Asbestosis

Lore & Background

Asbestosis is caused by breathing in microscopic asbestos mineral fibers suspended in the air. In the 1930s, E. R. A. Merewether found that greater exposure resulted in greater risk. The fibers, which can be amphibole (thin and straight) or serpentine (curly), penetrate deeply into the lungs, reaching the alveoli where they provoke a chronic inflammatory reaction. Macrophages attempt to ingest the fibers but are often killed, releasing reactive oxygen species and activating transcription factors that amplify pro-inflammatory cytokines, leading to the deposition of fibrous scar tissue.

Reader's Guide

Asbestosis remains a significant occupational disease, with its effects often manifesting decades after exposure. The condition is diagnosed based on a history of exposure and medical imaging, with chest x-rays and CT scans revealing small, irregular opacities primarily in the lung bases. While there is no cure, supportive treatments such as oxygen therapy, respiratory physiotherapy, and vaccinations against influenza and pneumococcal pneumonia can help manage symptoms. The disease has led to bans on asbestos use in many countries, though existing undamaged asbestos is generally recommended to be left undisturbed.

Did You Know?

• Asbestosis requires a relatively large exposure over a long period, typically only occurring in those who directly work with asbestos.
• The characteristic pulmonary function finding in asbestosis is a restrictive ventilatory defect, reducing lung volumes such as vital capacity and total lung capacity.
• Families of exposed workers can be affected because asbestos fibers from clothing and hair can end up in the home.
• While pleural plaques are often associated with asbestos exposure, they are a separate condition from asbestosis, and their prevalence in asbestosis patients is not universally established as exceeding 50%.