What do you mean by Coal worker’s pneumoconiotic?
There were 1,160 new cases of asbestos pneumoconiotic, excluding asbestosis, assessed in the Industrial Injuries Scheme in 2004. These numbers are rising but almost certainly due to publicity about compensation as the mining industry in this country has been in decline for many years and 65% of claimants are over 65 years old. Chronic bronchitis and emphysema became prescribed diseases in September 1993 for coal miners with a specified level of lung function impairment and a minimum of 20 years underground exposure to coal dust. The numbers have fluctuated considerably, based more on publicity and relaxation of criteria to be able to claim rather than upon incidence.
What are Asbestos related diseases?
Asbestos is a strong, flexible, durable fiber whose heat and chemical resistance led to its widespread use.
There are 3 types of asbestos, all of which are dangerous but the blue and brown asbestos are more dangerous than white asbestos. Much of the asbestos found in buildings contains a mixture. Undisturbed asbestos in good condition is not a risk to health but if disturbed, the asbestos fibers can break down into sharp fibers which can then be inhaled. If these fibers lodge in the lungs, they persist and may migrate peripherally where they can trigger the development of several diseases, some Of which are fatal. Treatment is symptomatic only.
What are High risk occupations?
Many of those now suffering from asbestos-related disease were exposed to very high levels of asbestos in the more traditional industries such as shipbuilding, construction and boiler work. 25% of the deaths from the disease are in people who have spent some o their working lives in the building and maintenance trades – they are often unaware he they were dealing with asbestos and exposed to risk.
Those who continue to be at risk from exposure to asbestos are those who disturb the fabric of buildings as part of their day to day work and include:
- Heating and ventilation engineers
- Gas fitters
- Roofing contractors
- Fire and burglar alarm installers
- Trades people (electricians, plumbers, carpenters, joiners)
- Plasterers, painters and decorators
- Demolition workers
- Telephone and computer installation engineers
- Site managers and surveyors
Asbestos related diseases include pleural plaques (usually asymptomatic); benign pleural effusions (may be recurrent), bilateral pleural thickening but also:
- Asbestosis tends to follow heavy exposure with a 5-10 year time interval. It usually presents with:
- Shortness of breath with a dry cough.
- Progressive dyspnoea.
- Repetitive inspiratory basal crackles, sometimes known as ‘velcro crepitation’.
- Clubbing of the fingers (late feature).
The rate of progression depends upon the level of exposure and eventually results in increasing disability and death from cardio respiratory failure. In smokers, there is a 40 to 50% risk of death from bronchial carcinoma.
- CXR shows a ground-glass pacification, small nodular opacities, “shaggy” cardiac silhouette, and an ill-defined diaphragmatic contour.
- Spirometry – restrictive pattern of lung function with reduced volumes/transfer factor.
- Sputum microscopy may show asbestos bodies.
These confirm exposure to asbestos but their significance in diagnosing asbestosis is uncertain.
Asbestos related lung cancer:
Lung cancer is a common disease amongst smokers but it has an increased incidence in those with asbestosis. All types can cause the disease with some evidence of more danger from blue and brown. It is commoner amongst those who have smoked but may occur in non- smokers. The presentation and investigation of lung cancer is discussed elsewhere.
This malignancy may arise in the chest or abdomen. Disease can he triggered by even light exposure to asbestos but typically has a long latency (typically 20-40 years). There is evidence of increased risk from exposure to blue or brown asbestos fibers. It has a very poor prognosis with median survival time of 6-18 months post diagnosis.
Mesothelioma presents with:
- Pleuritic pain or a dull ache
- Shortness of breath
- Systemic features (fatigue, anorexia, weight loss, fever, sweats).
- Pleural effusion (common, usually unilateral).
- Palpable mass (due to direct extension through the chest wall).
- CXR – evidence of pleural effusion and thickening with a lobulated outline.
- CT provides a better image.
- Pleural aspiration or pleural biopsy should give a definitive diagnosis.