title: Carbon nanotube risk assessment: implications for exposure and medical monitoring.
abstract: OBJECTIVE
  Quantitative risk estimates using toxicology data provide information for risk management to protect workers with potential exposure to carbon nanotubes (CNTs).
  
  
  METHODS
  Dose-response data from subchronic inhalation studies in rats were used in benchmark dose modeling. Dose was airborne mass concentration of multiwalled CNTs. Responses included pulmonary inflammation, lipoproteinosis, and fibrosis.
  
  
  RESULTS
  Estimated human-equivalent concentrations to the rat lowest observed adverse effect levels were similar to some workplace airborne concentrations of CNTs. Working lifetime risk estimates of early-stage adverse lung effects were more than 10% at the limit of quantification (7 μg/m³) of the National Institute for Occupational Safety and Health analytical method for measuring CNT airborne concentrations.
  
  
  CONCLUSIONS
  Exposure monitoring and control are the primary occupational health measures to protect workers from potential exposure to CNT. Medical monitoring for early detection of occupational respiratory diseases may also be warranted.
authors.affiliation: Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226, USA. ekuempel@cdc.gov
authors.forename: Eileen D
authors.initials: ED
authors.lastname: Kuempel
mesh_terms: D000395:Air Pollutants, Occupational / Q000009:adverse effects / Q000592:standards*; D000818:Animals; D015769:Granuloma, Respiratory Tract / Q000139:chemically induced; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects*; D037742:Nanotubes, Carbon / Q000633:toxicity*; D016273:Occupational Exposure / Q000009:adverse effects / Q000592:standards*; D011159:Population Surveillance; D011658:Pulmonary Fibrosis / Q000139:chemically induced; D051381:Rats; D018570:Risk Assessment
chemical_list: D000395:Air Pollutants, Occupational; D037742:Nanotubes, Carbon