Table of Contents
Definition of Asbestosis
Asbestosis is damage to the LUNGS resulting from inhalation of asbestos fibers.
During the first half of the 20th century asbestos, a natural substance mined from underground, became common in insulating materials because of its natural heat resistance.
In the 1950s researchers linked chronic asbestos inhalation with PULMONARY FIBROSIS and a rare form of LUNG CANCER, mesothelioma, found almost exclusively in people with asbestos exposure. In the 1970s the United States implemented strict regulations that prohibited the use of asbestos in many of its formerly common applications.
For people who had occupational exposure to asbestos before these restrictions, however, asbestosis is a significant risk. Millions of Americans live with asbestosis and hundreds die each year from it or from lung cancer associated with asbestos exposure.
Asbestos fibers embed in the tissues of the lungs, causing INFLAMMATION and granulation that eventually leads to fibrosis (SCAR tissue formation). Some forms of asbestos are more hazardous than others. Typically lung damage from asbestos takes 20 years or longer after exposure to manifest. The likelihood of developing health consequences from asbestos exposure correlates directly to the amount of asbestos and the duration of the exposure. Cigarette smokers face increased risk, particularly of lung cancer, as the asbestos and the carcinogenic chemicals in cigarette smoke potentiate each other (intensify each other’s actions in the lungs).
Symptoms of Asbestosis and Diagnostic Path
Many people do not show symptoms of asbestosis until the damage is fairly advanced. Because of this, health experts recommend people with known asbestos exposure receive annual examinations to monitor the health of their lungs. When symptoms manifest they typically include
- DYSPNEA (difficulty BREATHING) with physical exertion
- dry (nonproductive) COUGH
- chest discomfort, tightness, or pain
The diagnostic path includes comprehensive work and health histories, physical examination including AUSCULTATION, chest X-rays, and sometimes other diagnostic imaging procedures such as COMPUTED TOMOGRAPHY (CT) SCAN or MAGNETIC RESONANCE IMAGING (MRI). Finger clubbing, in which the ends of the fingers become thick, rales (crackling BREATH SOUNDS), and CYANOSIS (bluish hue to the lips and SKIN that signals inadequate oxygenation) are common signs of lung damage typical of lung diseases such as asbestosis. Doctors assign a numeric classification from grade 0 to grade 4 to indicate the severity of damage, along with letter designations A, B, or C to identify the extent of lung structure affected.
Asbestosis Treatment Options and Outlook
Treatment for asbestosis is largely supportive, as it is not possible to remove the fibers once they embed in the lungs. SMOKING CESSATION is of prime importance, as cigarette smoking in combination with asbestos exposure greatly increases the likelihood of lung cancer. Treatment also targets specific concerns or other problems as they arise. Generalized efforts to promote pulmonary health, such as BREATHING EXERCISES and regular physical activity to improve AEROBIC CAPACITY, increase the efficiency of undamaged lung tissue.
Because the latency period (time between exposure and symptoms) is so long, damage to the lungs can be quite extensive by the time symptoms become apparent. People who know they have had exposure to asbestos should have regular pulmonary examinations to monitor for asbestosis. Though asbestosis can be fatal, many people live without significant complications due to the condition. The most significant consequence of asbestosis is lung cancer, including mesothelioma, a type of lung cancer that only occurs with asbestos exposure.
Risk Factors and Preventive Measures
Asbestosis only occurs as a consequence of asbestos exposure, so eliminating exposure eliminates the risk of developing the condition. Preventive measures for those who continue to have occupational exposure include appropriate protective clothing and respirators.
|Grade||Severity||Extent of Lung Damage|
|grade 0||asymptomatic||asbestos fibers present but no fibrosis|
|grade 1||mild damage||fibrosis limited to bronchi and bronchioles, no alveolar involvement|
|grade 2||moderate damage||fibrosis extends to alveoli|
|grade 3||serious damage||fibrosis extends between alveolar clusters|
|grade 4||severe damage||fibrosis obliterates alveoli, replacing them with honeycombed SCAR tissue|
|grade A||mild involvement||scattered bronchial structures are involved|
|grade B||moderate involvement||fewer than half the bronchial structures are involved|
|grade C||severe involvement||greater than half the bronchial structures are involved|