Monitoring Internal and External Exposure

Personnel Monitoring is the measurement of personnel dose through the use of personnel dosimetry, air samples, bioassays, radiation surveys or any combination of the above with related calculations. EHS can monitor the internal and external exposure of RWs by utilizing dosimeters, bioassays, and more.

Dosimetry may be required for Radiation Workers depending on the isotope, activities, and use types. If you are unsure whether you will need dosimetry, contact your assigned HP or speak with your Authorized User. If you do need to wear dosimetry, fill out the Dosimetry Application found under the Rad Forms link to the right. On this page, you will also find resources and instructions for the following:


How to fill out the Dosimetry Application

Dosimetry can be requested by filling out the online Dosimetry Application through EHS Assistant. A tutorial video titled "Fill out the Dosimetry Application" is availabe on the EHSA Tutorial videos page. The information entered in the tutorial video is for example only. You will need to select your own information including your dosimetry coordinator. If you are unsure who that may be, contact the RSS. All digital forms must be filled out by the requesting individual because they require a digital signature.


How to Wear your Dosimeter(s)

  • Whole body badges should be worn as close to the midline of the body as possible between the waist and neck.
  • X-ray users may be assigned one or two whole body badges.
    • If assigned one whole body badge, it shall be worn outside the protective lead apron.
    • If assigned two whole body badges, one shall be worn under the lead apron and the second one shall be work outside the apron at the collar.  These dosimeters are marked as to the correct location and it is important to be sure they are used correctly.
  • Finger or wrist dosimetry should be worn with the detector medium facing towards the radiation source. 
  • Personnel radiation dosimetry is to be worn only by the worker assigned the dosimetry.
  • It is not the intent of EHS to interfere with any medical treatments or scans that might be medically necessary, but we do need to know if you are to receive a treatment that might impact the accuracy of your dosimeter.
  • Dosimetry issued by EHS is also not to be exposed to other sources of radiation at other facilities without consulting with EHS. This is also true for X-rays i.e. don’t wear your work related dosimeter to a personal radiology scan e.g. doctor’s visit.     
  • Do not store your personal dosimeter close to sources of radiation. For example, if you leave them on your lab coat or desk drawer, make for sure they are reasonably away from sources of ionizing radiation.  In other words don’t store you dosimeter near Radioactive Waste storage containers.
  • Ensure that you are wearing your assigned dosimeter, wearing it correctly as identified on the dosimeter itself, “Chest”, “Collar”, and wearing the correct color and date on dosimeter associated with wear period.  If you questions concerning your dosimetry contact your assigned HP at 882-7018.


General Bioassay Information and Scheduling

A bioassay is the determination of kinds, quantities or concentrations, and, in some cases, the locations of radioactive materials in the human body, whether by direct measurement (in vivo counting) or by analysis and evaluation of materials excreted or removed from the human body.

Generally, bioassays should be performed within seven (7) days after use of specified quantities of tritium (H-3) or within ten (10) days of specified quantities of radioiodines.  The activity level is determined by the way in which the isotopes are used i.e. either in fume hoods or in open bench conditions. 

Some isotopes may be volatile depending on their chemical structure. The Safety Data Sheets (SDS) should be consulted to determine airborne hazards for the specific chemical compounds in question involved in the use of the radioactive material reactions in question.  The SDS available on the EHS website may provide some guidance as to the volatility of the compounds and/or solutions but will not specifically address the radioactive properties.

If you have questions regarding the need for bioassays or to schedule one, contact your assigned HP at 882-7018.  Bioassays are conducted routinely throughout campus and one can usually be scheduled to meet your needs. Describe the isotope, activity and date the material was handled within the time frames mentioned above.


Declaring Pregnancy and Fetal Dosimeters

A pregnant individual may wish to declare pregnancy through EHS. This can be done by filling out the online Pregnancy Declaration Form available through EHS Assistant. A tutorial video titled "Fill out the Pregnancy Declaration Form" is available on the EHSA Tutorials page. If an individual decides to declare pregnancy, the individual will be provided with a fetal dosimeter which must be worn at waist level. The RSS will monitor the fetal dosimeter doses on a monthly basis an ensure that the fetal dose remains less than 50 mrem per month and less than 500 mrem during the entire gestation period. These dose limits are significantly less than the occupational Radation Worker limits. Because of the latter limit, it is important to include the conception date on the pregnancy declaration form. If an individual decides to not declare their pregnancy, they may still request a fetal dosimeter. However, the fetal dosimeter limits will not be reduced. Any pregnant individual may request additional counseling and training with a member of the RSS. Fetal dosimeters are typically shipped to the dosimetry coordinator along with all other dosimeters. However, individuals can pick up the monthly fetal dosimeters from the RSS directly if needed.


How to access Exposure History and the NRC Form 5

The following are instructions on accessing your exposure history and downloading the NRC Form 5 which may be required for a new employer.

  1. Log into the Form 5 EHS Assistant portal
  2. Enter your University Pawprint and associated password, and click the "Sign In" button.
  3. The "Individual Worker History" webpage will open. Select and click the "Dosimetry Exposure" tab at the top of the page next to "Training". This will display all current exposure history data.
  4. To view and download your NRC Form 5
    1. Click on your participant ID number located under the "Participant ID" cell and the line will highlight in red.
    2. Select "Dosimetry Exposure Reports" from the drop-down menu.
    3. Select "NRC Form 5 by Participant," and a pop-up box will appear.
    4. In the pop-up box, enter the calendar year of interest.
    5. Click "View Report"; the report will open in a new window with a pdf NRC Form 5
    6. To print the report, click the printer icon at the top right of the report window.
    7. To exit the report window, click the "x" on the internet menu tab. This will return you to the "Individual Worker History" webpage.
  5. To log out of the "Individual Worker History" web page, click the "Logout" ion at the web page's top right.


Page last updated on December 13, 2022.