosis occurs with rheumatoid arthritis, it is called Caplan syndrome.

Coal workers pneumoconiosis prevention

Wear a protective mask when working around coal, graphite, or man-made carbon. Companies should enforce the maximum permitted dust levels. Avoid smoking.

Coal workers pneumoconiosis symptoms

Symptoms of coal workers pneumoconiosis include:

• Cough
• Shortness of breath
• Coughing up of black sputum

Coal workers pneumoconiosis prognosis

Outcome for the simple form is usually good. It rarely causes disability or death. The complicated form may cause shortness of breath that worsens over time.

Coal workers pneumoconiosis possible complications

Complications may include:

• Chronic bronchitis
• Chronic obstructive pulmonary disease (COPD)
• Cor pulmonale (failure of the right side of the heart)
• Respiratory failure

Coal workers pneumoconiosis diagnosis

Your health care provider will perform a physical examination and ask about your symptoms.

Tests that may be done include:

• Chest x-ray
• Chest CT scan
• Lung function tests

Coal workers pneumoconiosis treatment

Treatment may include any of the following, depending on how severe your symptoms are:

• Medicines to keep the airways open and reduce mucus
• Pulmonary rehabilitation to help you learn ways to breathe better
• Oxygen therapy

You should also avoid further exposure to coal dust.

Farmer’s lung

Farmer’s lung is one of the most common types of hypersensitivity pneumonitis and its prevalence is estimated to be between 0.2 and 1.5% in farmers ²⁾. It is often considered that fibrosis is the most frequent finding in chronic Farmer’s lung. Hypersensitivity pneumonitis is an interstitial lung disease caused by an immune response to a variety of antigens to which patients have previously been sensitized to, such as inhaled dust, fungus, molds or chemicals.

Hypersensitivity pneumonitis is caused by an allergy to certain dust (allergens) that you breathe in. Commonly, these allergens are naturally occurring (organic). These allergens may be present at home, work or in the environment. Commonly, these dusts contain fungus spores from moldy hay or bird droppings.

When you breathe in the dust that you are allergic to, you will not notice any problems the first time. Some individuals may develop symptoms after a large exposure to the dust or after repeated smaller exposures. The tiny air sacs in the lungs become inflamed as their walls fill with white blood cells and, occasionally, the air sacs may also fill with fluid. The inflammation gets better within a few days if you no longer breathe in those dusts. If you breathe in those dusts repeatedly, the inflammation in the lung continues. This may lead to some portions of the lung developing scar tissue. When your lungs have scar tissue, you may have trouble breathing normally.

Hypersensitivity pneumonitis can become a serious condition for some individuals whose lungs develop scarring. Lung scarring (also called pulmonary fibrosis) may occur in the later stages of the disease. The lung scarring is permanent. Unfortunately, there is no cure or effective treatment for chronic (or long-standing) hypersensitivity pneumonitis. The good news is that if the disease is caught in the early stages and if you avoid the dust, then it can be completely reversed. That is why it is very important to catch this disease in the early stages to prevent permanent lung damage.

Both acute and subacute farmer’s lung are most often “active” forms, as they associate ongoing or recurrent respiratory symptoms and lymphocytic alveolitis on bronchoalveolar lavage ³⁾. Chronic farmer’s lung can either be active or residual, the latter being associated with the disappearance of lymphocytic alveolitis on bronchoalveolar lavage ⁴⁾. It is commonly acknowledged that lung fibrosis is the most frequent finding in chronic hypersensitivity pneumonitis, either active or residual ⁵⁾. However, three cohort studies of farmer’s lung have suggested that some patients with chronic farmer’s lung may develop emphysema ⁶⁾. Nevertheless, these studies date from more than fifteen years ago, and thus, exposure features may have changed over time, and at the same time, imaging techniques have improved. Furthermore, little is known about emphysema in active farmer’s lung. Indeed, in these studies, no distinction was made between active or residual forms. Few functional features, especially those associated with lung hyperinflation, and no detailed description of emphysema were provided. The recent European Academy of Allergy and Clinical Immunology position paper highlighted this absence of detailed description and emphasized that further research is needed into the factors involved in the development of emphysema in hypersensitivity pneumonitis ⁷⁾.

Key facts

• Hypersensitivity pneumonitis is caused by an allergy to certain dusta (allergens) that you inhale.
• This allergy causes inflammation in your lungs
• If detected early, and you avoid the allergy-producing substance, the inflammation can be reversed.
• Sometimes hypersensitivity pneumonitis can cause lung scarring if it is not detected early and you continue to be exposed to the substances.

