Asbestosis is a "chronic lung disease" caused by inhaling asbestos fibers. Asbestos is the commercial name to certain type of fibrous material. The term "asbestos" is used to refer to six naturally occurring silicates minerals. All are composed of long and tiny fibrous crystals, each fibre being composed of many microscopic ‘fibrils’ that can be released into the atmosphere. Asbestos fibres are usually from 20 to 500μ in length and 0.5 to 50μ in diameter. Asbestos is a group of heat resistant minerals. They are silicates of varying composition; the silica is combined with such bases as magnesium, iron, calcium, sodium and aluminium. Asbestos is of two types- serpentine or chrysolite variety and the amphibole type. Ninety per cent asbestos production in the world is serpentine variety, which is hydrated magnesium silicates, and the amphibole type contains little magnesium. Asbestos is used in the manufacturing of asbestos cement, fire-proof textiles, roof tiling, brake lining, gaskets and several other items.

Asbestosis is also known as “diffused pulmonary fibrosis”. Asbestos enters in the lungs by inhalation, and fine dust of asbestos may be deposited in the alveoli. The fibres are insoluble. The dust deposited in the lungs cause pulmonary fibrosis leading to respiratory insufficiency and death; carcinoma of the bronchus; cancer of gastro intestinal tract. It is most seen with those who work with asbestos or asbestos containing products. Shipbuilders, textile and construction workers, home remodelers, miners are at high risk of exposure of asbestos fibres.  

Symptoms of asbestosis:

In most cases, symptoms do not appear until after 5 to 10 years of exposure.

Common symptoms of asbestosis include:

  • Dyspnoea
  • Cardiac distress
  • Cyanosis
  • Shorten of breath
  • Chest pain
  • Clubbing of fingers
  • Persistent dry cough

Causes and risk factors associates with asbestosis:

Our nose and bronchi acts as filters and stop most of the particles present in our atmosphere, But because asbestos fibres are thin, needle-like, and microscopic, they are able to enter in our lungs. Where they are usually lodge in the lining of the lungs, known as the 'pleura'.  Mesothelioma, a rare form of cancer of the pleura and peritoneum, has been seen to have a strong association with the crocidolite variety of amphibole type of asbestos.

When we inhale asbestos fibres, they are deposited in our lungs and leads to formation of scar tissue. The risk of bronchial cancer is reported to high if regular exposure of asbestos is combined with cigarette smoking. The fibrosis in asbestosis is due to mechanical irritation and is peri-bronchial, diffuse in character and basal in location in contrast to silicosis in which the fibrosis is nodular in characters and present in the upper part of the lungs.

Diagnosis of asbestosis:

Chest X-ray or high resolution chest CT and sometime bronchoalveolar lavage or lung biopsy is performed by the doctors. At first, the doctor will usually use a stethoscope to listen for abnormal breathing sounds as a part of physical examination. Doctor may also order for X-ray. X-ray of chest shows a ground-glass appearance in the lower two-thirds of the lungs fields.

Pulmonary (lung) function test may be used to measure the amount of air you are able to inhale and the airflow to and from the lungs. The doctors see how much oxygen is transferred from your lungs to your bloodstream.

CT scan are done to know more details of lungs and biopsy to look asbestos fibres.

Treatment of asbestosis:

There is no specific treatment of asbestosis. You can avoid further exposure of asbestos fibre. A lung transplant might be an option if your condition is severe.

Supplemental oxygen from a portable oxygen tank is often necessary for patients with reduced lung capacity. The tank delivers extra oxygen to the lungs through a plastic tube with two prongs that fit into the patient’s nostrils.

Preventive measures:

  • Some of preventive measures include:

  • Stop additional exposure

  • Vaccination with pneumococcal vaccine and influenza vaccine.

  • Smoking cessation

  • Use of protective mask

  • Use safer type of asbestos (chrysolite and amosite)

  • Rigorous dust control

  • Periodic examination of workers

  • Biological monitoring (X-ray, lung function)