Answer to Question #102 Submitted to "Ask the Experts"

Q

I work in a research facility and work with ¹⁴C labeled sucrose(approximately .80 micro curies each, three days a week) and just learned I am pregnant. I know ¹⁴C cannot penetrate the skin, unless of course it spills, but I want to hear it's safe from the experts. I wear protective equipment such as double gloves, goggles, and labcoat. What is your opinion?

A

From your description of the protective measures you are taking while working with the ¹⁴C labeled sucrose, the possibility of you or your baby receiving any radiation exposure is minimal. You are correct that ¹⁴C, with a beta emission of a maximum energy of 156 keV and average energy of 49.5 keV, is NOT an external radiation exposure hazard. Typically, the container and even the solution or other matrix into which the ¹⁴C compound is embedded will fully stop the beta radiation.

The primary concern for you when working with low levels of nonvolatile ¹⁴C is the prevention of contamination which could lead to internal uptake. To that end, your protective laboratory clothing, as well as carefully performing your manipulation of the ¹⁴C labeling procedures, employing disposable absorbent surface coverings, and judiciously monitoring your work areas and hands by use of swipes counted by a liquid scintillation counter set for measurement of ¹⁴C should ensure a contamination-free activity.

You have a right under the regulations of the US Nuclear Regulatory Commission to declare your pregnancy to your employer. In doing so, the radiation safety program of your company may provide additional monitoring of you or suggest additional precautionary procedures. For example, collecting and counting a urine specimen periodically will provide assurances that no internal contamination has occurred. This is something you can do electively as well. This can be done by aliquoting 1 ml of urine into 10 ml of liquid scintillation counting solution and counting in the ¹⁴C channel. Be sure to establish a background value first.

Bob Zoon, Radiation Safety Officer
National Institutes of Health