Welders are exposed to many hazards at work and subsequently, they’re at risk of developing some very serious health issues. One area that this is particularly prevalent, is exposure to respiratory hazards created from welding fume. Unlike general hazards, such as trips and falls, the effects of exposure to respiratory hazards are cumulative and can take a considerable amount of time before the effects become apparent. Through years of research, a phenomenon known as Parkinsonism has been attributed to long-term exposure to welding fume, namely manganese metals.
What is Parkinsonism?
Parkinsonism refers to symptoms of Parkinson's disease (PD) that are caused by another condition. Like PD, Parkinsonism causes slow involuntary movements, tremors, impaired speech, and muscle stiffness. However, with PD, this is generally attributed to the degeneration of nerve cells in the brain, while Parkinsonism can be caused by many factors, such as drug use that interferes with dopamine, viral encephalitis, degenerative disorders, brain tumors or strokes, head injuries, Wilson disease, and toxin exposure.
Parkinsonism tends to progress a lot more rapidly than PD. If the following Parkinsonism symptoms are present then this generally indicates that the person is NOT suffering from PD.
Manganese and Parkinsonism
The first documentation of manganese overexposure was in 1837 by James Couper where psychiatric and motor disturbances were reported. Years later these discoveries have helped to support safer working conditions as legal exposure limits have been introduced. Although there are exposure limits that have been implemented and are supposed to protect operators, those with chronic low level exposure are still at risk of developing Parkinsonism. One study found that welders exposed to manganese (0.14 milligrams per cubic meter), well below the legal limit of 0.2 milligrams per cubic meter, were still developing parkinsonism symptoms particularly with movement. Those that are exposed to higher concentrations of manganese and work in confined spaces are more likely to have a faster onset of symptoms and suffer from the full effect of parkinsonism.
Although both Parkinsonism and PD have very similar appearing symptoms, they effect completely different regions of the brain. With PD, this is known to effect the substantia nigra through the loss of dopaminergic neurons which are essential for reward and movement. With Parkinsonism, the manganese creates slowness in movement through the disruption of dopamine signaling and does not affect the substantia nigra at all.
Parkinsonism can be difficult to diagnose as there are a variety of symptoms. This can make the process lengthy as medical professionals need to rule out a number of other conditions in order to make treatment recommendations. This will generally begin with understanding the persons medical history and working history to determine particular exposures. Blood tests may be taken to test for potential underlying causes, such as thyroid or liver problems. Imaging scans of the brain will be completed to rule out other causes such as a brain tumor and doctors may perform tests that track dopamine in the brain, such as the DaT-SPECT test which allows doctors to identify what areas of the brain do and don’t receive dopamine.
Treatment & Prevention
Treatment for parkinsonism is difficult and a lot of this is based around finding ways to gain mobility, independence and to relieve the person of any pain they are in. Because Parkinsonism that’s caused by manganese exposure is related to the persons working environment, the negative health effects of this can be entirely prevented. As the exposure risk is through contaminants in the atmosphere around the worker, respiratory protection is vital. By using PPE such as supplied air respirators (SAR) and powered air purifying respirators (PAPR), operators are able to work in environments with manganese exposure levels, without risk to their health. These measures are simple and offer other health benefits associated with their use. It is imperative that respiratory protection is used in all welding operations.
We are fortunate to now know exactly what is happening in environments with manganese exposure risks and so we can now make educated choices about how we protect ourselves in order to prevent Parkinsonism from affecting us, and subsequently impacting those that we love.
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