Summary of doses and approach: Wetland scenario A Bollhfer*, C - - PowerPoint PPT Presentation

Supervising Scientist - working to protect the environment from the impacts of uranium mining www.environment.gov.au/ssd

Summary of doses and approach: Wetland scenario

A Bollhöfer*, C Doering#, B Ryan&

* Environmental Research Institute of the Supervising Scientist (eriss), Darwin, NT, Australia # Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Yallambie, Vic, Australia & Paulka Radiation and Environment, Darwin, Australia

2 Supervising Scientist Division

Steel Creek

Steel Creek

1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01

G r a s s e s , s e d g e s A l d e r t r e e S h r u b s W i l l

• w

s e t c G r e e n t r e e f r

• g

A q u a t i c s n a k e s T e r r e s t r i a l s n a k e s D u c k s S p i d e r s B e e t l e s A p h i d s , c i c a d a s G r a s s h

• p

p e r s , c r i c k e t s

microGy/hr

Total internal (terrestrial) external (terrestrial) internal (aquatic) external (aquatic)

Organism Occupancy Factors Terrestrial Aquatic Grasses, sedges 1 Alder tree 1 Shrubs 1 Willows etc 1 Green treefrog 1 in air Aquatic snakes 0.5 in water, 0.5 at surface Terrestrial snakes 1 Ducks 0.5 on soil, 0.25 in air 0.25 water surface Spiders 0.5 on soil, 0.5 in air Beetles 1 on soil Aphids, cicadas 1 in air Grasshoppers, crickets 0.5 on soil, 0.5 in air

• ERICA default values (CR & geometry)
• Grass
• Tree
• terrestrial amphibian
• terrestrial reptile
• Bird
• flying insect

3 Supervising Scientist Division

Utnora Swamp

Utnora

1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01

S p r u c e F e r n A l d e r t r e e F

• r

b s , s e d g e s M

• r

f r

• g

microGy/hr

Total internal (terrestrial) external (terrestrial) internal (aquatic) external (aquatic)

Organism Occupancy Factors Terrestrial Aquatic Spruce 1 Fern 1 Alder tree 1 Forbs, sedges 1 Moor frog 0.66 on soil; 0.34 in soil (hibernation)

• ERICA default values (CR & geometry)
• Grass
• Tree
• terrestrial amphibian

4 Supervising Scientist Division

■ Approach

– Assumption: specific activity (Bq C-14 per gram carbon) in biota is the same as in air (or top soil, see input data) – C-14 activity concentration in biota calculated from specific activity in air and carbon content in biota tissue

• Carbon content from

– TRS472: grass and fodder, fish (for frogs and toads), average of animal products (for snakes and rodents) – For trees: On the variation of water content in trees,” by James Barkley Pollock of the University of Wisconson. and Canadian woods: Their properties and uses. 1981. Mullins, E.J.; McKnight, T.S., editors. Environment Canada. – For insects: Bertram et al 2008.Extensive natural intraspecific variation in stoichiometric (C:N:P) composition in two terrestrial insect species. J Insect

• Sci. 2008;8:1-7

– Biota activity concentrations were then put into ERICA to calculate doses

Duke Swamp

5 Supervising Scientist Division

Duke Swamp

Duke Swamp

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20

B a l s a m f i r C e d a r F e r n s F

• r

b s G r a s s P e a t m

• s

s f l i e s C a r r i

• n

b e e t l e s A m e r i c a n t

• a

d G r e y t r e e f r

• g

A m e r i c a n b u l l f r

• g

G r e e n f r

• g

N

• r

t h e r n l e

• p

a r d f r

• g

M i n k f r

• g

C

• m

m

• n

g a r t e r s n a k e N

• r

t h e r n s h

• r

t

• t

a i l e d s h r e w W h i t e

• f
• t

e d m

• u

s e D e e r m

• u

s e M e a d

• w

v

• l

e

microGy/hr

Total internal (terrestrial) external (terrestrial) internal (aquatic) external (aquatic)

• Doses entirely due to exposure to internal radiation from C-14