R01029: Review of data suitable for foodchain modelling of C-14, H-3 and S-35 in animals
Friday 26 September 2003
This research project aims to conduct a literature review on the uptake and retention of C-14, H-3 and S-35 in farm animals.
Background
The radionuclides C-14, H-3 and S-35 are released from nuclear installations in routine discharges and have the potential to be released in accidents. They are isotopes of elements which all play a major role in animal nutrition and will be retained in the various organs and tissues. They can also be present in animal feedingstuffs in organic forms, which may be metabolised differently from the inorganic forms originally released. However, the uptake and retention of these radionuclides is often treated simplistically. This project was to conduct a literature review on the uptake and retention of C-14, H-3 and S-35 in farm animals, to provide a basis for specifying metabolic models of the distribution and retention of the radionuclides in the body following their ingestion or inhalation in various chemical forms. The FSA (MAFF at the time) would thus be provided with assessment models which could be used in the context of environmental transport modelling systems such as SPADE.
Research Approach
Relevant literature was acquired by searching computerised databases, paper-based bibliographies and the reference lists of relevant papers. Supplementary papers and unpublished information were acquired by correspondence with colleagues working in the field. The literature was be reviewed in the context of relevant information on the biochemistry of carbon, hydrogen and sulphur. Models were formulated on the distribution and retention of various chemical forms of C-14, H-3 and S-35 in different types of farm animals. Distributions of parameter values were developed for use with the models. The sensitivities of model results to input model parameters were explored. Comparisons were made with existing models, using a defined suite of test calculations and taking parameter value uncertainties into account.
Results and findings
A review was presented of biokinetic data and models relevant to the retention of various chemical forms C-14, H-3 and S-35 in animals. Based on this review, multi-compartmental models were developed in relation to the uptake and retention of these radionuclides in various types of farm animals. The animals considered were dairy cows, beef cattle, calves, dairy goats, dairy sheep, lambs, pigs, laying hens and chickens. The chemical forms of the radionuclides included tritiated water, organically bound tritium, tritiated hydrogen gas, 14C-labelled carbon monoxide, 14C-labelled carbon dioxide, 14C-labelled methane, 14C-incorporated in feed, 35S incorporated in reactive gases, 35S in ingested inorganic forms and 35S in ingested organic forms. Models were produced for each of these cases, with parameters to be used. Sensitivity studies were undertaken. Comparisons were made with STAR models used by the FSA. The project provides information on the extent to which the uptake and retention of radionuclides in animals can differ from that predicted using the simplified models.
Dissemination information
Final report is available from the FSA Library and Information centre. To obtain a copy, please contact the Enquiry Desk, Dr. Elsie Widdowson Library and Information Services, Food Standards Agency (020 7276 8181/8182 or at library&info@foodstandards.gsi.gov.uk).
Contact: David Webbe-Wood
Tel: 020 7276 8742 (Intl. +44 (0) 20 7276 8742)
Email: david.webbe-wood@foodstandards.gsi.gov.uk