title: Issues in the development of epidemiologic studies of workers exposed to engineered nanoparticles.
abstract: OBJECTIVE
  Capitalizing on phenomena at the nanoscale may present great benefits to society. Nevertheless, until the hazards and risks of engineered nanoparticles are determined, the technological products and advances of nanotechnology may be impeded by the societal concerns. Although animal data provide the necessary first step in hazard and risk assessment, ultimately epidemiological studies will be required, especially studies of workers exposed to engineered nanoparticles. It may be too soon to conduct informative epidemiological studies but it is now appropriate to identify issues that will be pertinent and prepare strategies to address them.
  
  
  METHODS
  The published scientific literature on incidental and engineered nanoparticles and air pollution were reviewed to identify issues in the conduct of epidemiological studies of workers exposed to engineered nanoparticles.
  
  
  RESULTS
  Twelve important issues were identified-the most critical pertaining to particle heterogeneity, temporal factors, exposure characterization, disease endpoints, and identification of the study population.
  
  
  CONCLUSIONS
  Consideration of these issues provides the foundation for initiating epidemiologic research on workers exposed to engineered nanoparticles.
authors.affiliation: Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226, USA. PSchulte@cdc.gov
authors.forename: Paul A
authors.initials: PA
authors.lastname: Schulte
authors.forename: Mary K
authors.initials: MK
authors.lastname: Schubauer-Berigan
authors.forename: Candis
authors.initials: C
authors.lastname: Mayweather
authors.forename: Charles L
authors.initials: CL
authors.lastname: Geraci
authors.forename: Ralph
authors.initials: R
authors.lastname: Zumwalde
authors.forename: John L
authors.initials: JL
authors.lastname: McKernan
mesh_terms: D000395:Air Pollutants, Occupational; D016021:Epidemiologic Studies; D006801:Humans; D007221:Industry; D053758:Nanoparticles; D016273:Occupational Exposure; D016730:Program Development; D012107:Research Design
chemical_list: D000395:Air Pollutants, Occupational