Persistent effects of Libby amphibole and amosite asbestos following subchronic inhalation in rats.

Background: Human exposure to Libby amphibole (LA) asbestos increases risk of lung cancer, mesothelioma, and non-malignant respiratory disease. This study evaluated potency and time-course effects of LA and positive control amosite (AM) asbestos fibers in male F344 rats following nose-only inhalation exposure.

Methods: Rats were exposed to air, LA (0.

Genotoxicity of intermittent co-exposure to benzene and toluene in male CD-1 mice.

Benzene is an important industrial chemical. At certain levels, benzene has been found to produce aplastic anemia, pancytopenia, myeloblastic anemia and genotoxic effects in humans. Metabolism by cytochrome P450 monooxygenases and myeloperoxidase to hydroquinone, phenol, and other metabolites contributes to benzene toxicity.

Incorporation of tissue reaction kinetics in a computational fluid dynamics model for nasal extraction of inhaled hydrogen sulfide in rats.

Rodents exposed to hydrogen sulfide (H2S) develop olfactory neuronal loss. This lesion has been used by the risk assessment community to develop occupational and environmental exposure standards. A correlation between lesion locations and areas of high H2S flux to airway walls has been previously demonstrated, but a quantitative dose assessment is needed to extrapolate dose at lesion sites to humans.

Olfactory transport: a direct route of delivery of inhaled manganese phosphate to the rat brain.

Experiments examining the dosimetry of inhaled manganese generally focus on pulmonary deposition and subsequent delivery of manganese in arterial blood to the brain. Growing evidence suggests that nasal deposition and transport along olfactory neurons represents another route by which inhaled manganese is delivered to certain regions of the rat brain. The purpose of this study was to evaluate the olfactory uptake and direct brain delivery of inhaled manganese phosphate ((54)MnHPO(4)).