Manganese is a trace element essential for normal bone formation, carbohydrate and fat metabolism, antioxidant defence (as a cofactor for superoxide dismutase), and neurological function. The body maintains tight regulation of manganese through intestinal absorption and hepatic excretion. Dietary deficiency is rare, as manganese is widely available in plant foods.
Manganese toxicity is a significant occupational health concern, particularly in mining, welding, and battery manufacturing where inhaled manganese dust accumulates in the brain and causes manganism, a Parkinson's-like neurological syndrome. Blood manganese testing is primarily used in occupational health monitoring and in the investigation of neurological symptoms with relevant exposure history.
FAQs
What is manganism?
Manganism is a neurological disorder caused by chronic manganese overexposure, most commonly through occupational inhalation. It causes tremor, rigidity, cognitive changes, and Parkinson's-like features. Unlike Parkinson's disease, manganism tends to cause more prominent psychiatric features early and affects different brain regions.
Who is at highest risk of manganese toxicity?
Welders, miners, foundry workers, battery manufacturers, and steel production workers who inhale manganese-containing dust or fumes over long periods. People on long-term parenteral nutrition, especially with liver disease, are also at risk.
Is manganese dietary deficiency common?
No. Manganese deficiency is rare in people with a varied diet, as manganese is present in many plant foods including whole grains, nuts, legumes, and tea. Unlike some other trace minerals, supplementation is rarely needed.
How is manganism distinguished from Parkinson's disease?
Manganism is associated with occupational exposure history, tends to have more prominent early psychiatric features (emotional lability, psychosis), is symmetrical, and affects the globus pallidus rather than the substantia nigra. Dopamine transporter SPECT scanning and brain MRI with T1 hyperintensity in basal ganglia help distinguish the two.
