title: Manganese distribution in brains of Sprague-Dawley rats after 60 days of stainless steel welding-fume exposure.
abstract: Welders working in a confined space, as in the shipbuilding industry, are at risk of being exposed to high concentrations of welding fumes and developing pneumoconiosis or other welding-fume exposure related diseases. Among such diseases, manganism resulting from welding-fume exposure remains a controversial issue, as the movement of manganese into specific brain regions has not yet been clearly established. Accordingly, to investigate the distribution of manganese in the brain after welding-fume exposure, male Sprague-Dawley rats were exposed to welding fumes generated from manual metal arc-stainless steel (MMA-SS) at concentrations of 63.6 +/- 4.1 mg/m(3) (low dose, containing 1.6 mg/m(3) Mn) and 107.1 +/- 6.3 mg/m(3) (high dose, containing 3.5 mg/m(3) Mn) total suspended particulate (TSP) for 2 h per day in an inhalation chamber over a 60-day period. Blood, brain, lung, and liver samples were collected after 2 h, 15, 30, and 60 days of exposure and the tissues analyzed for their manganese concentrations using an atomic absorption spectrophotometer. Although dose- and time-dependent increases in the manganese concentrations were found in the lungs and livers of the rats exposed for 60 days, only slight manganese increases were observed in the blood during this period. Major statistically significant increases in the brain manganese concentrations were detected in the cerebellum after 15 days of exposure and up until 60 days. Slight increases in the manganese concentrations were also found in the substantia nigra, basal ganglia (caudate nucleus, putamen, and globus pallidus), temporal cortex, and frontal cortex, thereby indicating that the pharmacokinetics and distribution of the manganese inhaled from the welding fumes were different from those resulting from manganese-only exposure.
authors.affiliation: Center for Occupational Toxicology, Occupational Safety and Health Research Institute, Korea Occupational Safety Health Agency, 104-8 Munji-dong, Yuseong-gu, Daejeon 305-380, South Korea. u1670916@chollian.net
authors.forename: Il Je
authors.initials: IJ
authors.lastname: Yu
authors.forename: Jung Duck
authors.initials: JD
authors.lastname: Park
authors.forename: Eon Sub
authors.initials: ES
authors.lastname: Park
authors.forename: Kyung Seuk
authors.initials: KS
authors.lastname: Song
authors.forename: Kuy Tae
authors.initials: KT
authors.lastname: Han
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Han
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Chung
authors.forename: Byung Sun
authors.initials: BS
authors.lastname: Choi
authors.forename: Kyu Hyuck
authors.initials: KH
authors.lastname: Chung
authors.forename: Myung Haing
authors.initials: MH
authors.lastname: Cho
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D019570:Inhalation Exposure / Q000009:adverse effects*; D008297:Male; D008345:Manganese / Q000008:administration & dosage / Q000493:pharmacokinetics*; D016273:Occupational Exposure / Q000009:adverse effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013193:Stainless Steel / Q000633:toxicity*; D014896:Welding / Q000379:methods
chemical_list: D013193:Stainless Steel; D008345:Manganese