Cytologic examination of the nasal mucosa in formaldehyde-exposed workers.

A cross-sectional study of 80 individuals at three locations was undertaken to evaluate the health effects of long-term exposure to formaldehyde in a phenol-formaldehyde impregnating process and to develop a useful protocol for health surveillance of formaldehyde-exposed workers. Results of physical examinations showed a statistically significant prevalence of mucosal irritation in formaldehyde-exposed workers, particularly those with recent exposure. Cytologic examination of exfoliated nasal cells showed atypical squamous metaplasia, which was found to be a function of age. There was no statistical relationship to formaldehyde exposure.