Extrapulmonary tissue distribution of metals following repeated lung exposures to welding fumes with different elemental profiles.
Antonini-JM; Roberts-JR; Sriram-K; Benkovic-SA; O'Callaghan-JP; Miller-DB
Toxicologist 2008 Mar; 102(1):226
Welding fumes (WF) are a complex mixture of different metals. The pulmonary effects of WF have been well studied. Little is known about possible non-pulmonary effects (e.g., neurological, cardiovascular, renal). The goal was to study the translocation of metals from the lungs to other organ systems after treatment with chemically distinct WF. Fumes were collected from different welding processes: gas metal arc-mild steel (GMA-MS); manual metal arc-hardsurfacing (MMA-HS); flux-cored arc-hardsurfacing (FCA-HS). Metal analysis of WF indicated that GMA-MS was primarily composed of Fe (1.08 mu g/gm) and Mn (0.32 mu g/gm), whereas the Mn content of FCA-HS (2.0 mu g/gm) and MMA-HS (1.8 mug/gm) was ~6x higher than in GMA-MS. FCA-HS (0.07 mu g/gm) and MMA-HS (0.30 mu g/gm) contained Cr which was present in only trace amounts in the GMA-MS WF. The FCA-HS and MMA-HS WF were found to be more water-soluble than the GMA-MS WF. Male Sprague-Dawley rats were intratracheally treated with 0.5 mg/rat of the different WF 1/wk x 7 or 11 wk. Controls were treated with saline. Four days after the last treatment, the animals were sacrificed, and multiple organs and discrete brain regions were recovered for metal analysis. Significant increases in lung and kidney Mn and Cr, blood Mn, and heart Mn were observed for the FCA-HS and MMAHS groups compared to the GMA-MS and control groups after 11 wk. Lung Fe and Mn were significantly elevated in all three welding groups compared to controls after 11 wk. Slight elevations in Mn levels were observed in the striatum and cortex of brains from animals treated for 7 wk with each of the three WF compared to controls. These findings indicate that Cr and Mn, two potentially toxic metals, may translocate from the lungs to other organs after treatment with highly soluble WF generated from hardsurfacing processes. Welding particle source, composition, and solubility appear to be determinants of tranlocation to extrapulmonary tissues.
Fumes; Lung; Lung-cells; Lung-disorders; Lung-irritants; Inhalation-studies; Pulmonary-disorders; Pulmonary-system-disorders; Laboratory-animals; Respiratory-infections; Respiratory-system-disorders; Vapors; Metal-fumes; Metallic-fumes
The Toxicologist. Society of Toxicology 47th Annual Meeting and ToxExpo, March 16-20, 2008, Seattle, Washington