Research utilizing certain radioactive materials (RAM) or Radiation Producing Devices (RPD) may require issuance and use of personnel dosimetry.  Dosimetry is provided to GU researchers and staff on an as needed basis.  Radiation exposures to GU personnel are maintained well below established regulatory limits, and in keeping with ALARA principles.  Both whole body and extremity monitoring is performed.  In addition, internal monitoring (bioassay) is performed when necessary.
If you have any questions regarding your radiation exposure, please do not hesitate to contact the RSOS!

Personnel Dosimetry Procedures


Personnel monitoring is accomplished using a whole body or extremity thermoluminescent dosimeter (TLD). Personnel dosimetry is required for:

1. RAM Workers using Na-22, Rb-86, or greater than 10 millicuries, at one time, of P-32;

2. RAM Workers Performing Iodinations;

3. Approved Irradiator Operators;

4. Radiation Producing Device Users; and,

5. Any individual at the discretion of the RSOS.

Personnel monitoring devices are not required for persons working only with tritium (H-3), C-14,

S-35, or less than 100 microcuries of I-125 in pre-labeled compounds. Contact the RSOS for application forms and additional information.

Bioassay requirements are specified in each Authorization To Use Radioactive Materials, as follows:

1. All researchers using 10 millicuries or more of H-3 or P-32, at one time, must submit a baseline urine bioassay sample and routine urine bioassay samples at the frequency specified by the Radiation Safety Office.

2 All researchers performing iodinations are required to have a baseline thyroid bioassay and must have routine thyroid bioassays performed within 6 to 72 hours after each iodination.

The maximum permissible radiation exposure to the fetus from occupational exposure of the expectant mother during the entire gestation period may not exceed 500 millirem, at a rate not to exceed 50 millirem per month. The following outlines the steps that need to be followed:

1. Women who are pregnant may voluntarily inform the Authorized User and the RSO in writing by completing the NOTIFICATION OF PREGNANCY form.

2. The RSOS will evaluate personnel monitoring records, existing working conditions, types of radioactive materials and/or radiation producing devices being used and, the procedures being performed by the worker.

3. The RSOS may recommend any special precautions or actions that could be taken to ensure that the dose to the embryo/fetus is maintained ALARA.

4. The Radiation Safety Officer or his/her designee will meet with the individual to review the evaluation and discuss the risks and possible changes to any procedures that may be necessary.

5. Women who are pregnant shall not participate in iodination procedures using radioactive iodine.

Completing the Application


The application will be processed by the RSOS on the same day it arrives in the office.  The badges/rings are received from the vendor within 5 days and will be sent to you as soon as
possible.  Temporary dosimetry may be assigned when necessary, until permanent dosimetry arrives.

NOTE:  If your application is illegible or incomplete, the dosimetry will be ordered and the application returned to you for correction. 

  1. Write (Print) legibly.
  2. Complete ALL information.
  3. Indicate ALL sources of ionizing radiation which you  will  be using or encountering in your work.  If you will be working with only C-14, S-35 and/or H-3 you do not need dosimetry.
  4. Indicate the dosimetry service that you believe is appropriate for your work:
    • Whole Body (chest); - All personnel who require dosimetry will receive this badge.
    • Collar - If you are working with x-ray machines or gamma emitters and wear a lead apron, this badge is to be worn at the collar on the outside of the apron or as otherwise directed by the RSO.
    • For use when handling Rb-86, Na-22, or P-32 in quantities greater than 1 mCi.  Indicate Size:  S (size 5), M (size 8), L (size 11)
  5. All personnel MUST be briefed by their Authorized User in radiation safety precautions to be observed in the performance of their duties and indicate this on the application.
  6. All personnel MUST read “Instructions Concerning Prenatal Radiation Exposure, NRC Reg. Guide 8.13" and sign the statement on the application.
  7. If you were previously assigned a radiation badge at another facility, complete the Employment History section of the application.

The Radiation Badge and Its Use

Dosimetry is furnished to you in accordance with the existing Federal and District of Columbia regulations, which require that you wear it when in areas where potential radiation exposure may occur. The monthly reports regarding your exposure become a part of your permanent record and are open for your inspection. The dosimetry liaison in your department is furnished with copies of these reports.




DO: Always wear your dosimeter when working in radioactive materials areas.

Wear the dosimeter on the chest portion of your body (e.g., on your breast pocket). Under some circumstances the Radiation Safety Office Staff (RSOS) may direct otherwise.

If you perform fluoroscopy procedures you should have two badges assigned. One is for the collar outside the lead apron. The chest badge should be worn under the lead at chest level.

A new badge is issued at the beginning of each month. IT IS IMPERATIVE THAT YOU TURN IN YOUR OLD BADGE DURING THE FIRST WEEK OF THE FOLLOWING MONTH so that it can be processed.

DO NOT: Take your dosimeter home with you or leave it in a place where it could possibly be exposed to radiation in your department or laboratory.

Wear your dosimeter when you are having a x-ray or fluoroscopy procedure (this includes dental x-rays). Radiation received from medical exposures is not considered occupational.

Loss or damage of the dosimeter packet, or ring must be reported to the RSOS.

Upon any change in status i.e., transfer to another department, name change, leave scheduled for longer than 3 months, etc., notify the RSOS.