Farmer’s lung signs and symptoms

You may feel like you have caught the flu when the acute attack occurs. It appears about 4 to 6 hours after you inhale the dust. The symptoms seen are:

• Dry cough
• Shortness of breath
• Chest tightness
• Fever
• Chills
• Tiredness

You may notice a dry cough, shortness of breath, chest tightness, fever, chills, or tiredness about 4 to 6 hours after you inhale the dust. Unlike the common flu, which most commonly occurs during October to May, hypersensitivity pneumonitis symptoms can occur during any time of the year. You may notice dry cough or shortness of breath on activity if you have repeated exposure to the dust. Your coworkers or family members may not have any symptoms but your lungs could still be allergic to some dust at workplace or home respectively.

The initial symptoms may last for as little as 12 hours but may continue for several days in some individuals. If you have repeated exposure to the dust, the following symptoms may be seen.

• Shortness of breath, especially with activity
• Dry cough
• Unintentional weight loss

Farmer’s lung diagnosis

Your doctor may order any of the following tests to assist in the diagnosis process.

• Chest x-ray and CT (computerized tomography) scan which may be able to show early stages of the disease and if there is any scarring.
• Lung function tests show how well you breathe to see if your lungs are working correctly.
• Blood tests are done to find out if you have developed antibodies against the dust (allergen). These blood tests can help show if you have been exposed to a certain dust.
• Bronchoscopy is when a bronchoscope (small flexible tube about the size of a pencil with a video camera attached at its end) is passed either through your nose or mouth. The scope is then passed into your vocal cords, windpipe and the air passages. This tool can be used to collect specimens from your lung for further testing.
• Video-assisted thoracic surgery (VATS) or open lung biopsy is performed by a cardiothoracic surgeon under general anesthesia. It is another way to get lung tissue for further testing.

Farmer’s lung treatment

The single most important thing that you can do is avoid the dust that causes the disease. If you do so, your lungs can return to normal function, as the disease is completely reversible in the early stages. Completely avoiding the dust is sometimes not possible, unless you remove yourself from the dust-causing environment. Your doctor may recommend completely avoiding the dust by relocating to a new home or job. If you have bird fancier’s lung, then it is possible you may have to give up your pet bird.

In patients who have severe cases, treatment may include prescription steroids, such as prednisone. You may be required to take this medication for up to 3 months and sometimes longer. Steroids may help with your symptoms; however, it will not cure the disease. Steroids can also cause certain side effects such as weight gain, thinning of the bones, cataracts, abnormal blood sugar levels and increased pressure in your eyes. Medications that supress immunity such as mycophenolate and azahtioprine show promise as steroid-sparing agents in some individuals to reduce or eliminate steroids. In end stage lung disease with advanced scarring, lung transplantation may be a consideration.

Asbestosis

Asbestosis is scarring in the lungs caused by breathing asbestos fibers. When asbestos fibers are inhaled, they can cause inflammation and scarring of lung tissues. This is called “fibrosis”. The lungs become stiff and unable to expand. This causes difficulty breathing. Asbestosis disease gradually worsens over years, even when exposure to asbestos is stopped.

People with asbestosis have difficulty breathing, often have a cough and, in severe cases, have an enlarged heart.

Most people with asbestosis acquired it on the job before the federal government began regulating the use of asbestos and asbestos products in the 1970s. Health regulations in over the last 50 to 60 years have steadily reduced exposure of workers to asbestos, such that most people with asbestosis had their exposure before the late 1970s. Today, its handling is strictly regulated. With strict regulations contracting asbestosis on the job now now is extremely unlikely. Nonetheless, many workers in construction and some other industries still face significant workplace exposure.

Symptoms usually appear 10 to 40 years after exposure to asbestos dust.

Unfortunately there is no cure for asbestosis, the damage to the lungs caused by asbestosis is not reversible. Treatment of asbestosis focuses on relieving your symptoms. — such as treating shorteness of breath with oxygen.

The risk of asbestosis depends on many factors:

• How much asbestos is in the air
• How often and for how long exposure occurs
• How much time has passed since exposure began
• Whether the person already has lung or breathing conditions and
• Whether the person smokes tobacco

The amount of asbestos that gets into the air people breathe depends on many factors, including:

• the location,
• the type of material or soil the asbestos is in,
• the age and characteristics of that material,
• weather conditions and moisture, and
• the intensity of the activity disturbing the asbestos

Once the asbestos fibers get into the air, they will act the same no matter where they came from. A fiber of chrysotile will cause the same risk of disease whether it came directly from a natural deposit or from a commercial product.

People may also be exposed to asbestos by accidentally swallowing fibers or getting them on their skin. However, these types of contact only cause health effects after large amounts of exposure. Also, the effects of swallowing or touching asbestos are less serious than the health effects of breathing asbestos.

