From the Guidelines
Welding-associated parkinsonism is a serious neurological condition that can develop in welders due to chronic manganese exposure from welding fumes, and immediate medical evaluation is necessary if symptoms develop, with treatment typically involving removal from manganese exposure and symptomatic management with medications like levodopa/carbidopa. The condition is caused by manganese accumulation in the basal ganglia of the brain, particularly the globus pallidus, disrupting dopamine function and causing neuronal damage 1. Key symptoms to watch out for include:
- Tremors
- Stiffness
- Balance problems
- Slowed movements To minimize exposure, welders should use proper ventilation systems, respirators with HEPA filters, and follow OSHA guidelines for manganese exposure limits. Regular medical monitoring for welders, including neurological examinations and possibly blood manganese levels, is recommended for early detection and intervention 1. Unlike idiopathic Parkinson's disease, welding-associated parkinsonism may not respond as well to dopaminergic medications, and symptoms may persist or progress even after exposure cessation. Recent research recommendations have emphasized the need for further studies on the health effects of welding fumes, including the relative contributions of different fume components to carcinogenicity and neurotoxicity 1. Treatment with levodopa/carbidopa (Sinemet) may be initiated at 25/100 mg three times daily and titrated as needed, but the response to treatment may be variable and less effective than in idiopathic Parkinson's disease. Overall, prevention and early detection are critical in managing welding-associated parkinsonism, and welders should be aware of the risks and take steps to minimize their exposure to manganese-containing welding fumes.
From the Research
Definition and Prevalence of Welding-Associated Parkinsonism
- Welding-associated parkinsonism is a condition that has been linked to exposure to manganese, a common component of welding fume 2, 3.
- The prevalence of parkinsonism among welders has been estimated to be around 15.6% in one study, which is significantly higher than the prevalence in non-welding exposed workers 2.
- However, another study found that the incidence of manganism, a condition caused by manganese exposure, is low among welders, and that the evidence for a link between welding and parkinsonism is inconclusive 3.
Clinical Features of Welding-Associated Parkinsonism
- Welding-associated parkinsonism has been found to have similar clinical features to idiopathic Parkinson's disease, including tremor, bradykinesia, and rigidity 4.
- However, welders with parkinsonism tend to have a younger age at onset, with a mean age of 46 years compared to 63 years for idiopathic Parkinson's disease patients 4.
- The clinical features of welding-associated parkinsonism can be distinguished from idiopathic Parkinson's disease only by age at onset, suggesting that welding may be a risk factor for Parkinson's disease 4.
Diagnosis and Treatment of Welding-Associated Parkinsonism
- The diagnosis of welding-associated parkinsonism is based on history and examination, and can be supported by laboratory and radiologic findings 5.
- Treatment for welding-associated parkinsonism is symptomatic, and typically involves dopamine-based therapies such as levodopa-carbidopa 6.
- Advanced treatments such as deep brain stimulation and therapy with levodopa-carbidopa enteral suspension may be beneficial for individuals with medication-resistant tremor, worsening symptoms, and dyskinesias 6.
Pathophysiology of Welding-Associated Parkinsonism
- The pathophysiology of welding-associated parkinsonism is thought to involve the destruction of dopamine-producing cells in the substantia nigra, which can be caused by exposure to manganese 3, 4.
- The exact mechanisms by which manganese causes neurotoxicity are not fully understood, but it is thought to involve the formation of reactive oxygen species and the disruption of normal cellular function 3.