TY - JOUR T1 - Dose-effect relationships between manganese exposure and neurological, neuropsychological and pulmonary function in confined space bridge welders. AU - Bowler,Rosemarie M, AU - Roels,Harry A, AU - Nakagawa,Sanae, AU - Drezgic,Marija, AU - Diamond,Emily, AU - Park,Robert, AU - Koller,William, AU - Bowler,Russell P, AU - Mergler,Donna, AU - Bouchard,Maryse, AU - Smith,Donald, AU - Gwiazda,Roberto, AU - Doty,Richard L, Y1 - 2006/10/03/ PY - 2006/10/5/pubmed PY - 2007/3/21/medline PY - 2006/10/5/entrez SP - 167 EP - 77 JF - Occupational and environmental medicine JO - Occup Environ Med VL - 64 IS - 3 N2 - BACKGROUND: Although adverse neuropsychological and neurological health effects are well known among workers with high manganese (Mn) exposures in mining, ore-processing and ferroalloy production, the risks among welders with lower exposures are less well understood. METHODS: Confined space welding in construction of a new span of the San Francisco-Oakland Bay Bridge without adequate protection was studied using a multidisciplinary method to identify the dose-effect relationship between adverse health effects and Mn in air or whole blood. Bridge welders (n = 43) with little or no personal protection equipment and exposed to a welding fume containing Mn, were administered neurological, neuropsychological, neurophysiological and pulmonary tests. Outcome variables were analysed in relation to whole blood Mn (MnB) and a Cumulative Exposure Index (CEI) based on Mn-air, duration and type of welding. Welders performed a mean of 16.5 months of welding on the bridge, were on average 43.8 years of age and had on average 12.6 years of education. RESULTS: The mean time weighted average of Mn-air ranged from 0.11-0.46 mg/m(3) (55% >0.20 mg/m(3)). MnB >10 microg/l was found in 43% of the workers, but the concentrations of Mn in urine, lead in blood and copper and iron in plasma were normal. Forced expiratory volume at 1s: forced vital capacity ratios (FEV(1)/FVC) were found to be abnormal in 33.3% of the welders after about 1.5 years of welding at the bridge. Mean scores of bradykinesia and Unified Parkinson Disease Rating Scale exceeded 4 and 6, respectively. Computer assisted tremor analysis system hand tremor and body sway tests, and University of Pennsylvania Smell Identification Test showed impairment in 38.5/61.5, 51.4 and 88% of the welders, respectively. Significant inverse dose-effect relationships with CEI and/or MnB were found for IQ (p<or=0.05), executive function (p<or=0.03), sustaining concentration and sequencing (p<or=0.04), verbal learning (p<or=0.01), working (p<or=0.04) and immediate memory (p<or=0.02), even when adjusted for demographics and years of welding before Bay Bridge. Symptoms reported by the welders while working were: tremors (41.9%); numbness (60.5%); excessive fatigue (65.1%); sleep disturbance (79.1%); sexual dysfunction (58.1%); toxic hallucinations (18.6%); depression (53.5%); and anxiety (39.5%). Dose-effect associations between CEI and sexual function (p<0.05), fatigue (p<0.05), depression (p<0.01) and headache (p<0.05) were statistically significant. CONCLUSIONS: Confined space welding was shown to be associated with neurological, neuropsychological and pulmonary adverse health effects. A careful enquiry of occupational histories is recommended for all welders presenting with neurological or pulmonary complaints, and a more stringent prevention strategy should be considered for Mn exposure due to inhalation of welding fume. SN - 1470-7926 UR - https://www.unboundmedicine.com/medline/citation/17018581/Dose_effect_relationships_between_manganese_exposure_and_neurological_neuropsychological_and_pulmonary_function_in_confined_space_bridge_welders_ L2 - https://oem.bmj.com/lookup/pmidlookup?view=long&amp;pmid=17018581 DB - PRIME DP - Unbound Medicine ER -