Asbestosis signs and symptoms

The effects of long-term exposure to asbestos typically don’t show up for 10 to 40 years after initial exposure.

Signs and symptoms of asbestosis include:

• Shortness of breath
• A persistent dry cough
• Chest tightness
• Chest pain
• Loss of appetite with weight loss
• A dry, crackling sound in the lungs while breathing in
• Wider and rounder than normal fingertips and toes (clubbing)

Asbestosis complications

If you have asbestosis, you’re at increased risk of developing lung cancer — especially if you smoke or have a history of smoking.

Asbestosis causes

If you are exposed to high levels of asbestos dust over a long period of time, some of the airborne fibers can become lodged within your alveoli — the tiny sacs inside your lungs where oxygen is exchanged for carbon dioxide in your blood. The asbestos fibers irritate and scar lung tissue, causing the lungs to become stiff. This makes it difficult to breathe.

As asbestosis progresses, more and more lung tissue becomes scarred. Eventually, your lung tissue becomes so stiff that it can’t contract and expand normally.

Smoking cigarettes appears to increase the retention of asbestos fibers in the lungs, and often results in a faster progression of the disease.

Risk factors for asbestosis

People who worked in mining, milling, manufacturing, installation or removal of asbestos products before the late 1970s are at risk of asbestosis. Examples include:

• Asbestos miners
• Aircraft and auto mechanics
• Boiler operators
• Building construction workers
• Electricians
• Railroad workers
• Shipyard workers
• Workers removing asbestos insulation around steam pipes in older buildings

In general, it’s safe to be around materials that are made with asbestos as long as the asbestos fibers are contained. This prevents them from getting into the air.

Asbestosis prevention

Reducing exposure to asbestos is the best prevention against asbestosis. In the United States, federal law requires employers in industries that work with asbestos products — such as construction — to take special safety measures.

Many homes built before the 1970s have materials such as pipes and floor tiles that contain asbestos. Generally, there’s no cause for concern as long as the asbestos is enclosed and undisturbed. It’s when materials containing asbestos are damaged that there’s a danger of asbestos fibers being released into the air.

Here is a list of common products and materials containing asbestos:

• Insulation systems for attic, wall, wood-burning stoves, oil and coal furnaces and door gaskets
• Vinyl floor tiles and the backing on vinyl sheet flooring and adhesives
• Roofing and siding shingles
• Plaster, cement, putties and caulk used on wall and ceilings
• Hot water and steam pipe wrapping
• Heat-resistant fabrics
• Automobile clutch pads and brake linings

Reducing asbestos exposure

People who work around asbestos, or materials that contain it, should:

• Get proper training for handling asbestos
• Wear the right personal protective equipment

People who live in older homes should:

• Avoid disturbing materials that might contain asbestos, including:
  • pipe and furnace insulation, siding, flooring, and popcorn ceilings installed from the 1950s to the 1970s
  • vermiculite attic insulation
• Talk to their local or state environmental agency or a certified asbestos contractor if the materials are breaking down or need to be replaced
• Hire contractors who know and follow laws for safe asbestos removal and disposal to avoid contaminating the rest of the home or the environment

People who live in areas with natural asbestos deposits or near areas contaminated by old asbestos-containing products should:

• Keep asbestos levels low in the home by:
  • Using wet cleaning methods and high efficiency particulate air (HEPA) vacuums
  • Using doormats and removing shoes before entering
  • Keeping windows closed on windy days to keep asbestos out
• Avoid breathing dust outside by:
  • Using water to wet soil before gardening or playing
  • Spraying off patios with water instead of sweeping them
  • Staying on pavement or ground covered with grass or mulch

Asbestosis prognosis

Asbestosis prognosis depends on the amount of asbestos you were exposed to and how long you were exposed.

People who develop malignant mesothelioma tend to have a poorer outcome.

Asbestosis diagnosis

Asbestosis can be difficult to diagnose because its signs and symptoms are similar to those of many other types of respiratory diseases. A variety of diagnostic tests might be needed to help pinpoint the diagnosis.

During the visit, your doctor will ask about your breathing, both at rest and during exercise. Your doctor will also ask about your jobs in detail to determine how much you were exposed to asbestos. So, it would be a good idea to prepare the following information in advance:

• Your symptoms and the time they started
• Treatments given before for the symptoms
• The work you have done in your entire career; the length of time you spent in each job
• The products you were in contact with at work and whether or not you wore protective equipment
• Smoking history
• Any old medical records, including chest X-rays or CT scans

During the physical examination your doctor will listen to your lungs to determine if the sounds are normal or not. Your doctor may then order the following tests:

Imaging tests

• Chest X-ray. Advanced asbestosis appears as excessive whiteness in your lung tissue. If the asbestosis is severe, the tissue in both lungs might be affected, giving them a honeycomb appearance.
• Computerized tomography (CT). CT scans combine a series of X-ray views taken from many different angles to produce cross-sectional images of the bones and soft tissues inside your body. These scans generally provide greater detail and might help detect asbestosis in its early stages, even before it shows up on a chest X-ray.

