In the 1950s, it was a common practice to X-ray pregnant women to determine the position of their babies. At the time, low doses of X-ray were considered harmless and doctors wouldn’t think twice about using X-ray on their patients.

When Dr. Alice Stewart discovered that the children of mothers who had an X-ray were almost twice as likely to suffer from leukemia, she raised the alarm. But instead of due concern, her findings were met with outrage by doctors and the nuclear industry…