Abstract
This section covers three syndromes or diseases affecting the alveoli or interstitium of the lung: organic dust toxic syndrome (ODTS), hypersensitivity pneumonitis (HP), and interstitial fibrosis from mineral dusts. While ODTS is not an interstitial lung disease, it is presented in this section because of the overlap in both exposures and symptoms between ODTS and HP. Some of the dusts causing ODTS cause similar symptoms and signs in farmers or agricultural workers with HP, which is characterized by an interstitial lymphocytic pneumonitis. (The transient neutrophilic alveolitis of ODTS is not a true parenchymal disease.) Interstitial fibrosis stemming from exposure to inorganic or mineral dusts represents a true inflammatory and fibrotic reaction of the lung interstitium. The ODTS designation was proposed at a conference in 1985 (552). The name has been criticized (553), and others have been proposed (554, 555). However, the designation is retained in this document in order to avoid confusion. It is hoped that further knowledge about agents and effects may make it possible to suggest names that are more descriptive of the condition (or possibly conditions) now called ODTS. HP in agricultural workers is often called "farmer's lung," but this term has also become associated with conditions (notably, ODTS), that are not HP. Farmer's lung (in the narrow, specific sense) is one of the most prevalent forms of HP; however, HP is only one of many farm-related lung diseases. Thus, the term "farmer's lung" is necessarily confusing and needs to be reconsidered. A more appropriate term, which will be used here, is "farmer's hypersensitivity pneumonitis" (FHP). Although FHP occurs less often than other farm-related respiratory illnesses (e.g., ODTS, chronic bronchitis, and asthma), the disease is of major importance because of its severity, in terms of both permanent lung damage and psychosocial impact. Half of all FHP patients abandon farming because of their disease, and a third have permanent lung sequelae.The possibility that silica or other inorganic silicates in farm dusts in certain areas and stemming from certain farm activities might cause interstitial lung disease is a new concept that will be addressed here.
Keywords
Agricultural-industry; Agricultural-workers; Agriculture; Occupational-diseases; Occupational-hazards; Occupational-health; Inhalation-studies; Respiratory-irritants; Hazards; Inhalation-studies; Inorganic-chemicals; Organic-dusts; Microorganisms; Mycotoxins; Fungi; Fungicides; Endotoxins; Allergens; Allergies; Gases; Chemical-composition; Pesticides; Disinfectants
