title: A review and model assessment of (32)P and (33)P uptake to biota in freshwater systems.
abstract: Bioaccumulation of key short-lived radionuclides such as (131)I and (32,33)P may be over-estimated since concentration ratios (CRs) are often based on values for the corresponding stable isotope which do not account for radioactive decay during uptake via the food chain. This study presents estimates for bioaccumulation of radioactive phosphorus which account for both radioactive decay and varying ambient levels of stable P in the environment. Recommended interim CR values for radioactive forms of P as a function of bioavailable stable phosphorus in the water body are presented. Values of CR are presented for three different trophic levels of the aquatic food chain; foodstuffs from all three trophic levels may potentially be consumed by humans. It is concluded that current recommended values of the CR are likely to be significantly over-estimated for radioactive phosphorus in many freshwater systems, particularly lowland rivers. Further research is recommended to field-validate these models and assess their uncertainty. The relative importance of food-chain uptake and direct uptake from water are also assessed from a review of the literature. It can be concluded that food-chain uptake is the dominant accumulation pathway in fish and hence accumulation factors for radioactive phosphorus in farmed fish are likely to be significantly lower than those for wild fish.
authors.affiliation: School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Bldg, Burnaby Road, Portsmouth PO1 3QL, UK. jim.smith@port.ac.uk
authors.forename: J T
authors.initials: JT
authors.lastname: Smith
authors.forename: M J
authors.initials: MJ
authors.lastname: Bowes
authors.forename: C R
authors.initials: CR
authors.lastname: Cailes
mesh_terms: D000818:Animals; D004739:England; D004784:Environmental Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D005618:Fresh Water; D008954:Models, Biological; D010761:Phosphorus Radioisotopes / Q000493:pharmacokinetics*; D010944:Plants / Q000378:metabolism; D014852:Wales; D015048:Zooplankton / Q000378:metabolism
chemical_list: D010761:Phosphorus Radioisotopes