Increased risk of parkinsonism associated with welding exposure

Abstract

Objective Manganese (Mn), an established neurotoxicant, is a common component of welding fume. The neurological phenotype associated with welding exposures has not been well described. Prior epidemiologic evidence linking occupational welding to parkinsonism is mixed, and remains controversial. Methods This was a cross-sectional and nested case–control study to investigate the prevalence and phenotype of parkinsonism among 811 shipyard and fabrication welders recruited from trade unions. Two reference groups included 59 non-welder trade workers and 118 newly diagnosed, untreated idiopathic PD patients. Study subjects were examined by a movement disorders specialist using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3). Parkinsonism cases were defined as welders with UPDRS3 score ≥15. Normal was defined as UPDRS3 < 6. Exposure was classified as intensity adjusted, cumulative years of welding. Adjusted prevalence ratios for parkinsonism were calculated in relation to quartiles of welding years. Results The overall prevalence estimate of parkinsonism was 15.6% in welding exposed workers compared to 0% in the reference group. Among welders, we observed a U-shaped dose–response relation between weighted welding exposure-years and parkinsonism. UPDRS3 scores for most domains were similar between welders and newly diagnosed idiopathic Parkinson disease (PD) patients, except for greater frequency of rest tremor and asymmetry in PD patients. Conclusion This work-site based study among welders demonstrates a high prevalence of parkinsonism compared to nonwelding-exposed workers and a clinical phenotype that overlaps substantially with PD.

Health effects of manganese exposures for welders in Qingdao City, China

“…Our findings fit with others already noted in the scientific literature attesting to the release of manganese from welding activities causing neurologic damage, as well as a variety of other symptoms. This would include the work of Bowler [7], Chandra et al [16], Laohaudomchok et al [8], and Racette et al [9]. The finding in this study proves notable for the high rate of reported eye difficulties, even though most welders wear eye protection, albeit not very consistently.…”

“…If one looks at the scientific literature to date, there are differences of opinion as to the ability of manganese in welding rods being capable of causing neurologic damage. Santamaria [6] finds no problem while others [7][8][9] do find RESULTS Out of the 523 questionnaires distributed, 505 were found to be complete and useable. All welders were males of an average age of 33.5±7.6 years old (19-54 years old).…”

Evaluation of exposure to crystalline silica, welding fume, and isocyanates during water heater manufacturing.

“…These illnesses include metal fume fever, pneumonitis, pulmonary edema, and lung cancer. Exposure to manganese has been associated with Parkinson-like health effects such as poor hand-eye coordination, motor slowing, increased tremor, reduced response speed, mood disturbance, and possible memory and intellectual loss [Antonini et al 2006;Bowler et al 2006;Lundin et al 2014;Racette et al 2012;Welch et al 2004]. …”

Parkinson’s Disease: An Overview of Etiology, Clinical Manifestations, and Treatment

“…It should be noted that TCE is the most common organic contaminant in groundwater [ 20 ]. Welding and manganese exposure have been suggested as risk factors for PD [ 21 ]. However, a meta-analysis that pooled data from 13 studies for welding and 3 studies for manganese exposure failed to support this hypothesis [ 22 ].…”