Occupational Intakes of Radionuclides Part 1 - ICRP

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DRAFT REPORT FOR CONSULTATION
needed in the choice of the most appropriate measurement data and in defining the
time of the intake.
(45) Effective dose assessed from bioassay measurements is relatively insensitive
to choice of parameter values when the measured quantity is directly related to an
organ dose that makes a dominant contribution to the effective dose, e.g. in the case
of lung retention measurements after inhalation of an insoluble 60 Co compound,
where lung dose dominates the effective dose. However, sensitivity to parameter
values may be much higher when the measured quantity is not so closely related to the
effective dose, for instance when lung dose makes a dominant contribution to
effective dose and urine monitoring is employed. For such a case, the results of urine
monitoring can provide a reliable measure of doses to systemic organs, but assessed
lung dose is sensitive to choice of absorption parameter values. An example is the
assessment of effective dose from urine monitoring data after inhalation of an
insoluble 239 Pu compound.
1.8 Structure of the Report
(46) This report series provides revised dose coefficients for occupational intakes
of radionuclides (OIR) by inhalation and ingestion, replacing the Publication 30 series
(ICRP, 1979, 1980, 1981, 1988b) and Publication 68 (ICRP, 1994b). It also provides
data for the interpretation of bioassay measurements, replacing Publications 54 and 78
(ICRP, 1988a, 1997b).
(47) Chapter 2 of this report discusses the application of dose limits and constraints
to the control of occupational exposures to radionuclides. It also outlines the
objectives and requirements of monitoring programmes designed to ensure
compliance with regulatory requirements. Chapter 3 gives an overview of the
biokinetic and dosimetric models used to calculate dose coefficients and bioassay
data. It explains the changes made to the Publication 66 Human Respiratory Tract
Model (HRTM) (ICRP, 1994a) and describes the main features of the Publication 100
Human Alimentary Tract Model (HATM) (ICRP, 2006). Chapter 3 also provides an
introduction to the models used in this series of reports to describe the systemic
biokinetics of elements and their radioisotopes. Dosimetric models and methodology
are also explained.
(48) Routes of intake other than inhalation and ingestion are not considered in this
series of reports for the reasons discussed in Section 3.1. However, a summary of a
biokinetic model for radionuclide contaminated wounds, prepared by the U.S.
National Council on Radiation Protection and Measurements (NCRP, 2007), is
included in Chapter 3.
(49) A description of methods for individual monitoring is given in Chapter 4. The
Chapter covers in vivo measurements and the analysis of excreta and other biological
materials as well as workplace monitoring. The general principles for design of
monitoring programmes, types of programmes and monitoring requirements are
summarised in Chapter 5. Also covered briefly are wound monitoring and the
potential effects of medical intervention. General aspects of retrospective dose
assessment are considered in Chapter 6. The Chapter examines the need to understand
the exposure situation and radionuclide(s) being handled as well as their physico-
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