total amount of energy released over a long period by the short-lived progeny in equilibrium with 100 pCi of radon. 1 WL = 2.08 × 10−5 J m−3.

Working level month (WLM):

A cumulative exposure equivalent to 1 working level for 1 working month (170 hours). 1 WLM = 2.08 × 10−5 J h m−3 × 170 h = 3.5 × 10−3 J h m−3.


X radiation:

(A) Electromagnetic radiation emitted in de-excitation of bound atomic electrons, frequently occurring in decay of radionuclides, referred to as characteristic x rays, or (B) electromagnetic radiation produced in deceleration of energetic charged particles (such as beta radiation) in passing through matter, referred to as continuous x rays or bremsstrahlung; also called x rays.



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