EDIT: Someone linked to the Wikipedia article for uranium tiles, which says that the majority of the radiation comes from the decay products and is beta radiation[1]. Beta radiation has a weighing factor of 1, which means it's about 0.1 mSv/h. For comparison Wikipedia says:
"90 μSv/h: Natural radiation on a monazite beach near Guarapari, Brazil."
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EDIT 2: Looking more closely it appears that the dosimeter in the video is switched to µSv/h, so it's reading 0.1 mSv/h anyway and the whole discussion below can be skipped if you're not interested in the difference between Gy and Sv.
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Seems to be milliroentgen/h according to another commenter, which is an older unit. Today you'd use Gray (Gy), which is 1 J/kg of energy deposited in material, and Sievert (Sv), which is Gy adjusted by a factor to account for different radiation types and body parts to get comparable biological effects.
For soft tissue (~= humans) 1 R = 0.01 Gy, so the dose would be ~0.1 mGy/h.
Converting that to Sievert is more complicated. Uranium is an alpha emitter, for which you'd use a weighing factor of 20 [0], getting 2mSv/h.
1 mSv/h = "NRC definition of a high radiation area in a nuclear power plant, warranting a chain-link fence." [0]
However alpha radiation also gets blocked by very flimsy barriers, such as a few cm of air, or the layer of dead skin cells on your skin. So the effective dose might be closer to 0!
You also have to consider that the decay products or Uranium are beta emitters. Beta rays have a weighing factor of 1, but they do penetrate deeper (stopped by a few feet of air, can penetrate the skin).
The real effective dose in Sv depends on the exact ratio of decay products to U-238, and how deeply the beta rays of those products penetrate your body (there's different weighing factors for different body parts!).
In conclusion: probably not too much, but radiation and radiation shielding is a complicated subject we managed to spend a whole semester on.
I'm very surprised that radiation workers are allowed half the dose which is directly linked to cancer. Especially because you get that dose in two years, imagine how much you get over a 40 year career.
Generally kept lower than that. Exceeding the human exposure threshold for a worker amounts to an international nuclear incident. Literally. Must be reported and the IAEA will do a full investigation and eventually assign it an International Nuclear Event Scale number. (7 = Chernobyl. 2 = Worker dropped a small vial of tritium gas and breathed it in.)
The "banana equivalent dose" is an error that refuses to die. Based on tables that estimate the effect of various radioactive isotopes acting for 50 years, people ignoring physiology decided that the average K40 in a banana will produce 0.078 microsievert of damage (rounded to 0.1 because it's close enough for jazz and comics).
The reality is that, due to homoeostasis, the excess potassium you ingest is eliminated the next time you piss, so there's no accumulation inside the organism. Those 50 years become something like 12 hours and the radiation exposure is more in the ballpark of 0.00000213 microsievert.
But that value is now too small to use it in science fanboyism, isn't it?
"For radioisotopes of elements that are under tight homeostatic control by the human body, the inhalation or ingestion risk coefficients given in this document may not be appropriate for application to some exposure scenarios. For example, the ingestion risk coefficient for ^(40)K would not be appropriate for application to ingestion of ^(40)K in conjunction with an elevated intake of natural potassium. This is because the biokinetic model for potassium used in this document represents the relatively slow removal of potassium (biological half-time of 30 d) that is estimated to occur for typical intakes of potassium, whereas an elevated intake of potassium would result in excretion of a nearly equal mass of natural potassium, and hence of ^(40)K, over a short period." - ["Federal Guidance Report No. 13: Cancer Risk Coefficients for Environmental Exposure to Radionuclides"](https://www.epa.gov/sites/default/files/2015-05/documents/40...) - page 16
So, if you accept that the duration of exposure from eating a banana is 12 hours instead of 50 years, a dental x-ray is the equivalent of eating 2,347,417 bananas.
I'm not really sure about the unit of the measure here. So how does it compare really?
You need to realize, we are exposed to radiation all the time.