C.S. Glaze , L.S. Newman / Clin Chest Med 25 (2004) 467–478
Box 1. The components of a thorough occupational and exposure history
A chronologic list of all jobs held with the following information for each job
Job type and activities: employer, what products the company pro- duces, job title, years worked, de- scription of job tasks or activities, description of all equipment and ma- terials the patient used, description of process changes and dates they oc- curred, any temporal association be- tween symptoms and days worked
Exposure estimate: visible dust or mist in the air and estimated visibil- ity, dust on surfaces, visible dust in sputum (or nasal drainage) at end of work shift, hours worked per day and days per week, an open or closed work process system, presence and description of engineering controls on work processes (eg, wet process, local exhaust ventilation). Personal protective equipment used: type, training, fit testing, and storage loca- tions, sick co-workers
Bystander exposures Work: job activities and materials used at surrounding work stations, timing of worksite cleaning (during or after shift), individual performing cleanup and process used (wet ver- sus dry)
Home: spouse’s job, whether spouse wears work clothes home and who cleans them, surrounding industries
Other: hobbies, pets, problems with home heating or air conditioning, hu- midifier and hot tub use, water dam- age in the home
Data from Newman LS. Occupational ill- ness. N Engl J Med 1995;333:1128–34; and Blanc P, Balmes J. History and physi- cal examination. In: Harber P, Schenker M, Balmes J, editors. Occupational and environmental respiratory disease. St. Louis: CV Mosby; 1996. p. 28–38.
helpful. There are numerous published examples of pneumoconiosis that would have been missed if the history was limited to job title or industry alone [15,16]; asking questions specifically about the types of dusts and fumes is important. Finally, bystander exposures—in the home and the workplace—play an important role and require investigation, as illustrated by the occurrence of CBD in housewives and com- munity cases of asbestosis in areas of significant en- vironmental contamination [17,18]. A physician also can gather exposure information by obtaining the material safety data sheets from a patient’s worksite or consulting an industrial hygienist . After com- pleting a thorough occupational history, the clinician should understand the types and magnitude of a patient’s exposures.
The remaining evaluation of occupational ILD is the same as for nonoccupational ILD, including laboratory tests, pulmonary function testing, meas- ures of gas exchange, and imaging studies. As for all forms of ILD, consideration must be given to other causes, including infection, connective tissue disease, vasculitis, and drug reactions. Pulmonary function abnormalities vary with exposure and include mixed, restrictive, and obstructive abnormalities. Most occu- pational ILDs lead to impaired diffusion capacity. Likewise, radiologic abnormalities vary with expo- sure . Diagnosis of an occupational ILD requires a history of exposure to an agent known to cause ILD, an appropriate latency period, a consistent clini- cal course, physiologic and radiologic pattern, and exclusion of other known causes of ILD. Lung biopsy is not always required when these conditions are fulfilled. [20,21]. One should consider performing a biopsy for atypical presentations or when the expo- sure is to a new or poorly characterized agent, however. In these settings, tissue analysis for the suspected mineral or metal may be helpful .
A complete discussion of pathogenesis is beyond the scope of this article. It is clear that host and ex- posure factors play a role. Important host-related fac- tors include anatomic and physiologic characteristics that influence the deposition and clearance of inhaled particles (eg, efficiency of nasal filtering and the mu- cociliary blanket, overall length of the respiratory tree, respiratory pattern, tobacco use, and genetic fac- tors) .
Exposure factors important to pathogenesis vary by the type of agent. Some exposures act via the adoptive immune system. These agents act as anti-