What is Pneumoconiosis? Types, Causes of Lung Dust Diseases

Pneumoconiosis is a type of lung disease that arises with inhaling mineral dusts usually in the workplace (occupational). More recently the term pneumoconiosis has been used to describe lung disease associated with organic and inorganic dusts as well as chemical vapors which often result in hypersensitivity pneumonitis; obstructive airway disease, like chronic bronchitis and asthma; acute lung injury and acute respiratory distress. Pneumoconiosis is a restrictive pulmonary disease that is however not isolated to workers as air pollution in urban areas has seen the incidence rise among the general public. Stricter environmental regulations in most developed countries, however, has reduced this in recent years.

How does lung injury occur with dust?

Pneumoconiosis does not occur in every person who is exposed to these dusts and fumes. It depends on multiple factors, Smaller particles may pass through even the smallest distal airways and lodge in the alveoli of the lung. While the alveolar macrophages may attempt to phagocytose as much of these particles as possible, it may eventually be unable to cope with the concentration of incoming particles. These smaller particles, especially if highly soluble and very toxic to cells, may cause a greater degree of damage to the lung tissue. Larger particles though are not innocuous. These particles, which may often be less soluble, can be contained by scar tissue an remain  in the airways or lung for years. Particles can eventually cross the epithelial lining, enter the tissue spaces, blood stream or lymphatic system where it may elicit a host of immune responses.

Types and Causes of Pneumoconiosis

The most common of the different types of pneumoconiosis are coal worker’s pneumoconiosis, silicosis and asbestosis.

• Coal dust – coal worker’s pneumoconiosis
• Silica – silicosis
• Asbestos – asbestosis
• Iron oxide – siderosis
• Tin oxide – stannosis
• Beryllium – berylliosis
• Barium sulfate – baritosis
• Cotton, flax – byssinosis
• Bagasse – bagassosis
• Moldy hay – farmer’s lung
• Bird droppings – bird breeder’s lung

The types of pneumoconiosis are listed in association with a single element or compound. There are certain dusts tht contain more than one element that can irritate the lung tissue like silicosiderosis seen with inhalation of mixed dust containing silica and iron.