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James M Antonini - One of the best experts on this subject based on the ideXlab platform.
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altered ion transport in normal human bronchial epithelial cells following exposure to chemically distinct Metal welding fume particles
Toxicology and Applied Pharmacology, 2017Co-Authors: Jeffrey S Fedan, Terence Meighan, Patti C Zeidlererdely, Janet A Thompson, James M AntoniniAbstract:Abstract Welding fume inhalation causes pulmonary toxicity, including susceptibility to infection. We hypothesized that airway epithelial ion transport is a target of fume toxicity, and investigated the effects of fume particulates from Manual Metal Arc-stainless steel (MMA-SS) and gas Metal Arc-mild steel (GMA-MS) on ion transport in normal human bronchial epithelium (NHBE) cultured in air-interface. MMA-SS particles, more soluble than GMA-MS particles, contain Cr, Ni, Fe and Mn; GMA-MS particles contain Fe and Mn. MMA-SS or GMA-MS particles (0.0167–166.7 μg/cm 2 ) were applied apically to NHBEs. After 18 h transepithelial potential difference (V t ), resistance (R t ), and short circuit current ( I sc ) were measured. Particle effects on Na + and Cl¯ channels and the Na + ,K + ,2Cl¯-cotransporter were evaluated using amiloride (apical), 5-nitro-2-[(3-phenylpropyl)amino]benzoic acid (NPPB, apical), and bumetanide (basolateral), respectively. MMA-SS (0.0167–16.7 μg/cm 2 ) increased basal V t . Only 16.7 μg/cm 2 GMA-MS increased basal V t significantly. MMA-SS or GMA-MS exposure potentiated I sc responses (decreases) to amiloride and bumetanide, while not affecting those to NPPB, GMA-MS to a lesser degree than MMA-SS. Variable effects on R t were observed in response to amiloride, and bumetanide. Generally, MMA-SS was more potent in altering responses to amiloride and bumetanide than GMA-MS. Hyperpolarization occurred in the absence of LDH release, but decreases in V t , R t , and I sc at higher fume particulate doses accompanied LDH release, to a greater extent for MMA-SS. Thus, Na + transport and Na + ,K + ,2Cl¯-cotransport are affected by fume exposure; MMA-MS is more potent than GMA-MS. Enhanced Na + absorption and decreased airway surface liquid could compromise defenses against infection.
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Cardiovascular effects in rats after intratracheal instillation of Metal welding particles
Inhalation Toxicology, 2015Co-Authors: Wen Zheng, Jenny R. Roberts, James M Antonini, Michael L. Kashon, Vincent CastranovaAbstract:AbstractStudies have indicated that pulmonary exposure to welding fumes can induce a series of adverse effects in the respiratory system, including infection, bronchitis, siderosis and decreased pulmonary function. Recent clinical and epidemiological studies have found that pulmonary exposure to welding fumes is also associated with a higher incidence of cardiovascular events. However, there is insufficient evidence to confirm a direct effect of welding fumes on the cardiovascular system. The present study investigated the effects of pulmonary exposure to welding fumes on the heart and the vascular system in rats. Two chemically distinct welding fumes generated from Manual Metal Arc-hard surfacing (MMA-HS) and gas Metal Arc-mild steel (GMA-MS) welding were tested. Three groups of rats were instilled intratracheally with MMA-HS (2 mg/rat), GMA-MS (2 mg/rat) or saline as control once a week for seven weeks. On days 1 and 7 after the last treatment, basal cardiovascular function and the cardiovascular respon...
