title: Modern dosimetric tools for (60)Co irradiation at high containment laboratories.
abstract: OBJECTIVE
  To evaluate an innovative photo-fluorescent film as a routine dosimetric tool during (60)Co irradiations at a high containment biological research laboratory, and to investigate whether manufacturer-provided chamber exposure rates can be used to accurately administer a prescribed dose to biological specimens.
  
  
  METHODS
  Photo-fluorescent, lithium fluoride film dosimeters and National Institutes of Standards and Technology (NIST) transfer dosimeters were co-located in a self-shielded (60)Co irradiator and exposed to γ-radiation with doses ranging from 5-85 kGy. Film dose-response relationships were developed for varying temperatures simulating conditions present when irradiating infectious biological specimens. Dose measurement results from NIST transfer dosimeters were compared to doses predicted using manufacturer-provided irradiator chamber exposure rates.
  
  
  RESULTS
  The film dosimeter exhibited a photo-fluorescent response signal that was consistent and nearly linear in relationship to γ-radiation exposure over a wide dose range. The dosimeter response also showed negligible effects from dose fractionization and humidity. Significant disparities existed between manufacturer-provided chamber exposure rates and actual doses administered.
  
  
  CONCLUSIONS
  This study demonstrates the merit of utilizing dosimetric tools to validate the process of exposing dangerous and exotic biological agents to γ-radiation at high containment laboratories. The film dosimeter used in this study can be utilized to eliminate potential for improperly administering γ-radiation doses.
authors.affiliation: Radiation Safety Department, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH, Rocky Mountain Laboratories , Hamilton, MT 59840, USA. twardoskib@niaid.nih.gov
authors.forename: Barri
authors.initials: B
authors.lastname: Twardoski
authors.forename: Heinz
authors.initials: H
authors.lastname: Feldmann
authors.forename: Marshall E
authors.initials: ME
authors.lastname: Bloom
authors.forename: Joe
authors.initials: J
authors.lastname: Ward
mesh_terms: D002138:Calibration; D003037:Cobalt Radioisotopes; D005373:Film Dosimetry / Q000379:methods* / Q000592:standards; D005720:Gamma Rays; D007753:Laboratories; D015203:Reproducibility of Results; D012106:Research; D018570:Risk Assessment / Q000379:methods / Q000592:standards; D017751:Safety Management / Q000379:methods / Q000592:standards; D012680:Sensitivity and Specificity
chemical_list: D003037:Cobalt Radioisotopes