Asbestos can cause a variety of lung diseases from benign pleural plaques to mesothelioma.

Pleural plaques

Pleural plaques are benign and do not undergo malignant change. They, therefore don't require any follow-up. They are the most common form of asbestos-related lung disease and generally occur after a latent period of 20-40 years.

Pleural plaques - bilateral calcified diaphragmatic plaques & chest wall plaques - e Image used on license from Radiopaedia

Pneumoconiosis

• occupations at risk are classically firefighters, dockyard workers, and construction workers rather than miners

Investigations

• pleural plaques and lower lobe fibrosis

Pleural thickening

Asbestos exposure may cause diffuse pleural thickening in a similar pattern to that seen following an empyema or haemothorax. The underlying pathophysiology is not fully understood.

Asbestosis

The severity of asbestosis is related to the length of exposure. This is in contrast to mesothelioma where even very limited exposure can cause disease. The latent period is typically 15-30 years. Asbestosis typically causes lower lobe fibrosis.

Features

• dyspnoea and reduced exercise tolerance
• clubbing
• bilateral end-inspiratory crackles
• lung function tests show a restrictive pattern with reduced gas transfer

It is treated conservatively - no interventions offer a significant benefit.

Mesothelioma

Mesothelioma is a malignant disease of the pleura. Crocidolite (blue) asbestos is the most dangerous form.