Aerosol characterization and pulmonary responses in rats after short-term inhalation of fumes generated during resistance spot welding of galvanized steel

Details

• Personal Author:
  Afshari A ; Antonini JM ; Burns, Dru A. ; Chen BT ; Jackson M ; LeBouf, Ryan F. ; McKinney W ; Meighan TG ; Schwegler-Berry D ; Shoeb M ; Zeidler-Erdely PC
• Description:
  Resistance spot welding is a common process to join metals in the automotive industry. Adhesives are often used as sealers to seams of metals that are joined. Anti-spatter compounds sometimes are sprayed onto metals to be welded to improve the weldability. Spot welding produces complex aerosols composed of metal and volatile compounds (VOCs) which can cause lung disease in workers. Male Sprague-Dawley rats (n = 12/treatment group) were exposed by inhalation to 25 mg/m3 of aerosol for 4 h/day × 8 days during spot welding of galvanized zinc (Zn)-coated steel in the presence or absence of a glue or anti-spatter spray. Controls were exposed to filtered air. Particle size distribution and chemical composition of the generated aerosol were determined. At 1 and 7 days after exposure, bronchoalveolar lavage (BAL) was performed to assess lung toxicity. The generated particles mostly were in the submicron size range with a significant number of nanometer-sized particles formed. The primary metals present in the fumes were Fe (72.5%) and Zn (26.3%). The addition of the anti-spatter spray and glue did affect particle size distribution when spot welding galvanized steel, whereas they had no effect on metal composition. Multiple VOCs (e.g., methyl methacrylate, acetaldehyde, ethanol, acetone, benzene, xylene) were identified when spot welding using either the glue or the anti-spatter spray that were not present when welding alone. Markers of lung injury (BAL lactate dehydrogenase) and inflammation (total BAL cells/neutrophils and cytokines/chemokines) were significantly elevated compared to controls 1 day after exposure to the spot welding fumes. The elevated pulmonary response was transient as lung toxicity mostly returned to control values by 7 days. The VOCs or the concentrations that they were generated during the animal exposures had no measurable effect on the pulmonary responses. Inhalation of galvanized spot welding fumes caused acute lung toxicity most likely due to the short-term exposure of particles that contain Zn. [Description provided by NIOSH]
• Subjects:
  Aerosols Laboratories Occupational Health Respiratory System Safety Toxicology Volatile Organic Compounds Welding
• Keywords:
  Author Keywords: Aerosol Generation Exposure Assessment Inhalation Laboratory Animals Methyl Methacrylate Particle Size Analysis Resistance Spot Welding Ultrafine Particles VOCs Volatile Organic Compounds Welding Fumes Zinc

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• ISSN:
  2214-7500
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; RHD - Respiratory Health Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  123-133
• Volume:
  4
• NIOSHTIC Number:
  nn:20049470
• Citation:
  Toxicol Rep 2017 Feb; 4:123-133
• Contact Point Address:
  J.M. Antonini, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
• Email:
  jga6@cdc.gov
• CAS Registry Number:
  2-Propenoic acid, 2-methyl-, methyl ester (CAS RN 80-62-6) ; Zinc (CAS RN 7440-66-6)
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Construction ; Healthcare and Social Assistance ; Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Toxicology Reports
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:fb0f33272635fc0dc071402778108577535c038a579eb95deb3e92d6bc4c9275017a418a3757de0e89debd42952a7e70f529929d3fba37e0ec20107544b1ebde
• Download URL:
  https://stacks.cdc.gov/view/cdc/203913/cdc_203913_DS1.pdf
• File Type:
  [PDF - 3.64 MB ]