Brian Locke

Pneumoconioses and Occupational Lung Disease

Occupational lung disease: includes

  • pneumoconioses
  • HP
  • bronchiolitis
  • occupational asthma
  • (occupational pulmonary vascular disease)

Occupational lung disease criteria

  • exposure to known agent
  • has to meet known latency period criteria
  • consistent manifestations with the known presentation
  • exclusion of other likely culprits

Pneumoconioses

disease resulting from inhaling inorganic particles that cause a reaction in the lung.

Types

  • Fibrogenic, such as asbestosis
  • Granulomatous, such as beryllium or other metals
  • Begin, such as baritosis (barium)
  • Fibro/inflammatory, such as silicosis

Example associations:

Asbestosis: shipyard workers, auto/railroad mechanics, asbestos miners

Silicosis: mining, construction (tunneling, sand blasting, concrete work), glass manufacturing, ceramics, foundries, denim sanblasting

Coal worker's pneumonitis: coal mining

HP: farming, avian exposures, hot tubes, humidifiers

Berylliosis: fluorescent lamp manufacturing (historical), aerospace workers, nuclear workers, electronic manufacturing, dentistry

Hard Metal lung disease: manufacturing hard metal cutting tools, oil well drilling, armor plating, diamond polishing

Aluminoisis: alumina abrasive manufacture, pyrotechnic manufacture

Talcosis (inhalation): cosmetics manufacture, industrial manufacturing.

Radiographic findings:

Fibrosis: asbestosis, chronic silicosis, coal workers, chronic HP, chronic beryllium disease, aluminosis, hard metal lung disease

Centrilobular micro nodules: acute silicosis, chronic siliciosis, acute inhalations of many things

Perilymphatic micro nodules: chronic silicosis, coal worker's pneumoconiosis, chronic beryllium disease. (This represents a more chronic form of the disease as the macrophages clear things up)

Diffuse opacities: consolidation (acute silicosis, HP), ground glass (acute silicosis, HP, hard metal), Crazy paving (acute silicosis)

Mass-like opacities: Conglomerate masses, Rounded atelectasis (asbestosis), cysts (Chronic HP), air trapping (HP, occ asthma).

Pleural Disease - asbestosis, silicosis, berylliosis

Lymph disease - many

Silicosis

Silica - most abundant mineral on earth. Can be crystalline or amorphous.

Exposures: mining, tunneling, stone-quarrying, pottery/ceramics, sandblasting, boilermaking/cleaning, foundry work, railroad workers (ballast, locomotive sanders).

Manifestations:

  • simple silicosis (subcentimeter, rounded opacities in upper lobes)
  • progressive massive fibrosis (coalescence of these nodules leading to hilar/upper lobe retraction and you get hyperinflation of the lower lobes)
  • acute silicosis (overwhelming exposure to crystalline silica leads to acute alveolar filling - often basilar predominance)
  • (also emphysema, lung cancer though not pneumoconiosis)

Histopath: Silicotic nodules (concentric swirls of hyalinzed material with peripheral whorls)'

Symptoms: shortness of breath, cough. Intensity of symptoms correlates with radiographic appearance. Chest exam usually unremarkable.

Testing: FEV1 decline (cross-over with bronchitis and other airway exposures), though mild disease may have normal lung function. As progressive, get mixed restrictive-obstructive.

Diagnostic criteria: sufficient silica exposure, meet criteria (either HRCT or CxR) of imaging, exclusion of mycobacterial/sarcoidosis/malignancy (those these often co-exist)

Treatment: if progressive fibrosis, nintedanib may be considered. Early steroid or lavage considered in acute silicosis. Lung transplantation.

Coal Worker's Pneumoconiosis

Coal particle is not as fibrogenic as crystalline silica particles - but there is a lot of cross-over because exposures go together.

Manifestations:

  • bronchitis
  • emphysema
  • can result in progressive massive fibrosis that is radiographically indistinguishable from

West Virginia, Kentucky, Tennessee Ohio has the highest incidence because of the coal type and how it's mined there.

Pathology: focal collections of coal dust within pigmented macrophages and dilation. Increased centrilobular emphysema, nodules with anthracosis. Not required for diagnosis

[ ] anthracosis specific for coal? Or other carbon

Asbestos

Silicate mineral with a number of forms. Positively charged fibers -> aligns in a way they can get down the airway so far and how they are able to migrate through the lymph system. When they fracture, they fracture into long needles.

Forms: Chrysotile (serpentine) -> pliable, not so bad, Amphibole (crocidolite, anthophylite, amosite) -> rigid, rods, more dangerous.

Exposures: firefighters, shipbuilding, military (navy/marines - ships), electrical workers, construction workers, plumbers, demolition/structure mitigators. Relatively low in UT (high in Libby MT, for example)

Substantial latency

Manifestations:

  • asbestosis - progressive fibrotic ILD. Classically, UIP pattern
  • asbestos pleural disease (rounded, at elect, effusion, plaques, mesolithelioma)
  • non-mesothelioma lung cancer.

If you see an asbestos body on a BAL -> pathognomonic. UIP with calcified pleural plaque - almost pathognomonic (unless they have had prior pleural manipulation or hemothorax)

Mortality parallels IPF/UIP - can use nintedanib. Lung transplant.

Hard Metal Pneumoconioses

Cobalt - giant cell interstitial pneumonitis. Diffuse alveolar pattern. Coalescent giant cells in the airway.

Aluminum - atypical UIP or DIP pattern.

Titanium, copper, zirconium - granulomatous lung disease.