Many lost feet or parts of them, never making a connection back to the fluoroscope. Nobody knew how much radiation those things were actually putting out.
(Ironically or not, I now work in medical physics where even the slightest exposure gets noted and tracked)
> That 1948 study of 43 machines in Detroit showed ranges from 16 to 75 roentgens per minute. In 1946, the American Standards Association had issued a safety code for industrial use of X-rays, limiting exposure to 0.1 R per day.
I'd be curious how much a typical modern dental x-ray emits, but we no longer measure in roentgens these days as we have better measures of the actual dose (sieverts).
https://www.iaea.org/resources/rpop/health-professionals/den...
Less negligible are CT scans, which can expose you to multiples of the average annual background dose in a few minutes.
That's still relatively low level exposure. But there isn't really a safe minimum exposure level, and it's certainly not something you'd want to have regularly.
That's 2 years (CT) and 10 days (x-ray) of exposure to sea level background radiation respectively.