Derived air concentration
The DAC is the activity concentration in air in Bq m^(-3)of the radionuclide considered that would lead to intake of an annual limit on intake (ALI) assuming a sex-averaged breathing rate of 1.1 m^3 h^(-1) and an annual working time of 2000 h. DAC is given by:
[math] DAC_j = \frac{ALI_j}{2200} [/math]
The Commission does not recommend the use of DAC because it considers that for compliance with dose limits it is the total dose from external radiation as well as from intakes of radionuclides that must be taken into account.
(See also annual limit on intake).
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Previous glossary entries
from ICRP Publication 103, 2007
This equals the annual limit on intake, ALI, (of a radionuclide) divided by the volume of air inhaled by a Reference Person in a working year (i.e.,2.2 103 m3). The unit of DAC is Bq m-3.
Historically
The activity concentration in air (Bq m-3) of a radionuclide that would lead to an intake of an ALI (Bq) assuming a sex-averaged breathing rate of 1.1 m3 h-1 and an annual working time of 2000 h.