Progress on the Development of Parameter Progress on the Development - - PDF document

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Progress on the Development of Parameter Progress on the Development of Parameter Values for Reference Animals and Plants Values for Reference Animals and Plants

IAEA EMRAS II Transfer Group IAEA EMRAS II Transfer Group Vienna, Austria, 25 Vienna, Austria, 25-

• 29 January 2010

29 January 2010 T.L. Yankovich T.L. Yankovich AREVA Resources Canada AREVA Resources Canada tamara.yankovich@ tamara.yankovich@AREVA.ca AREVA.ca

Intake of radionuclide Concentration of Radionuclide in the Immediate Environment Radionuclide concentration in whole organism Concentration in reference organ Compartment-specific dose Information on effects on critical endpoints of dose to a given organ Effect(s) of radionuclide intake and concentration Internal radionuclide partitioning Compartment size, geometry, composition, etc. Metabolic models, absorbtion models, etc. Organ-specific radionuclide concentration

Air Water Soil Vegetation Sediments

Internal Compartmentalization (Compartment Identification)

Intake of radionuclide Concentration of Radionuclide in the Immediate Environment Radionuclide concentration in whole organism Concentration in reference organ Compartment-specific dose Information on effects on critical endpoints of dose to a given organ Effect(s) of radionuclide intake and concentration Internal radionuclide partitioning Compartment size, geometry, composition, etc. Metabolic models, absorbtion models, etc. Organ-specific radionuclide concentration

Air Water Soil Vegetation Sediments

Internal Compartmentalization (Compartment Identification)

Interactions and Chemical Exchange between Organisms and their Environment

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Where . . . Where . . .

 Doses to non-human biota

(“wildlife”) are typically predicted on a whole-body basis.

 However, depending on the

purpose of a given study, tissue-specific measurements may be taken, as opposed to those for the whole body.

(e.g., those for edible tissues in monitoring programs designed to assess radionuclide transfer to humans).

How do we use tissue-specific data to estimate whole-body values given the internal complexity of an organism?

Brain Bone Heart Kidney Liver Scales Swim Bladder Muscle Brain Bone Heart Kidney Liver Scales Swim Bladder Muscle

e.g., the potential complexity of a fish Specifically,

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To Address this Question . . . To Address this Question . . .

• In doing so, data on compartment sizes

and the internal partitioning of radionuclides in a given tissue relative to a “reference tissue” could be used.

• An organism can be

assessed using a mass balance approach (e.g., Yankovich, 2009).

With this in Mind . . . With this in Mind . . .

Efforts have been undertaken to Efforts have been undertaken to compile available data on internal compile available data on internal partitioning of radionuclides and stable partitioning of radionuclides and stable analogues in animal tissues. analogues in animal tissues.

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Where the Purpose was . . . Where the Purpose was . . .

To estimate whole To estimate whole-

• body

body radionuclide concentrations radionuclide concentrations based on measurements taken based on measurements taken for specific tissues. for specific tissues.

Data Requirements: Data Requirements:

 Measurements taken at under

steady state conditions.

 Realistic exposure conditions

for laboratory experiments.

 Concentration data for at

least two tissues or for one tissue plus whole-body.

 Tissue mass data for at least

• ne tissue plus whole-body.

 Measurements taken for the

same organism or group of

• rganisms.

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Scope of Compilation: Scope of Compilation:

 Radionuclides of stable

elements.

 Freshwater, marine and

terrestrial ecosystems.

 Wild and domesticated

vertebrates and invertebrates.

 Whole-body, muscle, bone, liver,

kidney and gonad tissues.

 Where possible, animals were

categorized by IAEA ‘wildlife’ category.

Outcome . . . Outcome . . .

An estimation of whole An estimation of whole-

• body

body radionuclide (or stable analogue) radionuclide (or stable analogue) concentrations based on measurements concentrations based on measurements taken for specific animal tissues. taken for specific animal tissues.

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To Date To Date… ….. ..

Focus has been placed on developing Focus has been placed on developing conversion factors for animals, with conversion factors for animals, with the intent to switch focus to plants, the intent to switch focus to plants,

• nce complete.
• nce complete.

Compilation of Compartment Size Compilation of Compartment Size

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Compilation of Internal Partitioning Data Compilation of Internal Partitioning Data

Based on this Analysis: Based on this Analysis:

Similarities between groups of elements have been used to estimate expected internal partitioning patterns within an organism.

