BIOLOGICAL MONITORING OF CHEMICAL-EXPOSURE IN NICKEL WORKERS BY IMAGING CYTOMETRY (ICM) OF NASAL SMEARS

Highly sensitive and inexpensive methods that are not time consuming a re desirable for monitoring the workplace environment for the detectio n of cytotoxic hazards, particularly cancerous risks. It is possible t o detect precancerous and cancerous lesions in samples taken by brushi ng the nose, but the cytological diagnoses can be affected by an inabi lity to obtain representative smears from the sometimes very small foc al lesions, and uncertainties in the subjective interpretation of susp icious cells when these are small in number. In an attempt to improve diagnosis we applied imaging cytometry (ICM) and tested the concept of malignancy-associated changes (MAC) in routinely Papanicolaou-stained smears. Cells of non-goblet type that visually appeared normal were s elected from nickel workers with and without dysplastic lesions of the nasal mucosa. A set of nuclear features was measured by ICM and used for discriminant analysis. We were able to differentiate between worke rs with non-dysplastic normal and suspicious mucosa smears and those w ith dysplastic lesions. Unexpectedly, it was found possible to disting uish between workers in the roasting/smelting and the electrolysis dep artments, who were exposed to different carcinogenic nickel compounds. A further surprising finding was the possibility to distinguish smoke rs and non-smokers among the nickel workers.