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manganese accumulation in nail clippings as a biomarker of welding fume exposure and neurotoxicity
Toxicology, 2012Co-Authors: Krishnan Sriram, Jenny R. Roberts, Michael L. Kashon, Gary X Lin, Amy M Jefferson, Ronnee N Andrews, James M AntoniniAbstract:Occupational exposure to welding fumes (WF) is thought to cause Parkinson's disease (PD)-like neurological dysfunction. An apprehension that WF may accelerate the onset of PD also exists. Identifying reliable biomarkers of exposure and neurotoxicity are therefore critical for biomonitoring and neurological risk characterization of WF exposure. Manganese (Mn) in welding consumables is considered the causative factor for the neurological deficits seen in welders. Hence, we sought to determine if Mn accumulation in blood or nail clippings can be a marker for adverse exposure and neurotoxicity. To model this, rats were exposed by intratracheal instillation to dissolved or suspended fume components collected from gas Metal Arc-mild steel (GMA-MS) or Manual Metal Arc-hard surfacing (MMA-HS) welding. Trace element analysis revealed selective Mn accumulation in dopaminergic brain areas, striatum (STR) and midbrain (MB), following exposure to the two fumes. This caused dopaminergic abnormality as evidenced by loss of striatal tyrosine hydroxylase (Th; 25-32% decrease) and Parkinson disease (autosomal recessive, early onset) 7 (Park7; 25-46% decrease) proteins. While blood Mn was not detectable, Mn levels in nails strongly correlated with the pattern of Mn accumulation in the striatum (R(2)=0.9386) and midbrain (R(2)=0.9332). Exposure to manganese chloride (MnCl(2)) caused similar Mn accumulation in STR, MB and nail. Our findings suggest that nail Mn has the potential to be a sensitive and reliable biomarker for long-term Mn exposure and associated neurotoxicity. The non-invasive means by which nail clippings can be collected, stored, and transported with relative ease, make it an attractive surrogate for biomonitoring WF exposures in occupational settings.
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lung tumor production and tissue Metal distribution after exposure to Manual Metal Arc stainless steel welding fume in a j and c57bl 6j mice
Journal of Toxicology and Environmental Health, 2011Co-Authors: Patti C Zeidlererdely, Michael L. Kashon, Aaron Erdely, Lori A Battelli, Rebecca Salmenmuniz, Petia P Simeonova, James M AntoniniAbstract:Stainless steel welding produces fumes that contain cArcinogenic Metals. Therefore, welders may be at risk for the development of lung cancer, but animal data are inadequate in this regard. Our main objective was to examine lung tumor production and histopathological alterations in lung-tumor-susceptible (A/J) and -resistant C57BL/6J (B6) mice exposed to Manual Metal Arc-stainless steel (MMA-SS) welding fume. Male mice were exposed to vehicle or MMA-SS welding fume (20 mg/kg) by pharyngeal aspiration once per month for 4 mo. At 78 wk postexposure, gross tumor counts and histopathological changes were assessed and Metal analysis was done on extrapulmonary tissue (aorta, heart, kidney, and liver). At 78 wk postexposure, gross lung tumor multiplicity and incidence were unremarkable in mice exposed to MMA-SS welding fume. Histopathology revealed that only the exposed A/J mice contained minimal amounts of MMA-SS welding fume in the lung and statistically increased lymphoid infiltrates and alveolar macrophages....
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pulmonary inflammation and tumor induction in lung tumor susceptible a j and resistant c57bl 6j mice exposed to welding fume
Particle and Fibre Toxicology, 2008Co-Authors: Patti C Zeidlererdely, Jenny R. Roberts, Michael L. Kashon, Shihhoung Young, Aaron Erdely, Lori A Battelli, Steven H Reynolds, James M AntoniniAbstract:Welding fume has been categorized as "possibly cArcinogenic" to humans. Our objectives were to characterize the lung response to cArcinogenic and non-cArcinogenic Metal-containing welding fumes and to determine if these fumes caused increased lung tumorigenicity in A/J mice, a lung tumor susceptible strain. We exposed male A/J and C57BL/6J, a lung tumor resistant strain, by pharyngeal aspiration four times (once every 3 days) to 85 μg of gas Metal Arc-mild steel (GMA-MS), GMA-stainless steel (SS), or Manual Metal Arc-SS (MMA-SS) fume, or to 25.5 μg soluble hexavalent chromium (S-Cr). Shams were exposed to saline vehicle. Bronchoalveolar lavage (BAL) was done at 2, 7, and 28 days post-exposure. For the lung tumor study, gross tumor counts and histopathological changes were assessed in A/J mice at 48 and 78 weeks post-exposure. BAL revealed notable strain-dependent differences with regards to the degree and resolution of the inflammatory response after exposure to the fumes. At 48 weeks, cArcinogenic Metal-containing GMA-SS fume caused the greatest increase in tumor multiplicity and incidence, but this was not different from sham. By 78 weeks, tumor incidence in the GMA-SS group versus sham approached significance (p = 0.057). A significant increase in perivascular/peribronchial lymphoid infiltrates for the GMA-SS group versus sham and an increased persistence of this fume in lung cells compared to the other welding fumes was found. The increased persistence of GMA-SS fume in combination with its Metal composition may trigger a chronic, but mild, inflammatory state in the lung possibly enhancing tumorigenesis in this susceptible mouse strain.
