Dosimetry and Bioassay Requirements


DOSIMETRY

Personnel radiation dosimetry is required for all persons that are likely to receive doses above 10 percent of the radiation protection limits or those who may enter a high radiation area. Finger dosimetry should be used by personnel routinely handling greater than 1.0 mCi of gamma emitters or beta emitters with beta energies above 0.2 MeV.

Workers assigned personnel radiation badges shall wear them when working with radiation sources. If a Radiation Worker (RW) is assigned dosimtery from the university which is used to monitor work related occupational exposure to ionizing radiation, and plans to receive a diagnostic or therapeutic treatment with RAM (radiopharmaceuticals), then the RW must inform the RSS prior to the treatment so the RSS can advise the RW on the particulars associated with how to continue to monitor occupational exposure without it being affected by the radiation from the treatment or scan. 

If pregnancy is declared, then the pregnant worker will be issued an embryo/fetus badge, similar to the badge she is already wearing, for use in monitoring the external exposure levels to the fetus. Declaration of pregnancy is not required. Need for monitoring internal dose to the fetus will be assessed based on the pregnant worker's possibility of having intake of radioactive materials.  The results of her monitoring will be reported on a monthly basis throughout the remainder of the gestation period.  Consult the assigned Health Physicist (HP) with any questions regarding the procedure.

 

Exposure History

A permanent exposure history of all monitored personnel is maintained by the RSS.  Annual dosimetry reports are provided for those individuals assigned personnel dosimetry that have been exposed to occupation radiation greater than 100 mrem/yr.  Anyone who is monitored by dosimetry can ask to see a copy of their record at any time.

 

BIOASSAYS

 

Iodine

A bioassay shall be performed immediately when greater than 0.100 µCi of material may have entered the body through absorption, ingestion, injection or other accidental deposition.

A bioassay shall be performed within 10 days for the following:

  • When greater than 1.0 mCi of material is processed in an open room,
  • When greater than 10.0 mCi of material is processed in an operating fume hood.
 
Tritium

A bioassay shall be performed within 7 days for the following:

  • When greater than 0.250 mCi of material may have entered the body through absorption, ingestion, injection or other accidental deposition,
  • When greater than 10 mCi of material is processed in an open room, or
  • When greater than 100 mCi of material is processed in an operating fume hood.

 

Page last updated on June 7, 2019.