Federal and state regulations require the UW to monitor the radiation dose to employees who may be exposed to radiation as part of their job duties.
Employees whose job duties result in exposure to radiation may be assigned dosimeters to monitor their exposure. Depending on the source and amount of exposure, this may include whole body badges, rings or both. Individual badges are collected monthly or quarterly, and the reported doses are reviewed by an EH&S Radiation Safety team member.
Bioassays may be required of UW employees who use large amounts of radioiodine or tritium, to monitor for any uptake. The As Low as Reasonably Achievable (ALARA) principle ensures individual doses are monitored closely, and helps ensure employees are not receiving excess radiation exposure from the jobs they perform.
What you need to know
The federal government has defined annual dose limits for radiation workers as follows:
| Body part | Dose limit |
|---|---|
| Whole body | 5,000 mrem |
| Lens of the eye | 15,000 mrem |
| Extremities, shallow, any single organ | 50,000 mrem |
| Declared pregnant worker (9 months) | 500 mrem |
Workers are required to wear dosimetry if they are likely to receive at least 10 percent of the annual dose limit.
EH&S is charged with enforcement of the ALARA principle. The Radiation Safety Committee and EH&S’s Radiation Safety team have determined quarterly dose levels that will trigger an ALARA investigation.
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Level I may trigger an investigation, depending on the individual’s normal job duties and dose history.
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Level II automatically triggers an investigation by a health physicist to determine if further action needs to be taken.
| Quarterly ALARA Investigation Levels | ||
| Dose | ALARA Level 1 | ALARA Level 2 |
| Category | (mrem) | (mrem) |
| Deep | 125 | 375 |
| Deep* | 375 | 625 |
| Lens | 375 | 1125 |
| Lens* | 1125 | 1875 |
| Shallow | 1875 | 5625 |
| Extremity | 1250 | 3750 |
Dose categories with an asterisk (*) denote a higher limit for some workers as determined by the EH&S Radiation Safety team
What you can do to stay safe
Wear your dosimeter(s) properly
Whole body badges, except for fetal badges, should be worn over any protective shielding, between the collar and the belt. Fetal badges should be worn at the waist under any protective shielding. Ring badges should be worn under gloves on the hand most likely to receive the most dose.
Refer to the Dosimetry page for more information.
Return your dosimeter(s) promptly
Timely return and processing of badges assure that any concerns with a higher than expected dose can be investigated and mitigated quickly.
Report for your bioassay on time
Timely bioassay measurements assure that any abnormal readings can be addressed and investigated quickly.
Services available
EH&S provides the following services:
- Consultation on concerns regarding occupational exposure to radiation
- Issue dosimetry to monitor external exposure to radiation
- Conduct bioassays for monitoring internal exposure to radioactive material
Frequently asked questions
Refer to the Dosimetry page for information about your dosimeter.
No. Since the radionuclides are already linked to a molecule and are at such a low activity, uptake is extremely unlikely.