Asbestosis

Asbestos is a group of minerals characterized by their fibrous crystalline structure that is composed mainly of silicate.  Asbestos has been used for about 3,000 years in a variety of manner.   An estimated 3,000 products in use today contain asbestos in some form.  Asbestos is overwhelmingly found in materials used in heat and acoustic insulation, fireproofing, and roofing and flooring.  Some of the more common products that may contain asbestos include pipe and duct insulation, building insulation, floor and ceiling tiles, patching and spackling compounds, artificial fireplaces and materials, roofing materials, and electrical wires. 

Asbestos has been found to be extremely hazardous to the health because of its friable nature.  If asbestos is disturbed or damaged, it can then break up, releasing microscopic crystal fibers into the air.  If inhaled, these fibers can cause damage by penetrating internal tissues.  One of the diseases that asbestos can cause is asbestosis. 

Asbestosis is a relatively uncommon disease, usually found predominantly in people who are chronically exposed to asbestos material.  Those who are at the highest risk are the people who directly handle asbestos material at their job.  This group includes miners working in asbestos mines and quarries, shipyard workers, automotive mechanics - particularly brake technicians, construction workers, electricians, and other workers in the building trades.  Exposure to asbestos is not limited to those who directly work with the material.  Asbestosis has been reported in these people family members, as asbestos fibers can enter the home if they are on your clothes or hair.  Also, asbestos can be encountered in many old buildings, putting those building inhabitants at risk if the asbestos is exposed and disturbed.    

The danger of asbestosis is that it can lead to more life-threatening asbestos-related diseases such as bronchogenic carcinoma (lung cancer), and mesothelioma, a cancer of the membrane lining the outside of the lungs.  

Pathophysiology of Asbestosis

Asbestosis is a chronic inflammatory medical condition affecting the parenchymal tissue of the lungs.  It is essentially a fibrosis, or scarring, of the lung tissue. 

The microscopic asbestos fibers enter the body when it is inhaled.  Since these fibers are so thin and light, they are not filtered by the nose of bronchi, thus having easy access to the alveolus of the lungs.  The alveolus are small sacs, that together, make up the lungs.  They serve as the site of gas exchange – where oxygen is captured for the body.  Since many materials can enter this region, the immune system has cells there to destroy any foreign materials and organisms.  These cells, called macrophages, function by engulfing (phagocytosis) the materials.  Once inside the macrophages, acidic digestive enzymes break down the foreign materials.  However, therein lies the problem leading to asbestosis.     

The macrophages gallantly perform their function by attempting to engulf the asbestos particles.  However, this will prove detrimental to these cells because the fibers are too long.  In trying to engulf these asbestos particles, the macrophage basically cuts itself open (lysis) and the digestive enzymes that were contained inside the macrophage are now released into the alveolus.  These enzymes go on to injure the alveolus.  In addition, since the asbestos fibers are still free in the alveolus, more macrophages migrate to the area to attempt to destroy it.  However, the problem compounds itself as more macrophages become destroyed and their enzymes released to harm the alveolus.  The damage caused by these enzymes lead to fibrosis – the scarring process.  Fibrosis is a function of the immune system that aims to repair any tissue damage and to minimize the spread of an infected area.  As one can imagine, s0carring of the alveolus impairs their function in gas exchange.  This leads to the problems that are associated with asbestosis such as breathing problems.

Asbestosis Symptoms

The signs and symptoms of asbestosis are non-specific, and many only show up many years after the asbestos exposure has ended.  This is why it is difficult to diagnose any asbestos-related diseases early on.  Since asbestosis is a chronic progressive disease, the symptoms will generally get worse after they start.  Fortunately, the disease progresses slowly giving your doctor time to catch it.

Asbestosis has been called a mono-symptomatic disease because the earliest, most consistently reported, and most distressing symptom is shortness of breath, which has a slow and sinister development.  The shortness of breath initially experienced will progressively get worse with time.  Besides shortness of breath, other symptoms have been reported such as: 

• A persistent and productive cough – this can be a symptom as common as shortness of breath.
• Chest tightness
• Chest pain
• Restless sleep
• Hemoptysis – coughing up of blood. 
• Fatigue
• Appetite loss

Asbestosis Diagnosis

Diagnosis of asbestosis is largely dependent on a good and accurate clinical history taking.  Occupational exposure to asbestosis is critical to the diagnosis.  If the patient has had a history with asbestos exposure, then doctors can look for certain signs when listening to your lungs.  An early distinctive feature of asbestos is basal crackles in your lower lungs, than is similar to Velcro opening up, that can be heard by a stethoscope.  X-rays are then utilized to confirm the diagnosis of asbestosis. 

In X-rays photographs, asbestos fibers can be seen as small irregular opacities that look similar to ground glass.  These fibers are usually seen in the lower lateral lobes of the lungs.  Borders of the heart, particularly the left side may be obscured.  X-rays are continually used to track the progress of the disease. 

Asbestos Treatment

Once asbestosis has been established by findings on chest X-ray, regression of the disease is rare.  The disease may remain unchanged, but it is generally slowly progressive due to accumulating damage caused by asbestos fibers in the lung.   Evidence of progression as seen on chest X-ray may require comparison of chest X-rays taken as many as 4-6 years apart.

There is no curative treatment for asbestosis.  In severe cases of shortness of breath, breathing assistance can be provided using oxygen therapy, which can be administered from home.  Asbestosis patients can also participate in respiratory therapies such as bronchial drainage, or the use of an ultrasonic mist humidifier that assists in the clearing of secretions from the lungs. 

There are certain measures a patient can take to slow the progression of the disease and in the process, prolong their life span.  Obviously, further exposure of asbestos is not recommended.  Another important precaution is to stop smoking.  Smoking may increase the rate of disease progression, and it significantly increases the risk of developing lung cancer and mesothelioma.  In fact, monitoring for mesothelioma is mandated in individuals diagnosed with asbestosis. 

People with asbestosis should act immediately should there be any signs of respiratory infection.  Aggressive medical care with frequent use of antibiotics is warranted if there is any lung infection.  That is why vaccinations for the flu virus and Pnuemococcus bacteria are critical, and should be kept up to date.  Patients should avoid situations that may expose them to respiratory infections such as large crowds.  These steps will help aid in avoiding the complications of serious lung infections.

With proper precautions and preventative living, severe asbestosis is becoming a less common cause of death.  More people are dying of other causes before their asbestosis progresses beyond the mild to moderate stage.