Mutagenesis, Vol. 16, No. 5, 449-452,
September 2001
© 2001 UK Environmental Mutagen Society/Oxford University Press
The micronucleus assay in human exfoliated urothelial cells: application in a genotoxicity study of workers exposed to a mineral jelly containing sodium nitrite and N-phenyl-1-naphthylamine
Institut de Médecine du Travail, Faculté de Médecine, 28 Place Henri Dunant, 63001 Clermont-Ferrand Cedex, 1 INSERM, EMIU 00-10, Faculté de Médecine, 2 bis Boulevard Tonnelé, Tours and 2 Service d'Épidémiologie, Économie de Santé et Prévention, CHU, Hôtel Dieu, Boulevard Léon Malfreyt, 63000 Clermont-Ferrand, France
Exposure to certain chemical agents in occupational settings has been identified as carcinogenic to the human bladder. Micronucleus (MN) analysis in exfoliated urothelial cells is an interesting method for biomonitoring genetic damage in human populations. However, few studies have been performed in an occupational context. The aim of this study was to examine whether the occupational use of a mineral jelly induced a genotoxic risk for workers employed at a single factory producing bearings using the MN test on exfoliated urothelial cells. The prevalence of micronucleated exfoliated urothelial cells (MNC) was determined in 35 female workers with dermal exposure to the jelly and 41 female controls. The mean percentage of MNC (expressed as percent cells with MN per 1000 cells scored) observed in the exposed worker group was 0.46 ± 0.11% (range 0–2.8) and in the control group 0.14 ± 0.03% (range 0–0.8). There is a significant job effect (P = 0.0018, MANCOVA) on the prevalence of MNC, whereas age and smoking habit had no significant effect (P = 0.90 and 0.91, respectively). There is no interaction between job and smoking habit (P = 0.4421). Exposure to the mineral jelly appeared to be the main factor inducing the increased prevalence of MNC. This may be due to the presence of mutagens/carcinogens in the jelly: an aromatic amine, N-phenyl-1-naphthylamine (CAS no. 90-30-2), which is carcinogenic in mice, or sodium nitrite (CAS no. 7632-00-0), which is genotoxic in human cell systems. In conclusion, these results suggest that use of the mineral jelly could present a genotoxic risk for workers. We think that the MN assay on exfoliated cells could be valuable for biological monitoring purposes in occupational contexts as a marker of significant exposure to bladder mutagenic/carcinogenic agents.
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