Figure 4: Simulated olfactory bulb (L) and striatum (R) manganese concentrations in adult and aged (16 month old) male rats following 6 hr/d inhalation MnSO4 exposure at 0.5 mg Mn/m3 for 90 days. Model simulations for aged rats had a 25% decrease in minute volume consistent with reported reduction in pulmonary function [22, 23].