title: Engineered carbonaceous nanomaterials manufacturers in the United States: workforce size, characteristics, and feasibility of epidemiologic studies.
abstract: OBJECTIVE
  Toxicology studies suggest that carbon nanotube (CNT) exposures may cause adverse pulmonary effects. This study identified all US engineered carbonaceous nanomaterial (ECN) manufacturers, determined workforce size and growth, and characterized the materials produced to determine the feasibility of occupational ECN exposure studies.
  
  
  METHODS
  Eligible companies were identified; information was assembled on the companies and nanomaterials they produced; and the workforce size, location, and growth were estimated.
  
  
  RESULTS
  Sixty-one companies manufacturing ECN in the United States were identified. These companies employed at least 620 workers; workforce growth was projected at 15% to 17% annually. Most companies produced or used CNT. Half the eligible companies provided information about material dimensions, quantities, synthesis methods, and worker exposure reduction strategies.
  
  
  CONCLUSIONS
  Industrywide exposure assessment studies appear feasible; however, cohort studies are likely infeasible because of the small, scattered workforce.
authors.affiliation: Division of Surveillance, Hazard Evaluations, and Field Studies, Industrywide Studies Branch, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, MS-R15, Cincinnati, OH 45226, USA. zcg3@cdc.gov
authors.forename: Mary K
authors.initials: MK
authors.lastname: Schubauer-Berigan
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Dahm
authors.forename: Marianne S
authors.initials: MS
authors.lastname: Yencken
mesh_terms: D015340:Epidemiologic Research Design; D037741:Fullerenes / Q000600:supply & distribution; D006108:Graphite / Q000600:supply & distribution; D006801:Humans; D057139:Nanofibers / Q000600:supply & distribution; D036103:Nanotechnology / Q000706:statistics & numerical data*; D037742:Nanotubes, Carbon / Q000600:supply & distribution; D011795:Surveys and Questionnaires; D014481:United States; D000078329:Workforce
chemical_list: D037741:Fullerenes; D037742:Nanotubes, Carbon; D006108:Graphite