Asbestosis

What is Asbestosis?

Asbestosis is a lung disease that occurs when you inhale asbestos fibers, which are types of mineral-based substances, especially forms of hydrated magnesium silicates. Asbestos has two main types, called serpentine and amphibole, which are categorized based on how they look. Serpentine fibers, which include a type known as chrysolite, are curly, flexible, and cause less damage than amphibole counterpart.

Because chrysolite is flexible and curves, it settles in the upper part of the respiratory tract. This part of the respiratory system has a robust cleaning mechanism, which helps to remove these chrysolite fibers easily. On the other hand, amphiboles, which include types like crocidolite, amosite, tremolite, and anthophyllite, are straight, rigid, and more prone to breaking. They are more harmful than serpentine fibers because they are less soluble and straighter, which allows them to move deeper into the lungs along the paths of inhaled air and penetrate further into lung tissues.

Historically, asbestos fibers have been widely used in fields like construction, shipping, mining, and aerospace engineering. This is because they can resist electricity and heat well and are quite inexpensive.

What Causes Asbestosis?

People are exposed to asbestos in three main ways. The first is direct work-related exposure, which is common in jobs like shipbuilding, mining, and aerospace. The second way is bystander exposure and often affects professionals like electricians, masons, and painters. The third, and most common type, is general community exposure that can happen from using asbestos in road surfaces, playground materials, landfills, and chemical paints.

The amount of exposure to asbestos plays a role in how likely someone is to get sick, with those in the first group having the highest exposure and consequently the highest risk. Furthermore, exposure to a type of asbestos called amphibole is more likely to cause health problems than serpentine asbestos fibers.

Risk Factors and Frequency for Asbestosis

The risk of getting this disease increases based on the level of exposure. For example, in a study from Okayama, Japan, construction workers who installed asbestos boards had the highest rate of the disease. The longer people are exposed, the greater the risk. In the UK, insulation workers and those who strip asbestos have the highest risk. Approximately 55,000 people worldwide die from asbestos-related issues every year. It’s more common in construction workers.

People start to show signs of this disease quicker than they would for other lung problems. How many people get the disease can also depend on where they were exposed. For example, heavily exposed groups have about 9 cases per 1,000 people. There are over 2,000 cases of mesothelioma (another asbestos-linked disease) reported in the US every year, but it’s less common than lung cancer. The use of asbestos has decreased in developed countries but remains high in developing countries like Nepal and Pakistan.

• The risk of disease is high amongst those with intense exposure, such as construction workers installing asbestos boards.
• The longer the exposure to asbestos, the higher the risk of contracting the disease.
• Approximately 55,000 people worldwide die each year due to asbestos-related issues.
• Early signs of the disease show up faster compared to other lung diseases.
• Heavily exposed groups have a higher incidence, with about 9 cases per 1,000 people.
• Mesothelioma, a disease linked to asbestos, is less common than lung cancer but still affected over 2,000 individuals in the US in recent years.
• The use of asbestos has decreased in developed countries but remains high in developing ones like Nepal and Pakistan.

Signs and Symptoms of Asbestosis

When diagnosing and managing lung conditions relating to asbestos exposure, a person’s occupational history is very important. If someone has had 10 to 20 years of asbestos exposure, it’s possible they could develop a lung disease called asbestosis. This is often characterized by symptoms such as shortness of breath that gets worse over time. Chest discomfort could also occur due to heart issues arising from high blood pressure in the lungs.

The presence of other symptoms like coughing with phlegm, chest pain, wheezing, and shortness of breath, especially during physical activity, could be contributing factors. Coughing, particularly the dry type, is common. If someone also has symptoms like losing appetite and weight, or coughing up blood, this could signal that they have lung tumors.

During a physical exam, a doctor might find symptoms like:

• Finger clubbing (seen in about a third of the cases)
• Asbestos warts
• Reduced chest expansion due to lung restrictions
• Abnormal breath sounds when listening to the lower sides and base of the lungs

In more advanced cases of the disease, signs might point to a condition called cor pulmonale, which is essentially right-sided heart failure caused by changes in the lung’s blood vessels. Signs of this could include swelling in the lower legs, visible neck veins, forceful heartbeats, liver congestion, and bluish discoloration of the skin.

Testing for Asbestosis

Asbestosis, a lung condition caused by exposure to asbestos, is primarily diagnosed based on a patient’s medical history. Symptoms typically involve a gradual decline in the function of the lungs, detected by shortness of breath, and can be seen on an x-ray as scarring in the lung tissue.

To investigate these symptoms further, several tests may be administered. In ‘spirometry and lung volume’ tests, patients are asked to take a deep breath and then blow out as much as they can in one second into a device which measures lung capacity. A reduction in the total volume of air a patient can blow out can be a sign of asbestosis. They may also test how efficiently gas is passed from the lungs to the bloodstream, by looking at the amount of carbon monoxide that can be breathed out, which tends to be lower than normal in cases of asbestosis.

