Uncommon causes of occupational interstitial lung diseases

Uncommon causes of occupational interstitial lung disease, or pneumoconiosis, are being increasingly recognized and diagnosed. The fibrogenic potential of numerous types of respirable inorganic particles remains poorly understood but is significantly determined by lung deposition and clearance, the agent's size and solubility, host susceptibility, and other factors. Microanalytic techniques have improved the identification of uncommon or unusual biopersistent particles or elements in fibrotic lung tissue. Recent findings in workers exposed to manmade vitreous fibers, silicon carbide, talc, titanium, cerium, and polyvinyl chloride provide new clinical insights into not only their specific fibrogenic capabilities but also in the broader appreciation that many cases of unexplained interstitial lung disease may be caused by occupational exposures to one or more uncommon airborne substances.