Pulmonary function tests

These tests determine how well your lungs are functioning. Pulmonary function tests measure how much air your lungs can hold and the airflow in and out of your lungs.

During the test, you might be asked to blow as hard as you can into an air-measurement device called a spirometer. More-complete pulmonary function tests can measure the amount of oxygen being transferred to your bloodstream.

Biopsy, where small samples of lung tissue are surgically removed and then examined for the scars and tiny asbestos fibers, is usually not necessary to diagnose asbestosis.

Asbestosis treatment

There is no treatment that can reverse the damage done by asbestos. Treatment focuses on slowing the progression of the disease and relieving symptoms.

You can take certain steps to help slow down the asbestosis progression, especially preventing further exposure to asbestos and quitting smoking. There are also treatments that your physician can prescribe to help ease your breathing and maintain your general lung health.

• Stopping smoking. Asbestosis increases the risk of lung cancer. Quitting smoking can reduce this risk. Try to avoid secondhand smoke. Smoking might also cause emphysema, which further reduces your lung reserves.
• In smokers, medications may be prescribed to help quit, or to ease symptoms that may be related to cigarette-related lung problems.
• Flu and pneumonia vaccines do not treat asbestosis, but are recommended for almost everyone with lung disease.
• Oxygen therapy – to ease breathing difficulty caused by advanced asbestosis, your doctor might prescribe supplemental oxygen. This is delivered by thin plastic tubing with prongs that fit into your nostrils or a mask.
• Pulmonary rehabilitation, which is an exercise program designed to help all patients with chronic lung conditions.

You’ll need routine follow-up care, such as chest X-rays and lung function tests, at regular intervals depending on the severity of your condition.

In very severe situations, you might be a candidate for a lung transplant and you doctor refer you to a lung transplant specialist.

Pulmonary siderosis

Pulmonary siderosis or welder’s lung is an occupational lung disease that is usually observed after chronic exposure to iron dust ⁸⁾. The occupations that lead to the development of pulmonary siderosis include mining, welding, foundry, steel manufacturing, iron oxide manufacturing, grinding wheel manufacturing, and silver jewelry manufacturing ⁹⁾. Pulmonary siderosis was first described in 1936 and occurs in about 7% of arc welders ¹⁰⁾. Inhaled iron dust is deposited in intra-alveolar spaces, which leads to radiological changes and respiratory symptoms. Since the original description of the condition in 1936 ¹¹⁾, it has been generally assumed that pulmonary siderosis is benign.

Although it takes years of exposure for a patient to become symptomatic, rapid development of symptomatic disease within a year after exposure has been reported ¹²⁾. In addition, high-intensity, brief exposure to iron dust can also result in future symptoms ¹³⁾. Furthermore, symptomatic interstitial fibrosis may occur, although rarely, when persons exposed to iron dust or smoke are also simultaneously exposed to other silicates, notably silica, and asbestos ¹⁴⁾. In this study ¹⁵⁾, the researchers revealed minimal fibrosis in two cases. These patients were welders. However, even though the researchers could not demonstrate any exposure to silicates pathologically, they believe that fibrosis is still possible given that dust from many compounds pollute working places during welding. There may be no symptoms at all in pulmonary siderosis, but affected patients may also present with a cough, sputum, and effort dyspnea, all depending on exposure time and any lesion developed in response ¹⁶⁾. Some authors, however, have also reported respiratory difficulties or histological findings of emphysema or pulmonary parenchymal fibrosis in welder’s lung disease ¹⁷⁾.

The diagnosis of pulmonary siderosis is made by identifying a patient’s exposure history and, chest radiographic findings, and confirming iron accumulation by iron dyeing the bronchoalveolar lavage fluid or lung biopsy specimen ¹⁸⁾. Recently, because of the development of radiological technology, radiological findings play an important role in the differential diagnosis of pulmonary siderosis. At the time of welding, the aspirated iron oxide is stored in alveolar macrophages and then transferred to the lung parenchyma. Subsequently, macrophages are distributed through the blood and peribronchial lymphatic vessels, and form small nodules. Because of these pathophysiological characteristics, typical CT findings of pulmonary siderosis may appear ¹⁹⁾.

