Occupational Intakes of Radionuclides Part 1 - ICRP

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DRAFT REPORT FOR CONSULTATION
(65) Workplace monitoring of internal exposures makes use of measurements
made in the working environment. An example is the measurement of radionuclide
concentration(s) in air using static air samplers. In general, workplace monitoring
complements individual monitoring. It may be used for monitoring internal exposures
in place of individual monitoring when the latter is not justified, or where the
sensitivity of individual monitoring is inadequate. It can be used to provide an
assessment of exposure for groups of workers, but this requires assumptions to be
made about exposure conditions. It is also of value in demonstrating that working
conditions meet safe working criteria and have not changed. It can indicate the release
of radionuclides into the working environment and so trigger subsequent individual
monitoring measurements.
(66) Individual monitoring of internal exposure uses measurements made for
individual workers for the assessment of their dose of record, together with other
dosimetric quantities if required. The principal objectives of individual monitoring in
planned and existing situations are:
to assess the worker’s dose of record and to demonstrate compliance with
regulatory requirements.
to contribute to the safety management and control of the operation of the
facility.
(67) The principal objectives of individual monitoring of workers in emergency
situations are:
to document the worker’s exposure in terms of dose of record and, if
appropriate, in terms of absorbed doses in significantly exposed tissues.
to provide information for the initiation and support of any appropriate health
surveillance and treatment.
(68) Usually it is necessary to carry out only a simple assessment of dose to
demonstrate compliance with regulatory requirements when annual doses are
expected to be only small fractions of the dose limits. In some countries it may be
unnecessary to make an assessment of individual dose, the measured value being
compared with an appropriate threshold or recording level. At higher doses more
emphasis will need to be placed upon specific dose assessments and the
circumstances of any exposure.
(69) Measurements, together with information about the workplace, should enable
each radionuclide to be identified, its activity quantified, and the measurement result
interpreted in terms of intake and/or committed effective dose. There may be some
circumstances where individual monitoring techniques are not adequate to assess
doses and it may be necessary to combine individual and workplace monitoring
techniques.
2.4 Categories of Individual Monitoring Programme
(70) Routine monitoring is performed under conditions of essentially continuous
risk of contamination of the workplace as a result of normal operations, or where
undetected accidental intakes may occur. Measurements in a routine monitoring
programme are made at pre-determined times not related to known intakes, and
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