Pneumoconiosis

 

Pneumoconiosis is one of a group of interstitial lung disease caused by breathing in certain kinds of dust particles that damage your lungs. most of people come in contact in these dusts only in the workplace, pneumoconiosis is called an occupational lung disease.

Dust within the size range of 0.5 to 3 micron, is a health hazard producing, after a variable period of exposure, a lung disease known as pneumoconiosis, which may gradually cripple a man by reducing his working capacity due to lung fibrosis and other complications.

The hazardous effects of dusts on the lungs depend upon a number of factors such as:

1. Chemical composition of dust.
2. Fineness
3. Concentration of dust in the air.
4. Period of exposure.
5. Health status of the person exposed.

Types of pneumoconiosis

The disease appears in different forms, depending on the types of dust you inhale. The important dust disease are:

1. Silicosis
2. Anthracosis
3. Byssinosis
4. Bagassosis
5. Asbestosis
6. Farmer's lung
7. Siderosis

As no cure for the pneumoconiosis is known, it is essential to prevent these diseases from arising. A brief account of these conditions is given below:

Silicosis

Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust (dust containing free silica or silicon dioxide).

The incidence of silicosis depends upon the chemical composition of the dust, size of the particles, duration of exposure and individual susceptibility. The higher the concentration of free silica in the dust, the greater hazard. Particles between 0.5 to 3 micron are the most dangerous because they reach the interior of the lungs with ease. The longer the duration of exposure, the greater the risk of developing silicosis. It is found that the incubation period may vary from a few months up to 6 years of exposure, depending upon the above factors.

The particles are ingested by the phagocytes which accumulate and block the lymph channels. Pathologically, silicosis is characterized by a dense nodular fibrosis, the nodules ranging from 3 to 4 mm in diameter. 

Clinically the onset of the disease is insidious. Some of the early manifestations are irritant cough, dyspnea on exertion and pain in the chest. With more advanced disease, impairment of the total lung capacity is commonly present. An X-ray of the chest shows "snow-storm" appearance in the lung fields.

There is no effective treatment for silicosis. Fibrotic changes that have already taken place cannot be reversed. The only way that silicosis can be controlled is by:

1. Rigorous dust control measures at workplace.
2. Use of personal protective measures.
3. Regular physical examination of workers.

Anthracosis

Anthracosis is a type of pneumoconiosis as caused by the accumulation of carbon in the lungs due to repeated exposure to air pollution or inhalation of smoke or coal dust particles. 

Anthracosis involvement mainly starts from the respiratory bronchioles Histopathology of the  lung tissue has shown carbon-like particles inside the cytoplasm of the macrophages in the bronchial wall and free particles in the mediastinal lymph nodes. Submucosal fibrosis may also seen in the bronchial wall and the epithelial lining is usually intact.

The main clinical features of anthracosis are enlargement of involved lymph nodes, prominent mediastinal lymphadenopathy. Shortness of breath, labored breathing, coughing, and production of phlegm.

Chest X-ray, CT scan, and pulmonary function test are used to find out anthracosis in client.

There is no cure. Treatments generally aim to ease symptoms, prevent further damage to person lungs, and improve your quality of life. Stop smoking and oxygen may be given , if person oxygen levels are low. Doctor may be prescribe medication to keep airways open, such as inhalers, especially if person have asthma systoms.

Byssinosis

Byssinosis is an occupational lung disease caused by inhalation of cotton fiber dust over long periods of time. Byssinosis is most common in textile industry workers. Smoking may increase the risk of developing byssinosis.

The symptoms are chronic cough and progressive dyspnea, ending in chronic bronchitis and emphysema.

For diagnosis of byssinosis doctor perform a physical examination of patients lungs and may order for a chest X-ray and CT scan of lungs. Pulmonary function tests are also often used to check lung health.

Treatment of byssinosis is to avoid exposure to harmful dust. Supportive medication like bronchodilators, inhaled corticosteroids,  and oxygen therapy is given if patient blood oxygen levels are low.

Bagassosis

Bagassosis is the name given to an occupational disease of the lung caused by inhalation of bagasse or sugarcane dust. It is most commonly occurs in those who are frequently close to this material, e.g. sugar factory workers.

