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A "working level" is that amount of Rn-222 daughter products
which would result in:
A) 1.3 E5 MeV per liter of air
B) 1 ALI in six months
C) 1 ALI in twelve months
D) one third of the DAC
E) one third of the MPC
The correct answer is: A
The definition of working level includes the daughter products
only, and not the radon itself. One working level is also
approximately equal to 100 pCi/L or three times the occupational
DAC for Rn-222. The occupational limit for uranium miners is 4
working level-months per year, which is equal to 170 working
level-hours x four months.