The most striking feature of pathology examination of pulmonary siderosis is the presence of hemosiderin-laden macrophages in the peribronchovascular space and interstitium. In pure pulmonary siderosis, fibrosis is either completely absent or minimal ²⁰⁾. Alveolar structures are spared; the stromal reaction is minimal, and it primarily consists of reticulin fibers. Iron granules stained by Prussian blue are also visualized. The reaction is potentially reversible ²¹⁾.

In 1995, Akira ²²⁾ reported that the most common CT findings, present in 15 of 21 arc welders studied, were ill-defined micronodules diffusely distributed in the lung. Emphysema was observed in 7 cases and was the predominant CT finding in 3 cases. A honeycomb pattern was found in 3 cases, presenting the predominant CT finding in all 3 cases. The CT appearance of this honeycomb pattern resembled that observed in usual interstitial pneumonia.

These chest CT findings are further supported by Han et al. ²³⁾ who reported that the most frequent thin-section CT findings in patients with welder’s lung disease were poorly defined small centrilobular nodules, branching linear structures, and less commonly, extensive ground-glass attenuation without zonal predominance. All of these findings represent macrophage accumulation in the alveolar space. However, in addition to these typical imaging findings, pulmonary siderosis can appear in unusual forms. Other chest CT findings in welder’s lungs included localized stable tuberculous lesions, bronchial dilatation or wall thickening, localized emphysema, non-calcified mediastinal lymphadenopathy, sub-segmental atelectasis, or tracheal dilatation ²⁴⁾.

Ferritin is the main iron storage protein, and it is a sensitive indicator of total iron depots in the absence of systemic inflammatory conditions ²⁵⁾. As an inflammatory marker, ferritin has been shown to increase in various chronic lung diseases ²⁶⁾. However, ferritin level in pulmonary siderosis is substantially higher than those encountered in inflammatory lung disease ²⁷⁾. Serum ferritin level increases parallel to bronchoalveolar lavage fluid level ²⁸⁾.

In 2004, since the report of a case of pulmonary siderosis with typical imaging findings in Korea ²⁹⁾, Kim et al. ³⁰⁾ reported a case of pulmonary siderosis suspected to be lung cancer. In that case, pulmonary siderosis showed a 3-cm sized pulmonary nodule in radiological findings, but was confirmed by histological examination. In 2011, there was a case of pulmonary siderosis with atypical imaging findings in Korea. In that case, chest CT showed a 1.3 × 1.5 – cm sized mass in the left upper lobe and multiple ill-defined irregular nodules in both lung fields. Thus, similarly, that pathologic lesion was misdiagnosed as metastatic lung cancer ³¹⁾. All the pulmonary siderosis cases with atypical imaging findings as described above included mass-like lesions or large nodules.

Pulmonary siderosis treatment

Treatment of pulmonary siderosis is to minimize the effects of exposure of iron dust. In addition to the respiratory symptoms, you can expect to improve the radiological findings. There was a case treated with bronchoalveolar lavage to remove iron dust accumulated in the lung, but it is not a universally used treatment ³²⁾. After diagnosis of pulmonary siderosis, some experts advised patients to discontinue welding and performed bronchoalveolar lavage twice ³³⁾.

Silicosis

Silicosis is a lung disease caused by breathing in (inhaling) silica dust or crystalline silicon dioxide.

Silica is the second most abundant naturally-occurring mineral crystal in the earth’s crust. It is found in most rock beds. Silica dust forms during mining, quarrying, tunneling, and working with certain metal ores. Silica is a main part of sand, so glass workers and sand-blasters are also exposed to silica.

Three types of silicosis occur:

1. Acute silicosis, which results from short-term exposure to very large amounts of silica. The lungs become very inflamed and can fill with fluid, causing severe shortness of breath and a low blood oxygen level. Acute silicosis causes cough, weight loss, and fatigue within a few weeks or years of exposure to inhaled silica.
2. Chronic silicosis, which results from long-term exposure (10 to 30 years) to low amounts of silica dust. The silica dust causes swelling and scarring in the lungs and chest lymph nodes. This disease may cause people to have trouble breathing. This is the most common form of silicosis.
3. Accelerated silicosis, which occurs after exposure to larger amounts of silica over a shorter period of time (5 to 15 years). Swelling in the lungs and symptoms occur faster than in simple silicosis.

Silicosis can develop within a few weeks to even decades after exposure. When people breathe silica dust, they inhale tiny particles of the mineral silica. This silica dust can cause fluid buildup and scar tissue in the lungs that cuts down your ability to breathe. This can lead to lung scarring and cough, weight loss, and fatigue.

