title: Exposure characterization of metal oxide nanoparticles in the workplace.
abstract: This study presents exposure data for various metal oxides in facilities that produce or use nanoscale metal oxides. Exposure assessment surveys were conducted at seven facilities encompassing small, medium, and large manufacturers and end users of nanoscale (particles <0.1 μm diameter) metal oxides, including the oxides of titanium, magnesium, yttrium, aluminum, calcium, and iron. Half- and full-shift sampling consisting of various direct-reading and mass-based area and personal aerosol sampling was employed to measure exposure for various tasks. Workers in large facilities performing handling tasks had the highest mass concentrations for all analytes. However, higher mass concentrations occurred in medium facilities and during production for all analytes in area samples. Medium-sized facilities had higher particle number concentrations in the air, followed by small facilities for all particle sizes measured. Production processes generally had the highest particle number concentrations, particularly for the smaller particles. Similar to particle number, the medium-sized facilities and production process had the highest particle surface area concentration. TEM analysis confirmed the presence of the specific metal oxides particles of interest, and the majority of the particles were agglomerated, with the predominant particle size being between 0.1 and 1 μm. The greatest potential for exposure to workers occurred during the handling process. However, the exposure is occurring at levels that are well below established and proposed limits.
authors.affiliation: National Institute for Occupational Safety and Health, Division of Surveillance, Hazard Evaluations, and Field Studies, Cincinnati, Ohio 45226, USA. bcurwin@cdc.gov
authors.forename: Brian
authors.initials: B
authors.lastname: Curwin
authors.forename: Steve
authors.initials: S
authors.lastname: Bertke
mesh_terms: D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D053768:Metal Nanoparticles / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D010087:Oxides / Q000032:analysis*; D017132:Workplace
chemical_list: D010087:Oxides