Thomas Kraus - One of the best experts on this subject based on the ideXlab platform.
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human biomonitoring of chromium and nickel from an experimental exposure to Manual Metal Arc welding fumes of low and high alloyed steel
Annals of Occupational Hygiene, 2015Co-Authors: Jens Bertram, Peter Brand, Thomas Schettgen, Klaus Lenz, Ellwyn Purrio, Uwe Reisgen, Thomas KrausAbstract:OBJECTIVES The uptake and elimination of Metals from welding fumes is currently not fully understood. In the Aachen Workplace Simulation Laboratory (AWSL) it is possible to investigate the impact of welding fumes on human subjects under controlled exposure conditions. In this study, the uptake and elimination of chromium or chromium (VI) respectively as well as nickel was studied in subjects after exposure to the emissions of a Manual Metal Arc welding process using low or high alloyed steel. METHODS In this present study 12 healthy male non-smokers, who never worked as welders before, were exposed for 6h to welding fumes of a Manual Metal Arc welding process. In a three-fold crossover study design, subjects were exposed in randomized order to either clean air, emissions from welding low alloyed steel, and emissions from welding high alloyed steel. Particle mass concentration of the exposure aerosol was 2.5mg m(-3). The content of chromium and nickel in the air was determined by analysing air filter samples on a high emission scenario. Urine analysis for chromium and nickel was performed before and after exposure using methods of human biomonitoring. RESULTS There were significantly elevated chromium levels after exposure to welding fumes from high alloyed steel compared to urinary chromium levels before exposure to high alloyed welding fumes, as well as compared to the other exposure scenarios. The mean values increased from 0.27 µg l(-1) to 18.62 µg l(-1). The results were in good agreement with already existing correlations between external and internal exposure (German exposure equivalent for cArcinogenic working materials EKA). The variability of urinary chromium levels was high. For urinary nickel no significant changes could be detected at all. CONCLUSIONS Six-hour exposure to 2.5mg m(-3) high alloyed Manual Metal Arc welding fumes lead to elevated urinary chromium levels far higher (7.11-34.16 µg l(-1)) than the German biological exposure reference value (BAR) of 0.6 µg l(-1) directly after exposure. On the other hand mean urinary nickel concentrations slightly increased, but did not exceed background levels due to lower bioavailability. We could underline with our single exposure experiment that a welding work related chromium exposure can be measured immediately after the work shift, while the same is not possible for nickel exposure due to lower nickel bioavailability. The data provide useful information for real occupational welding work places.
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human biomonitoring of aluminium after a single controlled Manual Metal Arc inert gas welding process of an aluminium containing worksheet in nonwelders
International Archives of Occupational and Environmental Health, 2015Co-Authors: Jens Bertram, Peter Brand, Laura Hartmann, Thomas Schettgen, Veronika Kossack, Klaus Lenz, Ellwyn Purrio, Uwe Reisgen, Thomas KrausAbstract:Purpose Several existing field studies evaluate aluminium welding works but no thoroughly controlled exposure scenario for welding fume has been described yet. This study provides information about the uptake and elimination of aluminium from welding fumes under controlled conditions.
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Number size distribution of fine and ultrafine fume particles from various welding processes.
The Annals of occupational hygiene, 2012Co-Authors: Peter Brand, Klaus Lenz, Uwe Reisgen, Thomas KrausAbstract:Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size distributions of various welding and joining techniques were measured close to the welding process using a fast mobility particle sizer (FMPS). It turned out that welding processes with high mass emission rates (Manual Metal Arc welding, Metal active gas welding, Metal inert gas welding, Metal inert gas soldering, and laser welding) show mainly agglomerated particles with diameters above 100 nm and only few particles in the size range below 50 nm (10 to 15%). Welding processes with low mass emission rates (tungsten inert gas welding and resistance spot welding) emit predominantly ultrafine particles with diameters well below 100 nm. This finding can be explained by considerably faster agglomeration processes in welding processes with high mass emission rates. Although mass emission is low for tungsten inert gas welding and resistance spot welding, due to the low particle size of the fume, these processes cannot be labeled as toxicologically irrelevant and should be further investigated.