From 2011-2013, 12 people younger than 45 years of age had silicosis listed as causing or contributing to death ³⁴⁾. Although experts at the Centers for Disease Control and Prevention (CDC) do not know the details of their cases, this is concerning because silicosis deaths in these young adults may reflect higher exposures than those causing chronic silicosis mortality in older individuals.

People who work in jobs where they are exposed to silica dust are at risk. These jobs include:

• Abrasives manufacturing
• Glass manufacturing
• Mining
• Quarrying
• Road and building construction
• Sand blasting
• Stone cutting
• 
  Removal of paint and rust with power tools
  
• Abrasive blasting of bridges, pipes, tanks, and other painted surfaces especially while using silica sand
• Grinding mortar
• Abrasive blasting of concrete (many bridges and buildings are made of concrete)
• Crushing, loading, hauling, chipping, hammering, drilling, and dumping of rock or concrete
• Chipping, hammering, drilling, sawing, and grinding concrete or masonry
• Demolition of concrete and masonry structures
• Dry sweeping or pressurized air-blowing of concrete or dust
• Jackhammering on various materials.

Intense exposure to silica can cause silicosis within a year. But it usually takes at least 10 to 15 years of exposure before symptoms occur. Silicosis has become less common since the Occupational Safety and Health Administration (OSHA) created regulations requiring the use of protective equipment, which limits the amount of silica dust workers inhale.

Silicosis affects the lungs by damaging the lining of the lung air sacs. Once this begins, it leads to scarring and, in some situations, to a condition called progressive massive fibrosis. This condition happens when there is severe scarring and stiffening of the lung, which makes it difficult to breathe.

People with acute silicosis experience cough, weight loss, tiredness, and may have fever or a sharp chest pain. You may also have shortness of breath over time, especially with chronic silicosis. Your healthcare provider might hear crackles or wheezing when they listen to your lungs. Having silicosis increases the risk of other problems, such as tuberculosis, lung cancer, and chronic bronchitis.

Each type of silicosis affects the body somewhat differently:

• In acute silicosis, the lungs become very inflamed and can fill with fluid, which causes severe shortness of breath and low blood oxygen levels.
• In chronic silicosis, the silica dust causes areas of swelling in the lungs and chest lymph nodes, which makes breathing more difficult.
• In accelerated silicosis, swelling in the lungs and symptoms occur faster than in chronic silicosis.

Over time, lung capacity decreases, and people with silicosis may need support with oxygen and other devices to help them breathe.

There is no cure for silicosis and only symptomatic treatment is available, including lung transplantation for the most severe cases.

Silicosis prevention

If you work in a high-risk occupation or have a high-risk hobby, always wear a dust mask and do not smoke. You might also want to use other protection recommended by Occupational Safety and Health Administration (OSHA), such as a respirator.

Silicosis symptoms

Symptoms of silicosis include:

• Cough
• Shortness of breath
• Weight loss

Silicosis prognosis

Outcome varies, depending on the amount of damage to the lungs.

Silicosis symptoms possible complications

Silicosis can lead to the following health problems:

• Connective tissue disease, including rheumatoid arthritis, scleroderma (also called progressive systemic sclerosis), and systemic lupus erythematosus
• Lung cancer
• Progressive massive fibrosis
• Respiratory failure
• Tuberculosis

Silicosis diagnosis

Your health care provider will take a medical history. You’ll be asked about your jobs (past and present), hobbies, and other activities that may have exposed you to silica. The provider will also do a physical exam.

Tests to confirm the diagnosis and rule out similar diseases include:

• Chest x-ray
• Chest CT scan
• Pulmonary function tests
• Tests for tuberculosis
• Blood tests for connective tissue diseases

Silicosis treatment

There is no specific treatment for silicosis. Removing the source of silica exposure is important to prevent the disease from getting worse. Supportive treatment includes cough medicine, bronchodilators, and oxygen if needed. Antibiotics are prescribed for respiratory infections as needed.

Treatment also includes limiting exposure to irritants and quitting smoking.

People with silicosis are at high risk of developing tuberculosis (TB). Silica is believed to interfere with the body’s immune response to the bacteria that cause tuberculosis. Skin tests to check for exposure to tuberculosis should be done regularly. Those with a positive skin test should be treated with anti-tuberculosis drugs. Any change in the appearance of the chest x-ray may be a sign of tuberculosis.

People with severe silicosis may need to have a lung transplant.

Pneumoconiosis causes

Pneumoconiosis can develop when airborne dusts, particularly mineral dusts, are inhaled at work. The dust particles remain in the lung where they can cause inflammation or fibrosis (scarring). The effects of damage from inhaled mineral dusts may not show up for many years, so patients may not develop symptoms until long after they are no longer exposed to these dusts. The most common causes of pneumoconiosis are inhalation of asbestos, silica (sand or rock dust) or coal dust. Only some workers exposed to these dusts will develop pneumoconiosis. Preventing inhalation of harmful dusts make pneumoconiosis a preventable disease.

