title: Sequelae of fume exposure in confined space welding: a neurological and neuropsychological case series.
abstract: Welding fume contains manganese (Mn) which is known to be bio-available to and neurotoxic for the central nervous system. Although an essential metal, Mn overexposure may cause manganism, a parkinsonian syndrome. The present welder study sought to improve the clinical portrait of manganism and to determine dose-effect relationships. The welders were employed in the construction of the new Bay Bridge (San Francisco) and welded in confined spaces for up to 2 years with minimal protection and poor ventilation. Neurological, neuropsychological, neurophysiological, and pulmonary examinations were given to 49 welders. Clinical cases were selected on the basis of apriori defined criteria pertaining to welding history and neurological/neuropsychological features. Among the 43 eligible welders, 11 cases of manganism were identified presenting with the following symptoms: sleep disturbance, mood changes, bradykinesia, headaches, sexual dysfunction, olfaction loss, muscular rigidity, tremors, hallucinations, slurred speech, postural instability, monotonous voice, and facial masking. Significant associations between outcome variables and cumulative exposure index (CEI) or blood Mn (MnB) were obtained with CEI for variables implicating attention and concentration, working and immediate memory, cognitive flexibility, and verbal learning; and with MnB for executive function, cognitive flexibility, visuo-spatial construction ability, and visual contrast sensitivity. This study strongly suggests that neuropsychological features contribute in a dose-effect related way to the portrait of manganism usually characterized by tremor, loss in balance, diminished cognitive performance, and signs and symptoms of parkinsonism.
authors.affiliation: San Francisco State University, San Francisco, CA, USA. rbowl@sfsu.edu
authors.forename: Rosemarie M
authors.initials: RM
authors.lastname: Bowler
authors.forename: Sanae
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Marija
authors.initials: M
authors.lastname: Drezgic
authors.forename: Harry A
authors.initials: HA
authors.lastname: Roels
authors.forename: Robert M
authors.initials: RM
authors.lastname: Park
authors.forename: Emily
authors.initials: E
authors.lastname: Diamond
authors.forename: Donna
authors.initials: D
authors.lastname: Mergler
authors.forename: Maryse
authors.initials: M
authors.lastname: Bouchard
authors.forename: Russell P
authors.initials: RP
authors.lastname: Bowler
authors.forename: William
authors.initials: W
authors.lastname: Koller
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D002490:Central Nervous System / Q000187:drug effects; D020378:Confined Spaces; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008345:Manganese / Q000097:blood; D017895:Manganese Compounds / Q000009:adverse effects*; D020149:Manganese Poisoning / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D001523:Mental Disorders / Q000139:chemically induced* / Q000503:physiopathology; D008875:Middle Aged; D009483:Neuropsychological Tests; D020258:Neurotoxicity Syndromes / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D009784:Occupational Diseases / Q000139:chemically induced* / Q000503:physiopathology / Q000523:psychology; D016273:Occupational Exposure; D011569:Psychiatric Status Rating Scales; D012129:Respiratory Function Tests; D012495:San Francisco; D013997:Time Factors; D014896:Welding
chemical_list: D000393:Air Pollutants; D017895:Manganese Compounds; D008345:Manganese