Comparison of lung injury and inflammation after repeated treatment with welding fumes collected from different welding processes.
Toxicologist 2007 Mar; 96(1):103-104
Welding fumes are a complex mixture of different metals. Depending on the welding process, some welders may be exposed to fumes that contain vastly different metal profiles. The goal was to compare the lung response in rats after multiple treatments with welding fumes that are vastly different both chemically and physically. Welding fumes were collected from three different processes: gas metal arcmild steel welding (GMA-MS); manual metal arc-hardsurfacing welding (MMAHS); flux-cored arc-hardsurfacing welding (FCA-HS). Male Sprague-Dawley rats were treated by intratracheal instillation 1/wk x 7 wk with 0.5 mg/rat of the fume samples. Controls were treated with saline. Bronchoalveolar lavage was performed 4 days after the final treatment, and parameters of lung injury (lactate dehydrogenase and albumin) and inflammation (neutrophil influx) were assessed. Metal analysis indicated that the GMA-MS fume was primarily composed of Fe (1.08 µg Fe/gm total metal) and Mn (0.32 µg Mn/gm total metal), whereas the Mn content of the FCA-HS (2.0 µg Mn/gm total metal) and MMA-HS (1.8 µg Mn/gm total metal) fumes was ~6x higher than in the GMA-MS fume. The FCA-HS (0.07 µg Cr/gm total metal) and MMA-HS (0.304 µg Cr/gm total metal) fumes contained Cr which was present in only trace amounts in the GMA-MS fume. The FCA-HS and MMA-HS fumes were found to be more water-soluble than the GMA-MS fume. Significant elevations in lactate dehydrogenase, albumin, and the number of lung neutrophils were observed for the MMA-HS and FCA-HS groups compared to the GMA-MS and saline groups. No significant differences in lung injury and inflammation were observed between the GMA-MS and saline group. The greater lung response caused by the FCA-HS and MMA-HS fumes is likely due to the presence of Cr and higher levels of Mn. Results from this study indicate that welders who are exposed to fumes generated from specific processes may be at a greater risk for adverse pulmonary effects.
Laboratory-animals; Animal-studies; Biodynamics; Pulmonary-disorders; Pulmonary-function-tests; Pulmonary-system-disorders; Alveolar-cells; Lung-cells; Lung-irritants; Lung-function; Welders-lung; Welding; Fumes; Gas-welders; Metal-fumes; Arc-welders; Arc-welding; Chemical-analysis; Chemical-indicators; Chemical-reactions
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505
The Toxicologist. Society of Toxicology 46th Annual Meeting and ToxExpo, March 25-29, 2007, Charlotte, North Carolina