Histopathological study in B6C3F1 mice chronically exposed by inhalation to glutaraldehyde.

Glutaraldehyde vapors are irritating for the skin, eyes, nose and lungs; respiratory symptoms and headaches have been described among workers exposed to low concentrations of glutaraldehyde far below to 190 ppb. This study was initiated to determine the chronic effects in mice of inhaled glutaraldehyde vapors. B6C3F1 mice were exposed using whole-body inhalation chambers, 6 h/day, 5 days/week, for 52 and 78 weeks to 100 ppb, or to filtered air (controls). In nasal passages at the level of the vestibule, hyperplasia of the squamous epithelium lining of the dorsal wall and lateral aspect of the atrioturbinate was observed in a greater number of exposed females than in controls. Epidermal erosion and ulceration as well as squamous and inflammatory exfoliation were also seen in the nasal lumens. All these changes were dependent on the length of glutaraldehyde exposure. The present data suggest that glutaraldehyde long term exposure only led to changes in nasal passages of female mice but did not induce mortality and/or tumors in nasal passages, in all mice. These results, along with the previous subchronic inhalation study of Gross et al., 1994, demonstrates that in a long term study, chronic glutaraldehyde exposure close to the current threshold limit values induced lesions at the more anterior part of the nasal passages in mice and that they likely result from an irritation mechanism (antero-posterior gradient).