Answer to Question #6465 Submitted to "Ask the Experts"

1. I recently had two x rays of my hip with no lead shield for my testes. Would this be enough to cause issues of fertility or birth defects?
2. We plan to take a plane trip from San Jose to Los Angeles, about 400 miles. If my wife is pregnant could the trip cause birth defects—especially if newly pregnant?

The radiation dose to an organ in the body from a medical x-ray exam depends on several factors, including the direction of the x-ray beam, whether the organ of concern is within the field of view, and x-ray machine settings such as the voltage, current, and time of exposure. Assuming you had a standard hip radiograph with a view from front to back (AP) and one from side to side (lateral), the total radiation dose to your testes would be approximately equal to the radiation dose to testes from 1.5 years of natural background radiation. This dose is less than 1 percent of the dose required to cause temporary infertility. While there is laboratory evidence that low doses of radiation can cause genetic birth defects in animals, there are no data that support such effects in humans. Thus, you should not be concerned about the possibility of either infertility or genetic birth defects caused by x rays of your hip.

Flying in a commercial airplane slightly increases background cosmic radiation dose due to a thinner atmosphere at high altitudes. The additional radiation dose received during one hour of flying at these altitudes is approximately 0.5 percent of the dose received from one year of natural background radiation at sea level. This additional dose is far less than the dose necessary to cause birth defects in an unborn child.

Richard J. Vetter, PhD CHP