[tomxor]

Hmm, 3 mSv is supposed to be the average annual background radiation absorption for humans [0], that's roughly 0.000342 mSv/h. Which would make 11.37 mSv/h 33245 times greater.

At the other end of the scale the minimum annual dose with a clear link to increased risk of cancer is supposedly 100 mSv [1]. But the risk is different depending on the distribution over time, so if we make it hourly for comparison that is 0.0114 mSv/h making this reading about 1000 times higher than that risk threshold (but the risk is over a year is effectively assuming continuous exposure).

Seconds or minutes isn't going to be terrible, but in only 9 hours leaning against it you would get a years worth of high risk cancer dose!... I'd stay away from the wall. happy to be corrected, this stuff is hard to interpret if you are not an expert. The falloff is really fast though, so it's basically harmless if you are just walking through... maybe the original intent was to stop people touching the walls :D like an electric fence without the need for power.

[0] https://en.wikipedia.org/wiki/Background_radiation

[1] https://upload.wikimedia.org/wikipedia/commons/9/9f/Exposure...

[edit]

Fixed various calculations.