A Haerian - One of the best experts on this subject based on the ideXlab platform.
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effects of chromium on the microstructure and inclusions of multipass low alloy steels weld Metal in shielded Metal Arc welding
2010Co-Authors: M Avazkonandeh H Gharavol, Haddad M Sabzevar, A HaerianAbstract:Effect of chromium content on the microstructure and inclusions formation in low alloy steel multipass welds was investigated. Manual Metal Arc welding was performed in flat position according to AWS A5.5-96 standard. The ferro-chromium content in the coating was varied such that the final weld Metal consists of 0.05, 0.53 and 0.91 wt.% chromium. Microstructure was studied by optical and scanning electron microscope in both columnar and reheated regions of the weld Metal. The results showed increase in acicular ferrite formed at the expense of primary ferrite and ferrite with second phase with steady refinement of microstructure. Amount of microphases also increase as the chromium content of the weld Metal increases. It is believed that chromium does not affect apparent characteristics (such as volume fraction and average size) and chemistry of inclusions.
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effect of copper content on the microstructure and mechanical properties of multipass mma low alloy steel weld Metal deposits
Materials & Design, 2009Co-Authors: M H Avazkonandehgharavol, M Haddadsabzevar, A HaerianAbstract:Abstract Effect of copper content in the range of 0.14–0.94 wt.% on the microstructure and mechanical properties of Cr–Ni–Cu low alloy steel weld Metal deposits was investigated. All welds were prepared by Manual Metal Arc welding technique in flat position. Microstructure of the welds was examined by optical and scanning electron microscopes. The results showed increase in acicular ferrite and microphases formed at the expense of primary ferrite and ferrite with second phase with steady refinement of microstructure. According to these microstructural changes, hardness, yield and ultimate tensile stresses increased while Charpy V-notch impact toughness and percent elongation reduced.
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effect of chromium content on the microstructure and mechanical properties of multipass mma low alloy steel weld Metal
Journal of Materials Science, 2009Co-Authors: M H Avazkonandehgharavol, M Haddadsabzevar, A HaerianAbstract:Effect of chromium content in the range of 0.05–0.91 wt% on the microstructure and mechanical properties of Cr–Ni–Cu low alloy steel weld Metal was investigated. All welds were prepared by Manual Metal Arc welding technique in flat position. Microstructure of the welds was examined by optical and scanning electron microscope in both columnar and reheated regions of the weld Metal. The results showed increase in acicular ferrite and microphases formed at the expense of primary ferrite and ferrite with second phase with steady refinement of microstructure. According to these microstructural changes, yield and ultimate tensile stresses, Hardness and Charpy V-Notch impact toughness increased, whereas elongation decreased. Increase in Charpy impact value is thought to be due to fine dispersed spheroidized dark microphases at high chromium contents.
Jenny R. Roberts - One of the best experts on this subject based on the ideXlab platform.
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Cardiovascular effects in rats after intratracheal instillation of Metal welding particles
Inhalation Toxicology, 2015Co-Authors: Wen Zheng, Jenny R. Roberts, James M Antonini, Michael L. Kashon, Vincent CastranovaAbstract:AbstractStudies have indicated that pulmonary exposure to welding fumes can induce a series of adverse effects in the respiratory system, including infection, bronchitis, siderosis and decreased pulmonary function. Recent clinical and epidemiological studies have found that pulmonary exposure to welding fumes is also associated with a higher incidence of cardiovascular events. However, there is insufficient evidence to confirm a direct effect of welding fumes on the cardiovascular system. The present study investigated the effects of pulmonary exposure to welding fumes on the heart and the vascular system in rats. Two chemically distinct welding fumes generated from Manual Metal Arc-hard surfacing (MMA-HS) and gas Metal Arc-mild steel (GMA-MS) welding were tested. Three groups of rats were instilled intratracheally with MMA-HS (2 mg/rat), GMA-MS (2 mg/rat) or saline as control once a week for seven weeks. On days 1 and 7 after the last treatment, basal cardiovascular function and the cardiovascular respon...
