Answer to Question #13237 Submitted to "Ask the Experts"

My mother was a nurse in the United Kingdom during the 1960s. She was required to stand next to cervical cancer patients being treated with radium (presumably ²²⁶Ra). She was given no barrier protection. The patients were lying on a trolley that she estimates to have been approximately 60 cm wide. She recalls that she stood approximately 10 cm from the trolley for a maximum of 90 minutes (45 minutes on two occasions). The trolley was roughly waist-height. She does not know how much radium was used, but my research about brachytherapy and radium pharmacology suggests that it was between 50 mg and 100 mg. She has not suffered any obvious consequences from this exposure, but she is very worried now because two of her children have recently had serious cancers (pancreatic cancer and Hodgkin's lymphoma) in their 30s and 40s. Her first child was born several years after the exposure. She would like to know the equivalent dose she received and whether this might have had any effect on her future children.

You pose a very interesting question. First, it is noteworthy that your mother's first pregnancy occurred several years after her radiation exposure, so the embryo/fetus was not directly exposed, meaning that the only potential effect would be a genetic effect (something that caused the mutation of the germ cells—the cells that divide to produce the eggs in females).

Second, it is important to note that the studies to date on the population exposed to radiation from the atomic bombings in Japan in 1945 have not detected any genetic effects attributable to radiation exposure, where the median radiation doses were about 0.14 gray. These studies are still ongoing, but to date do not show an increased risk of cancer in children of the survivors.

For comparison, we can roughly calculate your mother's possible dose from her exposure to patients treated with radium 226 (²²⁶Ra). You are correct that the typical treatments would use 50–100 milligrams of ²²⁶Ra. You state that on two occasions your mother stood for 45 minutes each approximately 10 cm from the patient trolley, which was about 60 cm wide. Using this information, and the gamma constant for ²²⁶Ra, I estimate your mother's exposure to have been approximately 0.013 gray, or about 10% of the median exposure for the atomic bomb survivor population. For added information gamma rays from ²²⁶Ra you can see the answer to Ask the Experts question 12800.

Given the dose, and the results to date from the atomic bomb survivors study with respect to genetic effects, it appears highly unlikely that your mother's exposure contributed to the cancers your siblings have suffered. I hope this information is of help to you and your family.

Barbara Hamrick, CHP