Cytopathology of the nasal mucosa in chronic exposure to diesel engine emission: a five-year survey of Swiss customs officers.

The simple and cheap technique of nasal cytology was used to assess possible adverse effects of chronic exposure to diesel engine emission (DEE) on respiratory mucous membranes. Brush cytology probes were taken from the noses of 194 male, nonsmoking customs officers twice a year (January and July) over a period of 5 years. The study group of 136 officers was solely occupied with clearing of diesel trucks (8.4 hr/day, 42 hr/week). Measured DEE concentrations varied between 31 and 60 microg/m3) and of benzo[a]pyrene concentrations were between 10 and 15 ng/m3). The control group of 58 officers worked only in the office. Over the 5-year period, similar results were obtained in summer and winter. In contrast to those not exposed to DEE, those who were had clear goblet cell hyperplasia with increased metaplastic and dysplastic epithelia and an increase in leukocytes. We found no evidence of progression of the cytopathologic changes. The findings may be described as a chronic inflammation of the nasal mucous membrane in the presence of chronic DEE exposure (chemical-induced rhinitis). Additionally, the findings of metaplastic and dysplastic nasal epithelia in the exposed subjects may indicate a genotoxic effect of chronic DEE exposure in humans.