Radiation Dosimetry
Care of Dosimeters
Understanding Your Dosimeter

Radiation Dosimetry

Research Laboratory & Safety Services (RLSS) provides radiation dosimetry for the University of Arizona. RLSS evaluates individuals working with radiation to determine if radiation monitoring is required. This determination is done when an individual responds to an online invitation from the RLSS.

Dosimeters are worn only at the facility or department for which they were issued. They are not to be worn at secondary locations of employment. Request a dosimeter for each place of employment.

There is a $25.00 fee issued when dosimeters are late or missing according to the Unreturned Dosimeter Policy. The $25.00 fee is waived if the Dosimeter Notice is completed and returned to RLSS within 10 days of receipt.


  • Bioassays are used to detect the internal presence of radioactivity in the body. They are not used for health screening or drug testing. Bioassays do not measure x-ray radiation.
  • Bioassays can be requested by an individual or Approval Holder and provided at no cost to the Radiation Worker.
  • Bioassays can be required as an Approval condition or for pregnancy declaration.
  • Two types of Bioassays performed by Research Laboratory & Safety Services are:
    • Urine bioassay can detect radioactivity in urine. A urine sample is provided to Research Laboratory & Safety Services for analysis.
    • Thyroid bioassay is a non-invasive procedure performed in Research Laboratory & Safety Services to detect radioactivity in the thyroid. This procedure will require a small amount of time to scan for possible thyroid uptake of I-125 or I-131 nuclides.

Contact Research Laboratory & Safety Services at 626-6850 or to schedule a bioassay.

Care of Radiation Dosimeters

  • Store dosimeters away from possible radiation exposure.
  • Immersion in water, puncturing, or exposure to high temperature can damage and alter the reliability.
  • Whole body dosimeter:
    • Use the holder provided because exposure outside the holder can produce inaccurate reporting.
    • Do not leave your dosimeter on aprons or lab coats that are used by other individuals
  • Report any lost or damaged dosimeter immediately to Research Laboratory & Safety Services, 626-6850. A replacement will be provided.
  • Check with your departmental dosimeter coordinator for exchange process and location.


Research Laboratory & Safety Services provides pregnancy counseling for radiation workers. This is a voluntary program available to all University of Arizona radiation workers. Counseling is provided for radiation workers who are pregnant, suspect they may be pregnant, or who are planning a pregnancy.

The appointment will include a review of their work situation, an evaluation of monitoring requirements, and a discussion of the risks of radiation exposure during pregnancy. Formal declaration of one's pregnancy is voluntary and can be confidential.  Please contact Research Laboratory & Safety Services at 626-6850 to arrange for an appointment.

Understanding Your Dosimeter 


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