Radiation monitoring is provided to UNM/UH personnel according to the provisions of the New Mexico Radiation Protection Regulations (Subpart 4).  Personnel monitoring devices called thermoluminescent dosimeters (TLDs) are used to detect and measure external radiation exposures to occupationally exposed workers.  TLDs are integrating detectors, that is they accumulate the radiation dose and give off an amount of light (when properly heated) which is proportional to that dose. The energy absorption properties of TLDs are very similar to tissue so they are used widely as personnel dosimeters. These devices are used to measure exposures from x-ray, gamma ray and high-energy beta particles.  TLDs are not suitable for measuring exposures to low energy beta particles or alpha particles.

Dosimeters are issued to personnel following an orientation and completion of required paperwork.  The worker should call the Radiation Safety Division (277-2753) to schedule a time for the orientation.
According to NM Radiation Protection Regulations, Subpart 10, all individuals likely to receive an occupational dose:

• shall be kept informed of the storage, transfer, or use of sources of radiation in  the licensee’s work place;
• shall be instructed in the health protection problems associated with exposure to such radioactive materials or radiation, in precautions or procedures to minimize exposure, and in the purposes and functions of all protective devices employed and;
• shall be instructed in, and instructed to observe, to the extent within the worker’s control, the applicable provisions of the Radiation Protection Regulations.

The orientation will cover topics that the Radiation Safety Division feels the individual needs to know.  Topics will included: dose limits, definitions, radiation protection practices to minimize exposure, procedures used to investigate suspected exposure above established "action levels", information on the dosimetry program, training that may be required, and other related material.

As stated in NM Radiation Protection Regulations, Subpart 4, the requirements for individual monitoring of external occupational exposures are:

1. individuals likely to receive, in 1 year from sources external to the body, a dose in excess of 10 percent of the applicable limits;
2. 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;
3. 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;
4. individuals working with medical fluoroscopic equipment.
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.  Individuals issued dosimetry are required to wear it while working in a restricted area or performing radiation related activities.
 Questions/Answers about Radiation Dosimetry

• All personnel who may be occupationally exposed to ionizing radiation at levels sufficient to demonstrate compliance with the occupational dose limits should wear a dosimeter.
• Individuals who may be users of high energy beta and gamma emitting radionuclides, neutron sources and ionizing radiation emitting machines.
• Personnel defined by the New Mexico Radiation Protection Regulations.

 To aid in your protection against ionizing radiation.

To keep a record of your accumulated occupational exposures to sources of ionizing radiation

To maintain your radiation exposure levels “as low as reasonably achievable” (ALARA).

• While working with radioactive materials or machines previously described.
• When visiting or working in any area where radioactive materials or radiation emitting machines as previously described are used.
• Do not wear it during personal diagnostic or therapeutic medical procedures. UNM radiation dosimetry is used strictly to ascertain YOUR OCCUPATIONAL EXPOSURE.

•  It does not shield you, but does protect you indirectly. The information it provides allows us to evaluate your working environment and take the steps necessary to minimize subsequent exposures.

• Attach it to the front of your lab coat, preferably at the chest area.
• Do not shield the dosimeter in any way. It must measure your maximum possible exposure.
• Wear it outside of your lead apron. The only exception to this are the “fetal monitors” worn by pregnant workers, which is worn underneath the lead apron on the stomach area.
• Consult with the Radiation Safety Division if you require an extremity dosimeter (ring or wrist).

•  Contact the Radiation Safety Division, at 277-2753, to schedule an appointment for a Dosimetry Program Orientation. Orientations are scheduled no sooner than two days after a dosimeter has been requested.

• Monthly dosimeters are exchanged on the last working day of each month.
• Quarterly dosimeters are exchanged on the last working day of each calendar quarter (January-March, April-June, July-September, October-December).
• The issue period is determined by the nature of your radiation work and potential for receiving occupational exposures.

•  A “badge coordinator” is designated for each group. They are responsible for exchanging the dosimeters, reporting lost dosimeters, obtaining new dosimeters, canceling dosimeters for your group and updating pertinent information on each individual in their groups as changes arise, e.g., name change.

•  To facilitate the exchange, store your dosimeters at work in a central area away from sources of ionizing radiation.
• If you will not be available on the exchange date leave your dosimeter with the badge coordinator.
• Return you dosimeter directly to the Radiation Safety Division upon your termination.

Report it immediately. A replacement will be issued to you.

A Lost Dosimeter Report – Form RSF 53-1 (Attachment E) must be completed.

• The dosimetry vendor issues an exposure report after their analysis of the dosimeters to the UNM Radiation Safety Division.

• Personnel are notified immediately if a high or unusual reading is obtained.
• A complete summary of your exposures is available upon request from the UNM Radiation Safety Division.