If I'm not mistaken that's 0.1137 milisievert / hour. Meaning you have to stand glued to the tiles for about 4 years to get the LD50 lethal dose of about 4000 Sievert. Also, the lethality of the dose only really applies when the exposure is short.
Or, alternatively, the average yearly background radiation of about 2 milisievert takes about 18 hours of being glued to those tiles.
Or, alternatively, the average yearly background radiation of about 2 milisievert takes about 18 hours of being glued to those tiles.