Miners' lung disease

Coal dust puts miners at risk of lung disease

A lifetime of breathing in large amounts of coal dust in relatively enclosed spaces puts coal miners at risk of developing respiratory diseases which can lead to serious disability. Coal dust can irritate the sensitive tissues of the lung and lead to the development of diseases such as pneumoconiosis, emphysema and chronic bronchitis.

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PNEUMOCONIOSIS:

Otherwise known as black lung disease, pneumoconiosis comes in two forms.

The simple form is not usually disabling, but the complicated form usually does lead to disability.

The symptoms of pneumoconiosis include:

• Shortness of breath
• Chronic cough

The complicated form of the disease can lead to:

• Failure of the right side of the heart (cor pulmonale)
• Pulmonary tuberculosis

Who is at risk?

The risk of developing the disease is related to the duration and extent of exposure to the coal dust.

Most affected workers are over the age of 50. The incidence is 6 out of 100,000 people.

Is smoking a factor?

Smoking does not increase the prevalence of pneumoconiosis, but, because it can damage lung function, it may exacerbate the symptoms of the disease.

How is it treated?

Pneumoconiosis is detected by chest X-rays and by testing the function of the lungs.

There is no specific treatment for this disorder other than treatment of complications.

Avoidance of further exposure to coal dust is recommended.

How can the disease be prevented?

The way to prevent the disease is to minimise the amount of coal dust breathed in by mine workers.

This can be done by using protective masks, and by strictly controlling maximum permitted dust levels in occupational settings.

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EMPHYSEMA:

Emphysema is a condition in which there is over-inflation of structures in the lungs known as alveoli or air sacs.

This over-inflation results from a breakdown of the walls of the alveoli, and reduces the ability of the lungs to function properly.

What are the symptoms?

Early symptoms of emphysema include shortness of breath and coughing.

About half of those who suffer from emphysema find that it restricts their ability to carry out their normal daily activities.

Complications can lead to heart disease.

Who is at risk?

Miners are not the only group at risk of developing emphysema.

Many of the people with emphysema are older men, but the condition is increasing among women.

What causes the disease?

The disease is sparked by a change in the balance of the chemicals which regulate the expansion and contraction of the lungs during breathing.

When this balance is altered, the lungs lose the ability to protect themselves against the destruction of the elastic fibres which control the breathing movements.

The chemical balance can be disrupted by a number of agents, including coal dust and cigarette smoke.

Emphysema can also be inherited. In these cases, sufferers are born with a deficiency of a protein crucial to proper lung function.

How does the disease develop?

Emphysema begins with the destruction of air sacs (alveoli) in the lungs where oxygen from the air is exchanged for carbon dioxide in the blood.

The walls of the air sacs are thin and fragile. Damage to the air sacs is irreversible and results in permanent "holes" in the tissues of the lowerlungs.

As air sacs are destroyed, the lungs are able to transfer less and less oxygen to the bloodstream, causing shortness of breath. The lungs also lose their elasticity. The patient experiences great difficulty exhaling.

How is it treated?

The aim of treatment is to help sufferers live more comfortably with the disease, and to prevent progression with a minimum of side effects.

Bronchodilator drugs can be used to relax and open air passages in the lungs.

Patients are also recommended to undertake exercises to strengthen the muscles used in the breathing process.

They should also maintain overall good health habits, such as good diet and adequate sleep to build up resistance to infections which may exacerbate the symptoms of emphysema.

In some extreme cases, the most severely diseased portions of the lung can be removed by surgery to allow the remaining lung and breathing muscles to work better.

How can the disease be prevented?

Researchers know that quitting smoking can prevent the occurrence and decrease the progression of emphysema. Other environmental controls can also help prevent the disease.

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CHRONIC BRONCHITIS:

People with chronic bronchitis suffer from long-term spitting and coughing continuing for months and returning each year, lasting longer each time.

The airways have become narrowed and partly clogged with mucus that is not moving along as it should, propelled by minute hairs called cilia.

Because of the obstruction, chronic bronchitis sufferers have continual difficulty breathing.

What causes the disease?

Cigarette smoke and coal dust has been associated with irritating the airways, causing them to narrow and paralyzing the cilia.

Those who quit smoking find that chronic bronchitis is lessened after a while.

What are the symptoms?

The breathing difficulties symptomatic of this condition are similar to asthma.

However, asthmatic breathing difficulties appear and disappear while chronic bronchitis stubbornly persists.

Chronic bronchitis can progress to emphysema. In tandem, the two diseases are known as Coronary Obstructive Pulmonary Disorder.

What is the treatment?

Chronic bronchitits is treated with bronchodilators and anti-inflammatory drugs delivered with an inhaler.

Oxygen may also be administered.

Antibiotics may be prescribed to check bacterial infections.

Atrovent - an inhaled medication - can block the nerves in the airways, helping to reduce coughing.

Can the disease be prevented?

Not smoking and avoiding air pollution are the best ways to prevent chronic bronchitis.