Effect of metal composition and the use of adhesive and anti-spatter chemicals on lung responses in rats after inhalation during spot welding

Details

• Personal Author:
  Afshari A ; Antonini JM ; Chen BT ; Fedan, Jeffery S. ; Jackson M ; McKinney W ; Meighan TG ; Schwegler-Berry D ; Thompson J ; Zeidler-Erdely PC
• Description:
  Spot welding (SW) is common in the automotive industry. Adhesives are used as sealers to the seams of metals that are joined. Anti-spatter compounds are sprayed onto metals to be welded to improve the weld surface finish. SW produces complex aerosols composed of metal and volatile compounds (VOCs) which have caused lung disease in workers. The goal was to evaluate the effect that different components of SW fumes may have on lung responses in an animal model. Sprague-Dawley rats were exposed by inhalation to 25 mg/m3 of aerosol for 4 h/d x 8 d during SW of mild steel or galvanized Zn-coated steel in the presence or absence of an adhesive or anti-spatter spray. Controls were exposed to air. Particle size distribution and chemical composition of the generated aerosol were determined. Particle size distribution was tri-modal with a MMAD of 0.25 microm. The metal fraction of the mild steel fume was >99% Fe, whereas the Zn-coated steel was 90% Fe, 7% Zn, and 2% Mn. VOCs (e.g., siloxanes, benzene, toluene) were present when an adhesive was used. After exposure, bronchoalveolar lavage (BAL) was performed to assess lung toxicity. Lung resistance (RL) was evaluated before and after challenge with inhaled methacholine (MCh). Lung toxicity and BAL neutrophils were significantly elevated compared to controls 1 d after exposure to the fumes from Zn-coated steel but not mild steel, indicating the development of acute lung inflammation. All markers of lung toxicity for the Zn-coated group returned to control values by 7 d. Immediately after exposure, baseline RL was significantly elevated in the group exposed when VOC levels were high. Basal RL returned to control level by 1 d. Reactivity to MCh was not affected at any time point after SW fume exposure. The use of an anti-spray compound had no effect on lung toxicity or function. Inhalation of SW fumes caused acute lung toxicity due to the presence of specific metals (e.g., Zn) as well as increase RL due to the use of adhesives. [Description provided by NIOSH]
• Subjects:
  Adhesives Aerosols Benzene Chemistry Environmental Monitoring Ferrous Compounds Hazardous Substances Immune System Inhalation Exposure Laboratories Lung Lung Diseases Manganese Metals Methacholine Compounds Occupational Health Respiratory System Respiratory Tract Diseases Safety Toluene Toxicology Welding Zinc Compounds

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• Keywords:
  Benzenes Chemical-composition Dose-response Exposure-assessment Immune-reaction Inhalants Iron-compounds Laboratory-animals Laboratory-testing Lung-disease Lung-function Lung-irritants Manganese-compounds Metal-compounds Metal-finishing Metal-fumes Methacholines Neutrophils Organo-silicon-compounds Sealing-compounds Sprays Steel-compounds Toluenes Toxic-effects Toxic-vapors Volatiles Zinc-compounds

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  California ; OSHA Region 3 ; OSHA Region 9 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  144
• Issue:
  1
• NIOSHTIC Number:
  nn:20045974
• Citation:
  Toxicologist 2015 Mar; 144(1):337
• CAS Registry Number:
  Benzene (CAS RN 71-43-2) ; Iron (CAS RN 7439-89-6) ; Manganese (CAS RN 7439-96-5) ; Toluene (CAS RN 108-88-3) ; Zinc (CAS RN 7440-66-6)
• Federal Fiscal Year:
  2015
• NORA Priority Area:
  Construction
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 54th Annual Meeting and ToxExpo, March 22-26, 2015, San Diego, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:36df2b4c4f0648ac78d3ff7ac5a9f1ab41f99fe259f3543ff0bda026f5815f43bba740c0258bb304f5768dec3fb597087c3e2bdff5e7574f4460cae18c6a6d96
• Download URL:
  https://stacks.cdc.gov/view/cdc/201178/cdc_201178_DS1.pdf
• File Type:
  [PDF - 217.83 KB ]