title: Development and characterization of a resistance spot welding aerosol generator and inhalation exposure system.
abstract: Limited information exists regarding the health risks associated with inhaling aerosols that are generated during resistance spot welding of metals treated with adhesives. Toxicology studies evaluating spot welding aerosols are non-existent. A resistance spot welding aerosol generator and inhalation exposure system was developed. The system was designed by directing strips of sheet metal that were treated with an adhesive to two electrodes of a spot welder. Spot welds were made at a specified distance from each other by a computer-controlled welding gun in a fume collection chamber. Different target aerosol concentrations were maintained within the exposure chamber during a 4-h exposure period. In addition, the exposure system was run in two modes, spark and no spark, which resulted in different chemical profiles and particle size distributions. Complex aerosols were produced that contained both metal particulates and volatile organic compounds (VOCs). Size distribution of the particles was multi-modal. The majority of particles were chain-like agglomerates of ultrafine primary particles. The submicron mode of agglomerated particles accounted for the largest portion of particles in terms of particle number. Metal expulsion during spot welding caused the formation of larger, more spherical particles (spatter). These spatter particles appeared in the micron size mode and accounted for the greatest amount of particles in terms of mass. With this system, it is possible to examine potential mechanisms by which spot welding aerosols can affect health, as well as assess which component of the aerosol may be responsible for adverse health outcomes.
authors.affiliation: Health Effects Laboratory Division, National Institute for Occupational Safety and Health , Morgantown, WV , USA.
authors.forename: Aliakbar
authors.initials: A
authors.lastname: Afshari
authors.forename: Patti C
authors.initials: PC
authors.lastname: Zeidler-Erdely
authors.forename: Walter
authors.initials: W
authors.lastname: McKinney
authors.forename: Bean T
authors.initials: BT
authors.lastname: Chen
authors.forename: Mark
authors.initials: M
authors.lastname: Jackson
authors.forename: Diane
authors.initials: D
authors.lastname: Schwegler-Berry
authors.forename: Sherri
authors.initials: S
authors.lastname: Friend
authors.forename: Amy
authors.initials: A
authors.lastname: Cumpston
authors.forename: Jared L
authors.initials: JL
authors.lastname: Cumpston
authors.forename: H Donny
authors.initials: HD
authors.lastname: Leonard
authors.forename: Terence G
authors.initials: TG
authors.lastname: Meighan
authors.forename: David G
authors.initials: DG
authors.lastname: Frazer
authors.forename: James M
authors.initials: JM
authors.lastname: Antonini
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D000336:Aerosols; D000395:Air Pollutants, Occupational / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D000830:Animals, Laboratory; D001273:Atmosphere Exposure Chambers; D057205:Automation, Laboratory; D005390:Fires; D019570:Inhalation Exposure / Q000009:adverse effects*; D008670:Metals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D009314:National Institute for Occupational Safety and Health, U.S.; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry / Q000633:toxicity; D013232:Steel / Q000737:chemistry; D018675:Toxicity Tests / Q000295:instrumentation*; D014481:United States; D055549:Volatile Organic Compounds / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D014896:Welding / Q000379:methods
chemical_list: D000269:Adhesives; D000336:Aerosols; D000395:Air Pollutants, Occupational; D008670:Metals; D052638:Particulate Matter; D055549:Volatile Organic Compounds; D013232:Steel
keywords: Aerosol generators; fumes; gases; inhalation; resistance spot welding