Seventy years ago, children considered a trip to the shoe store a real treat, because it gave them access to a fascinating toy — a shoe-fitting fluoroscope. Little did they know that this endlessly amusing contraption was exposing them to unsafe amounts of radiation that could have lasting impacts on their health.

 The fluoroscope was a small wooden podium that housed an X-ray tube in its base. When testing new shoes to see if they fit, customers would slide their foot into an opening near the bottom of the podium, and the store clerk would put his hands directly into the beam to squeeze the shoe around the foot to determine if there was enough room in the shoe. As customers looked through a hole in the top of the machine, they could see an X-ray of their foot and, presumably, determine whether the shoe fit correctly.

 But there were untold dangers in this common practice. Not only were the customers’ feet subjected to unshielded radiation, but the beam’s scatter rays would travel up their legs to other parts of their bodies. While customers were warned to limit themselves to 12 exposures per year, shoe store clerks were subject to repeated exposures — every single day.

 Shoe-fitting fluoroscopes first emerged in the 1920s, but it wasn’t until the 1950s that they reached their peak of popularity, being used in more than 10,000 stores across the United States. The machines were especially popular with children, who would often stick their fingers and hands in the machine for amusement while their parent paid for the shoes.

In the late 1950s, Americans started making the connection between fluoroscopes and dermatitis and cancer. The machines were banned in the 1970s. It’s not clear how many people experienced a negative effect from these incredibly dangerous devices, but with the evolution of research and advancements in technology, it’s no longer acceptable to unnecessarily expose people to ionizing radiation.