Another common test is the arterial blood gas analysis. Usually, this involves inserting a needle into an artery to take a blood sample, which is then analyzed for oxygen and carbon dioxide levels. If the oxygen levels are low, it could signal asbestosis. The presence of carbon dioxide could be a sign of late-stage disease and can also indicate an issue with the small airways in the lungs.

X-rays and high-resolution CT scans of the chest can help doctors visualize the lungs. They can reveal patterns of scarring typical of asbestosis, like ‘ground-glass’ opacities and fibrosis. However, asbestosis symptoms can look similar to another disease called idiopathic pulmonary fibrosis (IPF), so it’s important to note that a key difference is asbestosis starts more centrally in the lungs and moves outward, while IPF starts at the edges and moves inward.

In some cases, a lung biopsy may be necessary for a definitive diagnosis. This entails taking a small sample of lung tissue for microscopic examination. Again, the pattern of scarring can be a clue, as asbestosis typically shows fibrosis moving from the center to the periphery of the lung. In contrast, IPF shows irregular patches of scarring. Biopsies can be obtained using different methods, including a bronchoscope (a thin tube inserted through the mouth or nose into the lungs), or with a procedure called a video-assisted thoracoscopy, which uses a small camera and instruments inserted through small incisions in the chest.

Lastly, lab tests might be done to check levels of certain proteins and antibodies in the blood, many of which tend to be higher than normal in asbestosis patients.

Treatment Options for Asbestosis

Asbestosis, a lung disease caused by inhaling asbestos fibers, doesn’t have a specific cure, so the main approach is supportive care to manage symptoms. It’s crucial to avoid asbestos exposure as the best preventive measure, and keeping workplaces safe from asbestos is a key part of this.

Medication is sometimes used, including corticosteroid therapy. This treatment aims to lessen the inflammation in the lungs, which can reduce damage. However, its success rate isn’t high, and the appropriate dosage and treatment duration are still uncertain. High doses of corticosteroids, along with other drugs like azathioprine, may help to lessen serious bouts of asbestosis. If a patient isn’t getting better with this approach, other drugs may been tried or steroids may be stopped. Colchicine is another drug that might be helpful, as it has properties that can reduce fibrosis or scarring in the lungs. When lung infections occur, antibiotics are used. Regular vaccinations against pneumococcal pneumonia and influenza are also advised.

If the patient has smoked in the past and developed chronic obstructive pulmonary disease (COPD), inhalers with long-acting beta 2 agonists, inhaled corticosteroids, or long-acting muscarinic antagonists are often prescribed. And of course, quitting smoking is always recommended.

For patients who are severely lacking oxygen (a condition known as hypoxemia), oxygen therapy can be beneficial. Exercise programs specially designed for people with lung disease, as well as treatment for cor pulmonale (a type of heart disease), can improve quality of life as the disease develops.

Some surgical procedures may also be beneficial. For example, the removal of the outer layer of fibrous tissue in the lungs can help with collapsed lung tissue. If there’s scarring in the area around the lungs, a procedure to remove the lining of the lungs might be performed. If fluid builds up quickly in the pleural space (the area between the two layers of tissue that line the lungs), draining the fluid might provide temporary relief of breathing difficulties.

In extreme cases of asbestosis where other treatments have been ineffective and the scarring in the lungs is severe and irreversible, a lung transplant might be considered as a last resort.

What else can Asbestosis be?

Asbestosis is a lung disease that can be mistaken for a number of other lung conditions because of its similar symptoms. These conditions include:

• Idiopathic pulmonary fibrosis (unexplained scarring of the lungs)
• Interstitial pneumonitis (lung inflammation)
• Rheumatoid arthritis (a disease that can affect the lungs)
• Hypersensitive pneumonitis (lung inflammation caused by an allergic reaction)
• Pleuropulmonary fibroelastosis (a rare lung condition)
• Drug-induced pneumonitis (lung inflammation caused by some medications)
• Combined pulmonary fibrosis and emphysema (a combination of scarring and damage to the lungs)

To correctly diagnose asbestosis, these other conditions must be ruled out.

Non-specific Interstitial Pneumonitis, for instance, can be associated with other tissue disorders and can mimic asbestosis with its symptoms. But, it more often shows up in women and seldom results in lung scarring (honeycombing). A thorough medical history and evaluation of lung tissue can help to exclude this condition.

Chronic Hypersensitivity Pneumonitis, an allergic reaction following exposure to allergens, may also present similar symptoms to asbestosis. To differentiate, a lung biopsy would be necessary. In contrast to asbestosis, the inflammation in this condition encompasses the whole lung.

Rheumatic Disease, which affects the lung tissues in about 10% of cases, can present additional symptoms like arthritis, muscle weakness and skin changes that are not typically seen in asbestosis.