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manganese accumulation in nail clippings as a biomarker of welding fume exposure and neurotoxicity
Toxicology, 2012Co-Authors: Krishnan Sriram, Jenny R. Roberts, Michael L. Kashon, Gary X Lin, Amy M Jefferson, Ronnee N Andrews, James M AntoniniAbstract:Occupational exposure to welding fumes (WF) is thought to cause Parkinson's disease (PD)-like neurological dysfunction. An apprehension that WF may accelerate the onset of PD also exists. Identifying reliable biomarkers of exposure and neurotoxicity are therefore critical for biomonitoring and neurological risk characterization of WF exposure. Manganese (Mn) in welding consumables is considered the causative factor for the neurological deficits seen in welders. Hence, we sought to determine if Mn accumulation in blood or nail clippings can be a marker for adverse exposure and neurotoxicity. To model this, rats were exposed by intratracheal instillation to dissolved or suspended fume components collected from gas Metal Arc-mild steel (GMA-MS) or Manual Metal Arc-hard surfacing (MMA-HS) welding. Trace element analysis revealed selective Mn accumulation in dopaminergic brain areas, striatum (STR) and midbrain (MB), following exposure to the two fumes. This caused dopaminergic abnormality as evidenced by loss of striatal tyrosine hydroxylase (Th; 25-32% decrease) and Parkinson disease (autosomal recessive, early onset) 7 (Park7; 25-46% decrease) proteins. While blood Mn was not detectable, Mn levels in nails strongly correlated with the pattern of Mn accumulation in the striatum (R(2)=0.9386) and midbrain (R(2)=0.9332). Exposure to manganese chloride (MnCl(2)) caused similar Mn accumulation in STR, MB and nail. Our findings suggest that nail Mn has the potential to be a sensitive and reliable biomarker for long-term Mn exposure and associated neurotoxicity. The non-invasive means by which nail clippings can be collected, stored, and transported with relative ease, make it an attractive surrogate for biomonitoring WF exposures in occupational settings.
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pulmonary inflammation and tumor induction in lung tumor susceptible a j and resistant c57bl 6j mice exposed to welding fume
Particle and Fibre Toxicology, 2008Co-Authors: Patti C Zeidlererdely, Jenny R. Roberts, Michael L. Kashon, Shihhoung Young, Aaron Erdely, Lori A Battelli, Steven H Reynolds, James M AntoniniAbstract:Welding fume has been categorized as "possibly cArcinogenic" to humans. Our objectives were to characterize the lung response to cArcinogenic and non-cArcinogenic Metal-containing welding fumes and to determine if these fumes caused increased lung tumorigenicity in A/J mice, a lung tumor susceptible strain. We exposed male A/J and C57BL/6J, a lung tumor resistant strain, by pharyngeal aspiration four times (once every 3 days) to 85 μg of gas Metal Arc-mild steel (GMA-MS), GMA-stainless steel (SS), or Manual Metal Arc-SS (MMA-SS) fume, or to 25.5 μg soluble hexavalent chromium (S-Cr). Shams were exposed to saline vehicle. Bronchoalveolar lavage (BAL) was done at 2, 7, and 28 days post-exposure. For the lung tumor study, gross tumor counts and histopathological changes were assessed in A/J mice at 48 and 78 weeks post-exposure. BAL revealed notable strain-dependent differences with regards to the degree and resolution of the inflammatory response after exposure to the fumes. At 48 weeks, cArcinogenic Metal-containing GMA-SS fume caused the greatest increase in tumor multiplicity and incidence, but this was not different from sham. By 78 weeks, tumor incidence in the GMA-SS group versus sham approached significance (p = 0.057). A significant increase in perivascular/peribronchial lymphoid infiltrates for the GMA-SS group versus sham and an increased persistence of this fume in lung cells compared to the other welding fumes was found. The increased persistence of GMA-SS fume in combination with its Metal composition may trigger a chronic, but mild, inflammatory state in the lung possibly enhancing tumorigenesis in this susceptible mouse strain.
