Radiation Safety

MSC 08-4560
1 University of New Mexico
Albuquerque, NM 87131

Physical Location:
RHFH (Fitz Hall) - Room B89

Phone: 505-925-0743

Dosimetry

The UNM Radiation Control Committee has determined that any UNM employee who may be occupationally exposed to ionizing radiation shall receive training and, where indicated, a personnel dosimeter. 

 What is a Dosimeter?

Personnel monitoring devices called dosimeters are used to detect and measure external radiation exposures to occupationally exposed workers. Dosimeters are integrating detectors; that is, they accumulate the radiation dose and give off an amount of light (when properly treated) which is proportional to that dose. The energy absorption properties of dosimeters are designed to be very similar to tissue, so they are very effective as personnel dosimeters. These devices are used to measure exposures from x-ray, gamma ray and high energy beta particles. Dosimeters are not suitable for measuring exposures to low energy beta particles or alpha particles. 

Who Should Wear a Dosimeter?

Dosimeters are issued to personnel following a review of badge application forms. The Radiation Safety Office will determine if badges are required following an assessment of the applicant’s work scenario relative to radiation source use, and the likelihood of that individual receiving an occupational dose in excess of the badging requirements.

Workers are required to be badged when meeting one or more of the following conditions:

  • Adults likely to receive in 1 year from sources external to the body, a dose in excess of 10 percent of the limits or; 
  • Individuals entering a high radiation area in which radiation levels could result in a dose equivalent in excess of 100 mrem in 1 hour at 30 centimeters or; 
  • Individuals entering a very high radiation area in which radiation levels could result in an absorbed dose in excess of 500 rads in 1 hour at 1 meter or; 
  • The worker operates a medical or industrial fluoroscopic device or is directly involved in the set-up or operational support of such a device. This excludes personnel who may have a clinical need to occasionally access a room in which fluoroscopy equipment is in use, when they are continuously supervised by authorized personnel, maintain at least 6 feet of distance from the fluoroscopy device, and have no direct involvement in its use or; 
  • As deemed appropriate by the Radiation Safety Office. 

What is a Badge Coordinator?

For each department, research lab, or location of use of ionizing radiation, there is a person assigned to be the liaison between that location and the Radiation Safety Office. This can be a department administrative assistant, a charge nurse or a co-worker. This person will help you with your enrollment process, provide your new dosimeter during exchanges, collect your old dosimeter for return to Radiation Safety, and otherwise be the point of contact for you regarding dosimeters at your work location. However, you are always able to contact the Radiation Safety Office with questions. 

How do I Get a Dosimeter?

Dosimeters are issued to personnel following successful completion of the training module HSC 181 “Personnel Radiation Monitoring with Radiation Badges” on UNM’s Learning Central training website, https://learningcentral.health.unm.edu, and completion of required paperwork. Contact your badge coordinator or Radiation Safety, (505) 975-0743, for the enrollment packet. The training module covers topics that the Radiation Safety Office feels the individual needs to be aware of such as dose limits, definitions, radiation protection practices to minimize exposure, procedures used to investigate suspected exposure above established "action limits", information on the dosimetry program, training that may be required, and other related material.

Internal dosimetry will be provided upon request or when internal deposition is suspected. The mode of uptake may be inhalation, ingestion, injection or absorption. Contact the Radiation Safety Office for appropriate recommendations and/or follow-up. 

How do I know the results my dosimeter reported?

Dosimetry reports are reviewed by the Radiation Safety Officer or a designee after being received from the vendor. The reviewed reports are marked as reviewed, and then, a copy is sent to your Badge Coordinator. The Badge Coordinator is required to keep the last three years of dosimetry reports available either printed in a notebook or an electronic file that can be easily accessed by the staff. However, you can always contact the Radiation Safety Office if you have questions.