Certain drugs can also cause lung inflammation, which might be confused for asbestosis. However, a careful review of a patient’s medication history can help identify this cause.

Pleuropulmonary Fibroelastosis, although it resembles asbestosis, involves both the lining of the lungs (pleura) and the lung tissue beneath this lining almost simultaneously. Unlike asbestosis, this condition can affect the upper part of the lungs.

Another similar condition is Silicosis, which is more prone to cause fibrosis (scarring) than asbestosis. But a patient’s work history can help differentiate silicosis, particularly if they have been exposed to silica dust.

Sarcoidosis, a disease that can affect multiple body systems including the lungs, can also mimic asbestosis. However, certain features detected on lung tissue examination can help distinguish sarcoidosis from asbestosis.

The same goes for Coal Worker Pneumoconiosis, also known as black lung disease, which is caused by long-term exposure to coal dust. A lung biopsy will often show distinct black patches mixed with scarring.

Lastly, Combined Pulmonary Fibrosis and Emphysema can appear similar to asbestosis. However, this condition typically occurs in male smokers and involves both damage to the air sacs in the lungs (emphysema) and scarring in the lower parts of the lungs.

What to expect with Asbestosis

The seriousness of a disease often depends on how long a person was exposed to it and how intense the exposure was. If someone had a lot of contact with the cause of the disease over an extended period, their health prognosis is typically worse. However, if the first symptoms of the disease are quickly identified and treated, the person’s chances of surviving and living longer generally improve.

The disease can get worse during instances of intense flare-ups or additional infections. Performing x-ray screenings on workers has proven useful in detecting early signs of abnormal changes in their bodies. However, steroids only offer relief from symptoms and don’t always help ease the disease itself. Stopping the disease from progressing further can be achieved by getting rid of the root cause.

In the later stages, the disease process becomes irreversible and might lead to lung cancer. Patients with the disease spreading to the protective layers of their lungs usually don’t survive more than a year after their diagnosis. However, from the time of noticing the first symptom or the earliest screening, the maximum survival time is roughly four years. Also, in the case of mesothelioma (a type of cancer that affects the protective lining around the body’s organs), aggressive surgery or radiation therapy may help slow down the cancer’s spread to the chest wall.

Possible Complications When Diagnosed with Asbestosis

Asbestos exposure can lead to several health complications, which usually worsen with longer and more intense exposure. Here’s a simplified breakdown of these complications:

• Respiratory Failure: Asbestos can lead to a lung disease called asbestosis which restricts the lung’s ability to fill up with air. This often leads to breathing difficulties, persistent coughing, reduced oxygen levels in the blood, and issues with gas exchange in the lungs. Another potential complication is respiratory acidosis, a condition where the levels of carbon dioxide in the blood increase, causing the body fluids to become too acidic. Also, scarring in the lungs can prevent them from expanding correctly, and this can give rise to issues like pulmonary hypertension.
• Malignancy (Cancer): People with asbestosis have a higher chance of developing cancer, particularly lung cancer. Studies show that smokers exposed to asbestos have an even higher risk due to the combined effect of smoking and asbestos. In the case of lung cancer, the types most commonly seen are adenocarcinoma and squamous cell carcinoma. Mesothelioma, a cancer affecting the lining of the lungs and abdomen, is also common among people with asbestos exposure.
• Heart and Other Organs: Asbestos exposure may lead to various heart problems, including an enlarged heart due to excessive strain on the right side of the heart. This is caused by higher resistance in the lung’s blood vessels. If the situation worsens, it could lead to cor pulmonale, a condition where the right ventricle of the heart enlarges or fails. In such cases, the liver can also experience blood congestion.
• Cancers of Other Organs: Studies have shown that asbestosis can increase the risk of developing cancers in other parts of the body, including the gastrointestinal tract, ovaries, adrenal glands, larynx, and kidneys.

Preventing Asbestosis

Asbestosis is a disease often seen in workers exposed to asbestos. It’s a condition that’s gaining more attention these days because of its long-term harmful effects. Even though asbestos can be useful, it’s unsafe for regular and extended use and contact. The best way to handle asbestosis is to prevent it in the first place.

Studies have been conducted looking into how asbestos impacts a person’s health. This disease tends to develop slowly over time, but the progression can be halted by avoiding any further exposure. Some of the ways to mitigate the risks include educating people about health and safety, monitoring working environments, conducting regular medical checkups, and providing suitable treatment to affected workers.

Workers should be made aware of the symptoms and potential health issues related to asbestosis, the results of treatments, the harmful effects of medication, and their right to consult with healthcare professionals in a timely manner. If an individual is diagnosed with asbestosis, it’s important that they quit smoking. In addition, reducing their exposure to asbestos by changing their job or profession can contribute to better health.