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chromium in stainless steel welding fume suppresses lung defense responses against bacterial infection in rats
Journal of Immunotoxicology, 2007Co-Authors: James M Antonini, Jenny R. RobertsAbstract:Pulmonary infections have been reported to be increased in welders. Previous animal studies have indicated that Manual Metal Arc, stainless steel welding fume (MMA-SS) increased susceptibility to lung infections. MMA-SS is composed of a complex of Metals (e.g., iron, chromium, nickel). The objective was to determine which Metal component of MMA-SS welding fume alters lung defense responses. At Day 0, rats were intratracheally instilled one time with saline or MMA-SS at a concentration of 2 mg/rat. Additional rats were treated with the Metal constituents, Fe2O3, NiO, or Cr2Na2O7 alone or in combination, at concentrations that are present in the dose used for MMA-SS treatment. At Day 3, rats were intratracheally inoculated with 5 × 103 Listeria monocytogenes. At Days 6, 8 and 10, homogenized left lungs were cultured, and colony-forming units were counted after an overnight incubation to assess pulmonary bacterial clearance. At Day 3 (prior to infection) and at Days 6, 8 and 10, right lungs were lavaged to r...
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effect of stainless steel Manual Metal Arc welding fume on free radical production dna damage and apoptosis induction
Molecular and Cellular Biochemistry, 2005Co-Authors: James M Antonini, Jenny R. Roberts, Stephen S Leonard, Claudia Solanolopez, Shihhoung Young, Xianglin Shi, Michael D TaylorAbstract:Questions exist concerning the potential cArcinogenic effects after welding fume exposure. Welding processes that use stainless steel (SS) materials can produce fumes that may contain Metals (e.g., Cr, Ni) known to be cArcinogenic to humans. The objective was to determine the effect of in vitro and in vivo welding fume treatment on free radical generation, DNA damage, cytotoxicity and apoptosis induction, all factors possibly involved with the pathogenesis of lung cancer. SS welding fume was collected during Manual Metal Arc welding (MMA). Elemental analysis indicated that the MMA-SS sample was highly soluble in water, and a majority (87%) of the soluble Metal was Cr. Using electron spin resonance (ESR), the SS welding fume had the ability to produce the biologically reactive hydroxyl radical (•OH), likely as a result of the reduction of Cr(VI) to Cr(V). In vitro treatment with the MMA-SS sample caused a concentration-dependent increase in DNA damage and lung macrophage death. In addition, a time-dependent increase in the number of apoptotic cells in lung tissue was observed after in vivo treatment with the welding fume. In summary, a soluble MMA-SS welding fume was found to generate reactive oxygen species and cause DNA damage, lung macrophage cytotoxicity and in vivo lung cell apoptosis. These responses have been shown to be involved in various toxicological and cArcinogenic processes. The effects observed appear to be related to the soluble component of the MMA-SS sample that is predominately Cr. A more comprehensive in vivo animal study is ongoing in the laboratory that is continuing these experiments to try to elucidate the potential mechanisms that may be involved with welding fume-induced lung disease.
Kyung Seuk Song - One of the best experts on this subject based on the ideXlab platform.
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Inflammatory and genotoxic responses during 30-day welding-fume exposure period
Toxicology Letters, 2004Co-Authors: Kyung Seuk Song, Seung Hee Maeng, Yong-hyun Chung, Soo Jin Kim, Jae Hyuck Sung, Jeong Hee Han, Myung Haing Cho, Kyu Hyuck Chung, Kuy Tae HanAbstract:Abstract Welder’s pneumoconiosis has generally been determined to be benign and unassociated with respiratory symptoms based on the absence of pulmonary-function abnormalities in welders with marked radiographic abnormalities. In previous studies, the current authors suggested a three-phase lung fibrosis process to study the pathological process of lung fibrosis and found that the critical point for recovery was after 30 days of welding-fume exposure at a high dose, at which point early and delicate fibrosis was observed in the perivascular and peribronchiolar regions. Accordingly, the current study investigated the inflammatory and genotoxic responses during a 30-day period of welding-fume exposure to elucidate the process of fibrosis. As such, rats were exposed to Manual Metal Arc-stainless steel (MMA-SS) welding fumes at concentrations of 65.6 ± 2.9 (low dose) and 116.8 ± 3.9 mg/m3 (high dose) total suspended particulate for 2 h per day in an inhalation chamber for 30 days. Animals were sacrificed after the initial 2 h exposure, and after 15 and 30 days of exposure. The rats exposed to the welding fumes exhibited a statistically significant (P
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manganese distribution in brains of sprague dawley rats after 60 days of stainless steel welding fume exposure
Neurotoxicology, 2003Co-Authors: Jung Duck Park, Kyung Seuk Song, Yong-hyun Chung, Jeong Hee Han, Kyu Hyuck Chung, Kuy Tae Han, Eon Sub Park, Byungsun Choi, Myung Haing ChoAbstract: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. # 2003 Elsevier Science Inc. All rights reserved.
