No abstract available.
Manganese*

No abstract available.
Brain* ; Hepatic Encephalopathy* ; Manganese*

No abstract available.
Female ; Humans ; Manganese*

Cognition Disorders ; chemically induced ; Humans ; Manganese ; toxicity ; Manganese Poisoning ; epidemiology

BACKGROUND: Shipbuilding involves intensive welding activities, and welders are exposed to a variety of metal fumes, including manganese, that may be associated with neurological impairments. This study aimed to characterize total and size-fractionated manganese exposure resulting from welding operations in shipbuilding work areas. METHODS: In this study, we characterized manganese-containing particulates with an emphasis on total mass (n = 86, closed-face 37-mm cassette samplers) and particle size-selective mass concentrations (n = 86, 8-stage cascade impactor samplers), particle size distributions, and a comparison of exposure levels determined using personal cassette and impactor samplers. RESULTS: Our results suggest that 67.4% of all samples were above the current American Conference of Governmental Industrial Hygienists manganese threshold limit value of 100 μg/m3 as inhalable mass. Furthermore, most of the particles containing manganese in the welding process were of the size of respirable particulates, and 90.7% of all samples exceeded the American Conference of Governmental Industrial Hygienists threshold limit value of 20 μg/m3 for respirable manganese. CONCLUSION: The concentrations measured with the two sampler types (cassette: total mass; impactor: inhalable mass) were significantly correlated (r = 0.964, p < 0.001), but the total concentration obtained using cassette samplers was lower than the inhalable concentration of impactor samplers.
Humans ; Manganese* ; Particle Size ; Welding

Humans ; Manganese ; urine ; Potentiometry ; methods

Manganese ; blood ; Spectrophotometry, Atomic ; methods

China ; Manganese/toxicity* ; Stainless Steel

Chronic exposure to high levels of manganese leads a pronounce and debilitating disorder known as manganism. Research on the toxic manifestation of manganese have focused primarily on its neurological effects because exposure to high levels of the metal produces a distinct and irreversible extrapyramidal dysfunction resembling the dystonic movements associated with Parkinson's physiological and biochemical systems in the body. The purpose of this study was to evaluate the effect of manganeses on primary rat calvarial cell growth and toxicity. The experimental groups were in concentration of 0, 10, 30, 60, 100, 300 micrometer. Cell activity was assessed at day 1 and day 3 using a fluorescent molecular probe. Cell proliferation was evaluated at day 1 and day 3 by MTT assay. The amount of total protein synthesis was measured at day 3 and day 7. The results were as follows: The proliferation of primary rat calvarial cells were inhibited by MnCl2 in the concentration exceeding 100micrometer. The primary rat calvarial cells treated with MnCl2 showed similar protein synthesis to the control group except in 100 micrometer. These result suggest that manganese suppress the viability and protein synthesis of primary rat calvarial cells in concentration exceeding 100 micrometer.
Animals ; Cell Proliferation ; Manganese* ; Molecular Probes ; Rats*

To study neurobehavioral effects for manganese fume exposure of welders, we administrated questionnaire about subjective symptom, related with manganese exposure. Neurobehavioral Core Test Battery of World Health Qrganization(NCTB) and finger tapping for 98 welders and 29 non-welding workers. We adopted welding duration as a criterion for exposure assessment, because of the lack of the longitudinal valid data and differences in airborne concentrations of manganese in welding types, such as shielded metal arc and CO2 arc welding. Neurologic, musculoskeletal and concentration symptoms were significantly increased by increase of welding duration. Performance of finger tapping preferred hand, Santa Ana dexterity test preferred hand and correct number of pursuit aiming were significantly decreased by increase of welding duration. These results comparable with previous studies that suggest neurobehavioral test, especially motor test, to be an appropriate tool to detect early neurobehavioral abnormalities related with manganeses exposure.
Fingers ; Hand ; Manganese* ; Questionnaires ; Welding ; World Health