intake compartment: One of four compartments from which systemic uptake can occur: the respiratory
tract; the GI tract; a wound; or intact skin.
intake route: A pathway by which radioactive material enters the body. The main intake routes are
inhalation, ingestion, absorption through the skin, and entry through injection or a cut or wound in the
in vitro measurement: Synonymous with indirect bioassay.
in vivo measurement: Synonymous with direct bioassay.
lower limit of detection (LLD): Synonymous with minimum detectable amount (MDA).
minimum detectable amount (MDA): The smallest amount (activity or mass) of an analyte in a sample
that will be detected with a probability ß of non-detection (Type II error) while accepting a probability "
of erroneously deciding that a positive (non-zero) quantity of analyte is present in an appropriate blank
sample (Type I error).
minimum detectable concentration (MDC): The minimum detectable amount (MDA) expressed in units
of concentration. (HPS N13.30-1996)
minimum detectable (effective) dose: The minimum detectable committed (effective) dose equivalent
associated with a bioassay program. Formerly called "missed dose."
minimum testing level (MTL): The amount of radioactive material that the service laboratory should be
able to measure for participation in the performance testing program, assuming the samples are free of
interference from other radionuclides unless specifically addressed. The MTLs should not be construed as
being the appropriate MDA required for a specific internal dosimetry program, but rather an acceptable
minimum testing level for radiobioassay service laboratories based on good measurement practice. (HPS
potential alpha energy concentration (PAEC): The kinetic energy potentially released in a unit volume
of air by alpha particles emitted by the short-lived radioactive progeny of 222Rn (i.e., 218Po and 214Po) or
Rn (i.e., 216Po, 212Bi, and 212Po). PAEC is expressed in working levels (WL).
potential alpha energy exposure (PAEE): The average potential alpha energy concentration (PAEC) to
which a worker is exposed, multiplied by the time of exposure in working months of 170 hours: that is,
PAEE = PAEC × time. PAEE is expressed in working level months (WLM).
quality assurance: All those planned and systematic actions necessary to provide adequate confidence
that an analysis, measurement, or surveillance program will perform satisfactorily in service. (HPS
quality control: Those actions that control the attributes of the analytical process, standards, reagents,
measurement equipment, components, system, or facility according to predetermined quality
requirements. (HPS N13.30-1996)
radiobioassay: Measurement of amount or concentration of radioactive material in the body or in
biological material excreted or removed from the body and analyzed for purposes of estimating the
quantity of radioactive material in the body. (HPS N13.30-1996)