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recovery from Manual Metal Arc stainless steel welding fume exposure induced lung fibrosis in sprague dawley rats
Toxicology Letters, 2003Co-Authors: Kyung Seuk Song, Hee Kyung Chang, Yong-hyun Chung, Jeong Hee Han, Kyu Hyuck Chung, Kuy Tae Han, Ho Keun ChungAbstract:Welders with radiographic pneumoconiosis abnormalities have exhibited a gradual clearing of the X-ray identified effects following removal from exposure. In some cases, the pulmonary fibrosis associated with welding fumes appears in a more severe form in welders. Accordingly, to investigate the disease and recovery process of pneumoconiosis induced by welding-fume exposure, rats were exposed to welding fumes with concentrations of 63.6+/-4.1 mg/m(3) (low dose) and 107.1+/-6.3 mg/m(3) (high dose) of total suspended particulate for 2 h per day in an inhalation chamber for a total of 2 h or 15, 30, 60 or 90 days. Thereafter, the rats were no longer exposed and allowed to recover from the welding fume-induced lung fibrosis for 90 days. When compared to the unexposed control group, the lung weights significantly increased in both the low- and high-dose rats from day 15 to 90. A histopathological examination combined with fibrosis-specific staining revealed that the lungs from the low-dose rats did not exhibit any significant progressive fibrotic changes. Whereas, the lungs from the high-dose rats exhibited early delicate fibrosis from day 15, which progressed into the perivascular and peribronchiolar regions by day 30. Interstitial fibrosis appeared at day 60 and became prominent by day 90, along with the additional appearance of pleural fibrosis. Recovery, evaluated based on the body and lung weights and a histopathological examination, was observed in both the high and low-dose rats that were exposed up to 30 days. The rats exposed for 60-90 days at the low dose also recovered from the fibrosis, yet the rats exposed for 60-90 days at the high dose did not fully recover. Consequently, recovery from pneumoconiosis induced by welding-fume exposure was observed when the degree of exposure was short-term and moderate.
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lung fibrosis in sprague dawley rats induced by exposure to Manual Metal Arc stainless steel welding fumes
Toxicological Sciences, 2001Co-Authors: Kyung Seuk Song, Seung Hee Maeng, Hee Kyung Chang, Yong-hyun Chung, Jeong Hee Han, Kuy Tae Han, Kwang Jin Kim, Seung Hyun Park, Kyu Hyuk Chung, Ho Keun ChungAbstract:(low dose) and 105-118 mg/m 3 (high dose) total suspended par- ticulates for 2 h per day in an inhalation chamber for 90 days. The concentrations of the main Metals, Fe, Mn, Cr, and Ni, were measured in the welding fumes, plus the gaseous compounds, including nitrous gases and ozone, were monitored. During the exposure period, the animals were sacrificed after the initial 2-h exposure and after 15, 30, 60, and 90 days. Histopathological examinations were conducted on the animals' upper respiratory tract, including the nasal pathway and conducting airway, plus the gas exchange region, including the alveolar ducts, alveolar sacs, and alveoli. When compared to the control group, the lung weights did not increase significantly in the low-dose group, yet in the high-dose group there was a significant increase from day 15 to day 90. The histopatholgical examination combined with fibrosis- specific staining (Masson's trichrome) indicated that the lungs in the low-dose group did not exhibit any progressive fibrotic changes. Whereas, the lungs in the high-dose group exhibited early delicate fibrosis from day 15, which progressed into the perivas- cular and peribronchiolar regions by day 30. Interstitial fibrosis appeared at day 60 and became prominent by day 90, along with the additional appearance of pleural fibrosis. Accordingly, it would appear that a significant dose of welding-fume exposure was required to induce lung fibrosis.