Radiation Safety Review for Radiation Oncology Staff. MARCUS JEANNETTE RADIATION SAFETY OFFICER 744-2070. Office of Radiation Safety Responsibilities. Comply with regulations, laws, and guidelines regarding the safe use of radioactive material and radiation producing devices.
RADIATION SAFETY OFFICER
This training is mandated by regulation, but why?
There are a number of factors involved and during the process of this training session you should gain a larger understanding of the reason.
We will first look at where the regulations originate from and what agencies govern our operational use of radiation producing machines and radioactive materials.
International Commission on
The ICRP and NCRP are advisory bodies that collect and analyze data regarding ionizing radiation and put forth recommendations on radiation protection.
The regulatory groups utilize these recommendations when developing regulations.
National Council on Radiation
Protection and Measurements
Many Federal agencies have regulations that deal with radiation protection.
Each agency regulates a different aspect as it pertains to their particular program area.
NRC – Nuclear Regulatory Commission
FDA – Food & Drug Administration
FEMA – Federal Emergency Management Agency
OSHA – Occupational Safety and Health Administration
DOT – Department of Transportation
EPA – Environmental Protection Agency
USPS – United States Postal Service
-Physics Linear Accelerator
-High Dose Rate Applicator
A radiation that has sufficient energy to remove electrons from atoms or molecules as it passes through matter.
Examples: x-rays, gamma rays, beta particles, and alpha particles
A radiation that is not as energetic as ionizing radiation and cannot remove electrons from atoms or molecules.
Examples: light, lasers, heat, microwaves, and radarIonizing vs. Non-IonizingRadiations
Whether we talk about ionizing or non-ionizing radiation, its genesis is either within or very close to the exterior of the atom. The following is a brief review the atomic structure.
The atom is comprised of a nucleus, which is made up of positively charged protons and electrically neutral (no charge) neutrons, surrounded by negatively charged electrons.
In an electrically neutral atom, the number of positively charged protons and negatively charged electrons are equal.
Next: A review of both types of ionizing radiation generators – X-rays and Radioactive Materials.
GAMMA AND X-RADIATION
Generally, stopped by lead.
Sources include naturally occurring radioactive materials and cosmic radiation.
FYI: As discussed earlier, x-rays can be produced by radioactive decay or electronic production. Both originate outside the nucleus of the atom.
FYI: If you’ve ever had an x-ray, when the x-ray technologists takes your “picture,” it is over. The x-ray unit does not continue to produce radiation after the exposure is complete.
A measure of ionization produced in air by X or gamma radiation.
Highly specific in that the unit specifies the matter being exposed and radiation producing the ionizations.
Unit: roentgen (R)
1 R = 1000 mRRadiation Units
Now that you have a little understanding of the physics behind ionizing radiation, how do we measure or quantify radiation? Here are a few units of measure that are used (often interchangeably) in radiation protection:
FYI: If you wear a badge, your dose in reported in “mrem.”
Who cares about electrons being stripped from atoms?
FYI: There are other theories regarding the effects of radiation dose (as represented by the other lines – blue and gray), to include radiation hormesis. Radiation hormesis is a theory that chronic low doses of radiation is good for the body.
Did you know some of the foods you eat contain naturally occurring radioactive material?
Bananas contain low
quantities of Potassium-40.
Less Time = Less Exposure
Greater Distance = Less Exposure
More Shielding = Less Exposure
Exposure to a source of ionizing radiation is very similar to the exposure from a light bulb (i.e. light and heat).
The closer you are to the source, the more intense the light and heat are. Likewise, if you move away, the intensity decreases.
The longer you are close to the light bulb, you begin to feel the warming effects of the light. If however, you move quickly to and from the light, you’ll not likely feel the warming effect.
If you put something opaque between you and the light bulb, you effectively eliminate the light.
A difficult concept to understand is the difference between exposure and contamination when we talk about radioactive materials.
To illustrate the difference, consider a burning candle.
Remember: Being exposed by a radioactive source does not contaminate you. You must have interacted with the source to get some of the source on you. Once on you, the contamination will expose you until it is removed.
The occupational dose limits for workers in North Carolina and the US are as follows:
Whole Body (WB) 5,000 mrem/yr
Extremities/Skin 50,000 mrem/yr
Lens of the Eye 15,000 mrem/yr
Minor WB (< 18 years old) 500 mrem/year
Declared Pregnant Worker 500 mrem/gestation
By regulation, the institutional radiation protection program shall monitor individual’s exposure/dose if they are likely to receive 10% of the limit, or in the case of declared pregnant workers and minors the threshold is 100 mrem.
Monitoring RequiredMonitoring Method
Whole Body TLD or OSL Badge
Extremity Finger Ring TLD
Internal Contamination Urinalysis or Bioassay
Whole Body Badge
>200 mrem/monitoring period to whole body
> 2000 mrem/monitoring period to extremities
> 800 mrem/monitoring period to the skin
Action Required: Written notification from RSO to worker and investigation
Medical Event is the administration of radioactive material or radiation that results in:
1. A dose that differs from the prescribed dose by 5 rem effective dose equivalent, 50 rem to an organ or tissue.
2. The total dose delivered differs from the prescribed dose by 20% or more..
3. An administration of the wrong radioactive drug containing radioactive material.
4. An administration of a radiopharmaceutical by the wrong route of administration.
5. An administration to the wrong patient.
1. The licensee’s name
2. The name of the prescribing physician
3. Brief description of the event
4. Why the event occurred
5. The effect on the individual(s) who received the administration
6. Corrective Actions
7. Certification that we notified the individual involved
In the event of any malfunction of the treatment unit(s) (mechanical, electrical, or otherwise) which may prove hazardous to the patient, therapist or the any member of the public:
1. Press any emergency off button.
2. Remove patient and other personnel from vault.
3. Close accelerator door.
4. Call the Radiation Safety Officer AND the Medical Physicist listed below.
5. Remain at the console and prevent entry of personnel into vault until problem has been resolved, if possible.
Beeper: 754-3422 Home: 524-5720
Beeper: 561-9445 Home:412-2875
Radiation Safety Officer:
Beeper: 757-5056 Home: 258-8005
Radiation protection is not just the responsibility of management, the Radiation Safety Committee, the Radiation Safety Officer or co-workers, it is all of our responsibility.