Here is a walk down memory lane for anyone old enough to remember the fluoroscope, an x-ray device that was available in thousands of shoe stores worldwide. It also had several proprietary names, including the Pedoscope, X-ray Shoe Fitter, and the Foot-o-scope.

Fluoroscopes were once a common sight in shoe stores. Thousands of the devices were installed in the mid-20th century. Eventually, customers, shoe salespeople, and medical authorities alike finally realized that a shoe store isn’t the best place for a boxful of radioactive isotopes.

I well remember my mother taking me to Reed's Footwear and Clothing store where she we and Bill Reed (the owner of the store) all looked at live x-ray images of my feet inserted into new shoes in the store to see if the shoes fit properly or not. 

Nobody seemed to realize these unregulated, unshielded x-ray machines were a health hazard. While they were perhaps a minor hazard to customers, they apparently caused cancer amongst shoe salespeople who were exposed to x-rays off and on, all day, every day. In 1957, Pennsylvania became the first US state to ban use of these machines. Other states and most other countries banned the use of these machines soon after.

The image above shows a typical fluoroscope. The customer, often a child, would try on the new shoes and then stand on a "platform" on the back of the device. (The platform is barely visible on the back of the fluoroscope in the above picture.) Then there are three viewing ports on top. These allowed the shoe salesperson, the customer (such as my mother), and the person wearing the shoes (that's me!) to simultaneously view the live x-rays. I well remember that I wasn't so interested in the shoes but was fascinated by the fact I could see a live image of the bones in my toes as I wiggled them a bit.

It wasn't until several years later that the risks became well-known. According to an article in Wikipedia (at https://en.wikipedia.org/wiki/Shoe-fitting_fluoroscope):

"Large variations in dose were possible depending on the machine design, displacement of the shielding materials, and the time and frequency of use. Radiation surveys showed that American machines delivered an average of 13 roentgen (r) (roughly 0.13 sievert (Sv) of equivalent dose in modern units) to the customer's feet during a typical 20 second viewing, with one capable of delivering 116 r (~1 Sv) in 20 seconds. British Pedoscopes were about ten times less powerful. A customer might try several shoes in a day, or return several times in a year, and radiation dose effects may be cumulative. A dose of 300 r can cause growth disturbance in a child, and 600 r can cause erythema in an adult. Hands and feet are relatively resistant to other forms of radiation damage, such as carcinogenesis.

"Although most of the dose was directed at the feet, a substantial amount would scatter or leak in all directions. Shielding materials were sometimes displaced to improve image quality, to make the machine lighter, or out of carelessness, and this aggravated the leakage. The resulting whole-body dose may have been hazardous to the salesmen, who were chronically exposed, and to children, who are about twice as radiosensitive as adults. Monitoring of American salespersons found dose rates at pelvis height of up to 95 mr/week, with an average of 7.1 mr/week (up to ~50 mSv/a, avg ~3.7 mSv/an effective dose). A 2007 paper suggested that even higher doses of 0.5 Sv/a were plausible. The most widely accepted model of radiation-induced cancer posits that the incidence of cancers due to ionizing radiation increases linearly with effective (i.e., whole-body) dose at a rate of 5.5% per Sv."

An estimated 10,000 machines were sold in the US, 3,000 in the UK, 1,500 in Switzerland, and 1,000 in Canada before authorities began discouraging their use. It seems that several shoe salespeople later developed various forms of cancer, but no follow-up studies were ever conducted simply because nobody ever kept records of the people who had been exposed.

I find it interesting that Bill Reed, the owner and chief salesperson at the small Reed's Footwear and Clothing store mentioned earlier, lived to be 88 years old; it appears that the fluoroscope did not affect his health very much!