Coal miners are exposed to a variety of dusts, Coal Workers’ pneumoconiosis refers to disease from inhalation of coal dust. Silicosis is a particular problem of coal miners but about 10% of cases of silicosis occur in the construction industry. Stonemasons, potter and workers involved in sandblasting may also be at risk, Tiny particles of coal dust, just 2 to 5 microns in diameter, are retained in the alveoli. They engulfed by macrophages bus eventually the system overwhelmed and an immune response follows. This produces pulmonary fibrosis. If this associated with rheumatoid arthritis, called Caplan’s syndrome. Morbidity and mortality are related to the type of coal dust and the duration of exposure. Dust that is high in silica increases the risk of fibrosis.
Coal miners’ pneumoconiosis is divided into
Simple pneumoconiosis – graded according to CXR appearance. Patients are often asymptomatic and the diagnosis is an incidental finding on CXR. There has been much debate as to the effect on lung function – but it does increase the risk of chronic bronchitis, diminish FEV and have additive effects combined with smoking.
Progressive massive fibrosis – symptoms progress from shortness of breath on exertion, cough, black sputum to respiratory failure. CXR reveals large nodular, fibrotic masses in the upper lobes. Respiratory function tests show a mixed obstructive and restrictive picture with decreased lung volumes and gas transfer.
The rate of progression and severity of the diseases influenced by the amount of silica that inhaled, the level and duration of exposure and also whether other minerals present in the inhaled dust. A high percentage of free silica gives a high degree of pulmonary fibrosis.
What is Pulmonary siderosis?
Those who work with metal grinding or welding have a risk of inhalation of metallic particles. Iron absorbs x-rays and produces very impressive shadows on chest x-ray but has little effect on pulmonary function and little long term morbidity. Tin and barium produce similar clinical and radiological pictures (stannosis and baritosis respectively).
What is Berylliosis?
This is rare, affecting those working in the aerospace, nuclear, telecommunications, semi- conductor and electrical industries. It causes a granulomatous lung disease, and presents with symptoms similar to sarcoidosis.
Prevention and control measures
Management of suspected industrial dust disease-
- Take a good occupational history, going back over many years and looking also at hobbies and pastimes.
- CXR and lung function tests required.
- Referral to a chest physician for further diagnostic and management advice.
- There may considerable financial implications and a tribunal may required to make a decision, often requiring expert opinion.
- None of these diseases is curable.
- Smoking cessation should encouraged strongly. Treat/palliate symptoms.
- Support the patient and their family through the disease and its social/occupational/legal ramifications.