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Summary of Collated Data: Animals Summary of Collated Data: Animals

Univalent Elements in Mature Northern Pike Element

Cs K Na Rb C(organ)/C(reference organ) 0.1 1 10 100

Reference Organ blood bone kidney liver gonads

Divalent Elements in Mature Northern Pike Element

Ba Ca Mg Sr C(organ)/C(reference organ) 0.1 1 10 100 1000

Reference Organ blood bone kidney liver gonads

Bone Seekers Non-Bone Seekers

Simplifying Reference Fish: Defining Chemically-Distinct Compartments

B r a i n B o n e H e a r t K i d n e y L i v e r S c a l e s S w i m B l a d d e r M u s c l e B r a i n B o n e H e a r t K i d n e y L i v e r S c a l e s S w i m B l a d d e r M u s c l e

Sc B ST Sc B ST

Conceptual Model I:

Conceptual Model II:

Whole Fish Whole Fish

It appears that compartmentalization of fishes and frogs can be simplified based on the partitioning patterns of a given element..

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Work is Available on This . . . . . Work is Available on This . . . . .

Yankovich, 2009. Yankovich, 2009. Mass balance approach to Mass balance approach to estimating radionuclide loads and concentrations estimating radionuclide loads and concentrations in edible fish tissues using stable analogues. in edible fish tissues using stable analogues. Journal of Environmental Journal of Environmental Radiactivity Radiactivity, , doi:10.1016/ j.jenvrad.2009.05.001 doi:10.1016/ j.jenvrad.2009.05.001. . … from a human perspective. (from the EMRAS I (from the EMRAS I update of I AEA TRS 364) update of I AEA TRS 364)

Summary of Outcome: Animals Summary of Outcome: Animals

 A series of look-up tables with

tissue-to-whole body for radionuclides and stable isotopes in the specified animal categories.

 As context, tables containing

the % biomasses of specified tissues with respect to the whole-body biomass have been compiled.

 Data are also available on tissue

water contents, ash contents, % C contents.

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Summary of Findings for Summary of Findings for Reference Plant Reference Plant

Similar Work is Underway for Plants Similar Work is Underway for Plants

Element

Ba Ca Mg Sr

C(organ)/C(reference organ)

0.1 1 10

Reference Organ stems fruit roots

 It seems possible to

develop conversion factors for plants, as well.

 With relatively

consistent patterns

• ccurring for similar

types of elements.

 A key question is how to

compartmentalize the plant.

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F L ST R

AG BG AG BG

Whole Plant Whole Plant

Group 1: Group 2: Group 3:

Conceptual Models of Reference Plant

Status Summary: Status Summary:



Look up tables have been generated for marine fish, mammals, birds reptiles and amphibians (freshwater fish tables to be finalized this week).



Based on these data, a paper has been drafted for submission as part of a special edition.



Input of data has been received from UK, Japan, Norway, Sweden, Australia and Canada.



Work is underway to compile data

• n plants (participation welcome!)

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Applications . . . . .

 Development of Reference Biota

 Use/Standardization of Existing Data  Sample Processing  Improvement of Dose Estimates  Further Understanding

Database QA/QC Document: Database QA/QC Document:

1. BACKGROUND INFORMATION......................................................................... 1 1.1 DOCUMENT OBJECTIVE........................................................................................ 2 2. COLLECTION AND ANALYSIS OF AQUATIC MEDIA.................................. 2 2.1 SURFACE WATER................................................................................................. 2 2.1.1 Physicochemical Measurements.................................................................... 2 2.1.2 Sample Preparation for Analysis of Major and Minor Cations ................... 3 2.1.3 QA/QC............................................................................................................. 3 2.2 SEDIMENT............................................................................................................ 3 2.2.1 Sample Homogenization ................................................................................ 4 2.2.2 Microwave Digestion...................................................................................... 4 2.2.3 Sample Analysis.............................................................................................. 4 2.2.4 Assurance/Quality Control (QA/QC)............................................................. 5 3. PROCESSING OF NON-HUMAN BIOTA FOR ANALYSIS............................. 5 3.1 SAMPLE PREPARATION ........................................................................................ 5 3.3 QA/QC................................................................................................................ 6 4. REFERENCES .......................................................................................................... 6

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tamara.yankovich@areva.ca

. . . . . Thank YOU!