Module 4: Metals And The Lung - Lecture (Continued)

INVESTIGATING METAL INDUCED LUNG DISEASE:

1. History: Try to document exposure!
   May be hidden or unpredictable: for example, in mixed exposures such as in welding, smelting, scrap burning.

2. Chest x-ray: Particularly for parenchymal disease, but also for obstructive airways disease such as emphysema.

3. Lung function tests: To diagnose airways disease; to measure severity and impact of any lung disease.

4. Blood, urine: To confirm exposure, e.g. arsenic, cadmium, mercury, but if effect primarily on lung, body burden may be small.
   
   Lymphocyte transformation (or proliferation) test (beryllium disease). (It is not known whether this is available in South Africa).

5. Skin prick tests: Allergenic metals such as platinum salts under controlled conditions.

6. Bronchial hyperreactivity testing: Non-specific, for example, with histamine, or specific challenge in laboratory.

7. Bronchoscopy:
   Bronchiolo-alveolar lavage (B.A.L.), and bronchial biopsy.

8. Open lung biopsy: Histology, but pattern will not be specific for metal causation.
   Note: demonstrating metal content does not prove disease causation, merely exposure.

   Metal analysis (National Centre of Occupational Health or metallurgy laboratories):
   Macroanalytical (bulk or "destructive") methods allow identification and quantitation of metal content. Microanalytical techniques: for example, energy dispersive x-ray analysis, allows analysis of individual cells and particles within tissues.