Policy on Occupational Radiation Dose:

The Radiation Safety Division of Washington University in St. Louis’ Environmental Health and Safety Department maintains the Occupation Radiation Dose Monitoring Program for Washington University in St. Louis, Barnes-Jewish Hospital, St. Louis Children’s Hospital, and the St. Louis College of Pharmacy.

The Occupational Radiation Dose Monitoring Program is maintained in accordance with relevant regulatory and accreditation requirements. Relevant regulatory requirements include those from the US Nuclear Regulatory Commission (NRC), the Missouri Radiation Control Program (MRCP), the US Department of Labor Occupational Safety and Health Administration (OSHA), and the US Department of Health and Human Services Centers for Medicare and Medicaid Services (CMS). Relevant accreditation requirements include those from The Joint Commission (TJC) and the American College of Radiology (ACR).

The links below provide information and help regarding your involvement with the program.

Radiation Monitoring Device Assignment Requirements

While the NRC requires us to monitor anyone who is likely to receive in excess of 10% of the federal radiation exposure limits, or 500 mrem per year, we in fact provide dosimeters at much lower levels.  We monitor anyone likely to receive just 100 mrem per year.  Prospective evaluations are done at the time every authorization is initiated, renewed or amended to ensure that anyone who needs dosimetry is provided with it.  If you will not use radioactive materials at levels high enough for elevated potential exposure, you will not be required to wear dosimetry.  In many cases, it will be provided to individuals below these threshold amounts at their request.

Individuals working around x-ray machines capable of delivering significant amounts of radiation dose are also issued dosimeters.  This category includes fluoroscopy machines, typical diagnostic x-ray machines (excluding bone densitometers), and x-ray diffraction machines.  Electron microscopes and bone densitometers do not emit significant radiation doses. 

Dosimeters are also provided to all declared pregnant radiation workers.

Bioassay Requirements

Any individual who uses greater than 1 mCi of volatile iodine products per experiment is required to submit to a thyroid bioassay during every calendar quarter in which the material was used.  Radiation Safety tracks the need for thyroid bioassay and, should one be necessary, will come to your lab to obtain it.  The process is simple – you will simply hold a probe (much like a regular survey meter) to your thyroid for one minute.  A background reading must also be taken.

Urine Sample Requirements

Vials containing high amounts of activity can be an exposure issue simply upon opening, so urine bioassay might be required of anyone opening such vials.  If this is necessary, a notice will be sent with the package.  This rarely happens at Washington University.  It is much more likely that someone will actually use a relatively large amount of material out of one or more lower activity vials in a single experiment.  The level for urine bioassay differs depending on whether the material is used in a glovebox, a fumehood, or in open-air on a benchtop.   Please refer to Chapter 10 of the Radiation Safety Manual for amounts requiring urine bioassay.