Manganese is a naturally occurring, non-magnetic element, often found in groundwater. Manganese is used as an additive to steel, to reduce corrosion.
As a trace mineral, manganese assists with important biological functions including growth, proper formation of bones and cartilage, and brain function. However, prolonged inhalation of manganese fumes or dust will cause injury to the central nervous system.
Manganese poisoning results from prolonged exposure to manganese fumes or dust. This poisoning most often occurs in industrial or workplace settings, where welding occurs. The heat of the welding process causes small amounts of manganese to be released from metal into the air, where the dust or fumes can be inhaled.
Welding rods and welding wire, used to fuse pieces of metal together through the welding process, may contain very high levels of manganese, placing welders at a high risk of exposure. Risks increase when welding activity occurs in enclosed spaces or without proper ventilation.
Manganism is a condition of the central nervous system caused by prolonged exposure to manganese fumes or dust. Manganism may result from as little as six months to two years of workplace exposure.
The symptoms of manganism closely resemble Parkinson's disease. The progression of manganism includes:
Behavioral Changes - Symptoms include fatigue, headache, muscle cramps, loss of appetite, apathy, insomnia, and diminished libido. These symptoms may be associated with psychotic reactions known as "locura manganica" ("manganese madness"), involving aggressive behavior and difficulty controlling emotional reactions.
Parkinsonian Features - Symptoms include difficulty with movement and balance, muscle stiffness, tremors, an expressionless face, impaired writing, and postural instability.
Dystonia and Gait Disturbances - As the disease progresses, dystonia (abnormal muscle tone) becomes evident, and the patient displays a "cock-walk" gait (walking with an extended trunk and flexed arms, while strutting on one's toes). Patients usually display a low amplitude postural tremor of the arms, forearms and hands (the "upper extremities").
Once established in the most severe stage, manganism is a progressive disease that may continue even after removal from exposure. Symptoms may be moderated through medication.
Lawyers allege that the manufacturers of manganese welding products, such as welding rods, wire and electrodes, have known since the 1930's that use of their products can result in exposure to dangerous levels of manganese. Their liability is premised upon their failure to disclose these known dangers, and failure to make their products safer despite their awareness of the dangers.
The manufacturers deny any cover-up, but attorneys respond that manganism was first recognized in 1837, and there are documents from the mid-1930's acknowledging a connection between welders' exposure to manganese and the symptomology of manganism. As a consequence, some manufacturers have been held liable for injuries through product liability actions.
Even when a manufacturer cannot be proved liable, an employee who is injured through workplace exposure to manganese may seek medical and wage loss benefits through workers' compensation.