Brain accumulation of inhaled uranium in the rat depends on aerosol concentration, exposure repetitions, particle size and solubility

A rostro-caudal gradient of uranium (U) in the brain has been suggested after its inhalation. To study factors influencing this mapping, we first used 30-min acute inhalation at 56 mg/m3 relatively soluble form UO4 rat. These exposure parameters were then as a reference comparison with other experimental conditions. Other groups received different concentrations, repeated low dose (10 exposures) or insoluble UO2. At 24 h last exposure, all rats showed U accumulation compared to controls. However, total concentration was greater than demonstrating an accumulative effect. In higher front observed dose, particles and following repetition exposures, thus effect influences solubility exposures. part, ultrafine made it possible show presence according gradient. Finally, time-course micronic nanometric revealed residence times for nanoparticles.