Asbestosis
Pulmonary fibrosis caused by asbestos inhalation is more commonly referred to as asbestosis, a respiratory disease that causes chronic inflammation in the lungs. The word asbestos is derived from Greek and means “inextinguishable.” Asbestos include a group of naturally occurring, heat-resistant, fiber.
Extended inhalation of asbestos fibers can cause inflammation of the parenchymal tissue in the lungs. Chronic inflammation causes scar tissue to form inside the lung which inhibits the lungs from expanding and contracting normally, diminishing the ability to breathe.
Symptoms
- Dypsnea (Shortness of breath upon exertion)
- Dry (non-productive) cough
- Tightness in the chest
- Chest pain
- Nail abnormality
- Clubbing of the fingers
- Pleural plaques (calcification of the lungs)
- Pleural effusions (fluid accumulation in the lungs)
The severity of this disease may depend on the duration of asbestos exposure and the amount of asbestos inhaled. Asbestosis can become a serious or fatal health concern. It can also lead to the development of other diseases such as lung cancer or malignant mesothelioma.
Causes
When we inhale, air passes through our nose or mouth into our throat, though the larynx and into the trachea. The trachea is the main passageway into the lungs and splits into two branches called bronchi. One of the bronchi carries air into the left lung and the other carries air into the right.
Within the lungs, bronchi branch further into smaller and smaller airways until they eventually end in microscopic air sacs called alveoli.
Alveoli are made of thin, elastic walls that allow oxygen to flow into the bloodstream and remove carbon dioxide from the bloodstream to expel it from the body.
Sometimes we also inhale various microorganisms, dust, and other foreign materials but usually these particles are trapped by microscopic hairs on the surface of our airways known as cilia. Cilia sweep particles into our upper airway where they are swallowed and digested or coughed out.
Occasionally unwanted particles do get into our lungs but our body has a series of built-in immune cells that destroy them. The immune cells in the alveoli are known as macrophages which ingest and destroy particles such as dust or chemicals.
However, asbestos fibers are more resistant to breakdown than dust particles. When asbestos fibers are inhaled into the lungs, macrophages leak a substance designed to destroy the particles. This process usually fails because asbestos fibers are too long and too durable. Instead, the leaked chemical causes the alveoli to become inflamed. Over an extended period of time, this inflammation causes scarring or fibrosis.
The scarring inhibits alveoli from exchanging oxygen and carbon dioxide which diminishes the abilities of the lungs.Treatment Options
No cure currently exists to reverse the effects of asbestos in the lungs. Treatment for asbestosis includes draining fluid build up and perhaps administering aerosol medication to thin fluid secretions. In some cases oxygen masks may be helpful.
Preventing progression of the disease may be accomplished by eliminating exposure to carcinogens such as asbestos and smoking. Smoking cessation may also prevent the heightened risk of lung cancer or emphysema that could even further reduce lung capacity.
Patients with asbestosis should be mindful of other diseases that might impair lung capacity such as pneumonia. Treat the common cold or the flu promptly and adequately. Your doctor should actively monitor your condition with X-rays and CT scans.
Prevention
Currently, research into preventive treatment options is underway. COX-2 inhibitors such as Celebrex prevent the COX-2 enzyme from inflaming. Laboratory research into this area is promising.
Celebrex is currently offered in clinical trial at the University of California at Los Angeles, California as a preventive measure against lung cancer. Laboratory testing has been very successful.
More about the preventive strategy known as chemoprevention: www.lungcancerprevention.com/Home.html
Patients can also take preventive measures by reducing their level of exposure to asbestos. Generally, many homes built before the 1970s contained asbestos products as insulation, decorative material, in paint, roofing, vinyl floor tiles, and in other products. Talk to a professional about removing asbestos materials if they are at risk of being disturbed such as in a remodeling project or if they are disintegrating. For more information into this area, contact PHLBI’s administrative office at (310) 622-4960.