Asbestosis Overview

AsbestosisAsbestosis is a respiratory problem caused by inhaling asbestos fibers into the lungs. The condition generally doesn’t start immediately after exposure, but rather may take many years to develop. The asbestos fibers in the lungs cause scarring and thickening of the tissue of the lungs, and if exposure continues can lead to serious medical problems and even death (1).

People with long-term exposure to asbestos are at the greatest risk for getting asbestosis. The risk is most increased for people who have had ten years or more of moderate or grater exposure. Since asbestosis has been a recognized carcinogen for many years, the government has put a lot of regulations in place to ensure that people have considerably less exposure risk today, than they did in the past. Nevertheless, new cases continue to show up, mostly among people who had job-related asbestos exposure prior to the implementation of stricter regulation in the 1970’s. Today most asbestos exposure is caused by removing old asbestos from old buildings, and modern protective gear limits the amount of fibers that could potentially make it to the lungs.

The asbestos fibers enter the lungs when they are inhaled. They travel through the trachea and down into the lungs. Inside the lungs the fibers get into the alveoli, the part of the lungs where fresh oxygen moves into the blood stream to be carried throughout the body. The body can cough out or break down most substances that are inhaled, so while they may cause coughing for a while, they don’t do permanent damage. Asbestos fibers however, resist being eliminated by the body.

The alveoli produce cells called macrophages whose purpose is to break down any foreign substances that get to the alveoli. Asbestos fibers are too long for the macrophage cells to completely enclose them. When the macrophage works to break down the fiber then, some of the substance that is supposed to break down the fiber leaks out and gets into the alveoli. The alveoli get inflamed, and over time scar tissue builds up. This process is called fibrosis. Over time this causes the lungs to become stiffer and stiffer making breathing difficult and painful.

People who have had long term exposure to asbestos and who have ongoing respiratory problems should consult with a doctor, and should inform their doctor about the asbestos exposure. On general, the symptoms for asbestosis are difficulty in breathing caused by inflexibility of the lung tissue, coughing, and chest pain. In some cases the asbestosis victim’s fingers get thicker in a process called clubbing.

In addition to the medical problems asbestosis creates on its own, it can also lead to other related medical problems. The restriction of movement in the lungs caused by the scar tissue can cause pressure to build up in the arteries that supply the lungs with blood. High blood pressure in the lungs is referred to as pulmonary hypertension. This condition is turn can create stress on the heart. The heart can compensate for a while, but in serious cases the heart eventually fails from the strain. Asbestosis especially combined with smoking leads to a much increased risk for lung cancer, and malignant Mesothelioma, a cancer of the lining of the lungs.

To help the doctor diagnose the problem, he or she may order any number of tests. Pulmonary function tests give the doctor a measure of how effectively and efficiently the lungs are working. What the doctor is looking at is how well the lungs are able to exchange carbon dioxide from the veins with oxygen. The doctor measures this exchange by having the person blow into a device that measures how much air the person can exhale and what percentage of oxygen and carbon dioxide the breath holds.

To get a general idea of whether there is lung damage the doctor may order an X-ray. A chest X-ray is just like an X-ray for any other part of the body. A machine sends the X-rays through the body and a camera on the other side of the body records the X-rays that come out. The X-rays intensity on exit varies with how much of the wave was absorbed by the body. The resultant picture essentially shows shadows where the tissue is thicker or denser and absorbed more of the X-rays. If a doctor sees a “shadow of the lung” it means there is an area of thickening in that area that shows up as a shadow on the X-ray.

A more detailed picture than the two dimensional shadow picture created by a traditional X-ray is the three-dimensional detailed computer picture created by a computerized tomography (CAT or CT) scan. A CT scan is the same thing as an X-ray, only instead of getting only one picture that can only show shadows, a CT scan produces many pictures that are combined into a detailed image on a computer screen. The person getting a CT scan lies on a table that slides into the machine. While the person lies still, the machine circles around their body taking multiple X-ray pictures from many different angles. When the pictures are all put together the doctor can get a very accurate detailed view of the lungs or other internal organs.

A doctor may order a biopsy to rule out any cancer if he or she fins suspicious masses in and around the lungs.

Once a diagnosis of asbestosis is reached, the doctor will determine the appropriate treatment. While there is no cure for asbestosis, the doctors can treat the symptoms. In serious cases where a portion of lung simply cannot function, the doctor may do surgery to remove that part of the lung. In less severe cases, the doctor may put the patient on oxygen to help the lungs get more oxygen to the blood with less effort, thereby easing strain on the heart as well. If the person has a build up of mucus in the lungs the doctor may instruct on way to help drain the mucus.

'Asbestosis Overview' Resources:
  1. Asbestosis, Mayo clinic staff, © 1998-2007 Mayo Foundation for Medical Education and Research (MFMER), Asbestosis