Answer to Question #10496 Submitted to "Ask the Experts"

Category: Radiation Workers

The following question was answered by an expert in the appropriate field:


National Council on Radiation Protection and Measurements (NCRP) Report No. 116 provides dose limits for occupational workers. It also provides extremely low dose limits for a category they term "educational and training." Many current radiography training programs require up to two years of full-time (35 to 40 hours per week) clinical experience working in a department where the hired workers adhere to occupational limits. The Nuclear Regulatory Commission has stated that nuclear medicine students (and even volunteers) who are regularly scheduled in a clinical area should adhere to occupational limits, which makes sense due to the amount of time spent there.

Please clarify. And does this need to be revised by NCRP to reflect the amount of clinical training and involvement these students actually have?


Thank you for your question. I did a reread of NCRP Report No. 116 to remind myself of what it said. It does indicate that persons under the age of 18 shall be exposed to only 1 mSv (100 mrem) maximum per year.

A few comments about this:

  1. NCRP is not regulatory—thus you are not obliged to follow it. You are required to follow your state regulations for x-ray use.
  2. This is only a recommendation for persons in training programs if they are under the age of 18. I suspect most of your students have graduated high school so are that age or older.

If you do have students under the age of 18, you are required to follow your state regulations with regard to their limit on exposure. For instance, in the state of Ohio, persons under the age of 18 are not permitted to receive more than one-tenth of the adult limit of 50 mSv or 5 rem—so a person under age 18 can receive only up to 5 mSv (see item G on page 7 of the Ohio state regulations). This is just one example of what state regulations say, but it is pretty consistent across the United States.

Kelly Classic
Certified Medical Health Physicis

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