Occupational Lung Disease (Silicosis & Pneumoconiosis)

Overview

Pneumoconiosis is dust accumulation in the lung with a subsequent fibrotic reaction. Silicosis — caused by inhalation/deposition of respirable crystalline silica (RCS) — is currently the dominant occupational lung disease concern in Australia, driven by a sharp rise in cases since ~2015 linked to cutting, grinding and polishing of engineered (artificial) stone benchtops (kitchen/bathroom/laundry). Unlike natural stone (e.g. granite, typically ≤30% silica), engineered stone can exceed 90% silica content. No safe level of silica exposure has been established.

Other pneumoconioses include coal workers’ pneumoconiosis (historically the most common worldwide), siderosis (metallic iron oxide), and asbestosis.

Types of silicosis

Classified by the time taken to accumulate a sufficient total lung burden of RCS to trigger a fibrotic reaction:

Type	Latency	Notes
Chronic (nodular)	>10 years (typically 10–20, up to 40)	Classic silicosis; most frequent form overall
Accelerated	3–10 years	Historically rare; now much more common, specifically in engineered-stone workers
Acute	<1 year	Historically very rare

The rate of lung function decline in accelerated silicosis averages 10x faster than normal age-related decline. Silicotic nodules may continue to develop and coalesce even after exposure ceases, progressing to progressive massive fibrosis (PMF). Disease may not become clinically evident until after a worker has already left the industry — a long latent tail matters for history-taking even in patients no longer occupationally exposed.

Clinical features

Most cases are asymptomatic until disease is advanced — a key reason health surveillance (rather than waiting for symptoms) is emphasised.

• Early: exertional dyspnoea, harsh dry cough.
• Advancing disease: increasing dyspnoea.
• Advanced disease: disturbed sleep, productive cough, anorexia, weight loss.

There is currently no treatment to arrest the progression of accelerated silicosis other than lung transplantation — prevention and early detection (to enable exposure cessation) are the only levers available once established.

Health surveillance

Long-term regular health surveillance is recommended for all workers in the engineered stone industry, and for at-risk workers in other silica- exposed industries (mining, construction, tunnelling).

Surveillance should include: a respiratory questionnaire, occupational/ exposure history, lung function tests, and lung imaging — specifically spirometry + DLCO + CT, per RACP guidance (standards set out in the TSANZ Respiratory Surveillance Position Paper).

National Occupational Respiratory Disease Registry (NORDR) commenced 22 May 2024 — a national registry intended to track occupational respiratory disease (including silicosis) in Australia going forward.

Referral

Refer for specialist respiratory assessment on diagnosis or strong clinical suspicion — management (surveillance intensification, exposure-cessation counselling, transplant assessment in advanced disease) is specialist-led. Notify per jurisdictional workplace/occupational disease reporting requirements where applicable — check current state/territory rules, as notification obligations have been tightening in response to the engineered- stone epidemic.