Manganese Toxicity Observed in Workers at a Ferromanganese Plant

We evaluated 11 male workers with elevated serum manganese levels and T1 hyperintensities in the globus pallidus, features of manganese toxicity, all of whom were employed at a single ferromanganese plant. They exhibited clinical features of manganism, including behavioral issues, forgetfulness, headache, decreased sleep, generalized weakness, tingling and stretching sensations in the limbs, hand and jaw tremors, dysarthria, hypophonia, rapid speech, rigidity, difficulty in walking, and falls. Positron emission tomography scans performed on two patients showed presynaptic dopaminergic deficits. All patients ceased working in the environment and experienced partial improvement with levodopa therapy.