Radiation Monitoring Badges
Overview
Radiation monitoring devices are provided by the Radiation Safety Office to measure an individual's radiation exposure from X-ray or radioactive sources. The standard monitoring device is a clip-on dosimeter badge or ring badge bearing the individuals name & date of the monitoring period.
A radiation dosimeter badge does not protect the worker from radiation, but detects and measures radiation to which you have been exposed. The badge will detect high energy beta, gamma or x-ray radiation. These dosimeters cannot detect low energy beta radiation from some isotopes including tritium (H-3).
In order to minimize your exposure to radioactive materials or radiation- producing devices, always practice ALARA measures which include minimizing time near a source, maximize distance and shielding between you and the source.
Monitoring Requirements
State of Tennessee requires monitoring of individuals' radiation exposure when:
· It is expected that a person will receive a dose in excess of 10% of any of the following annual occupational dose limits:
Annual Occupational Dose Limits for AdultsDescription / Dose Limit
Whole Body / 5,000 mrem/yr
Skin / 50,000 mrem/yr
Extremity / 50,000 mrem/yr
Lens of the eye / 15,000 mrem/yr
· Are less than 18 years of age and are likely to receive a radiation dose in any calendar quarter in excess of 1 percent of the occupational dose limits listed above.
· Are radiation workers and have declared a pregnancy or planned pregnancy.
· Enter a High Radiation Area (exposure to greater than 100 millirem in any one hour).
· Operate analytical X-ray devices (ring and whole body badges).
· Meet special criteria as assessed by the Radiation Safety Officer.
How to Obtain a Monitoring Badge
Authorized Users must fill out the on-line dosimeter request form located on the Radiation Safety web page when requesting a badge for radiation workers. The following information is required: name, date of birth, department, authorized users name, gender and hire date. Extremity monitoring badges (rings) are available in large or small sizes for the right or left hand, which must be indicated on the form.
http://www.etsu.edu/ospa/rso/forms/dosimeterRequest.html
Badge Exchange and Processing
Badges are exchanged quarterly (except for Declared Pregnant Workers whose badges are exchanged monthly). The departmental dosimetry contact person shall:
· Distribute new quarterly badges no later than the first day of the new calendar quarter.
· Collect quarterly badges at the end of the calendar quarter (badges must be returned to the Radiation Safety Department within two weeks).
Snap the old badge out of the gray holder and return just the badge itself. Keep the gray holder so that you nap the new badge into it.
Guidelines for Wearing and Storing Monitoring Badges
· Never share your badges or wear another person’s badges. Each badge is intended to be worn by only the designated person.
· Do not intentionally expose badges to radiation. Intentional tampering with badges is a very serious matter.
· No matter how curious you are, do not wear your badges when you receive a medical x-ray or other medical radiation treatment. Your badges are intended to document occupational dose, not medical dose.
· Store your badges in a safe place at work, rather than at home. Be sure to store badges away from sources of radiation. Be careful to consider all sources of radiation. For example, if you store your badge clipped to your lab coat, make sure that your lab coat (or any other lab coat near it) is not contaminated.
· Wear your body badge on the part of the body between your neck and waist most likely to be exposed to the greatest amount of radiation. Wear it so that the name tag faces toward the source of radiation.
· Your ring badge should be worn so that the label is facing out from the side of the hand most likely to receive a radiation exposure. In most cases, such as when performing radioactive labeling experiments, this means that the label will face out from the palm side of your hand. To avoid contaminating your ring badge when using open sources, wear your ring under the glove. Additionally, take care not to dispose of the ring in the trash when you remove your gloves.
· If you lose your badge notify the Radiation Safety Officer to obtain a replacement badge as soon as possible.
· Occasionally check your badge for contamination.
Emergency Processing
If you believe that you may have received an unusual dose (if you may have placed your hand in an x-ray beam, for example), notify Radiation Safety immediately. Your badges will be returned for rapid emergency processing.
Radiation Monitoring Reports and How to Read Them
After you return your monitoring badges, the badges are sent out to the badge service company for processing. Radiation Safety receives the dose reports several weeks after the end of a monitoring period and reviews the dose reports. Each report includes the name, monitoring period date, dose (millirem) for the immediate past period, current calendar quarter and calendar year. A copy of the report is forwarded to the departmental radiation safety representative who is responsible for issuing the monitoring report to the radiation users. A summary of your badge results can also be obtained by contacting the Radiation Safety Officer.
East Tennessee State University, Radiation Safety has established investigational levels at doses that are 10% of the state dose limits. If a dose is reported that exceeds ETSU’s investigational level, Radiation Safety will contact you to determine whether the reported dose is likely to be accurate and to investigate the causes of the dose in an effort to minimize dose in the future.
In the case of body badges, doses are reported as deep or shallow or as doses to the lens of the eye. Deep dose is due to penetrating radiations such as x- or gamma radiation. Deep doses are applied against the whole body dose limit. Shallow dose is due to less penetrating radiations such as beta radiation and low energy x-rays. Shallow doses are applied against the skin dose limit. Dose to the lens of the eyes is due to an intermediate range of radiations and energies and is applied against the lens of the eye dose limit. In the case of ring badges, dose is only reported as shallow dose and is applied against the extremities dose limit.
Doses are reported in millirem. The minimum reportable dose for body badges is 1 millirem for x-ray and gamma rays or 10 millirem for energetic beta radiation. Ring badges are 30 millirem for x-rays & gamma rays or 40 millrem for energetic beta radiation. If a dose of "M" is reported, the total dose received was minimal, i.e., less than the minimum reportable dose.
Contact EHS if you change your name, if your name is misspelled, or if any other information on the dose report is incorrect.
Pregnant Employee - Fetal Dose Policy
ETSU’s fetal dose policy incorporates safety information and radiation dose guidelines for ensuring safe radiation limits for the embryo/fetus of occupationally exposed employees. Pregnant radiation workers must declare in writing that she is pregnant. The Declaration of Pregnancy Form, located on the radiation safety web page must be submitted to the Radiation Safety Department as soon as possible after learning of their pregnancy.
A potentially harmful situation arises when a pregnant worker is exposed to radiation. Exposure of such a worker to ionizing radiation from either external or internal sources would also involve exposure of the embryo or fetus. A number of studies have indicated that the embryo or fetus is more sensitive than an adult, particularly during the first three months after conception, when a woman may not be aware that she is pregnant.
Federal and state regulations require that special precautions be taken to limit exposure to radiation sources when an occupationally exposed woman could be pregnant.
The current maximum permissible radiation exposure is 500 millirem for the duration of the gestation period, and the monthly exposure should be limited to 50 millirem.