Occupational formaldehyde exposure and the nasal mucosa.

This study was undertaken to evaluate the possible cytotoxic effect of formaldehyde on the nasal mucosa in man. 38 men with an average age of 38 years and average exposure time of 10.5 years were studied. They were exposed to formaldehyde when processing laminae. All men passed a medical examination and a nasal biopsy. The histological findings were scored, 0-8, according to a system proposed by Torjussen. The findings were compared with a non-exposed reference group of 25 men (mean age 35 years). 35% of the exposed were smokers compared to 48% of the nonexposed. The average histological score was 2.8 for the exposed versus 1.8 for the non-exposed (p less than 0.05, Wilcoxon). The more common findings in the exposed were loss of cilia, goblet cell hyperplasia and squamous metaplasia. In four cases (11%) there was a mild dysplasia. Smoking had a slight modifying effect on the histological picture. The results indicate that the suspected precancerous findings in animal studies after exposure to formaldehyde might be present in workers exposed to formaldehyde at relatively low levels.