When mineral dusts are inhaled, dust particles can land (deposit) in the airways (bronchial tubes) or all the way in the alveoli (air sacs) that are deep in the lungs. How far into the lungs the dust particles can get depends on the size and shape of the particles. The smaller the particles the deeper in the lung they get. After the dust particles land and settle in the lung, the lung tissue may try to get rid of the dust particles or try to surround them to prevent them from causing damage. Cells from your immune system travel to these affected areas of lung, and inflammation develops as it tries to fight the dust particle. In some cases, the inflammation is severe enough to cause scar tissue to form. The formation of scar tissue in the lung is called fibrosis. If the inflammation or fibrosis is severe enough or involves a large enough area of lung tissue, breathing will be affected. Dry cough and shortness of breath are common symptoms of fibrosis.

Risk factors for pneumoconiosis

Pneumoconiosis includes asbestosis, silicosis and coal workers’ pneumoconiosis (CWP). CWP is sometimes called “Black Lung Disease” because the charcoal dust in the lungs can turn them black in color. Below are the dusts which cause these diseases.

Asbestos fibers are very durable and resistant to heat, leading to their use in insulation and fireproofing, as well as in textile manufacturing. Examples of workers who might be exposed to asbestos include plumbers, roofers, mechanics and shipyard workers, including naval officers. People are at higher risk of developing asbestosis if they have higher levels of exposure to asbestos dust over longer periods of time. The disease typically does not develop for 10 or 20 years after first exposure.

Crystalline silica is a main component of dust from sand and rock. Examples of workers who might be exposed to silica include miners, sandblasters, stonemasons and foundry workers. Risk factors for developing silicosis include higher levels of silica exposure and longer time of exposure. Lower levels of exposure over many years most commonly lead to “chronic simple silicosis” in which many small nodules of inflammation form in the lungs. This is the most common form of silicosis. In a small percentage of cases, simple silicosis develops in to a more severe form of silicosis called “progressive massive fibrosis” when many small nodules “grow” together into large masses. In progressive massive fibrosis, patients have more severe respiratory symptoms because the masses limit the function of normal lung. If exposure to silica is very intense over a shorter period of time, patients may develop “accelerated” or “acute silicosis.” Acute silicosis is rare and generally occurs only after extremely high exposures, but it causes death in most cases.

Coal dust is made of carbon-containing particles, and coal miners are at risk of inhaling this dust. Coal miners may also be exposed to silica-containing dust because coal mining may involve some drilling into silica-containing rock. Workers exposed to graphite dust can also develop pneumoconiosis similar to coal workers pneumoconiosis. Just like with silicosis, coal workers pneumoconiosis is most commonly “simple” disease with nodules of inflammation forming in the lungs, but it can become progressive massive fibrosis in a small percentage of patients.

Chronic beryllium disease (also called berylliosis) is another work-related lung disease that may be considered pneumoconiosis. Beryllium is a very strong and lightweight metal that is used in the electronics, aerospace and nuclear power industries. Chronic beryllium disease is caused by inhalation of airborne beryllium during its processing such as in melting or grinding it. There are other less common mineral dusts that might also cause pneumoconiosis including cobalt, talc and aluminum oxide.

Pneumoconiosis symptoms

Patients with pneumoconiosis may have no symptoms at all, particularly early in the disease. The most common symptoms of pneumoconiosis are cough, with or without mucous (sputum) production, and chest tightness or shortness of breath. Patients may first notice getting more breathless or winded with activity, like walking or climbing stairs. Some patients may feel breathless even when they are at rest.

If pneumoconiosis involves a large part of the lungs or causes a lot of scarring, oxygen may be prevented from easily reaching the blood during breathing. This results in hypoxemia (low blood oxygen levels). Hypoxemia may only be present during activity or while sleeping. Hypoxemia may be present all the time if pneumoconiosis is severe or progresses. Many patients with hypoxemia do not know that their oxygen levels are low because hypoxemia itself does not always cause symptoms like breathlessness. Oxygen in the blood delivers oxygen to all the internal organs, so recognizing hypoxemia is important to prevent stress on other organs, like the heart and brain.

Pneumoconiosis diagnosis

Pneumoconiosis may be diagnosed by routine workplace surveillance in exposed workers, or it may be diagnosed because symptoms develop in a person previously exposed to mineral dusts. Workplace surveillance programs may involve workers having breathing tests and/or chest X-rays every year or periodically to look for abnormalities.

