Asbestos related diseases are either Non-Malignant (not cancerous) or malignant (cancerous). There are two non-malignant conditions: Asbestosis and Pleural Disease. Asbestos related Malignancies are: Esophageal Cancer, Laryngeal Cancer, Lung Cancer Stomach Cancer and Mesothelioma. The medical criteria for diagnosing an asbestos related disease is very specific. The tests required and the manner in which they must be interpreted have been standardized by NIOSH (The National Institute for Occupational Safety and Health) and are very definitive.
The most basic medical test required to diagnose an asbestos related disease is an X-Ray. This X-Ray must be interpreted by a Dr. who has obtained special certification through NIOSH as a B-Reader*1. His findings or interpretation are recorded on a B-Reader Form. A medical report that grades an X-Ray based on a standardized method of classification. The guidelines for use of the ILO International Classification of Radiographs of Pneumoconioses prescribe side-by-side viewing of subject and standard radiographs, and state that the standard films take precedence in defining profusion categories. In other words, on one side there is a picture of what a lung looks like with the designated profusion (0/0 – 3/3) and on the other, there is an X-Ray to be evaluated. The X-Ray being evaluated is compared to the X-Rays with the varying profusions and the doctor determines which profusion that X-Ray most closely resembles. Although the presence of an asbestos related condition can be determined by other radiological methods such as a CT scan, such a comparison cannot be made between the two different types of radiography with sufficient accuracy. Therefore, for the purpose of obtaining a correct B-Reading (necessary for the claims filing process) it is a good old-fashioned X-Ray that is necessary. The second medical test used, not to determine the existence of an asbestos related disease but only to measure the severity, is a PFT or Pulmonary Function Test. A PFT is used to measure the function of the lungs. This group of tests measure how well the lungs take in and release air and how well they move gases such as oxygen from the atmosphere into the body’s circulation.
- Spirometry, using a spirometer, is the most common of the pulmonary function tests, measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled.
- Body plethysmography is a very sensitive lung measurement used to detect lung pathology that might be missed with conventional pulmonary function tests. This method of obtaining the absolute volume of air within one’s lungs may also be used in situations where several repeated trials are required or where the patient is unable to perform the multibreath tests.
- Peak expiratory flow may, in addition to the spirometer, be measured with a more handy peak flow meter. Nitrogen washout (or Fowler’s method) is a test for measuring dead space in the lung during a respiratory cycle, as well as some unique parameters related to the closure of airways.
- A ventilation/perfusion lung scan, also called a V/Q lung scan, uses scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient’s lungs, in order to determine the ventilation/perfusion ratio.
Lung diseases such as asbestosis are restrictive; They make the lungs scarred and smaller so that they contain too little air. The results of this test demonstrate the degree of severity that this is occurring.
All malignancies must be diagnosed pathologically. A biopsy must be performed and the tissue is then analyzed for the existence of malignant cells.To confirm an asbestos related malignancy or cancer, the cancer must have originated in the Esophagus, Larynx, Lung, Pleura (the lining of the lung) or the Stomach. Additionally, a diagnosis of non-malignant asbestos related condition as outlined above must also be made.
Asbestos, derived from the Greek words asbestinon and/or sbestos meaning extinguished or quenched, is the name given to a set of six naturally occurring silicate minerals. In the United States, chrysotile has been the most commonly used type of asbestos, but all are thin fibrous crystals and all were exploited commercially for their desirable physical properties:
- its sound absorption
- average tensile strength,
- resistance to fire and heat,
- resistance to electrical and chemical damage.
Diagnosis of an asbestos related disease is not just the existence of specific medical condition, but is contingent on the ability to demonstrate that the individual suffering from these medical abnormalities was also in such an environment that he or she would have been exposed to an asbestos containing product – Proof of Exposure.
1- B Reader approval is granted to physicians with a valid U.S. state medical license who demonstrate proficiency in the classification of chest radiographs for pneumoconioses using the International Labour Office (ILO) Classification System. Proficiency is evaluated via the B Reader Examination, which was developed in response to the mandates of the Federal Mine Safety and Health Act. Since the examination was first administered in 1974, more than 1000 physicians have passed it. Currently, there are about 300 B Readers (Current B Reader List).