The purpose of this guide is to establish a uniform protocol for the placement of radiation dosimeters throughout all departments utilizing x-ray and fluoroscopy at the University of Iowa Hospitals and Clinics. The definitions below list each type of dosimeter along with the area it is to be worn and the significance of each reading.
P1 - Whole Body dosimeter -
The P1 dosimeter provides a measurement of the deep (DDE) and shallow (SDE) radiation dose equivalent received by the whole body when used in conjunction with the P8 collar whole body dosimeter. A black body icon (as shown on the left) identifies the P1 whole body dosimeter. Wear this dosimeter on the torso at waist or chest level under the protective lead apron.
P8 - Collar Whole Body Dosimeter –
The P8 dosimeter provides a comparative measurement of the deep (DDE), shallow (SDE), and lens of the eye (LDE) radiation dose equivalent when used in conjunction with the P1 whole body dosimeter. A red body icon (as shown on the left) identifies the P8 collar whole body dosimeter. This dosimeter is to be worn at the collar level, external to the lead apron and thyroid shield, if one is used.
U3 - Ring Dosimeter –
The U3 ring dosimeter provides a measurement of the extremity radiation dose equivalent received by the lower arm and hand. This dosimeter is to be worn under the protective latex glove on a finger of the hand likely to receive the highest radiation exposure.
The following table lists the regulatory and external dose limits against which personnel dosimeter results are compared.
State of Iowa Limits
|Type of Exposure||Annual Limit|
|Whole Body Deep Dose Equivalent (DDE) which includes: head, trunk, active blood forming organs & gonads
|| 5000 mrem/year total
|Whole Body Shallow Dose Equivalent (SDE) which includes: skin
||50000 mrem/year total
|Lens of Eye Dose Equivalent (LDE)
||15000 mrem/year total|
||50000 mrem/year total
|Limit for person completing pregnancy declaration
|| 500 mrem/gestation period
UI ALARA Limits (Monthly)
|Area of Body||ALARA Action Level I||ALARA Action Level II|
|Whole Body Deep Dose Equivalent (DDE)||200 mrem||400 mrem|
|Whole Body Shallow Dose Equivalent (SDE)||2000 mrem||4000 mrem|
|Lens of Eye Dose Equivalent (LDE)||600 mrem||1200 mrem|
|Extremities||2000 mrem||4000 mrem|
PLEASE NOTE: Wearing your dosimeters in accordance with the guidelines given above is required in order to obtain an accurate assessment of your radiation dose. When not in use, store your dosimeters in an area that will not be exposed to radiation in excess of background levels.
In addition: All personnel who are in the procedure room during x-ray fluoroscopy are required by regulation to wear a protective apron (0.25 mm lead equivalent) and a dosimeter. Protective glasses and thyroid shields are also highly recommended for fluoroscopy use. Please contact Environmental Health & Safety at 335-8501 with any questions or concerns.