Your healthcare provider will ask you about your symptoms and also about past exposures to dusts like asbestos or silica. It is common that you would be referred to a pulmonologist (lung doctor) for your evaluation. You may also be referred to an occupational medicine provider to find out more about past exposures and to evaluate you further.

Chest X-rays or CT scans may show your health-care provider:

• nodules (“spots”) or masses
• areas of inflammation
• pneumonia
• excess fluid in or around the lungs

Sometimes additional, more invasive testing is necessary to diagnose pneumoconiosis. Evaluation might include bronchoscopy in which a thin tube with a camera is inserted through your mouth into your trachea (windpipe) to look at your airways, to obtain a fluid sample to look for infection, or to take small biopsy samples of lung tissue. If more lung tissue is needed, surgery may be necessary to take a larger biopsy specimen. While invasive procedures and biopsies are generally not necessary to diagnose pneumoconiosis, these tests may be necessary to exclude other diagnoses.

Pneumoconiosis treatment

There are no specific treatments or medications for pneumoconiosis, and there is no cure. Most treatments for patients with pneumoconiosis are aimed at limiting further damage to the lung, decreasing symptoms and improving quality of life.

Patients may be treated with inhaled medications (inhalers) if they have symptoms of asthma or chronic obstructive pulmonary disease (COPD). A pulmonary rehabilitation program may be recommended to improve a patient’s ability to exercise. Oxygen is prescribed if patients have a low oxygen level. Some patients need to wear oxygen all the time, while others only need it when they are active or while they sleep.

In rare, very severe cases, your healthcare provider may refer you for a lung transplant. You would have many tests to find out if you are healthy enough to undergo a lung transplant and if it would improve or prolong your life.

If you are a smoker, you will be strongly advised to quit smoking. Quitting cigarette smoking (or smoking any other drugs) is very important to prevent further decline in lung function. Smoking with some types of pneumoconiosis can actually increase your chance of developing lung cancer more than just smoking without pneumoconiosis.

Living with pneumoconiosis

Pneumoconiosis is different for every person. Some patients have very mild disease that is stable (does not get worse and worse over time). Other people have more severe disease, or disease that gets much worse over time. Because there is no cure, living with pneumoconiosis involves taking the best care of your lungs and your general health as you can and following up regularly with your health-care provider to manage your symptoms, to monitor you for worsening of your lung function and to watch for other diseases that can develop in patients who have pneumoconiosis.

If you have pneumoconiosis, you should expect to have regular visits to your health-care provider(s). You may need to have regular testing, such as pulmonary function tests (“breathing tests”) or chest X-rays to monitor you and your disease closely. You should have a flu shot every year, and you should ask your health-care provider about pneumonia vaccines. People with silicosis should expect a tuberculosis skin test to make sure tuberculosis hasn’t started growing in your lung also.

Managing pneumoconiosis

Taking care of your heart and lungs is one of the most important things you can do for your health if you are living with pneumoconiosis. This means not smoking and avoiding secondhand smoke. You should also avoid any further exposure to harmful dusts. Keeping your weight in a healthy range and exercising regularly helps with symptoms of breathlessness. For people with more severe breathing symptoms, exercising may be difficult, and a pulmonary rehabilitation program can be helpful.

People with pneumoconiosis can have a higher risk of developing some other diseases. Your health-care provider may need to watch for these. For instance, patients with asbestosis are at higher risk of developing lung cancer. This risk is especially high if the patient has been a cigarette smoker. One lung cancer that is related to asbestos exposure but not to cigarette smoking is called mesothelioma. Mesothelioma is rare compared to other types of lung cancer, but asbestos exposure is its only known cause. Your health-care provider may ask you to have a chest X-ray or chest CT scan to check for lung cancer.

Patients with silicosis are at a higher risk of developing tuberculosis. Your health-care provider may do a skin test or a blood test to see if you have been exposed to tuberculosis in the past, or they may ask you about other risk factors for tuberculosis. If you have been exposed to tuberculosis in the past and are carrying the tuberculosis bacteria (latent tuberculosis infection), it may be recommended that you take antibiotics to help prevent you from getting active tuberculosis.

Patients with silicosis are also at higher risk of developing rheumatoid arthritis, a form of arthritis in which the body’s immune system attacks the joints causing pain, swelling and stiffness. People with silicosis who develop certain symptoms or signs of arthritis may need blood tests or other evaluation to check for rheumatoid arthritis. Patients with rheumatoid arthritis often need special medications to control the symptoms of their arthritis.

Patients with coal workers pneumoconiosis may also be at an increased risk of tuberculosis or rheumatoid arthritis since coal dust can be contaminated with silica.