Maganese Poisoning
Manganese is toxic in high amounts. Exposure to manganese fumes should not exceed the ceiling value of 5 mg/m3 for even short periods of time. People have known about manganese-related neurodegeneration (manganism) since 1837. Manganese is listed as a hazardous substance by OSHA. Manganese is a gray/white metal that may appear like iron; however, it is hard and brittle. In metal alloys such as steel, manganese improves rolling and forging qualities, strength, toughness, stiffness, wear resistance, and hardness.
Manganism symptoms are similar to those of Parkinson's disease, but there are some differences in the symptoms, area of basal ganglia affected, and lack of effectiveness of Levodopa, a Parkinson’s drug. The basal ganglia is the portion of the brain that transmits signals to various portions of the body for motor functions. In patients with manganese toxicity there is degeneration of basal ganglia, in particular the globus pallidus. The onset of symptoms can be several months to several years following exposure to manganese. Symptoms of manganism are also similar to Lou Gehrig's disease and multiple sclerosis. There is no cure yet for victims of manganese-induced Parkinsonism. Successful treatment of manganism is only possible in early phases of the disease, when immediate elimination of exposure is possible. Some studies have shown that welders show signs of Manganism symptoms up to fifteen years before the general population would show Parkinson’s symptoms. The early onset of Parkinson’s Disease in welders is often the result of the negligence of welding rod manufacturers and employers.
Early symptoms of manganese toxicity include asthenia, headache, hypersomnolence, nervousness, muscle cramps, and decreased libido. Behavioral and cognitive impairment in patients with manganese toxicity include lowered concentration, emotional liability, and psychotic symptoms such as hallucinations. Akinetic-rigid symptoms of manganese toxicity include monotone speech and hypophonia, reduced facial expression. Other symptoms include bradykinesia, hypokinesia, and rigidity. Postural reflexes may be impaired, and gait disturbances are often present. Patients with manganese-induced parkinsonism often walk differently than those with Parkinson’s, and their tremors are often less prominent. Manganism has been known to cause dystonia, including dystonic posturing of the limbs, dystonia of the trunk, and focal dystonias such as blepharospasm, grimacing, torticollis, and oculogyric crises.