The sugarcane fiber which earlier went to waste, is now utilized in the manufacturing of paper, cardboard and rayon. 

Bagassosis is mainly occur due to a thermophilic actinomycete for which the name Thermoactinomyces sacchari was suggested.

The symptoms consist of breathlessness, cough, haemoptysis and slight fever. Initially there is acute diffuse bronchiolitis. There is impairment of pulmonary function. If treated early, there is resolution of the acute inflammatory condition of the lung. If left untreated, there is diffuse fibrosis, emphysema and bronchiectasis.

There is no role for drugs in the management of bagassosis. Preventive measures are important to control bagassosis. 

1. Dust Control : Measures for the prevention and suppression of dust such as wet process, enclosed apparatus, exhaust ventilation etc.
2. Personal Protection : Personal protective equipment such as masks or respirators with mechanical filters or with oxygen or air supply may be necessary.
3. Medical Control : Initial medical examination and periodical medical check-ups of the workers are play important role in control of bagassosis.
4. Bagasse Control : By keeping the moisture content above 20 per cent and spraying the bagasse with 2 per cent propionic acid, a widely used fungicide, bagasse can be rendered safe for manufacturing use.

Asbestosis

Asbestosis is a chronic lung disease caused by inhalation of asbestos fibers. Asbestos is the commercial name given to certain types of fibrous materials. They are silicates of varying composition; the silica is combined with such bases as magnesium, iron, calcium, sodium and aluminium.

Types of asbestos

[A] Serpentine / Chrysolite

Ninety per cent of the world's production of asbestos is of the serpentine variety, which is hydrated magnesium silicate.

[B] Amphibole

The amphibole type contains little magnesium. The amphibole type occurs in different varieties, e.g. crocidolite (blue), amosite (brown), and anthophyllite (white). 

Asbestos is used in the manufacture of cement, fire-proof textiles, roof tiling, brake lining, gaskets, and several other items. 

Asbestos enters the body by inhalation, and fine dust may be deposited in the alveoli. The fibers are insoluble. The dust deposited in the lungs causes pulmonary fibrosis leading to respiratory insufficiency and death; carcinoma of the bronchus; mesothelioma of the pleura or peritoneum; and cancer of the gastro-intestinal tract.

The disease does not usually appear until after 5 to 10 years of exposure. Clinically the disease is characterized by dyspnea. In advanced cases, there may be clubbing of fingers, cardiac distress and cyanosis.

The sputum shows "asbestos bodies" which are asbestos fibers coated with fibrin. An X-ray of the chest shows a ground-glass appearance in the lower two- thirds of the lung fields. Once established, the disease is progressive even after removal of the worker from contact.

The following preventive measures are use full in prevention of asbestosis. 

1. Use of safer types of asbestos.
2. Substitution of other insulants : glass fibre, mineral wool, calcium silicate, plastic foams etc.
3. Rigorous dust control.
4. Periodic health examination of workers.
5. Continuing research.

Farmer's Lung

Farmer's lung is due to the inhalation of moldy hay or grain dust. In grain dust or hay with a moisture content of over 30% bacteria and fungi grow rapidly, causing a rise of temperature to 40 to 50 degree centigrade. This heat encourages the growth of thermophilic actinomycetes, of which Micropolyspora faeni is the main cause of farmer's lung. 

The acute illness is characterized by general and respiratory symptoms and physical signs. Repeated attacks cause pulmonary fibrosis and inevitable pulmonary damage and Cor-pulmonale. 

Farmer's lung disease is cure with treatment in one to two weeks. The main treatment options are rest and reducing the exposure of moldy hay and grain dust.

Siderosis

Siderosis is the deposition of excess iron in body tissue. Pulmonary siderosis (Welder's disease) is caused by repeated inhalation of fine iron or rust dust that happens usually over a number of years, which is a form of pneumoconiosis.

affected person have persistent breathlessness, coughing and decreased lung function. The pulmonary siderosis is diagnosed by lung X-ray and tissue sample from lungs.

There is no cure for pulmonary siderosis. Any damage is thus permanent. Outcome of pulmonary siderosis is often good if the inhalation of iron or dust is permanently avoided.